1
|
Kanaabi M, Settumba MB, Nuwamanya E, Muhumuza N, Iragaba P, Ozimati A, Namakula FB, Kayondo IS, Baguma JK, Nanyonjo AR, Esuma W, Kawuki RS. Genetic Variation and Heritability for Hydrogen Cyanide in Fresh Cassava Roots: Implications for Low-Cyanide Cassava Breeding. PLANTS (BASEL, SWITZERLAND) 2024; 13:1186. [PMID: 38732401 PMCID: PMC11085877 DOI: 10.3390/plants13091186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/08/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024]
Abstract
Breeding for low-hydrogen-cyanide (HCN) varieties is a major objective of programs targeting boiled cassava food products. To enhance the breeding of low-HCN varieties, knowledge of genetic variation and trait heritability is essential. In this study, 64 cassava clones were established across four locations and evaluated for HCN using three HCN assessment methods: one with a 1 to 9 scale, on with a 0 ppm to 800 ppm scale, and a quantitative assay based on spectrophotometer readings (HCN_Spec). Data were also collected on the weather variables precipitation, relative humidity, and temperature. Highly significant differences were observed among clones (p < 0.001) and locations (p < 0.001). There was also significant clone-environment interactions, varying from p < 0.05 to p < 0.001. Locations Arua and Serere showed higher HCN scores among clones and were associated with significantly higher (p < 0.001) mean daily temperatures (K) and lower relative humidity values (%) across 12 h and 18 h intervals. Within locations, HCN broad sense heritability estimates ranged from 0.22 to 0.64, while combined location heritability estimates ranged from 0.14 to 0.32. Relationships between the methods were positive and strong (r = 0.75-0.92). The 1 to 9 scale is more accurate and more reproducible than either the 0 to 800 ppm scale or spectrophotometric methods. It is expected that the information herein will accelerate efforts towards breeding for low-HCN cassava varieties.
Collapse
Affiliation(s)
- Michael Kanaabi
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Mukasa B. Settumba
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
| | - Ephraim Nuwamanya
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Nicholas Muhumuza
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Paula Iragaba
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Alfred Ozimati
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- College of Natural Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda
| | - Fatumah B. Namakula
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Ismail S. Kayondo
- International Institute for Tropical Agriculture (IITA), Ibadan 200113, Nigeria;
| | - Julius K. Baguma
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Ann Ritah Nanyonjo
- College of Agricultural and Environmental Sciences, Makerere University (MAK), Kampala P.O. Box 7062, Uganda; (M.B.S.); (E.N.); (N.M.); (A.O.); (J.K.B.)
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Williams Esuma
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| | - Robert S. Kawuki
- National Crops Resources Research Institute (NaCRRI), Kampala P.O. Box 7084, Uganda; (P.I.); (F.B.N.); (R.S.K.)
| |
Collapse
|
2
|
Impact of Seasonal Variation and Processing Methods on the Cassava-Derived Dietary Cyanide Poisoning, Nutritional Status, and Konzo Appearance in South-Kivu, Eastern D.R. Congo. Processes (Basel) 2022. [DOI: 10.3390/pr10020337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study aimed at evaluating the impact of seasons on the nutritional status and on dietary cassava-related cyanide exposure in Burhinyi and Idjwi, two areas in the eastern Democratic Republic of the Congo, witnessing similarly high cassava-derived cyanide poisoning but differently affected by konzo and malnutrition. Cyanide content in cassava roots and flour, and urinary thiocyanate levels (uSCN) of 54 subjects (40 from Burhinyi and 14 from Idjwi, aged 28.7 (12.1) years, 63% women) were measured during the rainy season (RS) and dry season (DS), using picrate paper kits A and D1. Local processing methods proved to be efficient in removing cyanogenic compounds in fresh cassava roots during the RS. However, the cyanide content in flour samples significantly increased during DS, with ~50% of samples containing unsafe levels (>10 ppm) of cyanide content. Strikingly, the uSCN (µmol/L), from being comparably high in RS (~172.0), slightly decreased during DS in Burhinyi (~103.2; p = 0,3547), but not in Idjwi (~172; p = 0,1113). Furthermore, serum proteins and albumin levels significantly decreased during the DS, witnessing a worsening of nutritional status, in Burhinyi but not in Idjwi. The consumption of bitter cassava roots (OR = 5.43, p = 0.0144) and skipping heap fermentation (OR = 16.67, p = 0.0021) were independently associated with very high uSCN levels during the DS. Thus, restoring the traditional processing methods, and complying with them in either season should ensure the safe consumption of cassava.
Collapse
|
3
|
Baguma M, Malembaka EB, Bahizire E, Mudumbi GZ, Shamamba DB, Matabaro AN, Rigo JM, Njamnshi AK, Chabwine JN. Revisiting Konzo Risk Factors in Three Areas Differently Affected by Spastic Paraparesis in Eastern Democratic Republic of the Congo Discloses a Prominent Role of the Nutritional Status-A Comparative Cross-Sectional Study. Nutrients 2021; 13:2628. [PMID: 34444788 PMCID: PMC8399762 DOI: 10.3390/nu13082628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/16/2022] Open
Abstract
This comparative cross-sectional study aimed to better understand the respective contributions of protein malnutrition and cassava-derived cyanide poisoning in the development of konzo. We compared data on nutritional status and cyanide exposure of school-age adolescent konzo-diseased patients to those of non-konzo subjects of similar age from three areas in the Eastern Democratic Republic of the Congo. Our results show that konzo patients had a high prevalence of both wasting (54.5%) and stunting (72.7%), as well as of cyanide poisoning (81.8%). Controls from Burhinyi and those from Idjwi showed a similar profile with a low prevalence of wasting (3.3% and 6.5%, respectively) and intermediate prevalence of stunting (26.7% and 23.9%, respectively). They both had a high prevalence of cyanide poisoning (50.0% and 63.0%, respectively), similar to konzo-patients. On the other hand, controls from Bukavu showed the lowest prevalence of both risk factors, namely chronic malnutrition (12.1%) and cyanide poisoning (27.6%). In conclusion, cassava-derived cyanide poisoning does not necessarily coexist with konzo outbreaks. The only factor differentiating konzo patients from healthy individuals exposed to cyanide poisoning appeared to be their worse nutritional status. This further suggests that, besides the known role of cyanide poisoning in the pathogenesis of konzo, malnutrition may be a key factor for the disease occurrence.
Collapse
Affiliation(s)
- Marius Baguma
- Faculty of Medicine, Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo; (E.B.M.); (E.B.); (J.N.C.)
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Bukavu 285, Democratic Republic of the Congo
- Biomedical Research Institute (BIOMED), Faculty of Health and Life Sciences, UHasselt—Hasselt University, 3590 Diepenbeek, Belgium;
- Center for Tropical Diseases & Global Health (CTDGH), Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo
| | - Espoir Bwenge Malembaka
- Faculty of Medicine, Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo; (E.B.M.); (E.B.); (J.N.C.)
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, W6030, Baltimore, MD 21205, USA
| | - Esto Bahizire
- Faculty of Medicine, Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo; (E.B.M.); (E.B.); (J.N.C.)
- Center for Tropical Diseases & Global Health (CTDGH), Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo
- Center for Research in Natural Sciences of Lwiro, Bukavu 285, Democratic Republic of the Congo
- Department of Medical Microbiology, University of Nairobi, Nairobi 00100, Kenya
| | - Germain Zabaday Mudumbi
- Department of Pediatrics, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Bukavu 285, Democratic Republic of the Congo;
| | - Dieudonné Bahati Shamamba
- Plant Pathology Laboratory, Faculty of Agronomy, Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo;
| | - Alain-Narcisse Matabaro
- Department of Medical Biology, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Bukavu 285, Democratic Republic of the Congo;
| | - Jean-Michel Rigo
- Biomedical Research Institute (BIOMED), Faculty of Health and Life Sciences, UHasselt—Hasselt University, 3590 Diepenbeek, Belgium;
| | - Alfred Kongnyu Njamnshi
- Department of Internal Medicine and Specialties/Neuroscience, Faculty of Medicine and Biomedical Sciences, The University of Yaoundé I, Yaoundé P.O. Box 25625, Cameroon;
- Brain Research Africa Initiative (BRAIN), Yaoundé P.O. Box 25625, Cameroon
- Brain Research Africa Initiative (BRAIN), Thônex, 1226 Geneva, Switzerland
| | - Joelle Nsimire Chabwine
- Faculty of Medicine, Université Catholique de Bukavu (UCB), Bukavu 285, Democratic Republic of the Congo; (E.B.M.); (E.B.); (J.N.C.)
- Neurology Unit, Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| |
Collapse
|
4
|
Baguma M, Nzabara F, Maheshe Balemba G, Malembaka EB, Migabo C, Mudumbi G, Bito V, Cliff J, Rigo JM, Chabwine JN. Konzo risk factors, determinants and etiopathogenesis: What is new? A systematic review. Neurotoxicology 2021; 85:54-67. [PMID: 33964344 DOI: 10.1016/j.neuro.2021.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Konzo is a toxico-nutritional upper motor neuron disease causing a spastic paraparesis in schoolchildren and childbearing women in some African countries. Almost a century since the first description of konzo, its underlying etiopathogenic mechanisms and causative agent remain unknown. This paper aims at refreshing the current knowledge of konzo determinants and pathogenesis in order to enlighten potential new research and management perspectives. Literature research was performed in PubMed and Web of Science databases according to the PRISMA methodology. Available data show that cassava-derived cyanide poisoning and protein malnutrition constitute two well-documented risk factors of konzo. However, observational studies have failed to demonstrate the causal relationship between konzo and cyanide poisoning. Thiocyanate, the current marker of choice of cyanide exposure, may underestimate the actual level of cyanide poisoning in konzo patients as a larger amount of cyanide is detoxified via other unusual pathways in the context of protein malnutrition characterizing these patients. Furthermore, the appearance of konzo may be the consequence of the interplay of several factors including cyanide metabolites, nutritional deficiencies, psycho-emotional and geo-environmental factors, resulting in pathophysiologic phenomena such as excitotoxicity or oxidative stress, responsible for neuronal damage that takes place at sparse cellular and/or subcellular levels.
Collapse
Affiliation(s)
- Marius Baguma
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium.
| | - Fabrice Nzabara
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; École Régionale de Santé Publique (ERSP), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Ghislain Maheshe Balemba
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Espoir Bwenge Malembaka
- École Régionale de Santé Publique (ERSP), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Christiane Migabo
- Faculty of Agronomy, Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Department of Geography and Environmental Studies, College of Social Sciences and Humanities, Jimma University, Jimma, Ethiopia
| | - Germain Mudumbi
- Department of Pediatrics, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo
| | - Virginie Bito
- Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium
| | - Julie Cliff
- Faculty of Medicine, Department of Community Health, Eduardo Mondlane University, Maputo, Mozambique
| | - Jean-Michel Rigo
- Biomedical Research Institute (BIOMED), UHasselt - Hasselt University, Agoralaan, 3590 Diepenbeek, Belgium
| | - Joëlle Nsimire Chabwine
- Department of Internal Medicine, Hôpital Provincial Général de Référence de Bukavu (HPGRB), Université Catholique de Bukavu (UCB), Bukavu, Democratic Republic of the Congo; Department of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
5
|
Rivadeneyra-Domínguez E, Rodríguez-Landa JF. Preclinical and clinical research on the toxic and neurological effects of cassava (Manihot esculenta Crantz) consumption. Metab Brain Dis 2020; 35:65-74. [PMID: 31802307 DOI: 10.1007/s11011-019-00522-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/21/2019] [Indexed: 10/25/2022]
Abstract
Cassava (Manihot esculenta Crantz) is a tropical plant that is used as fresh food, processed food, or raw material for the preparation of flours with high nutritional value. However, cassava contains cyanogenic glycosides, such as linamarin and lotaustralin, that can trigger severe toxic effects and some neurological disorders, including motor impairment, cognitive deterioration, and symptoms that characterize tropical ataxic neuropathy and spastic epidemic paraparesis (Konzo). These alterations that are associated with the consumption of cassava or its derivatives have been reported in both humans and experimental animals. The present review discusses and integrates preclinical and clinical evidence that indicates the toxic and neurological effects of cassava and its derivatives by affecting metabolic processes and the central nervous system. An exhaustive review of the literature was performed using specialized databases that focused on the toxic and neurological effects of the consumption of cassava and its derivatives. We sought to provide structured information that will contribute to understanding the undesirable effects of some foods and preventing health problems in vulnerable populations who consume these vegetables. Cassava contains cyanogenic glycosides that contribute to the development of neurological disorders when they are ingested inappropriately or for prolonged periods of time. Such high consumption can affect neurochemical and neurophysiological processes in particular brain structures and affect peripheral metabolic processes that impact wellness. Although some vegetables have high nutritional value and ameliorate food deficits in vulnerable populations, they can also predispose individuals to the development of neurological diseases.
Collapse
Affiliation(s)
- E Rivadeneyra-Domínguez
- Facultad de Química Farmacéutica Biológica, Universidad Veracruzana, Xalapa, 91000, Veracruz, Mexico.
| | - J F Rodríguez-Landa
- Facultad de Química Farmacéutica Biológica, Universidad Veracruzana, Xalapa, 91000, Veracruz, Mexico
- Laboratorio de Neurofarmacología, Instituto de Neuroetología, Universidad Veracruzana, Xalapa, 91190, Veracruz, Mexico
| |
Collapse
|
6
|
Mbah EU, Nwankwo BC, Njoku DN, Gore MA. Genotypic evaluation of twenty-eight high- and low-cyanide cassava in low-land tropics, southeast Nigeria. Heliyon 2019; 5:e01855. [PMID: 31194086 PMCID: PMC6546964 DOI: 10.1016/j.heliyon.2019.e01855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/20/2019] [Accepted: 05/28/2019] [Indexed: 12/01/2022] Open
Abstract
A two-year field experiment was carried out in a randomized complete block design with two replications in 2015/16 and 2016/17 cropping seasons at the National Root Crops Research Institute, Umudike (05° 29′N; 07° 33′E; 122 m above sea level) in Nigeria. The objectives of the study were to assess growth, disease status and yield responses of twenty-eight (28) newly developed high- and low-cyanide cassava genotypes in low-land humid tropics of Umudike, Nigeria. Plant height, stem girth, canopy diameter, number of leaves/plant, cassava mosaic disease (CMD) and cassava bacterial blight (CBB) incidence and severity as well as bulking rate and fresh root yield varied significantly (P < 0.05) amongst the high- and low-cyanide cassava genotypes in both cropping seasons. Also, the results showed that bitter cassava genotypes exhibited greater tolerance to CMD than sweet cassava. However, there was no significant (P > 0.05) difference in bulking rate and fresh root yield between the two groups. The Pearson's and Spearman's ranked associations between fresh root yield of the cassava genotypes and other variables analysed across the two cropping seasons were highly significant (P ≤ 0.01) and positive contrary to the other variables. However, they exhibited different degrees of associations amongst themselves, especially CMD incidence that indicated highly significant and positive association with severity. The principal component analysis across the two cropping seasons indicated eigen-values of the four axes > unity with cumulative variance of 68.98 %. Most of the characters that contributed to the 22.35 % observed variability in principal component (PC1) were CMD incidence and severity, and number of leaves/plant while PC2 also exhibited high vector load from plant attributes such as number of leaves/plant, bulking rate ha−1 and canopy diameter. The bi-plot clustering indicated that genotypes (BI-56, NR110439 and B1-29) exhibited strong similarity amongst themselves across the tested variables. The combined fresh root yield sequence of the first ten high yielder genotypes was in the order: NR110439 > TMS010354 > NR110315 > NR 110238 > NR 110228 > NR 060169 > BI-117 > BI-50 > NR110084 > NR 110181. These cassava genotypes were considered to be better endowed genetically, hence their improvement can be encouraged to ensure high and sustainable root yield. A poly-linear and positive regression was recorded between CMD and root yield as well as between CBB and root yield indicating that they affected fresh root yield of high- and low-cyanide cassava genotypes and demands attention also in cassava improvement studies.
Collapse
Affiliation(s)
- Emmanuel Ukaobasi Mbah
- Department of Agronomy, College of Crop and Soil Sciences, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
| | - Blessing Chinwoke Nwankwo
- Department of Agronomy, College of Crop and Soil Sciences, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
| | | | - Michael A Gore
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
7
|
Imakumbili MLE, Semu E, Semoka JMR, Abass A, Mkamilo G. Farmers' perceptions on the causes of cassava root bitterness: A case of konzo-affected Mtwara region, Tanzania. PLoS One 2019; 14:e0215527. [PMID: 30998724 PMCID: PMC6472768 DOI: 10.1371/journal.pone.0215527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 04/03/2019] [Indexed: 11/18/2022] Open
Abstract
In areas where konzo (a cassava cyanide related paralytic disorder) persists, the agronomic factors causing increased cyanogenic glucoside levels in cassava, during periods without water stress, are hardly known. However, through their assessment of cassava root toxicity, using its bitter taste, farmers may have noticed factors unrelated to water stress that additionally influence the cyanogenic glucoside content of cassava cultivated in these areas. Increased cassava root bitterness is often associated with an increase in cyanogenic glucoside levels, making it a good indicator of changes in root cyanogenic glucoside content. Bitter cassava varieties that are preferentially planted by people living in most konzo-affected areas, are an additional known contributor to high cyanogenic glucosides. It is water stress that further increases the inherent toxicity of the planted bitter cassava varieties. Using konzo-affected Mtwara region in Tanzania as a case study, a household survey was carried out to identify the overlooked agronomic factors that additionally influence cyanogenic glucoside levels in cassava cultivated in konzo-affected areas. A total of 120 farmers were interviewed and they mentioned a number of factors unrelated to water stress, as agronomic factors that influenced cassava root bitterness and hence cyanogenic glucoside production in cassava. The mentioned factors included; certain soil characteristics (14.2%), plant age at harvest (7.5%), poor weeding (0.8%), piecemeal harvesting (0.8%), and branch pruning (0.8%). The revealed factors constitute permanent environmental characteristics and crop management practices commonly used by farmers living in konzo-affected Mtwara region in Tanzania. The revealed factors could be contributing to increased cyanogenic glucoside levels in cassava, during periods without water stress in areas where konzo persists.
Collapse
Affiliation(s)
- Matema L. E. Imakumbili
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Ernest Semu
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Johnson M. R. Semoka
- Department of Soils and Geological Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Adebayo Abass
- The International Institute of Tropical Agriculture, Dar es Salaam, Tanzania
| | - Geoffrey Mkamilo
- Roots and Tubers Department, Naliendele Agricultural Research Institute, Mtwara, Tanzania
| |
Collapse
|
8
|
Schrenk D, Bignami M, Bodin L, Chipman JK, Del Mazo J, Grasl-Kraupp B, Hogstrand C, Hoogenboom LR, Leblanc JC, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Vleminckx C, Wallace H, Benford D, Brimer L, Mancini FR, Metzler M, Viviani B, Altieri A, Arcella D, Steinkellner H, Schwerdtle T. Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels. EFSA J 2019; 17:e05662. [PMID: 32626287 PMCID: PMC7009189 DOI: 10.2903/j.efsa.2019.5662] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In 2016, the EFSA Panel on Contaminants in the Food Chain (CONTAM) published a scientific opinion on the acute health risks related to the presence of cyanogenic glycosides (CNGs) in raw apricot kernels in which an acute reference dose (ARfD) of 20 μg/kg body weight (bw) was established for cyanide (CN). In the present opinion, the CONTAM Panel concluded that this ARfD is applicable for acute effects of CN regardless the dietary source. To account for differences in cyanide bioavailability after ingestion of certain food items, specific factors were used. Estimated mean acute dietary exposures to cyanide from foods containing CNGs did not exceed the ARfD in any age group. At the 95th percentile, the ARfD was exceeded up to about 2.5-fold in some surveys for children and adolescent age groups. The main contributors to exposures were biscuits, juice or nectar and pastries and cakes that could potentially contain CNGs. Taking into account the conservatism in the exposure assessment and in derivation of the ARfD, it is unlikely that this estimated exceedance would result in adverse effects. The limited data from animal and human studies do not allow the derivation of a chronic health-based guidance value (HBGV) for cyanide, and thus, chronic risks could not be assessed.
Collapse
|
9
|
Ingenbleek L, Sulyok M, Adegboye A, Hossou SE, Koné AZ, Oyedele AD, Kisito CSKJ, Dembélé YK, Eyangoh S, Verger P, Leblanc JC, Le Bizec B, Krska R. Regional Sub-Saharan Africa Total Diet Study in Benin, Cameroon, Mali and Nigeria Reveals the Presence of 164 Mycotoxins and Other Secondary Metabolites in Foods. Toxins (Basel) 2019; 11:E54. [PMID: 30658506 PMCID: PMC6356755 DOI: 10.3390/toxins11010054] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 12/14/2022] Open
Abstract
In the framework of the first multi-centre Sub-Saharan Africa Total Diet Study (SSA-TDS), 2328 commonly consumed foods were purchased, prepared as consumed and pooled into 194 composite samples of cereals, tubers, legumes, vegetables, nuts and seeds, dairy, oils, beverages and miscellaneous. Those core foods were tested for mycotoxins and other fungal, bacterial and plant secondary metabolites by liquid chromatography, coupled with tandem mass spectrometry. The highest aflatoxin concentrations were quantified in peanuts, peanut oil and maize. The mean concentration of the sum of aflatoxins AFB1, AFB2, AFG1 and AFG2 (AFtot) in peanut samples (56.4 µg/kg) exceeded EU (4 µg/kg) and Codex (15 µg/kg) standards. The AFtot concentration (max: 246.0 µg/kg) was associated with seasonal and geographic patterns and comprised, on average, 80% AFB1, the most potent aflatoxin. Although ochratoxin A concentrations rarely exceeded existing Codex standards, it was detected in unregulated foods. One palm oil composite sample contained 98 different metabolites, including 35.4 µg/kg of ochratoxin A. In total, 164 different metabolites were detected, with unspecific metabolites like asperglaucide, cyclo(L-pro-L-val), cyclo (L-pro-L-tyr), flavoglaucin, emodin and tryptophol occurring in more than 50% of composite samples. Aflatoxin B1 (AFB1), fumonisin B1 (FB1), sterigmatocystin (STC), ochratoxin A (OTA), citrinin (CIT) and many other secondary fungal metabolites are frequent co-contaminants in staple foods, such as maize and sorghum. Populations from North Cameroon and from Benin may, therefore, suffer chronic and simultaneous exposure to AFB1, FB1, STC, OTA and CIT, which are prevalent in their diet.
Collapse
Affiliation(s)
- Luc Ingenbleek
- Centre Pasteur du Cameroun (CPC), Yaoundé BP1274, Cameroon.
- LABERCA, Oniris, INRA, 44307 Nantes, France.
| | - Michael Sulyok
- Department IFA-Tulln, University of Natural Resources and Life Sciences, Vienna (BOKU), 3430 Tulln, Austria.
| | - Abimbola Adegboye
- National Agency for Food and Drug Administration and Control (NAFDAC), Abuja 900288, Nigeria.
| | | | - Abdoulaye Zié Koné
- Agence Nationale de la Sécurité Sanitaire des Aliments (ANSSA), Bamako BP 2362, Mali.
| | - Awoyinka Dada Oyedele
- National Agency for Food and Drug Administration and Control (NAFDAC), Abuja 900288, Nigeria.
| | - Chabi Sika K J Kisito
- Laboratoire Central de Sécurité Sanitaire des Aliments (LCSSA), Cotonou BP 6874, Benin.
| | | | - Sara Eyangoh
- Centre Pasteur du Cameroun (CPC), Yaoundé BP1274, Cameroon.
| | | | - Jean-Charles Leblanc
- Food and Agriculture Organization of the United Nations (FAO), 00153 Rome, Italy.
| | | | - Rudolf Krska
- Department IFA-Tulln, University of Natural Resources and Life Sciences, Vienna (BOKU), 3430 Tulln, Austria.
- Institute for Global Food Security, School of Biological Sciences, Queens University Belfast, Belfast BT7 1NN, Northern Ireland, UK.
| |
Collapse
|
10
|
Boivin MJ, Okitundu D, Makila-Mabe B, Sombo MT, Mumba D, Sikorskii A, Mayambu B, Tshala-Katumbay D. Cognitive and motor performance in Congolese children with konzo during 4 years of follow-up: a longitudinal analysis. Lancet Glob Health 2017; 5:e936-e947. [PMID: 28807191 PMCID: PMC5594926 DOI: 10.1016/s2214-109x(17)30267-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 06/13/2017] [Accepted: 06/26/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND Konzo is an irreversible upper-motor neuron disorder affecting children dependent on bitter cassava for food. The neurocognitive ability of children with konzo over time has yet to be fully documented. METHODS We did a longitudinal study in a konzo outbreak zone continuously affected by konzo since 1990, in the district of Kahemba, southern Bandundu Province, Congo. We enrolled children with a record of neurological diagnosis of konzo in Kahemba town. For all study children with konzo enrolled in the final sample for the baseline assessment, a neurological exam was done by neurologists to confirm konzo diagnosis using the 1996 WHO criteria at 2 years and 4 years. In the initial baseline sample for each child with konzo, we attempted to get consent from a comparison child without konzo (1996 WHO criteria) within 2 years of age, from a neighbouring household who met inclusion criteria. The neuropsychological assessments were the Kaufman Assessment Battery for Children, second edition (KABC-II), and the Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2). FINDINGS Data collection occurred between Oct 12, 2011, and Aug 14, 2015, in the town of Kahemba. 123 children from the Congo with konzo and 87 presumably healthy children without konzo from neighbouring households were enrolled. The planned assessments were completed by 76 children with konzo and 82 children without konzo at 2-year follow-up, and by 55 children with konzo and 33 children without konzo at 4-year follow-up. Boys with konzo did worse than those without konzo on the KABC-II Learning (p=0·0424) and on the Mental Processing Index (MPI; p=0·0111) assessments at 2-year follow-up, but girls did not. These differences observed in boys might have been caused by stunting. At 4-year follow-up, the difference in KABC-II MPI score between boys or girls with or without konzo was not significant. Both boys and girls with konzo had lower scores on BOT-2 than children without konzo at both follow-up times (p<0·0001). These differences were not attenuated when controlling for physical growth. Boys with and without konzo declined on BOT-2 fine motor proficiency at 2-year follow-up (boys with konzo p=0·0076; boys without konzo p=0·0224) and KABC-II MPI performance at 2-year follow-up and 4-year follow-up (2 years: boys with konzo p<0·0001, boys without konzo p=0·0213; 4 years: boys with konzo p=0·0256, boys without konzo p=0·10), but that was not the case for the girls with scores remaining stable regardless of konzo status. For boys, increases in urinary thiocyanate concentration was significantly associated with reductions in BOT-2 motor proficiency (p=0·0321), but was not significantly associated in girls and urinary thiocyanate concentration was not associated with KABC-II MPI score for either boys or girls. INTERPRETATION Motor and cognitive performance continues to be significantly impaired in boys with konzo at 2-year follow-up compared with boys without konzo. Because these impairments are associated in part with exposure to poorly processed cassava as measured by urinary thiocyanate, interventions are urgently needed to ensure improved processing of cassava to detoxify this food source. FUNDING US National Institutes of Health.
Collapse
Affiliation(s)
- Michael J Boivin
- Department of Psychiatry and Neurology & Ophthalmology, Michigan State University, East Lansing, MI, USA.
| | - Daniel Okitundu
- Centre NeuroPsychopathologique (CNPP), University of Kinshasa, Kinshasa, Congo
| | - Bumoko Makila-Mabe
- Centre NeuroPsychopathologique (CNPP), University of Kinshasa, Kinshasa, Congo
| | - Marie-Therese Sombo
- Centre NeuroPsychopathologique (CNPP), University of Kinshasa, Kinshasa, Congo
| | - Dieudonne Mumba
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Congo; National Institute for Biomedical Research (INRB), Kinshasa, Congo
| | - Alla Sikorskii
- Department of Psychiatry and Department of Statistics and Probability, Michigan State University, East Lansing, MI, USA
| | - Banea Mayambu
- Ministry of Health National Program on Nutrition (PRONANUT), Kinshasa, Congo
| | - Desire Tshala-Katumbay
- Centre NeuroPsychopathologique (CNPP), University of Kinshasa, Kinshasa, Congo; National Institute for Biomedical Research (INRB), Kinshasa, Congo; Department of Neurology and School of Public Health, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
11
|
Tshala-Katumbay DD, Ngombe NN, Okitundu D, David L, Westaway SK, Boivin MJ, Mumba ND, Banea JP. Cyanide and the human brain: perspectives from a model of food (cassava) poisoning. Ann N Y Acad Sci 2016; 1378:50-57. [PMID: 27450775 DOI: 10.1111/nyas.13159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/29/2016] [Accepted: 06/01/2016] [Indexed: 11/26/2022]
Abstract
Threats by fundamentalist leaders to use chemical weapons have resulted in renewed interest in cyanide toxicity. Relevant insights may be gained from studies on cyanide mass intoxication in populations relying on cyanogenic cassava as the main source of food. In these populations, sublethal concentrations (up to 80 μmol/l) of cyanide in the blood are commonplace and lead to signs of acute toxicity. Long-term toxicity signs include a distinct and irreversible spastic paralysis, known as konzo, and cognition deficits, mainly in sequential processing (visual-spatial analysis) domains. Toxic culprits include cyanide (mitochondrial toxicant), thiocyanate (AMPA-receptor chaotropic cyanide metabolite), cyanate (protein-carbamoylating cyanide metabolite), and 2-iminothiazolidine-4-carboxylic acid (seizure inducer). Factors of susceptibility include younger age, female gender, protein-deficient diet, and, possibly, the gut functional metagenome. The existence of uniquely exposed and neurologically affected populations offers invaluable research opportunities to develop a comprehensive understanding of cyanide toxicity and test or validate point-of-care diagnostic tools and treatment options to be included in preparedness kits in response to cyanide-related threats.
Collapse
Affiliation(s)
- Desire D Tshala-Katumbay
- Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, Oregon. .,Department of Neurology, University of Kinshasa, Kinshasa, Congo. .,National Nutrition Program, Ministry of Health, and Kinshasa School of Public Health, Kinshasa, Congo.
| | | | - Daniel Okitundu
- Department of Neurology, University of Kinshasa, Kinshasa, Congo
| | - Larry David
- Department of Biochemistry and Proteomic Share Resource, Oregon Health & Science University, Portland, Oregon
| | - Shawn K Westaway
- Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Michael J Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, Michigan
| | - Ngoyi D Mumba
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Congo.,Institut National de Recherches Biomédicales (INRB), Kinshasa, Congo
| | - Jean-Pierre Banea
- National Nutrition Program, Ministry of Health, and Kinshasa School of Public Health, Kinshasa, Congo
| |
Collapse
|
12
|
Dufour DL, Piperata BA, Murrieta RSS, Wilson WM, Williams DD. Amazonian foods and implications for human biology. Ann Hum Biol 2016; 43:330-48. [DOI: 10.1080/03014460.2016.1196245] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Darna L. Dufour
- Department of Anthropology, University of Colorado, Boulder, CO, USA
| | | | | | - Warren M. Wilson
- Department of Anthropology and Archaeology, University of Calgary, AB, Canada
| | - Drake D. Williams
- Department of Anthropology, University of Colorado, Boulder, CO, USA
| |
Collapse
|
13
|
Kambale KJ, Ali ER, Sadiki NH, Kayembe KP, Mvumbi LG, Yandju DL, Boivin MJ, Boss GR, Stadler DD, Lambert WE, Lasarev MR, Okitundu LA, Mumba Ngoyi D, Banea JP, Tshala-Katumbay DD. Lower sulfurtransferase detoxification rates of cyanide in konzo-A tropical spastic paralysis linked to cassava cyanogenic poisoning. Neurotoxicology 2016; 59:256-262. [PMID: 27246648 DOI: 10.1016/j.neuro.2016.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/26/2016] [Accepted: 05/27/2016] [Indexed: 11/17/2022]
Abstract
Using a matched case-control design, we sought to determine whether the odds of konzo, a distinct spastic paraparesis associated with food (cassava) cyanogenic exposure in the tropics, were associated with lower cyanide detoxification rates (CDR) and malnutrition. Children with konzo (N=122, 5-17 years of age) were age- and sex-matched with presumably healthy controls (N=87) and assessed for motor and cognition performances, cyanogenic exposure, nutritional status, and cyanide detoxification rates (CDR). Cyanogenic exposure was ascertained by thiocyanate (SCN) concentrations in plasma (P-SCN) and urine (U-SCN). Children with a height-for-age z-score (HAZNCHS)<-2 were classified as nutritionally stunted. CDR was measured as time required to convert cyanide to SCN, and expressed as ms/μmol SCN/mg protein or as mmolSCN/ml plasma/min. Mean (SD) U-SCN in children with konzo was 521.9 (353.6) μmol/l and was, significantly higher than 384.6 (223.7) μmol/l in those without konzo. Conditional regression analysis of data for age- and sex- matched case-control pairs showed that konzo was associated with stunting (OR: 5.8; 95% CI: 2.7-12.8; p<0.01; N=83 paired groups) and higher U-SCN (OR: 1.1; 95% CI: 1.02-1.20 per 50-μmol increase in U-SCN; p=0.02; N=47 paired groups). After adjusting for stunting and U-SCN, the odds of developing konzo was reduced by 63% (95% CI: 11-85%, p=0.03; N=41 paired groups) for each 5mmol SCN/(ml plasma/min)-increase in CDR. Linear regression analysis indicated a significant association between BOT-2 or KABC-II scores and both the HAZNCHS z-score and the U-SCN concentration, but not the CDR. Our findings provide evidence in support of interventions to remove cyanogenic compounds from cassava prior to human consumption or, peharps, enhance the detoxification of cyanide in those relying on the cassava as the main source of food.
Collapse
Affiliation(s)
- K J Kambale
- Department of Biomedical Sciences, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - E R Ali
- Department of Biology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo
| | - N H Sadiki
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - K P Kayembe
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - L G Mvumbi
- Department of Biomedical Sciences, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - D L Yandju
- Department of Biology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - M J Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, MI, USA
| | - G R Boss
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - D D Stadler
- Graduate Programs in Human Nutrition, Oregon Health & Science University, Portland, OR, USA
| | - W E Lambert
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, USA
| | - M R Lasarev
- Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, USA; Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| | - L A Okitundu
- Department of Neurology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo
| | - D Mumba Ngoyi
- Department of Tropical Medicine, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo
| | - J P Banea
- School of Public Health, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; National Nutrition Program, Ministry of Health, Congo-Kinshasa, Democratic Republic of the Congo
| | - D D Tshala-Katumbay
- Department of Neurology, University of Kinshasa, Congo-Kinshasa, Democratic Republic of the Congo; Institut National de Recherches Biomédicales (INRB), Congo-Kinshasa, Democratic Republic of the Congo; Department of Neurology, Oregon Health & Science University, Portland, OR, USA.
| |
Collapse
|
14
|
Oso A, Li L, Zhang B, Uo R, Fan J, Wang S, Jiang G, Liu H, Rahoo T, Tossou M, Pirgozliev V, Oduguwa O, Bamgbose A. Effect of fungal fermentation with Aspergillus niger and enzyme supplementation on metabolizable energy values of unpeeled cassava root meal for meat-type cockerels. Anim Feed Sci Technol 2015. [DOI: 10.1016/j.anifeedsci.2015.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
15
|
Makila-Mabe BG, Kikandau KJ, Sombo TM, Okitundu DL, Mwanza JC, Boivin MJ, Ngoyi MD, Muyembe JJT, Banea JP, Boss GR, Tshala-Katumbay D. Serum 8,12-iso-iPF2α-VI isoprostane marker of oxidative damage and cognition deficits in children with konzo. PLoS One 2014; 9:e107191. [PMID: 25222616 PMCID: PMC4164531 DOI: 10.1371/journal.pone.0107191] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 08/07/2014] [Indexed: 11/21/2022] Open
Abstract
We sought to determine whether motor and cognitive deficits associated with cassava (food) cyanogenic poisoning were associated with high concentrations of F2-isoprostanes, well-established indicators of oxidative damage. Concentrations of serum F2-isoprostanes were quantified by LC-MS/MS and anchored to measures of motor proficiency and cognitive performance, which were respectively assessed through BOT-2 (Bruininks/Oseretsky Test, 2nd Edition) and KABC-II (Kaufman Assessment Battery for Children, 2nd edition) testing of 40 Congolese children (21 with konzo and 19 presumably healthy controls, overall mean age (SD): 9.3 (3.2) years). Exposure to cyanide was ascertained by concentrations of its main metabolite thiocyanate (SCN) in plasma and urine. Overall, SCN concentrations ranged from 91 to 325 and 172 to 1032 µmol/l in plasma and urine, respectively. Serum isoprostanes ranged from 0.1 to 0.8 (Isoprostane-III), 0.8 to 8.3 (total Isoprostane-III), 0.1 to 1.5 (Isoprostane-VI), 2.0 to 9.0 (total Isoprostane-VI), or 0.2 to 1.3 ng/ml (8,12-iso-iPF2α-VI isoprostane). Children with konzo poorly performed at the BOT-2 and KABC-II testing relative to presumably healthy children (p<0.01). Within regression models adjusting for age, gender, motor proficiency, and other biochemical variables, 8,12-iso-iPF2α-VI isoprostane was significantly associated with the overall cognitive performance (β = −32.36 (95% CI: −51.59 to −13.03; P<0.001). This model explained over 85% of variation of the KABC-II score in children with konzo, but was not significant in explaining the motor proficiency impairment. These findings suggest that cognitive deficits and, possibly, brain injury associated with cassava poisoning is mediated in part by oxidative damage in children with konzo. 8,12-iso-iPF2α-VI isoprostane appears to be a good marker of the neuropathogenic mechanisms of konzo and may be used to monitor the impact of interventional trials to prevent the neurotoxic effects of cassava cyanogenic poisoning.
Collapse
Affiliation(s)
| | - Kambale J. Kikandau
- Department of Biomedical Sciences, University of Kinshasa, Kinshasa, Congo-Kinshasa
| | - Thérèse M. Sombo
- Department of Neurology, University of Kinshasa, Kinshasa, Congo-Kinshasa
| | - Daniel L. Okitundu
- Department of Neurology, University of Kinshasa, Kinshasa, Congo-Kinshasa
| | - Jean-Claude Mwanza
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michael J. Boivin
- Department of Psychiatry and Neurology/Ophthalmology, Michigan State University, East Lansing, Michigan, United States of America
| | - Mumba D. Ngoyi
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Congo-Kinshasa
- Department of Parasitology, Institut National de Recherches Biomédicales, Kinshasa, Congo-Kinshasa
| | - Jean-Jacques T. Muyembe
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Congo-Kinshasa
- Department of Parasitology, Institut National de Recherches Biomédicales, Kinshasa, Congo-Kinshasa
| | - Jean-Pierre Banea
- Department of Nutrition, School of Public Health & National Nutrition Program, Ministry of Health, Kinshasa, Congo-Kinshasa
| | - Gerard R. Boss
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Desiré Tshala-Katumbay
- Department of Neurology, University of Kinshasa, Kinshasa, Congo-Kinshasa
- Department of Neurology, Oregon Health & Science University, Portland, Oregon, United States of America
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
| |
Collapse
|
16
|
Okitundu Luwa E-Andjafono D, Bumoko Makila-Mabe G, Ayanne MTSS, Kikandau JK, Mashukano N, Kazadi Kayembe T, Mumba Ngoyi D, Boivin MJ, Tamfum-Muyembe JJ, Banea Mayambu JP, Tshala-Katumbay D. [Persistence of konzo epidemics in Kahemba, Democratic Republic of Congo: phenomenological and socio-economic aspects]. Pan Afr Med J 2014; 18:213. [PMID: 25419339 PMCID: PMC4237598 DOI: 10.11604/pamj.2014.18.213.4572] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 07/08/2014] [Indexed: 12/02/2022] Open
Abstract
Introduction Identifier les facteurs déterminant la persistance du konzo à Kahemba en République Démocratique du Congo. Méthodes Une enquête transversale a été réalisée à Kahemba en 2011 auprès des ménages de 123 enfants avec konzo (critères OMS) et de 87 enfants sans konzo. La récolte des données s'est faite par interviews, enquête socio-économique par le questionnaire HOME; observation, mesures anthropométriques et examen clinique; mesure du taux de cyanure (CN) dans la farine de manioc et thiocyanate (SCN) urinaire; et analyses sérologiques pour exclure les infections rétrovirales HTLV-I/II et HIV-I/II. L'analyse statistique a été faite par ANOVA, test de Chi-carré, et Kruskall-Wallis au seuil de signification de 0.05. Résultats La survenue et la sévérité du konzo étaient associées à la pauvreté des ménages (p < 0,05). Les enfants atteints de konzo présentaient une dégradation nutritionnelle avancée (p < 0,05 ml/l) chez les enfants konzo vs. non-konzo. La population attribuait souvent la maladie à la sorcellerie. Conclusion L'intoxication chronique au manioc amer, la malnutrition, ainsi que les croyances superstitieuses favorisent la persistance du konzo à Kahemba. La pauvreté porte le risque d'apparition et de gravité du konzo. Les épidémies de Kahemba dévoilent le risque transgénérationel associé au konzo. L'antécédent de konzo dans la famille élargie constituait un facteur de risque pour la survenue de la maladie (OR= 1,92; p = 0,042). Le taux moyen (±ET) de cyanure dans la farine de manioc était de 92,2 (± 56,2) ppm pour les ménages testés. Les taux moyens (±ET) de SCN urinaire étaient respectivement de 520,4 ± 355,7vs. 382,5± 226,3.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Dieudonné Mumba Ngoyi
- Département de Médecine Tropicale, UNIKIN & Institut National de Recherche Biomédicale, République Démocratique du Congo (RDC)
| | | | - Jean-Jacques Tamfum-Muyembe
- Département de Médecine Tropicale, UNIKIN & Institut National de Recherche Biomédicale, République Démocratique du Congo (RDC)
| | | | - Désiré Tshala-Katumbay
- Centre Neuro-psycho-pathologique, Département de Neurologie, RDC ; Département de Médecine Tropicale, UNIKIN & Institut National de Recherche Biomédicale, République Démocratique du Congo (RDC) ; Department of Neurology, Médecine Tropicale, UNIKIN &Institut National de Recherche Biomédicale, République Démocratique du Congo (RDC) and Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
17
|
Bumoko GM, Sombo MT, Okitundu LD, Mumba DN, Kazadi KT, Tamfum-Muyembe JJ, Lasarev MR, Boivin MJ, Banea JP, Tshala-Katumbay DD. Determinants of cognitive performance in children relying on cyanogenic cassava as staple food. Metab Brain Dis 2014; 29:359-66. [PMID: 24481810 PMCID: PMC4024334 DOI: 10.1007/s11011-014-9492-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
While risk factors for konzo are known, determinants of cognitive impairment in konzo-affected children remain unknown. We anchored cognitive performance (KABC-II scores) to serum levels of free-thyroxine (free-T4), thyroid-stimulating hormone (TSH), albumin, and motor proficiency (BOT-2 scores) in 40 children including 21 with konzo (median age: 9 years) and 19 without konzo (median age: 8 years). A multiple regression model was used to determine variables associated with changes in KABC-II scores. Age (β: -0.818, 95% CI: -1.48, -0.152) (p = 0.018), gender (β: -5.72; 95% CI: -9.87, -1.57 for females) (p = 0.009), BOT-2 score (β: 0.390; 95% CI: 0.113, 0.667) (p = 0.008), and free-T4 (β: 1.88; 95% CI: 0.009, 3.74) (p = 0.049) explained 61.1 % of variation in KABC-II scores. Subclinical hypothyroidism was not associated with poor cognition. A crude association was found between serum albumin and KABC-II scores (β: 1.26; 95 % CI: 0.136, 2.39) (p = 0.029). On spot urinary thiocyanate reached 688 μmol/l in children without konzo and 1,032 μmol/L in those with konzo. Female gender and low serum albumin are risk factors common to cognitive and proportionally associated motor deficits in children exposed to cassava cyanogens. The two types of deficits may share common mechanisms.
Collapse
Affiliation(s)
- G M Bumoko
- Department of Neurology, University of Kinshasa, Kinshasa, Congo
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Kimani S, Sinei K, Bukachi F, Tshala-Katumbay D, Maitai C. Memory deficits associated with sublethal cyanide poisoning relative to cyanate toxicity in rodents. Metab Brain Dis 2014; 29:105-12. [PMID: 24293006 PMCID: PMC3944471 DOI: 10.1007/s11011-013-9459-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/21/2013] [Indexed: 01/17/2023]
Abstract
Food (cassava) linamarin is metabolized into neurotoxicants cyanide and cyanate, metabolites of which we sought to elucidate the differential toxicity effects on memory. Young 6-8 weeks old male rats were treated intraperitoneally with either 2.5 mg/kg body weight (bw) cyanide (NaCN), or 50 mg/kg bw cyanate (NaOCN), or 1 μl/g bw saline, daily for 6 weeks. Short-term and long-term memories were assessed using a radial arm maze (RAM) testing paradigm. Toxic exposures had an influence on short-term working memory with fewer correct arm entries (F(2, 19) = 4.57 p < 0.05), higher working memory errors (WME) (F(2, 19) = 5.09, p < 0.05) and longer RAM navigation time (F(2, 19) = 3.91, p < 0.05) for NaOCN relative to NaCN and saline treatments. The long-term working memory was significantly impaired by cyanide with fewer correct arm entries (F(2, 19) = 7.45, p < 0.01) and increased working memory errors (F(2, 19) = 9.35 p < 0.05) in NaCN relative to NaOCN or vehicle treated animals. Reference memory was not affected by either cyanide or cyanate. Our study findings provide an experimental evidence for the biological plausibility that cassava cyanogens may induce cognition deficits. Differential patterns of memory deficits may reflect the differences in toxicity mechanisms of NaOCN relative to NaCN. Cognition deficits associated with cassava cyanogenesis may reflect a dual toxicity effect of cyanide and cyanate.
Collapse
Affiliation(s)
- S Kimani
- Department of Pharmacology and Pharmacognosy & School of Nursing Sciences, University of Nairobi, Kenyatta National Hospital, P.O. Box 19676, Nairobi, Kenya,
| | | | | | | | | |
Collapse
|
19
|
Cross-species and tissue variations in cyanide detoxification rates in rodents and non-human primates on protein-restricted diet. Food Chem Toxicol 2014; 66:203-9. [PMID: 24500607 DOI: 10.1016/j.fct.2014.01.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 11/21/2022]
Abstract
We sought to elucidate the impact of diet, cyanide or cyanate exposure on mammalian cyanide detoxification capabilities (CDC). Male rats (~8 weeks old) (N=52) on 75% sulfur amino acid (SAA)-deficient diet were treated with NaCN (2.5mg/kg bw) or NaOCN (50mg/kg bw) for 6 weeks. Macaca fascicularis monkeys (~12 years old) (N=12) were exclusively fed cassava for 5 weeks. CDC was assessed in plasma, or spinal cord, or brain. In rats, NaCN induced seizures under SAA-restricted diet whereas NaOCN induced motor deficits. No deficits were observed in non-human primates. Under normal diet, the CDC were up to ~80× faster in the nervous system (14 ms to produce one μmol of thiocyanate from the detoxification of cyanide) relative to plasma. Spinal cord CDC was impaired by NaCN, NaOCN, or SAA deficiency. In M. fascicularis, plasma CDC changed proportionally to total proteins (r=0.43; p<0.001). The plasma CDC was ~2× relative to that of rodents. The nervous system susceptibility to cyanide may result from a "multiple hit" by the toxicity of cyanide or its cyanate metabolite, the influences of dietary deficiencies, and the tissue variations in CDC. Chronic dietary reliance on cassava may cause metabolic derangement including poor CDC.
Collapse
|
20
|
Kimani S, Moterroso V, Lasarev M, Kipruto S, Bukachi F, Maitai C, David L, Tshala-Katumbay D. Carbamoylation correlates of cyanate neuropathy and cyanide poisoning: relevance to the biomarkers of cassava cyanogenesis and motor system toxicity. SPRINGERPLUS 2013; 2:647. [PMID: 24349951 PMCID: PMC3862856 DOI: 10.1186/2193-1801-2-647] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 11/25/2013] [Indexed: 12/01/2022]
Abstract
We sought to elucidate the protein carbamoylation patterns associated with cyanate neuropathy relative to cyanide poisoning. We hypothesized that under a diet deficient in sulfur amino acids (SAA), the carbamoylation pattern associated with cyanide poisoning is similar to that of cyanate neuropathy. Male rats (6–8 weeks old) were fed a diet with all amino acids (AAA) or 75%-deficiency in SAA and treated with 2.5 mg/kg/body weight (bw) NaCN, or 50 mg/kg/bw NaOCN, or 1 μl/g/bw saline, for up to 6 weeks. Albumin and spinal cord proteins were analyzed using liquid chromatography mass spectrometry (LC-MS/MS). Only NaOCN induced motor deficits with significant levels of carbamoylation. At Day 14, we found a diet-treatment interaction effect on albumin carbamoylation (p = 0.07). At Day 28, no effect was attributed to diet (p = 0.71). Mean number of NaCN-carbamoylated sites on albumin was 47.4% higher relative to vehicle (95% CI:16.7-86.4%). Only NaOCN carbamoylated spinal cord proteins, prominently, under SAA-restricted diet. Proteins targets included myelin basic and proteolipid proteins, neurofilament light and glial fibrillary acidic proteins, and 2', 3' cyclic-nucleotide 3'-phosphodiesterase. Under SAA deficiency, chronic but not acute cyanide toxicity may share biomarkers and pathogenetic similarities with cyanate neuropathy. Prevention of carbamoylation may protect against the neuropathic effects of cyanate.
Collapse
Affiliation(s)
- Samuel Kimani
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya ; School of Nursing Sciences, University of Nairobi, Nairobi, 19676 Kenya
| | - Victor Moterroso
- Department of Comparative Medicine, Oregon Health & Science University (OHSU), Portland, OR 97239 USA
| | - Mike Lasarev
- Center for Research on Occupational & Environmental Toxicology, OHSU, Portland, OR 97239 USA
| | - Sinei Kipruto
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya
| | - Fred Bukachi
- Department of Medical Physiology, University of Nairobi, Nairobi, 30197 Kenya
| | - Charles Maitai
- Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, 19676 Kenya
| | - Larry David
- Biochemistry and Molecular Biology & Proteomics Shared Resource, OHSU, Portland, OR 97239 USA
| | - Desire Tshala-Katumbay
- Center for Research on Occupational & Environmental Toxicology, OHSU, Portland, OR 97239 USA ; Department of Neurology, OHSU, Portland, OR 97239 USA ; Center for Research on Occupational and Environmental Toxicology & Department of Neurology, Oregon Health & Science University, 3181 Sam Jackson Park Road, Mail code L606, Portland, OR 97239 USA
| |
Collapse
|
21
|
Rivadeneyra-Domínguez E, Vázquez-Luna A, Rodríguez-Landa JF, Díaz-Sobac R. Neurotoxic effect of linamarin in rats associated with cassava (Manihot esculenta Crantz) consumption. Food Chem Toxicol 2013; 59:230-5. [DOI: 10.1016/j.fct.2013.06.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 05/31/2013] [Accepted: 06/06/2013] [Indexed: 11/17/2022]
|
22
|
Oso AO, Akapo O, Sanwo KA, Bamgbose AM. Utilization of unpeeled cassava (Manihot esculenta Crantz) root meal supplemented with or without charcoal by broiler chickens. J Anim Physiol Anim Nutr (Berl) 2013; 98:431-8. [PMID: 23721067 DOI: 10.1111/jpn.12088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 04/13/2013] [Indexed: 11/30/2022]
Abstract
A 42-day feeding trial was conducted using 480-day-old, male Marshall broilers to study the utilization of unpeeled cassava root meal (UCRM) supplemented with or without 6 g/kg charcoal. The experimental design was laid out in a 3 × 2 factorial arrangement of treatments having three inclusion levels of UCRM (0, 100 and 200 g/kg) with or without 6 g/kg charcoal supplementation. Each treatment consisted of 80 birds replicated eight times with 10 birds per replicate. Main effect of inclusion level of UCRM and supplementation of charcoal showed reduced (p < 0.05) final live weight, weight gain, feed intake and apparent crude protein digestibility of the birds with increasing inclusion levels of UCRM. Birds fed diets supplemented with charcoal showed higher (p < 0.05) final live weight, weight gain and feed intake than birds fed diets without charcoal. Supplementation of charcoal in diet containing 100 g/kg UCRM resulted in improved (p < 0.05) weight gain when compared with birds fed similar diet but not supplemented with charcoal. Broilers fed diet containing no UCRM but supplemented with charcoal had the highest overall (p < 0.05) final live weight and weight gain, while birds fed diet containing 200 g/kg UCRM supplemented with charcoal recorded the poorest (p < 0.05) final live weight and weight gain. Serum glutamate oxaloacetate transaminase (SGOT) and serum thiocyanate concentration increased (p < 0.05) with increasing dietary inclusion levels of UCRM. Dietary supplementation of charcoal resulted in increased (p < 0.05) concentration of serum glucose and cholesterol and reduced (p < 0.05) SGOT concentration. Birds fed diets containing UCRM had high (p < 0.05) serum thiocyanate concentration irrespective of dietary supplementation or not with 6 g/kg charcoal. In conclusion, supplementation of diet containing up to 100 g/kg UCRM with 6 g/kg charcoal showed improved weight gain without any deleterious effect on serum metabolites.
Collapse
Affiliation(s)
- A O Oso
- Department of Animal Nutrition, College of Animal Science and Livestock Production, University of Agriculture, Abeokuta, Nigeria
| | | | | | | |
Collapse
|
23
|
Boivin MJ, Okitundu D, Makila-Mabe Bumoko G, Sombo MT, Mumba D, Tylleskar T, Page CF, Tamfum Muyembe JJ, Tshala-Katumbay D. Neuropsychological effects of konzo: a neuromotor disease associated with poorly processed cassava. Pediatrics 2013; 131:e1231-9. [PMID: 23530166 PMCID: PMC3608487 DOI: 10.1542/peds.2012-3011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Konzo is an irreversible upper-motor neuron disorder affecting children dependent on bitter cassava for food. Although the neuroepidemiology of konzo is well characterized, we report the first neuropsychological findings. METHOD Children with konzo in the Democratic Republic of Congo (mean age 8.7 years) were compared with children without konzo (mean age 9.1 years) on the Kaufman Assessment Battery for Children, second edition (KABC-II), and the Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2). Both groups were also compared with normative KABC measures from earlier studies in a nearby nonkonzo region. RESULTS Using a Kruskal-Wallis test, children with konzo did worse on the KABC-II simultaneous processing (visual-spatial analysis) (K [1] = 8.78, P = .003) and mental processing index (MPI) (K [1] = 4.56, P = .03) than children without konzo. Both konzo and nonkonzo groups had poorer KABC sequential processing (memory) and MPI relative to the normative group from a nonkonzo region (K [2] = 75.55, P < .001). Children with konzo were lower on BOT-2 total (K [1] = 83.26, P < .001). KABC-II MPI and BOT-2 total were predictive of konzo status in a binary logistic regression model: odds ratio = 1.41, P < .013; 95% confidence interval 1.13-1.69. CONCLUSIONS Motor proficiency is dramatically affected, and both children with and without konzo have impaired neurocognition compared with control children from a nonoutbreak area. This may evidence a subclinical neurocognitive form of the disease, extending the human burden of konzo with dramatic public health implications.
Collapse
Affiliation(s)
| | | | | | | | - Dieudonne Mumba
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo;,Institut National de Recherches Biomédicales, Kinshasa, Democratic Republic of Congo
| | - Thorkild Tylleskar
- Center for International Health, University of Bergen, Bergen, Norway; and
| | - Connie F. Page
- Department of Statistics and Probability, Michigan State University, East Lansing, Michigan
| | - Jean-Jacques Tamfum Muyembe
- Department of Tropical Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo;,Institut National de Recherches Biomédicales, Kinshasa, Democratic Republic of Congo
| | - Desire Tshala-Katumbay
- Department of Neurology, and,Department of Neurology and Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon
| |
Collapse
|
24
|
The Abundance and Biting Patterns of Culex quinquefasciatus Say (Culicidae) in the Coastal Region of Nigeria. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/640691] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study was aimed at determining the abundance and biting patterns of Culex quinquefasciatus in the coastal region of Nigeria. Collections were done by human landing catch and by CDC miniature light traps from September 2005 to August 2006. A total of 3798 C. quinquefasciatus females were collected. The highest number of females was caught in the month of August and it represented nearly a quarter (24.0%) of the total females collected. In all, 38.8% of females dissected were parous. The abundance of C. quinquefasciatus followed the pattern of rainfall with the population starting to expand at the onset of the rains. The highest increase was found after the temperature had peaked. The mean of biting was 3.2 times more in the rainy season than in the dry season, whereas the transmission potential was higher in the dry season. C. quinquefasciatus is presently regarded as a biting nuisance having no significant epidemiological importance yet. Efforts at its control should be intensified before it is too late.
Collapse
|
25
|
Leyva-Guerrero E, Narayanan NN, Ihemere U, Sayre RT. Iron and protein biofortification of cassava: lessons learned. Curr Opin Biotechnol 2012; 23:257-64. [PMID: 22226461 DOI: 10.1016/j.copbio.2011.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 10/26/2011] [Accepted: 12/14/2011] [Indexed: 11/28/2022]
Abstract
Over two hundred and fifty million Africans rely on the starchy root crop cassava (Manihot esculenta) as their primary source of calories. Cassava roots, however, have the lowest protein:energy ratio of all the world's major staple crops. Furthermore, a typical cassava-based diet provides less than 10-20% of the required amounts of iron, zinc, vitamin A and vitamin E. The BioCassava Plus program employed modern biotechnologies to improve the health of Africans through development and delivery of novel cassava germplasm with increased nutrient levels. Here we describe the development of molecular strategies and their outcomes to meet minimum daily allowances for protein and iron in cassava based diets. We demonstrate that cyanogens play a central role in cassava nitrogen metabolism and that strategies employed to increase root protein levels result in reduced cyanogen levels in roots. We also demonstrate that enhancing root iron uptake has an impact on the expression of genes that regulate iron homeostasis in multiple tissues. These observations demonstrate the complex metabolic interactions involved in enhancing targeted nutrient levels in plants and identify potential new strategies for further enhancing nutrient levels in cassava.
Collapse
|
26
|
Nzwalo H, Cliff J. Konzo: from poverty, cassava, and cyanogen intake to toxico-nutritional neurological disease. PLoS Negl Trop Dis 2011; 5:e1051. [PMID: 21738800 PMCID: PMC3125150 DOI: 10.1371/journal.pntd.0001051] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Konzo is a distinct neurological entity with selective upper motor neuron damage, characterized by an abrupt onset of an irreversible, non-progressive, and symmetrical spastic para/tetraparesis. Despite its severity, konzo remains a neglected disease. The disease is associated with high dietary cyanogen consumption from insufficiently processed roots of bitter cassava combined with a protein-deficient diet. Epidemics occur when these conditions coincide at times of severe food shortage. Up to 1993, outbreaks in poor rural areas in Africa contributed to more than 3,700 cases of konzo. The number of affected people is underestimated. From unofficial reports, the number of cases was estimated to be at least 100,000 in 2000, in contrast to the 6,788 cases reported up to 2009 from published papers.
Collapse
|
27
|
Diasolua Ngudi D, Banea-Mayambu JP, Lambein F, Kolsteren P. Konzo and dietary pattern in cassava-consuming populations of Popokabaka, Democratic Republic of Congo. Food Chem Toxicol 2011; 49:613-9. [DOI: 10.1016/j.fct.2010.06.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 05/10/2010] [Accepted: 06/11/2010] [Indexed: 10/19/2022]
|
28
|
Adamolekun B. Etiology of Konzo, epidemic spastic paraparesis associated with cyanogenic glycosides in cassava: Role of thiamine deficiency? J Neurol Sci 2010; 296:30-3. [DOI: 10.1016/j.jns.2010.06.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 05/25/2010] [Accepted: 06/16/2010] [Indexed: 11/17/2022]
|
29
|
Chabwine JN, Masheka C, Balol'ebwami Z, Maheshe B, Balegamire S, Rutega B, Wa Lola M, Mutendela K, Bonnet MJ, Shangalume O, Balegamire JM, Nemery B. Appearance of konzo in South-Kivu, a wartorn area in the Democratic Republic of Congo. Food Chem Toxicol 2010; 49:644-9. [PMID: 20691241 DOI: 10.1016/j.fct.2010.07.050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 06/22/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
Abstract
Konzo is an upper motor neuron disease characterized by sudden-onset and irreversible spastic paraparesis occurring in nutritionally compromised people. It is associated with consumption of insufficiently processed cyanogenic-toxic cassava. Cassava, the main caloric source in the Democratic Republic of Congo, has been safely consumed for decades in the Eastern Province of South-Kivu. However, in the context of long-lasting war and violent conflicts, cases of spastic paraparesis resembling konzo appeared in a populous area (Burhinyi). Two field surveys (2003 and 2005) identified 41 subjects meeting clinical criteria of konzo and suffering from (chronic) malnutrition. Their urinary thiocyanate concentrations (median 129, range 20-688, SD 146 μg/L), and cyanogen levels (median 20 ppm, range 5-300 ppm, SD 73 ppm) in cassava roots from their household stocks were high. The source of cyanogenic-toxicity was unprocessed fresh cassava roots during harvest period, but probably also insufficiently processed roots. This first report of konzo in South-Kivu concludes that occurrence of konzo was triggered by food shortages because of the longstanding state of insecurity. Contributory factors included the introduction of new varieties of (bitter) cassava, but konzo may actually be caused by a combination of factors that are yet to be understood.
Collapse
Affiliation(s)
- J N Chabwine
- Faculty of Medicine, Université Catholique de Bukavu, PO Box 02, Cyangugu, Rwanda
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Konzo outbreak among refugees from Central African Republic in Eastern region, Cameroon. Food Chem Toxicol 2010; 49:579-82. [PMID: 20538034 DOI: 10.1016/j.fct.2010.05.081] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 05/07/2010] [Accepted: 05/31/2010] [Indexed: 11/22/2022]
Abstract
Konzo is a spastic paraparesis of sudden onset, linked to the exclusive consumption of insufficiently processed bitter cassava as staple food combined with low protein intake. Around 60,000 refugees from the Central African Republic sought refuge in villages in eastern Cameroon between 2005 and 2007. Médecins Sans Frontières was providing nutritional and medical assistance in the villages affected by displacement. We describe cases of konzo seen at the mobile clinics organized in these villages. Basic information including demographic data, history and clinical presentation was recorded for each konzo patient. All patients were given nutritional supplements, and selected cases were referred for physiotherapy to a rehabilitation center. A total of 469 patients were diagnosed with konzo. The majority (80%) were refugees. Children and women of reproductive age predominated. Most of the patients developed symptoms after 2007 in a seasonal pattern with most of the cases occurring during the dry winter season. Most of the patients complained about walking difficulties and weight loss and had exaggerated lower limb reflexes and muscle wasting on observation. Eastern Cameroon is an area with konzo. More effort needs to be put into preventive and educational measures. In addition, timely balanced food rations have to be provided to refugees.
Collapse
|
31
|
Kassa RM, Kasensa NL, Monterroso VH, Kayton RJ, Klimek JE, David LL, Lunganza KR, Kayembe KT, Bentivoglio M, Juliano SL, Tshala-Katumbay DD. On the biomarkers and mechanisms of konzo, a distinct upper motor neuron disease associated with food (cassava) cyanogenic exposure. Food Chem Toxicol 2010; 49:571-8. [PMID: 20538033 DOI: 10.1016/j.fct.2010.05.080] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 05/18/2010] [Accepted: 05/19/2010] [Indexed: 12/29/2022]
Abstract
Konzo is a self-limiting central motor-system disease associated with food dependency on cassava and low dietary intake of sulfur amino acids (SAA). Under conditions of SAA-deficiency, ingested cassava cyanogens yield metabolites that include thiocyanate and cyanate, a protein-carbamoylating agent. We studied the physical and biochemical modifications of rat serum and spinal cord proteins arising from intoxication of young adult rats with 50-200mg/kg linamarin, or 200mg/kg sodium cyanate (NaOCN), or vehicle (saline) and fed either a normal amino acid- or SAA-deficient diet for up to 2 weeks. Animals under SAA-deficient diet and treatment with linamarin or NaOCN developed hind limb tremors or motor weakness, respectively. LC/MS-MS analysis revealed differential albumin carbamoylation in animals treated with NaOCN, vs. linamarin/SAA-deficient diet, or vehicle. 2D-DIGE and MALDI-TOF/MS-MS analysis of the spinal cord proteome showed differential expression of proteins involved in oxidative mechanisms (e.g. peroxiredoxin 6), endocytic vesicular trafficking (e.g. dynamin 1), protein folding (e.g. protein disulfide isomerase), and maintenance of the cytoskeleton integrity (e.g. α-spectrin). Studies are needed to elucidate the role of the aformentioned modifications in the pathogenesis of cassava-associated motor-system disease.
Collapse
Affiliation(s)
- Roman M Kassa
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, OR, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Llorens J, Soler-Martín C, Saldaña-Ruíz S, Cutillas B, Ambrosio S, Boadas-Vaello P. A new unifying hypothesis for lathyrism, konzo and tropical ataxic neuropathy: nitriles are the causative agents. Food Chem Toxicol 2010; 49:563-70. [PMID: 20553991 DOI: 10.1016/j.fct.2010.06.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 05/26/2010] [Accepted: 06/01/2010] [Indexed: 11/17/2022]
Abstract
Konzo and lathyrism are associated with consumption of cassava and grass pea, respectively. Cassava consumption has also been associated with a third disease, tropical ataxic neuropathy (TAN). This review presents a new unifying hypothesis on the causative agents for these diseases: namely, that they are nitriles, compounds containing cyano groups. The diseases may be caused by different but similar nitriles through direct neurotoxic actions not mediated by systemic cyanide release. Both cassava and Lathyrus contain nitriles, and other unidentified nitriles can be generated during food processing or in the human body. Available data indicate that several small nitriles cause a variety of neurotoxic effects. In experimental animals, 3,3'-iminodipropionitrile (IDPN), allylnitrile and cis-crotononitrile cause sensory toxicity, whereas hexadienenitrile and trans-crotononitrile induce selective neuronal degeneration in discrete brain regions. IDPN also induces a neurofilamentous axonopathy, and dimethylaminopropionitrile is known to cause autonomic (genito-urinary) neurotoxicity in both humans and rodents. Some of these actions depend on metabolic bioactivation of the parental nitriles, and sex- and species-dependent differences in susceptibility have been recorded. Recently, neuronal degeneration has been found in rats exposed to acetone cyanohydrin. Taken together, the neurotoxic properties of nitriles make them excellent candidates as causative agents for konzo, lathyrism and TAN.
Collapse
Affiliation(s)
- Jordi Llorens
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Spain.
| | | | | | | | | | | |
Collapse
|
33
|
Soler-Martín C, Riera J, Seoane A, Cutillas B, Ambrosio S, Boadas-Vaello P, Llorens J. The targets of acetone cyanohydrin neurotoxicity in the rat are not the ones expected in an animal model of konzo. Neurotoxicol Teratol 2009; 32:289-94. [PMID: 19932169 DOI: 10.1016/j.ntt.2009.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 11/30/2022]
Abstract
Konzo is a neurotoxic motor disease caused by excess consumption of insufficiently processed cassava. Cassava contains the cyanogenic glucoside linamarin, but konzo does not present the known pathological effects of cyanide. We hypothesized that the aglycone of linamarin, acetone cyanohydrin, may be the cause of konzo. This nitrile rapidly decomposes into cyanide and acetone, but the particular exposure and nutrition conditions involved in the emergence of konzo may favor its stabilization and subsequent acute neurotoxicity. A number of preliminary observations were used to design an experiment to test this hypothesis. In the experiment, young female Long-Evans rats were given 10mM acetone cyanohydrin in drinking water for 2 weeks, and then 20mM for 6 weeks. Nutrition deficits associated with konzo were modeled by providing tapioca (cassava starch) as food for the last 3 of these weeks. After this period, rats were fasted for 24h in order to increase endogenous acetone synthesis, and then exposed to 0 (control group) or 50 micromol/kg-h of acetone cyanohydrin for 24h (treated group) through subcutaneous osmotic minipump infusion (n=6/group). Motor activity and gait were evaluated before exposure (pre-test), and 1 and 6 days after exposure. Brains (n=4) were stained for neuronal degeneration by fluoro-jade B. Rats exposed to 50 micromol/kg-h of acetone cyanohydrin showed acute signs of toxicity, but no persistent motor deficits. Two animals showed fluoro-jade staining in discrete thalamic nuclei, including the paraventricular and the ventral reuniens nuclei; one also exhibited labeling of the dorsal endopiriform nucleus. Similar effects were not elicited by equimolar KCN exposure. Therefore, acetone cyanohydrin may cause selective neuronal degeneration in the rat, but the affected areas are not those expected in an animal model of konzo.
Collapse
Affiliation(s)
- Carla Soler-Martín
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Spain
| | | | | | | | | | | | | |
Collapse
|
34
|
Résurgence de la maladie de konzo dans la région sanitaire no 2 en République centrafricaine. Rev Neurol (Paris) 2009; 165:466-70. [DOI: 10.1016/j.neurol.2008.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/04/2008] [Accepted: 10/08/2008] [Indexed: 11/18/2022]
|
35
|
Montagnac JA, Davis CR, Tanumihardjo SA. Processing Techniques to Reduce Toxicity and Antinutrients of Cassava for Use as a Staple Food. Compr Rev Food Sci Food Saf 2009. [DOI: 10.1111/j.1541-4337.2008.00064.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Chapter 18 Toxic disorders of the upper motor neuron system. HANDBOOK OF CLINICAL NEUROLOGY 2007; 82:353-72. [DOI: 10.1016/s0072-9752(07)80021-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
37
|
Mwanza JC, Tshala-Katumbay D, Tylleskär T. Neuro-ophthalmologic manifestations of konzo. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:491-496. [PMID: 21783517 DOI: 10.1016/j.etap.2004.12.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Konzo is a permanent spastic paraparesis of acute onset attributed to the effect of cyanogenic compounds from insufficiently processed bitter cassava in combination with low protein intake. In all studies of konzo, ophthalmologic complaints have been presented but only recently systematic studies of the neuro-ophthalmologic disturbances in konzo have been done. In this review, we see that about half the patients have an optic neuropathy with decreased visual acuity, alterations of the visual fields, atrophy of the temporal part of the retinal nerve fibre layer linked with temporal pallor of the optic disk. About half of the konzo patients also have abnormal visual evoked potentials, with both delayed latency and reduced amplitude. A small number of konzo patients have an ocular motor disturbance leading to a pendular nystagmus. The severity of the neuro-ophthalmologic involvement is not parallel to the severity of the motor disturbance in konzo. This may suggest that two different pathogenic mechanisms are involved.
Collapse
Affiliation(s)
- Jean-Claude Mwanza
- Department of Ophthalmology, Kinshasa University Hospital, Kinshasa, Congo
| | | | | |
Collapse
|
38
|
Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) on hydrocyanic acid in flavourings and other food ingredients with flavouring properties. EFSA J 2004. [DOI: 10.2903/j.efsa.2004.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
39
|
Enfermedades neurológicas asociadas al consumo de variedades de mandioca con alto contenido en gluconitrilos. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1575-0922(04)74638-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
40
|
Mwanza JC, Lysebo DE, Kayembe DL, Tshala-Katumbay D, Nyamabo LK, Tylleskär T, Plant GT. Visual Evoked Potentials in Konzo, a Spastic Paraparesis of Acute Onset in Africa. Ophthalmologica 2003; 217:381-6. [PMID: 14573969 DOI: 10.1159/000073066] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2003] [Accepted: 05/23/2003] [Indexed: 11/19/2022]
Abstract
AIM To assess whether or not visual evoked potentials (VEPs) are abnormal in konzo, a para/tetraparesis of sudden onset, and to correlate the findings to the clinical picture of the disorder. METHODS VEPs were recorded in 23 patients (9 men and 14 women, mean age: 23 +/- 10 years) suffering from konzo, and 38 healthy subjects (20 men and 18 women, mean age: 27 +/- 15 years). The mean P100 latencies and peak-to-peak N75-P100 amplitudes of each eye were measured and compared in the two groups. The mean interocular P100 latency and amplitude differences were calculated and also compared. RESULTS VEPs were abnormal in 11/23 patients (48%) consisting of P100 prolongation (7 subjects), absence of P100 wave (2 subjects) or an atypical waveform (2 subjects). The mean P100 latency value of the konzo group was significantly increased as compared with the mean (+ 2.5 SD) of the reference values from healthy subjects (p < 0.05). There was a statistically significant decrease of amplitude in konzo patients compared to normal subjects (p < 0.05) with, however, only 2 patients outside the 95% confidence limits. Six patients (27%) had abnormal VEPs despite normal visual acuity. These abnormalities were symmetric and a relation could be found between neither the duration nor the severity of the disease and the VEP perturbation. CONCLUSION The main features of these abnormalities are delayed P100 latency and decreased amplitude. These findings indicate involvement of visual pathways and seem to suggest the presence of axonal loss in the prechiasmal visual pathways in konzo. This study provides evidence that the neurodamage in konzo extends to the visual pathways.
Collapse
Affiliation(s)
- J-C Mwanza
- Department of Ophthalmology, Kinshasa University Hospital, Kinshasa, Democratic Republic of Congo.
| | | | | | | | | | | | | |
Collapse
|
41
|
Dorea JG. Fish are central in the diet of Amazonian riparians: should we worry about their mercury concentrations? ENVIRONMENTAL RESEARCH 2003; 92:232-244. [PMID: 12804520 DOI: 10.1016/s0013-9351(02)00092-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Amazon rain forest extends over an area of 7.8x10(6)km(2) in nine countries. It harbors a diverse human population distributed in dense cities and isolated communities with extreme levels of infrastructure. Amazonian forest people, either autochthons or frontier riparians (ribeirinhos) living in isolated areas, share the same environment for survival and nutritional status. The peculiarities of the hydrological cycle determine disease patterns, agricultural conditions, and food availability. Feeding strategies depend heavily on cassava products and fish. These two foods carry toxic substances such as linamarin (naturally present in cassava) and monomethyl mercury (MMHg) (bioconcentrated in fish flesh) that cause neurotoxic diseases in other parts of the world but not in Amazonia, where neurotoxic cases of food origin are rare and not related to these staples. While cassava detoxification processes may partly explain its safe consumption, the Hg concentrations in Amazonian fish are within traditionally safe limits for this population and contribute to an important metabolic interaction with cassava. The gold rush of the 1970s and 1980s brought large-scale environmental disruption and physical destruction of ecosystems at impact points, along with a heavy discharge of metallic Hg. The discharged Hg has not yet impacted on MMHg concentrations in fish or in hair of fish consumers. Hair Hg concentration, used as a biomarker of fish consumption, indicates that the Amazonian riparians are acquiring an excellent source of protein carrying important nutrients, the lack of which could aggravate their existing health problems. Therefore, in a scenario of insufficient health services and an unhealthy environment, food habits based on fish consumption are part of a successful survival strategy and recommendations for changes are not yet justifiable.
Collapse
Affiliation(s)
- Jose G Dorea
- Faculdade de Ciências da Saúde, Universidade de Brasília, Nutrition C.P. 04322, 70910-970, DF, Brasília, Brazil.
| |
Collapse
|
42
|
Mwanza JCK, Tshala-Katumbay D, Kayembe DL, Eeg-Olofsson KE, Tylleskär T. Neuro-ophthalmologic findings in konzo, an upper motor neuron disorder in Africa. Eur J Ophthalmol 2003; 13:383-9. [PMID: 12872796 DOI: 10.1177/112067210301300409] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To investigate the neuro-ophthalmological manifestations in konzo, a non-progressive symmetric spastic para/tetraparesis of acute onset associated with consumption of insufficiently processed bitter cassava roots combined with a low protein intake. METHODS Twenty-one Congolese konzo patients underwent neuro-ophthalmological investigations including visual acuity testing, assessment of light pupillary reflexes, evaluation of ocular motility and deviation, direct ophthalmoscopy, and visual field perimetry. Objective refraction including retinoscopy and keratometry, and slit-lamp biomicroscopy were also done. RESULTS Five patients had visual impairment, and 14 had temporal pallor of the optic disc. Fourteen presented visual field defects, the most frequent being concentric constriction and peripheral defects. Overall, 11 subjects had symptoms qualifying for the diagnosis of optic neuropathy. Two had spontaneous pendular nystagmus in primary position of gaze. Visual field defects and pallor of the optic discs were found in mild, moderate and severe forms of konzo. No correlation was found between the severity of the motor disability of konzo and the extent of visual field loss. CONCLUSIONS Konzo was associated with optic neuropathy and a few patients had nystagmus. Although the etiopathogenesis of this optic neuropathy remains to be elucidated, the symmetry of the involvement suggests a toxic origin. We suggest that cyanide causes the neuro-ophthalmological damage in konzo. However, the optic neuropathy in konzo patients does not resemble the features of the epidemic optic neuropathy in Tanzania, Cuba or Nigeria, Leber's hereditary optic neuropathy, tobacco amblyopia or vitamin B deficiency.
Collapse
Affiliation(s)
- J C K Mwanza
- Department of Ophthalmology, Kinshasa University Hospital, Kinshasa.
| | | | | | | | | |
Collapse
|
43
|
Abstract
To test the hypothesis that equine grass sickness may be associated with the ingestion of cyanogenic glycosides from white clover (Trifolium repens), the concentrations of whole blood cyanide, and plasma and urinary thiocyanate, the main metabolite of cyanide, were measured in 12 horses with acute grass sickness and 10 horses with subacute grass sickness, and in 43 control horses, of which 21 were co-grazing with cases of acute grass sickness, 12 grazed pastures where grass sickness had not been reported, and 10 were stabled horses. The healthy horses which grazed with cases of acute grass sickness had higher concentrations of blood cyanide, and plasma and urinary thiocyanate than the other control horses, consistent with an increased exposure to cyanogens. The horses with grass sickness had no evidence of a recent intake of cyanogens, but may have been exposed to increased levels of cyanogens before they became anorexic.
Collapse
Affiliation(s)
- B C McGorum
- Department of Veterinary Clinical Studies, Easter Bush Veterinary Centre, Roslin, Midlothian
| | | |
Collapse
|
44
|
Gleadow RM, Woodrow IE. Constraints on effectiveness of cyanogenic glycosides in herbivore defense. J Chem Ecol 2002; 28:1301-13. [PMID: 12199497 DOI: 10.1023/a:1016298100201] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cyanogenesis is the process by which hydrogen cyanide is released from endogenous cyanide containing compounds. Many cyanogenic plants release HCN in sufficient quantities to be toxic and, as a result, tend to be avoided by herbivores. However, there are many exceptions with some herbivores either immune to the cyanogenic status of the plant, or in some cases attracted to cyanogenic plants. This has led to a certain degree of scepticism regarding the role of cyanogenic glycosides as defense compounds. In this review, we examine evidence showing that differences in the effectiveness of cyanogenic glycosides in deterring herbivory can usually be reconciled when the morphology, physiology, and behavior of the animals, together with the concentration of cyanogenic glycosides in the host plant, are taken into account. Cyanogenic glycosides are not effective against all herbivores, and not all cyanogenic plants release enough cyanide to be considered toxic. Nevertheless, they do form part of the broad spectrum of toxic and distasteful compounds that herbivores must accommodate if they are to feed on cyanogenic plants.
Collapse
Affiliation(s)
- Roslyn M Gleadow
- School of Botany, The University of Melbourne Victoria, Australia.
| | | |
Collapse
|
45
|
Onabolu A, Bokanga M, Tylleskär T, Rosling H. High cassava production and low dietary cyanide exposure in mid-west Nigeria. Public Health Nutr 2001; 4:3-9. [PMID: 11255490 DOI: 10.1079/phn200049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate if high cassava production levels indicate high consumption and high dietary cyanide exposure in three villages situated within the area of Nigeria with higher cassava production than predicted by a geographic model for cassava production in Africa. DESIGN Exploratory assessment of: cassava production and processing by qualitative research methods and quantification of residual cyanogens in products; cassava consumption by food frequency and weighed food records and dietary cyanide exposure by urinary thiocyanate and linamarin. SETTING Rural communities of Afuze, Ebue and Ofabo in mid-west Nigeria. SUBJECTS 110 subjects from 42 households in three villages for food frequency interviews; 118 subjects in nine Ofabo households for weighed food records. RESULTS Cassava cultivation was reported to have increased in the preceding 20 years. It was consumed daily by 37 (88%) households, but its mean contribution to daily energy intake was only 13% The range of residual cyanogens in cassava foods was 0 to 62 mg HCN equivalent/kg dry weight (dw). Ten samples (19%) had levels above the 10 mg HCN equivalent/kg dw FAO/WHO safety limit. Mean urinary thiocyanate and linamarin were 51 and 20 micromol/L, indicating low cyanogen intake and dietary cyanide exposure. CONCLUSION High cassava production levels did not result in high consumption and high dietary cyanide exposure levels, therefore cassava production levels cannot be used to predict consumption or cyanide exposure levels in the study area. A large part of the production is explained by intensive sales.
Collapse
Affiliation(s)
- A Onabolu
- International Institute of Tropical Agriculture (IITA), c/o L.W. Lambourn & Co., 26 Dingwall Road, Croydon CR9 3EE, UK.
| | | | | | | |
Collapse
|
46
|
Cyanogens in Cassava Flour and Roots and Urinary Thiocyanate Concentration in Mozambique. J Food Compost Anal 2000. [DOI: 10.1006/jfca.1999.0847] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
47
|
Abstract
Abstract
Background: It would be useful to develop a simple kit method for determination of thiocyanate in urine, which could be used to monitor cyanide overload in cassava-consuming populations.
Methods: The method was based on the quantitative oxidation of thiocyanate in acid permanganate at room temperature in a closed vial with liberation of HCN, which reacted with a picrate paper. For semiquantitative analysis in the field, the colored picrate paper was matched with a color chart prepared using known amounts of KSCN. In the laboratory, a more accurate result was obtained by elution of the colored complex in water and measurement of the absorbance at 510 nm. Over the range 0–100 mg/L, there was a linear relationship given by the equation: thiocyanate content (mg/L) = 78 × absorbance.
Results: The picrate thiocyanate method gave no interference with urine samples containing protein at less than 7 g/L, 21 amino acids, histamine, glucose, NaCl, urea, blood, and linamarin. For 53 urine samples analyzed by an accurate column method and the thiocyanate picrate method, a regression line gave very good agreement (r2 = 1.000). Quantitative recoveries of thiocyanate added to urine samples were obtained with the picrate method.
Conclusions: A simple picrate kit for determination of thiocyanate in urine was developed and is available free of charge for workers in developing countries.
Collapse
Affiliation(s)
| | - J Howard Bradbury
- Division of Botany and Zoology, Australian National University, Canberra, ACT 0200, Australia
| |
Collapse
|
48
|
Banea‐Mayambu J, Nkiabungu B, Tylleskär T, Rosling H. High cassava consumption without cyanide exposure in Kinshasa, in former Zaire. Ecol Food Nutr 1998. [DOI: 10.1080/03670244.1998.9991554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|