An ethnobotanical study of anti-malarial plants among indigenous people on the upper Negro River in the Brazilian Amazon

Dysphania ambrosioides (L.) Mosyakin and Clemants: bridging traditional knowledge, photochemistry, preclinical investigations, and toxicological validation for health benefits

Dysphania ambrosioides L. (Chenopodiaceae) is a Moroccan medicinal plant known locally as "M'Khinza." It is widely used in traditional medicine to treat numerous ailments, such as diabetes, digestive disorders, fever, fertility problems, immune disorders, hypertension, bronchitis, respiratory conditions, pharyngitis, cough, and flu. As part of this review, comprehensive preclinical investigations, including in vitro, in vivo, and in silico studies, were conducted to better understand the mechanisms of action of D. ambrosioides. Additionally, the phytochemical profile of the plant was examined, highlighting the presence of certain bioactive secondary metabolites. The information was gathered from electronic data sources such as Web of Science, PubMed, Science Direct, Scopus, Springer Link, and Google Scholars. Numerous studies have mentioned the pharmacological properties of D. ambrosioides, including its antioxidant, anti-inflammatory, antiparasitic, antiviral, antibacterial, and antifungal activities. Furthermore, research has also suggested its potential as an anticancer, antidiabetic, and vasorelaxant agent. Phytochemical characterization of D. ambrosioides has revealed the presence of over 96 major bioactive compounds, including terpenoids, polyphenols, flavonoids, alkaloids, and fatty acids. As for the toxicity of this plant, it is dose-dependent. Furthermore, more in-depth pharmacological studies are needed to establish the mechanisms of action of this plant more accurately before considering clinical trials. In conclusion, this review highlights the traditional use of D. ambrosioides in Moroccan medicine and emphasizes its potential pharmacological properties. However, to fully harness its therapeutic potential, further research, both in terms of chemistry and pharmacology, is necessary. These future studies could help identify new active compounds and provide a better understanding of the mechanisms of action of this plant, thus opening new prospects for its pharmaceutical application.

In Vitro and in Vivo Antimalarial Activity, Cytotoxicity and Phytochemical HRMS2 Profile of Plants from the Western Pará State, Brazilian Amazonia

Ethnopharmacology and botanical taxonomy are valid criteria used to selecting plants for antimalarial bioprospection purposes. Based on these two criteria, ethanol extracts of 11 plants from Santarém City vicinities, Western Pará State, Brazilian Amazonia, had their in vitro antiplasmodial activity against chloroquine-resistant Plasmodium falciparum (W2 clone) assessed by the PfLDH method, whereas their cytotoxicity to HepG2-A16 cells was assessed through MTT assay. Acmella oleracea, Siparuna krukovii and Trema micrantha extracts disclosed the highest rate of parasite growth inhibition (90 %) in screening tests. In vivo antimalarial assays were conducted with these extracts against Plasmodium berghei (NK 65 strain) infected mice. Inhibition rate of parasite multiplication ranged from 41.4 % to 60.9 % at the lowest extract dose (25 mg/kg). HPLC-ESI-HRMS2 analyses allowed the putative identification of alkylamides, fatty acids, flavonoid glycosides and alkaloids in ethanol extracts deriving from these three plant species. Results pointed towards A. oleracea flowers ethanol extract as the most promising potential candidate to preclinical studies aiming the development of antimalarial phytomedicine.

Bioprospection for new larvicides against Aedes aegypti based on ethnoknowledge from the Amazonian São Sebastião de Marinaú riverside community

ETHNOPHARMACOLOGICAL RELEVANCE

Vector-borne diseases represent a huge global burden impacting health systems. Aedes aegypti is the main vector of arboviral diseases including dengue, Zika, chikungunya and urban yellow fever in both tropical and subtropical areas. Ethnopharmacological investigations provide potential avenues for developing new vector control strategies.

AIM OF THE STUDY

The objective of this study is to document the São Sebastião de Marinaú riverside community's ethnoknowledge of local plants used to control mosquitoes and perform bioguided fractionation to isolate the compounds active against the arboviral disease vector Ae. aegypti.

MATERIALS AND METHODS

Semi-structured interviews were conducted with residents of the Marinaú community located in the Caxiuanã National Forest, in the Amazon biome, Pará, Brazil. The plants used to control mosquitoes were subjected to phytochemical studies guided by Ae. aegypti assays. Extracts were obtained from seven species using distinct organic solvents. Active extracts and fractions were separated by chromatographic techniques. Isolated compounds were characterized by NMR, LC/MS and GC/MS. Sample activity against Ae. aegypti larvae and pupae was evaluated after 24, 48 and 72 h exposure. The extracts were also investigated against adult female mosquitoes. The LC₅₀ values were determined by diluting each sample to obtain different concentrations in the respective activity range.

RESULTS

The Marinaú community uses more than ten plants as a repellent, most of which are trees native to the region. The primary applications of these plants to protect against insect bites were: burning plants (fumigation), application of body oils and bathing in macerated plants. Carapa guianensis is the predominant species used as a repellent. Extracts from Diospyros guianensis fruits, Carapa guianensis seed shells and Aspidosperma nitidum wood demonstrated Ae. aegypti larvicidal activity. The C. guianensis seed shell extract demonstrated a residual larvicidal effect. Plumbagin, stigmasterol, β-sitosterol, betulinic, ursolic and oleanolic acids, and betulin were identified in the D. guianensis extract. The plumbagin, ursolic and oleanolic acids displayed larvicidal activity. Oleanolic, ursolic and betulinic acids, and betulin were considered pupicidal. Aricine, the major alkaloid isolated from A. nitidum wood, also presented larvicidal activity.

CONCLUSIONS

Ten plant species traditionally used by the Marinaú community to afford protection against mosquitoes were reported. C. guianensis, D. guianensis and A. nitidum extracts were considered larvicidal against Ae. aegypti. Four triterpenes stood out as very active compounds against pupae. Aricine, an indole alkaloid, displayed larvicidal activity. Therefore, traditional knowledge of Amazonian plants combined with bioguided fractionation constitutes a strategy for the development of eco-friendly insecticides to control Ae. aegypti, an arbovirus vector.

Brazilian tucumã-do-Amazonas (Astrocaryum aculeatum) and tucumã-do-Pará (Astrocaryum vulgare) fruits: bioactive composition, health benefits, and technological potential

Latin America has a wide range of native plants spread through its territory. The palms of the Astrocaryum genus are examples of crops occurring in Central and South America, including the large plant life in Brazil. Although not very well known, the Astrocaryum spp. possess edible and non-edible fractions with potential technological and medicinal uses, as evidenced by recent research. Two native Brazilian fruits, tucumã-do-Amazonas (Astrocaryum aculeatum) and tucumã-do-Pará (Astrocaryum vulgare), typically found in the north and northeast of the country, respectively, stand out for their high antioxidant capacity and rich content in bioactive compounds, mainly carotenoids and phenolic compounds. Accordingly, experimental studies indicate their potential to prevent and treat inflammatory and oxidative stress-related conditions, including cancer. The tucumã plants have also been suggested as tools in the industry, for example for biofuel production, activated carbon technology, and as alternative packaging. Considering the importance of bringing light to underestimated yet culturally relevant native crops with potential benefits for small and large communities, this review aims to present and discuss the characteristics, bioactive composition, health effects, and technological potential of tucumã-do-Amazonas and tucumã-do-Pará fruits.

Plants used traditionally as antimalarials in Latin America: Mining the tree of life for potential new medicines

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria remains a serious and challenging disease. Traditional antimalarial medicines are largely based on plants, and ethnopharmacological research has inspired the development of antimalarial pharmaceuticals such as artemisinin. Antimalarial drug resistance is an increasing problem in Plasmodium species, and new therapeutic strategies to combat malaria are needed. Although the number of malaria cases has been decreasing in Latin America, malaria remains a significant threat in many regions. Local people in Latin America have been using numerous plant species to treat malaria, some of which have been scientifically studied, but many others have not.

AIM OF THE STUDY

Our principal objective is to harness ethnobotanical data on species used traditionally to treat malaria, combined with phylogenetic approaches, to understand how ethnobotany could help identify plant genera as potential sources of new medicines.

MATERIALS AND METHODS

Plants used to treat malaria in Latin America were compiled from published and grey literature, unpublished data, and herbarium specimens. Initial assessment of potentially important species/genera/families included compiling the number of species used within the genus, the number of use reports per genus and species, and the geographic distribution of their use. The analysis of taxonomic distribution of species reported as antimalarial in Latin America (excluding the Southern Cone) was conducted, to determine which genera and families with reputed antimalarial properties are over-represented, and phylogenetic analyses were performed to identify if there was evidence for antimalarial species being dispersed/clustered throughout the tree or at its tips. This approach enabled 'hot-nodes' in certain families to be identified, to predict new genera with potential antimalarial properties.

RESULTS

Over 1000 plant species have been used to treat malaria in Latin America, of which over 600 species were cited only once. The genera with the highest number of antimalarial species were Aspidosperma, Solanum, Piper, Croton and Aristolochia. In terms of geographic distribution, the most widely used genera were Aspidosperma, Momordica, Cinchona, Senna and Stachytarpheta. Significant phylogenetic signal was detected in the distribution of native species used for malaria, analysed in a genus-level phylogenetic framework. The eudicot and magnoliidae lineages were over-represented, while monocots were not.

CONCLUSION

Analysis of ethnobotanical use reports in a phylogenetic framework reveals the existence of hot nodes for malaria across the Latin American flora. We demonstrate how species and genera currently lacking such reports could be pinpointed as of potential interest based on their evolutionary history. Extending this approach to other regions of the world and other diseases could accelerate the discovery of novel medicines and enhance healthcare in areas where new therapeutic strategies are needed.

Snakebites in "Invisible Populations": A cross-sectional survey in riverine populations in the remote western Brazilian Amazon

In the Brazilian Amazon, long distances, low healthcare coverage, common use of ineffective or deleterious self-care practices, and resistance to seeking medical assistance have an impact on access to antivenom treatment. This study aimed to estimate snakebite underreporting, and analyze barriers that prevent victims from obtaining healthcare in communities located in 15 municipalities on the banks of the Solimões, Juruá and Purus Rivers, in the remote Western Brazilian Amazon. Information on the participants' demographics, previous snakebites, access to healthcare, time taken to reach medical assistance, use of self-care practices, and the reason for not accessing healthcare were collected through semi-structured interviews. In the case of deaths, information was collected by interviewing parents, relatives or acquaintances. A total of 172 participants who reported having suffered snakebites during their lifetime were interviewed. A total of 73 different treatment procedures was reported by 65.1% of the participants. Participants living in different river basins share few self-care procedures that use traditional medicine, and 91 (52.9%) participants reported that they had access to healthcare. Living in communities along the Juruá River [OR = 12.6 (95% CI = 3.2-49.7; p<0.001)] and the use of traditional medicine [OR = 11.6 (95% CI = 3.4-39.8; p<0.001)] were variables that were independently associated to the lack of access to healthcare. The main reasons for not accessing healthcare were the pprioritization of traditional treatments (70.4%), and the failure to recognize the situation as being potentially severe (50.6%). Four deaths from complications arising from the snakebite were reported, and three of these were from communities on the banks of the Juruá River. Only one of these received medical assistance. We found an unexpectedly high underreporting of snakebite cases and associated deaths. Snakebite victims utilized three main different healing systems: 1) self-care using miscellaneous techniques; 2) official medical healthcare generally combined with traditional practices; and 3) self-care using traditional practices combined with Western medicines. To mitigate snakebite burden in the Brazilian Amazon, an innovative intervention that would optimize timely delivery of care, including antivenom distribution among existing community healthcare centers, is needed.

Ethnomedical uses, chemical constituents, and evidence-based pharmacological properties of Chenopodium ambrosioides L.: extensive overview

Background

The Chenopodium genus is a plant family widely spread worldwide that includes various plant species reputed to possess several medicinal virtues in folk medicines. Chenopodium ambrosioides L. is among the most used plants in traditional medicines worldwide. This review aimed to highlight ethnomedicinal uses, phytochemical status, and pharmacological properties of C. ambrosioides L.

Main body of the abstract

The analysis of relevant data highlights various ethnomedicinal uses against human and veterinary diseases in forty countries. Most indications consisted of gastrointestinal tract dysfunctioning troubles and worms parasitemia. Around 330 chemical compounds have been identified in different plant parts, especially in its essential oil fractions (59.84%). However, only a few compounds—mainly monoterpenes and glycosides—have been isolated and characterized. Experimental pharmacological studies validated a large scale of significant health benefits. It appeared that many monoterpenes are antioxidant, insecticidal, trypanocidal, analgesic, antifungal, anti-inflammatory, anti-arthritic, acaricidal, amoebicidal, anthelmintic, anticancer, antibacterial, antidiabetic, antidiarrheal, antifertility, antifungal, anti-leishmanial, antimalarial, antipyretic, antisickling, antischistosomal, antiulcer, anxiolytic, immunomodulatory, molluscicidal, and vasorelaxant agents.

Short conclusion

Thus, the Chenopodium ambrosioides species necessitates further chemical studies to isolate and characterize new bioactive secondary metabolites and pharmacological investigations to precise the mechanisms of action before clinical trials.

Bioactive Olivacine Derivatives-Potential Application in Cancer Therapy

Olivacine and its derivatives are characterized by multidirectional biological activity. Noteworthy is their antiproliferative effect related to various mechanisms, such as inhibition of growth factors, enzymes, kinases and others. The activity of these compounds was tested on cell lines of various tumors. In most publications, the most active olivacine derivatives exceeded the effects of doxorubicin (a commonly used anticancer drug), so in the future, they may become the main new anticancer drugs. In this publication, we present the groups of the most active olivacine derivatives obtained. In this work, the in vitro and in vivo activity of olivacine and its most active derivatives are presented. We describe olivacine derivatives that have been in clinical trials. We conducted a structure-activity relationship (SAR) analysis that may be used to obtain new olivacine derivatives with better properties than the available anticancer drugs.

Antimalarial herbal remedies of Bukavu and Uvira areas in DR Congo: An ethnobotanical survey

ETHNOPHARMACOLOGICAL RELEVANCE

The main objective of the present study was to collect and gather information on herbal remedies traditionally used for the treatment of malaria in Bukavu and Uvira, two towns of the South Kivu province in DRC.

MATERIAL AND METHODS

Direct interview with field enquiries allowed collecting ethnobotanical data; for each plant, a specimen was harvested in the presence of the interviewed traditional healers (THs). The recorded information included vernacular names, morphological parts of plants, methods of preparation and administration of remedies, dosage and treatment duration. Plants were identified with the help of botanists in the herbaria of INERA/KIPOPO (DRC) and the Botanic Garden of Meise (Belgium), where voucher specimens have been deposited. The results were analysed and discussed in the context of previous published data.

RESULTS

Interviewees cited 45 plant species belonging to 41 genera and 21 families used for the treatment of malaria. These plants are used in the preparation of 52 recipes, including 25 multi-herbal recipes and 27 mono-herbal recipes. Apart of Artemisia annua L. (Asteraceae; % Citation frequency = 34%) and Carica papaya L. (Caricaceae; % Citation frequency = 34%), the study has highlighted that the most represented families are Asteraceae with 12 species (26%), followed by Fabaceae with 7 species (16%) and Rubiaceae with 4 species (9%). For a majority of plants, herbal medicines are prepared from the leaves in the form of decoction and administered by oral route.

CONCLUSION

Literature data indicate that part of cited species are already known (38%) and/or studied (30%) for antimalarial properties, which gives credit to the experience of Bukavu and Uvira interviewees and some level of confidence on collected information. The highly cited plants should be investigated in details for the isolation and identification of active ingredients, a contribution to the discovery of new possibly effective antimalarials.

Medium-Chain Fatty Acids from Eugenia winzerlingii Leaves Causing Insect Settling Deterrent, Nematicidal, and Phytotoxic Effects

Eugenia winzerlingii (Myrtaceae) is an endemic plant from the Yucatan peninsula. Its organic extracts and fractions from leaves have been tested on two phloem-feeding insects, Bemisia tabaci and Myzus persicae, on two plant parasitic nematodes, Meloidogyne incognita and Meloidogyne javanica, and phytotoxicity on Lolium perenne and Solanum lycopersicum. Results showed that both the hexane extract and the ethyl acetate extract, as well as the fractions, have strong antifeedant and nematicidal effects. Gas chromatography-mass spectrometry analyses of methylated active fractions revealed the presence of a mixture of fatty acids. Authentic standards of detected fatty acids and methyl and ethyl derivatives were tested on target organisms. The most active compounds were decanoic, undecanoic, and dodecanoic acids. Methyl and ethyl ester derivatives had lower effects in comparison with free fatty acids. Dose-response experiments showed that undecanoic acid was the most potent compound with EC₅₀ values of 21 and 6 nmol/cm² for M. persicae and B. tabaci, respectively, and 192 and 64 nmol for M. incognita and M. javanica, respectively. In a phytotoxicity assay, medium-chain fatty acids caused a decrease of 38-52% in root length and 50-60% in leaf length of L. perenne, but no effects were observed on S. lycopersicum. This study highlights the importance of the genus Eugenia as a source of bioactive metabolites for plant pest management.

Bioactive compounds and health benefits of some palm species traditionally used in Africa and the Americas - A review

ETHNOPHARMACOLOGICAL RELEVANCE

According to previous ethno-medicinal reviews, Cocos nucifera, Elaeis guineensis and Phoenix dactylifera are among the main palms which are often used on the American and African continents to treat infections, infestations and disorders in the digestive, respiratory, genito-urinary, dermal, endocrine, cardiovascular, muscular-skeletal, mental and neural systems, as well as neoplasms, dental issues and metabolic and nutritional disorders. In addition, one or more species of the wild genera Acrocomia, Areca, Astrocaryum, Attalea, Bactris, Borassus, Calamus, Chamaedorea, Chamaerops, Euterpe, Hyphaene, Mauritia, Oenocarpus and Syagrus have a high number of records of these ethno-medicinal uses. The most used parts of the palm tree are the fruits, followed by roots, seeds, leaves and flower sap.

AIM OF THE STUDY

This review discusses the phytochemical composition and the pharmacological properties of these important ethno-medicinal palms, aiming to provide a contribution to future research prospects.

MATERIALS AND METHODS

Significant information was compiled from an electronic search in widely used international scientific databases (Google Scholar, Science Direct, SciFinder, Web of Science, PubMed, Wiley on line Library, Scielo, ACS Publications), and additional information was obtained from dissertations, theses, books and other relevant websites.

RESULTS

Palms, in general, are rich in oils, terpenoids and phenolic compounds. Fruits of many species are notable for their high content of healthy oils and fat-soluble bioactive compounds, mainly terpenoids, such as pigment carotenoids (and provitamin A), phytosterols, triterpene pentacyclics and tocols (and vitamin E), while other species stood out for their phenolic compounds derived from benzoic and cinnamic acids, along with flavan-3-ol, flavone, flavonol, and stilbene compounds or anthocyanin pigments. In addition to fruits, other parts of the plant such as seeds, leaves, palm heart, flowers and roots are also sources of many bioactive compounds. These compounds are linked to the ethno-medicinal use of many palms that improve human health against infections, infestations and disorders of human systems.

CONCLUSIONS

Palms have provided bioactive samples that validate their effectiveness in traditional medicine. However, the intensive study of all palm species related to ethno-medicinal use is needed, along with selection of the most appropriate palm accessions, ripe stage of the fruit and /or part of the plant. Furthermore, the complete profiles of all phytochemicals, their effects on animal models and human subjects, and toxicological and clinical trials are suggested, which, added to the incorporation of improved technological processes, should represent a significant advance for the implementation of new opportunities with wide benefits for human health.

A disseminação cultural das garrafadas no Brasil: um paralelo entre medicina popular e legislação sanitária

RESUMO Garrafadas, em geral, são combinações de plantas medicinais veiculadas em bebidas alcoólicas, utilizadas com diversas finalidades na medicina popular. O presente estudo apresentou um panorama das garrafadas, relacionando-as à regulamentação sanitária no Brasil. Para tal, foi realizada uma pesquisa descritiva exploratória das garrafadas divulgadas na internet, bem como das notificações de queixas técnicas e eventos adversos junto à Agência Nacional de Vigilância Sanitária (Anvisa). A pesquisa mostrou que as garrafadas são amplamente divulgadas na internet. Concluiu-se que as garrafadas são comercializadas em todo País, sem nenhuma barreira, sendo órfãs de regulamentação sanitária específica, mas legitimadas pela cultura popular.

Aspidosperma (Apocynaceae) plant cytotoxicity and activity towards malaria parasites. Part II: experimental studies withAspidosperma ramiflorum in vivo and in vitro

Several species of Aspidosperma plants are used to treat diseases in the tropics, including Aspidosperma ramiflorum, which acts against leishmaniasis, an activity that is experimentally confirmed. The species, known as guatambu-yellow, yellow peroba, coffee-peroba and matiambu, grows in the Atlantic Forest of Brazil in the South to the Southeast regions. Through a guided biofractionation of A. ramiflorum extracts, the plant activity against Plasmodium falciparum was evaluated in vitro for toxicity towards human hepatoma G2 cells, normal monkey kidney cells and nonimmortalised human monocytes isolated from peripheral blood. Six of the seven extracts tested were active at low doses (half-maximal drug inhibitory concentration < 3.8 µg/mL); the aqueous extract was inactive. Overall, the plant extracts and the purified compounds displayed low toxicity in vitro. A nonsoluble extract fraction and one purified alkaloid isositsirikine (compound 5) displayed high selectivity indexes (SI) (= 56 and 113, respectively), whereas compounds 2 and 3 were toxic (SI < 10). The structure, activity and low toxicity of isositsirikine in vitro are described here for the first time in A. ramiflorum, but only the neutral and precipitate plant fractions were tested for activity, which caused up to 53% parasitaemia inhibition of Plasmodium berghei in mice with blood-induced malaria. This plant species is likely to be useful in the further development of an antimalarial drug, but its pharmacological evaluation is still required.

Molecular Farming in Artemisia annua, a Promising Approach to Improve Anti-malarial Drug Production

Malaria is a parasite infection affecting millions of people worldwide. Even though progress has been made in prevention and treatment of the disease; an estimated 214 million cases of malaria occurred in 2015, resulting in 438,000 estimated deaths; most of them occurring in Africa among children under the age of five. This article aims to review the epidemiology, future risk factors and current treatments of malaria, with particular focus on the promising potential of molecular farming that uses metabolic engineering in plants as an effective anti-malarial solution. Malaria represents an example of how a health problem may, on one hand, influence the proper development of a country, due to its burden of the disease. On the other hand, it constitutes an opportunity for lucrative business of diverse stakeholders. In contrast, plant biofarming is proposed here as a sustainable, promising, alternative for the production, not only of natural herbal repellents for malaria prevention but also for the production of sustainable anti-malarial drugs, like artemisinin (AN), used for primary parasite infection treatments. AN, a sesquiterpene lactone, is a natural anti-malarial compound that can be found in Artemisia annua. However, the low concentration of AN in the plant makes this molecule relatively expensive and difficult to produce in order to meet the current worldwide demand of Artemisinin Combination Therapies (ACTs), especially for economically disadvantaged people in developing countries. The biosynthetic pathway of AN, a process that takes place only in glandular secretory trichomes of A. annua, is relatively well elucidated. Significant efforts have been made using plant genetic engineering to increase production of this compound. These include diverse genetic manipulation approaches, such as studies on diverse transcription factors which have been shown to regulate the AN genetic pathway and other biological processes. Results look promising; however, further efforts should be addressed toward optimization of the most cost-effective biofarming approaches for synthesis and production of medicines against the malaria parasite.