Biochemical investigation of human exposure to aflatoxin M1 and its association with risk factors of diabetes mellitus

Incidence and mortality of acute aflatoxicosis: A systematic review

BACKGROUND

Aflatoxins are mycotoxins produced by Aspergillus fungi in crops intended for food and feed. Acute exposure to high levels of aflatoxin B1, one of the most toxic mycotoxins, can result in severe poisoning, defined as acute aflatoxicosis, which manifests as acute hepatic failure followed by death in severe cases. Currently global burden estimates of acute aflatoxicosis are lacking - in contrast to burden estimates of chronic exposure - making it difficult to implement and prioritize risk management strategies in the prevention and control of aflatoxin exposure.

AIM

This systematic review assessed global evidence on the incidence and mortality of acute aflatoxicosis from 1990 to 2023. While symptomology & disease duration was also examined, it served as a secondary outcome to provide additional clinical context.

SEARCH STRATEGY AND ELIGIBILITY

A structured search was conducted in PubMed, Web of Science, Embase, Scopus, INASP and grey literature. Studies were imported into Covidence for review.

STUDY SELECTION AND EXTRACTION

Two independent reviewers screened and extracted titles, abstracts, and full texts. Eligible studies included all human studies.

RESULTS

From 11,539 references, 9 studies were included. Heterogeneity existed in study design, region, age of the study population and aflatoxin analysis. Number of cases ranged from 1 to 317, with aflatoxin concentrations varying widely, i.e. between 10 and 51,100 µg/kg in food, 36 and 209,000 pg/mg albumin in serum, and 19 and 18,521 pg/g in tissue. Only one outbreak provided sufficient data to estimate an attack rate of 8 cases per 100,000. Mortality ranged from 16.2 to 76.5 %, affecting children under 15 and adults over 40 most severely. Common symptoms included vomiting (77-100 %), jaundice (88-100 %), and abdominal pain (8-87 %). The risk of bias was generally low.

CONCLUSION

This review shows that acute aflatoxicosis remains a significant public health burden, especially among vulnerable groups in African countries, although the variability in studies and lack of standardized reporting make burden estimation difficult, highlighting the need for better warning systems and standardized reporting, despite challenges with infrastructure and resources in affected areas.

Aflatoxin B1-induced hepatotoxicity through mitochondrial dysfunction, oxidative stress, and inflammation as central pathological mechanisms: A review of experimental evidence

Aflatoxin B1 (AFB1) is a class of mycotoxin known to contaminate agricultural products, animal feed and animal food products, subsequently causing detrimental effects on human and animal health. AFB1 is the most common and potent aflatoxin found in food and contributes significantly to liver injury as well as the development of hepatocellular carcinoma. Although the liver is a primary target organ for AFB1 toxicity and biotransformation, underlying mechanisms implicated in liver injuries induced by these mycotoxins remain to be fully elucidated for therapeutic purposes. This review aims to dissect the complexities of the pathophysiological and molecular mechanisms implicated in hepatotoxicity induced by AFB1, including mitochondrial dysfunction, oxidative stress and hepatic inflammation. Mechanistically, AFB1 disrupt mitochondrial bioenergetics and membrane potential, promotes mitochondrial cholesterol trafficking and induces mitophagy. Moreover, mitochondrial dysfunction may lead to hepatic oxidative stress as a consequence of uncontrolled production of reactive oxygen species and defects in the antioxidant defense system. Retrieved experimental evidence also showed that AFB1 may lead to hepatic inflammation through gut microbiota dysbiosis, the release of DAMPs and cytokines, and immune cell recruitment. Overall, these mechanisms could be utilized as potential targets to extrapolate treatment for liver injury caused by AFB1.

May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects

The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.

Factor structure of the diabetes knowledge questionnaire and the assessment of the knowledge of risk factors, causes, complications, and management of diabetes mellitus: A national population-based study in Singapore

This study evaluated the knowledge of diabetes mellitus and predictors of the level of diabetes knowledge among the general public of Singapore. Confirmatory factor analysis and exploratory factor analysis were used to evaluate the fit of different factor models for the diabetes knowledge questionnaire. Multiple linear regressions were performed to determine the sociodemographic characteristics associated with diabetes knowledge. The final factor model identified three domains for diabetes knowledge: general knowledge, diabetes specific knowledge and causes of diabetes, and complications of untreated diabetes. Overall knowledge scores were 23.8 ± 2.4 for general diabetes knowledge, 2.3 ± 0.8 for diabetes specific knowledge, 2.3 ± 1.2 for causes, and 5.2 ± 1.2 for complications of untreated diabetes. Patients with diabetes were more knowledgeable than adults without diabetes in the population. While the general public in Singapore has adequate knowledge of diabetes, misconceptions were identified in both groups which underscores the need to tailor specific educational initiatives to reduce these diabetes knowledge gaps.

Prevalence and factors associated with inappropriate anti- diabetic medication therapy among type 2 diabetes mellitus patients at the medical and surgical wards of Mbarara Regional Referral Hospital, Uganda

Background

Inappropriate Anti-diabetic Medication Therapy (IADT) refers to a drug-related problem and includes ‘ineffective drug therapy’, ‘unnecessary drug therapy’, ‘dosage too high’, and ‘dosage too low’. This study aimed to determine the prevalence and factors associated with IADT among T2DM patients at Mbarara Regional Referral Hospital, Uganda (MRRH).

Method

A prospective cross-sectional study was conducted at the medical and surgical wards of MRRH from November 2021 to January 2022. One hundred and thirty-eight adult patients aged 18 years and above, with T2DM, were recruited using consecutive sampling. Patient file reviews and interviewer-administered questionnaire was used for data collection. The data were entered into and analyzed using SPSS version 25. Descriptive analysis was employed to describe the population and determine the prevalence of IADT. Types of IADTs were identified using Cipolle’s DRP classification tool. A univariate and multivariate logistic regression analysis was used to identify factors significantly associated with IADT. The P-value of < 0.05 was considered statistically significant at 95% confidence interval.

Results

A total of 138 hospitalized T2DM patients were studied. Eighty (58.0%) were females, and 70 (50.7%) were ≥ 60 years of age. Out of a total of 138 participants, 97 experienced at least one IADT, with an estimated prevalence of 70.3%. ‘Dosage too high’ (29.2%) and ‘dosage too low’ (27.9%) were the most common type of IADTs. Age ≥ 60 years (AOR, 8.44; 95% CI, 2.09–10.90; P-value = 0.003), T2DM duration of < 1 year (AOR, 0.37; 95% CI, 0.11–0.35; P-value = 0.019), and HbA1c of < 7% (AOR, 9.97; 95% CI, 2.34–13.57; P-value = 0.002) were found to be factors significantly associated with the occurrence of IADTs.

Conclusion

The overall prevalence of inappropriate anti-diabetic medication therapy among T2DM patients admitted to medical and surgical wards of MRRH was 70.3%. The most common type of IADT in this study was ‘dosage too high’, accounting for almost one-third followed by ‘dosage too low’ accounting for a quarter of total IADTs. Age greater or equal to 60 years, T2DM duration of < 1 year, and HbA1c of < 7% during the current admission were found to be factors significantly associated with the occurrence of IADTs in hospitalized T2DM patients.

Does Bentonite Cause Cytotoxic and Whole-Transcriptomic Adverse Effects in Enterocytes When Used to Reduce Aflatoxin B1 Exposure?

Aflatoxin B1 (AFB1) is a major food safety concern, threatening the health of humans and animals. Bentonite (BEN) is an aluminosilicate clay used as a feed additive to reduce AFB1 presence in contaminated feedstuff. So far, few studies have characterized BEN toxicity and efficacy in vitro. In this study, cytotoxicity (WST-1 test), the effects on cell permeability (trans-epithelial electrical resistance and lucifer yellow dye incorporation), and transcriptional changes (RNA-seq) caused by BEN, AFB1 and their combination (AFB1 + BEN) were investigated in Caco-2 cells. Up to 0.1 mg/mL, BEN did not affect cell viability and permeability, but it reduced AFB1 cytotoxicity; however, at higher concentrations, BEN was cytotoxic. As to RNA-seq, 0.1 mg/mL BEN did not show effects on cell transcriptome, confirming that the interaction between BEN and AFB1 occurs in the medium. Data from AFB1 and AFB1 + BEN suggested AFB1 provoked most of the transcriptional changes, whereas BEN was preventive. The most interesting AFB1-targeted pathways for which BEN was effective were cell integrity, xenobiotic metabolism and transporters, basal metabolism, inflammation and immune response, p53 biological network, apoptosis and carcinogenesis. To our knowledge, this is the first study assessing the in vitro toxicity and whole-transcriptomic effects of BEN, alone or in the presence of AFB1.