Assessment of dietary exposure and levels of mycotoxins in sorghum from Niger State of Nigeria.

This study reports levels of mycotoxins in sorghum from Niger State, Nigeria, and provides a comprehensive assessment of their potential health risks by combining mycotoxin levels and dietary exposure assessment. A total of 240 samples of red and white sorghum were collected from both stores and markets across four microclimatic zones. Fungal species were identified using a dilution plate method. Aflatoxins (AFs), deoxynivalenol, nivalenol, and ochratoxin (OTA) were quantified using HPLC, whereas cyclopiazonic acid, fumonisins (FUMs) and zearalenone were quantified using ELISA. A. flavus and A. fumigatus were dominant fungal species followed by F. verticilloides, A. oryzae and P. verrucosum. Aflatoxins (mean: 29.97 µg/kg) were detected in all samples, whereas OTA (mean: 37.5 µg/kg) and FUMs (mean: 3269.8 µg/kg) were detected in 72% and 50% of the samples, respectively. Mycotoxins frequently co-occurred in binary mixtures of AFs + OTA and AFs + FUMs. Dietary exposure estimates were highest for FUMs at 230% of TDI and margin of exposures (MOEs) for both AFs and OTA (<10,000) indicating a potential risk associated with combined exposure to AFs and OTA. The Risk of hepatocellular carcinoma cases (HCC/year) attributable to AFs and OTA exposure from sorghum was estimated to be 5.99 × 105 and 0.24 × 105 cases for HBsAg + individuals based on 13.6% HBV incidence. Similarly, the HCC/year for AFs and OTA were assessed to be 3.59 × 105 and 0.14 × 105 at an 8.1% prevalence rate. Therefore, the results of this study demonstrate the high prevalence and dietary exposure to mycotoxins through sorghum consumption, raising public health and trade concerns.

Mycotoxin levels and characterization of natural anti-fungal phytochemicals in pearl millet (Pennisetum glaucum) from Nigeria's six agroecological zones.

This study reports levels of multiple mycotoxins across Nigeria's six agro-ecological zones and corresponding levels of natural anti-fungal phytochemicals present in pearl millet (PM). 220 representative composite samples of PM were collected for mycotoxin analysis using ultrahigh performance liquid chromatography-mass spectrometry (UHPLC-MS), and 24 were randomly selected for determination of metabolites using gas chromatography-high resolution time of flight-mass spectrometry (GC-HRTOF-MS). In total, 15 mycotoxins were detected, all with levels below the European Union (EU) permissible limits and level of aflatoxins only up to 1.34 µg/kg. This is in sharp contrast to high levels of mycotoxins reported in maize samples from the same agroecological zones. Phytochemical analysis of the same samples identified a total of 88 metabolites, 30 of which are known anti-fungal properties from other previously published studies. The most common of these include methyl ester, bis (2-ethylhexyl) phthalate, and ç-tocopherol. The number of anti-fungal metabolites recovered from each sample ranged from 3 to 17 and varied widely in both number and composition across the agroecological zones. The anti-fungal metabolites may probably make PM less susceptible to fungal proliferation compared to other grains. Hence, it is worth exploring for possible sources of biological control products from PM.

Effect of partially purified sub-fractions of Pterocarpus mildbraedii extract on carbon tetrachloride intoxicated rats.

BACKGROUND: This study was designed to determine the hepatoprotective effect of partially purified fractions from Pterocarpus mildbraedii extract on carbon tetrachloride (CCl4) intoxicated rats. METHODS: The methanol extract of P. mildbraedii was subjected to solvent partitioning using n-hexane, chloroform, ethylacetate and water. Separation of fractions with proven antioxidant activity was achieved by chromatographic techniques. Acute toxicity and hepatoprotective studies of the methanol sub-fraction 6 (Me 6), methanol sub-fraction 7 (Me 7) and methanol sub-fraction 8 (Me 8) from P. mildbraedii extract on carbon tetrachloride (CCl4) intoxicated Wister rats. RESULTS: Intoxication of rats with CCl4 resulted in significant (p < 0.05) increase in the activities of aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), level of malondialdehyde (MDA) while glutathione (GSH) concentration, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were decreased. Administration of Me6, Me7 and Me8 sub-fractions of P. mildbraedii caused a significant reduction (p > 0.05) in the activities of the liver enzymes, MDA level, total and direct bilirubin in dose-dependent manner. There were significant (p < 0.05) increases in GSH concentration, SOD, CAT, and Gpx activities in the treated groups. The subfractions also restored the damaged hepatic-architecture in the treated groups. CONCLUSION: Therefore, Me6, Me7 and Me8 leaf sub-fractions of P. mildbraedii extract have hepatoprotective effect. Therefore, this vegetable can further be exploited as a source of drug/supplement development in the prevention and treatment of liver damage.