The occurrence and human health risk assessment of total and aflatoxin B1 in selected food commodities in Bhutan.

Aflatoxins are mycotoxins that contaminate staple foods globally and pose a significant health risk. To the best of our knowledge, information on the occurrence of aflatoxins in Bhutanese diets is scarce. This study aimed to estimate the aflatoxin levels in selected foodstuffs in Bhutan and determine the health risk associated with aflatoxin exposure. Ten different types of food commodities were randomly collected from farmers' markets, shelves of supermarkets, and wholesale and retail shops from 20 districts of the country. The samples were subjected to analysis by an enzyme-linked immunosorbent assay for both total aflatoxins (B1, B2, G1 and G2) and aflatoxin B1. Among the 315 samples included, 48.81% and 79.35% were positive for total aflatoxins and aflatoxin B1, respectively. The overall mean total aflatoxin concentration was 11.49 ± 12.83 µg/kg, and that for B1 was 17.62 ± 23.99 µg/kg. The most prevalent food commodity with the highest aflatoxin contamination was chili products. In addition, the estimated daily intake and margin of exposure to aflatoxin B1 via the consumption of chili products ranged from 0.98 to 5.34 ng kg-1 bw day-1 and from 74.90 to 408.10, indicating a risk for public health. The liver cancer risk was estimated to be 0.01 and 0.007 cancers per year per 100,000 population resulting from the consumption of chili products. The present findings revealed the presence of total aflatoxins and aflatoxin B1 in the selected samples. The margin of exposure values was exorbitant, demanding a stringent public health measure. Notably, these results suggest the need for routine monitoring of aflatoxin contamination in the region and stress rigorous safety management strategies to reduce exposure.

Effects of Itraconazole on Pharmacokinetics of Mitragynine and 7-Hydroxymitragynine in Healthy Volunteers.

CYP3A4-mediated metabolic conversion of mitragynine to 7-hydroxymitragynine (7OH) has been demonstrated in human liver microsomes, and in rodents. Pharmacokinetics (PK) of mitragynine and 7OH in humans is still limited. We aimed to examine the pharmacokinetics of mitragynine and the formation of 7OH in healthy volunteers. To elucidate involvement of CYP3A4 in 7OH formation, inhibition by itraconazole was implemented. Two study periods with PK study of mitragynine alone in period 1, followed by period 2 including itraconazole pretreatment was conducted. Freshly prepared kratom tea consisting of 23.6 mg of mitragynine was given to participants in both study periods. Serial blood samplings were performed for 72 hours, and analyzed using a validated LCMS in multiple reaction monitoring mode. The median Cmax for mitragynine of 159.12 ± 8.68 ng/mL was attained in 0.84 h. While median Cmax for 7OH of 12.81 ± 3.39 ng/mL was observed at 1.77 h. In period 1, Cmax and AUC 0-inf of 7OH accounted for 9% and 20 %, respectively, of those parameters for mitragynine. The geometric mean ratio of AUC0-72 for 7OH/mitragynine (metabolic ratio, MR) was 13.25 ± 1.07. Co-administration of itraconazole 200 mg per day orally for 4 days (period 2) decreased 7OH exposure by 56% for Cmax and 43% for AUC0-72 after a single oral dose of kratom tea. While the Cmax of mitragynine increased by 1.5 folds without a significant change in Tmax. The geometric mean metabolic ratio was 3.30 ± 1.23 (period 2), indicating the attenuation for the formation of 7OH by the pretreatment with itraconazole. This suggested the CYP3A4-mediated formation of 7OH from mitragynine in healthy volunteers. This study provides the first evidence of metabolic conversion of mitragynine to 7OH in humans.

Assessment of exposure to pesticides and the knowledge, attitude and practice among farmers of western Bhutan.

An estimated 69% of the population of Bhutan is engaged in agriculture. Farmers are exposed to a wide variety of pesticides during the preparation, transport, storage, mixing and application of pesticides posing a significant health risk. A controlled cross-sectional study of farmers in selected sites of Bhutan was conducted to characterize the level of exposure to pesticides and assess their knowledge attitude and practice on the safe handling of pesticides. A total of 399 participants were enrolled in the study comprising of 295 exposed farmers and 104 healthy and unexposed controls. A structured investigator administered questionaries was used to assess their Knowledge, Attitude and practice, and their blood samples were taken for measuring Acetyl Cholinesterase enzyme activity level. There was a significant difference between the Acetyl Cholinesterase enzyme inhibition of exposed and non-exposed control groups observed in the study (P < 0.001). Of the total of 295 farmers, 62 (21.01%) had severe enzyme inhibition of >30% as compared to the unexposed group. Safety practices of handling pesticides were low. The most common symptoms self-reported were headache (OR 1.08, 0.60-1.93) and neurological problems like forgetfulness, lack of concentration (OR 1.12, 0.50-2.48) and increased tiredness (OR 1.075, 0.52-2.19) that were significantly associated with the enzyme inhibition. In addition, we record a very low level of knowledge (17.0%), a fair attitude (63.0%) and poor practice (35.0%) on the safe handling and management of pesticides. This pilot study provides indication of exposure to pesticides in the selected sites of the country. Furthermore, it provides evidence for public health interventions by identifying the exposure patterns and pathways of individuals most at risk in the farming communities of the country. Surveillance and bio-monitoring programs are deemed necessary.