NovaSil clay (NS) has been found to prevent aflatoxicosis in multiple animal species by decreasing toxin bioavailability from the gastrointestinal tract. A randomized, double-blinded, placebo controlled phase IIa clinical trial was conducted in 177 healthy Ghanaian volunteers who received NS clay capsules either in 1.5 g/day (low dose), 3.0 g/day (high dose), or placebo for a period of 3 months. Our objectives were to evaluate the efficacy of NS for reducing AFM1 biomarkers of exposure in more than 600 urine samples. AFM1 was measured by immunoaffinity HPLC-fluorescence methods. The cleanup procedure involved acidification of urine with ammonium formate followed by dilution with deionized H20. Samples were passed through preparative monoclonal antibody columns followed by sequential washing steps with PBS and deionized H20. AF metabolites were eluted from the column with 80% MeOH then evaporated to dryness and resuspended in MeOH and ammonium formate. Fluoresence intensity was measured using HPLC. The protocol was validated, and the structure of AFM1 was confirmed by mass spectrometry. Levels of AFM1 in urine samples collected at baseline and 1-month after intervention did not show a statistically significant difference between the placebo group and low dose group or between the placebo group and high dose group. In urine samples collected after 3-months of the intervention, no statistically significant difference was found between the placebo group and low dose group; however, a significant decrease (up to 58%) in the median level of AFM1was found in the high dose group as compared to the median level in the placebo group (P=0.0391). These results suggest that intervention with NS can considerably reduce urine levels of AFM1. (Supported by USAID LAG-G-00-96-90013-00).
- Novasil Clay,
- Urinary Afloatoxin
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