Title: Calcium montmorillonite clay reduces urinary biomarkers of fumonisin B1 exposure in rats and humans Authors
Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 16, 2011
Publication Date: May 1, 2012
Citation: Robinson, A., Johnson, N.M., Strey, A.A., Taylor, J.F., Marroquin-Cardona, A., Mitchell, N.J., Afriyie-Gyawu, E., Ankrah, N., Williams, J.H., Wang, J., Jolly, P.E., Nachman, R.J., Phillips, T.D. 2012. Calcium montmorillonite clay reduces urinary biomarkers of fumonisin B1 exposure in rats and humans. American Journal of Clinical Nutrition. Part A 29:809-818. Interpretive Summary: Chronic exposure to fumonisin B1 (FB1), a hazardous fungal contaminant frequently found in corn and other staple foods, has been correlated with an increased incidence of esophageal cancer and other nerve tissue defects. Frequent and concurrent exposure to aflatoxin (AF) and fumonisin (FB1) in the diet can adversely affect human health by magnifying the toxic and carcinogenic effects of these two chemicals. Based on urinary FB1 assessment, the present work demonstrates that treatment with a commercial clay material known as NovaSil significantly reduces exposure to FB1 in both rats and a West African human population. Importantly, NovaSil may act as a multifunctional absorbent material for acute and chronic exposures to FB1 and AF and mitigate their adverse health affects to human populations at risk for morbidity and mortality arising from fungal toxin contaminants.
Technical Abstract: Background: Fumonisin B1 (FB1) is often a co-contaminant with aflatoxin (AF) in grains and may enhance AF’s carcinogenicity by acting as a cancer promoter. An oral dose of calcium montmorillonite clay (i.e. NovaSil, NS) was able to reduce aflatoxin exposure in a Ghanaian population at risk. In vitro analyses from our laboratory indicated that FB1 (like aflatoxin) could also be sorbed onto the surfaces of NS. Objectives: Our objectives were to evaluate the efficacy of NS clay to reduce urinary FB1 in a rodent model and then in a human population highly exposed to AF. Design: Male Fisher rats were randomly assigned to either, FB1 control, FB1 + 2% NS or absolute control group. FB1 alone or with clay was given as a single dose by gavage. For the human trial, participants received NS (1.5 or 3 g/day) or placebo for 3 months. Urines from weeks 8 and 10 were collected and analyzed. Results: In rats, NS significantly reduced urinary FB1 by 20% in 24 h and 50% after 48 h compared to controls. In the humans, 56% of the urine samples analyzed (n = 186) had detectable levels of FB1. Median urinary FB1 levels were significantly (p < 0.05) decreased by > 90% in the high dose NS group compared to the placebo. Conclusions: Findings from this research are ground breaking in that NS clay reduces the bioavailability of two foodborne contaminants (FB1 and AFs) that are important dietary risk factors for hepatocellular and esophageal cancer in humans.