Efficacy of Tunisian montmorillonite for in vitro aflatoxin binding and in vivo amelioration of physiological alterations

Aflatoxins (AFs), a group of closely related, extremely toxic mycotoxins produced by Aspergillus flavus and A. parasiticus , can occur as natural contaminants of food and feeds. AFs have been shown to be hepatotoxic, carcinogenic, mutagenic and teratogenic to different animal species. In the current study Tunisian montmorillonite (TM) was evaluated versus AFs caused toxicities in human colon cancer cell line (Caco-2) and in rats as a sensitive model. The aims of this study were threefold: (1) to evaluate the efficacy of TM to adsorb AFs from aqueous solution, (2) to protect Caco-2 cell line against AFs-induced cytotoxicity, DNA fragmentation and caspase-3-dependent apoptosis induction and (3) to evaluate the protective effect of TM against AFs toxicity in Sprague–Dawley rats. In the in vitro study, three concentrations of TM (0.5, 1, and 2 mg/L aqueous solution) and three concentrations of AFB ₁ (10, 20, 50 mg/L) were tested. The results indicated that TM had a high capacity of adsorbing AFB ₁ at different concentrations tested. The quantity adsorbed was 19.26 mg of AFB ₁ /g of TM. TM protects Caco-2 cells, inhibits DNA fragmentation and reduces caspase-3 enzymes activity in aflatoxin-treated Caco-2 cell culture. The in vivo results indicated that rats fed AFs-contaminated diet (2.5 mg kg ^{− 1} diet) for 2 weeks showed severe serum biochemical changes typical of aflatoxicosis. Rats treated with TM alone (5%) or in combination with aflatoxin were comparable to the control. The TM was found to be safe and successful in the prevention of aflatoxin toxicity and cytotoxicity.