Differential Hepatic Gene Expression and Antioxidant Activity in Male and Female Rats Induced by Subchronic Aflatoxicosis B1

Abstract

Aflatoxin B1 (AFB1) is the most toxic mycotoxin that was proven to be deleterious to human and several animal species. Current work aimed at evaluating the sex-based differential hepatic genotoxic effect and the antioxidant activity as implications of subchronic aflatoxicosis B1. Albino rats were used that comprised two equal AFB1treated groups with AFB1 contaminated olive oil (50µg/kg) and a control group for each gender that received the vehicle only. Parts of animals’ livers were homogenized for gene expression assessment using quantitative RT-PCR and antioxidant activity analyses. Caspase-3 immunohistopathological examination was concomitantly undertaken. Results showed that AFB1 induced significant overexpression in cell cycle proliferation (ODC1), apoptosis (Aen), and antioxidant heme oxygenase (Hmox) genes in males alongside Bax (Bcl2- associated protein) under-expression. Meanwhile, female rats showed significant overexpression for (Hmox) and under-expression of Bax and Tnf (Tumor necrosis factor). Concomitant total hepatic antioxidant activity of liver homogenates showed a reduction in males, contrasting females. Degenerate vacuolated hepatocytes, polymorphic nuclei, cellular infiltration with concomitant Caspase-3 positive cells were profound findings in male rats. Hence, AFB1 is deferentially genotoxic at the given dose especially to male rats towards carcinogenicity, oxidative stress and apoptosis compared to a brief but compensated oxidative stress in females.