Effect of Some Natural Antioxidants on Afla- Toxin B1-induced Hepatic Toxicity

Aflatoxins are potent hepatotoxic and hepatocarcinogenic agents. This hepatotoxicity is thought to be mediated by their ability to generate reactive oxygen species and cause peroxidative damage. In the present investigation we assessed the ability of some natural antioxidants namely, vitamin E and Se, β-carotene, silymarin and coenzyme Q10 on aflatoxin B1 (AFB1)-induced hepatotoxicity in a rat model. Alanine and aspartate aminotransferases and alkaline phosphatase (ALP) were found to be significantly increased in the serum of AFB1 administered (250 μg/kg body weight/day for 2 weeks) rats, suggesting hepatic damage. There was a marked increase in the lipid peroxide levels and a concomitant decrease in the hepatic reduced glutathione (GSH) and serum protein thiol (PrSHs) along with a nearly twofold increase in hepatic glutathione-S-transferase (GST) activity. The significant increase in GST may be attributed to its being a phase ΙΙ enzyme that predominately participates in the detoxification of the ultimate electrophilic metabolite AFB1-8, 9 epoxide. On the other hand, no significant change was detected in the activities of glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G-6-PDH), cytochrome creductase and levels of DNA and RNA in the hepatic tissue of AFB1 administered rats. Results also revealed that cotreatment with studied antioxidants offered substantial hepatoprotective effects in the AFB1 administered rats. Moreover, results revealed that vitamin E and selenium combination and β-carotene are more efficient than coenzyme Q10 and silymarin in modulating the liver antioxidant enzymatic system.