Inhibition by the bioflavonoid ternatin of aflatoxin B1-induced lipid peroxidation in rat liver

Aflatoxin B-1, a metabolite of Aspergillus flavus is a potent hepatotoxic and hepatocarcinogenic mycotoxin. Lipid peroxidation and oxidative DNA damage are the principal manifestations of aflatoxin B1 induced toxicity which could be mitigated by antioxidants. Many plant constituents, e.g. flavonoids, lignans and spice principles (capsaicin, curcumin, eugenol, etc.) have been reported to prevent liver damage associated with lipid peroxidation, In this study we investigated ternatin, a tetramethoxyflavone isolated from Egletes viscosa, for possible protection against liver injury induced by aflatoxin B-1 in rats. Seventy two hours after a single intraperitoneal dose of aflatoxin B-1 (1 mg kg(-1)), the concentration of malondialdehyde, the product of lipid peroxidation in liver homogenates, and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly elevated (P < 0.01). Subcutaneous ternatin (25 mg kg(-1)) pretreatment greatly reduced aflatoxin B-1-induced increases in the levels of serum enzymes (ALT from 5071 +/- 763 to 293 +/- 66 international units L-1 and AST from 4241 +/- 471 to 449 +/- 108 international units L-1) and elevated malondialdehyde levels (from 11.37 +/- 1.27 to 0.79 +/- 0.22 nmol (mg wet tissue)(-1)) in a manner similar to oral vitamin E (300 mg kg(-1)), a standard antioxidant. Further, histological changes induced by aflatoxin B-1 such as hepatocellular necrosis and bile-duct proliferation were markedly inhibited in animals pretreated with ternatin or vitamin E. These data provide evidence that ternatin inhibits lipid peroxidation and affords protection against liver damage induced by aflatoxin B-1. Ternatin might, therefore, be a suitable candidate for the chemoprevention of aflatoxicosis associated liver cancer.