Modifications of microsomal and nuclear fractions by butylated hydroxyanisole and its effect on benzo(a)pyrene metabolites binding to macromolecules.

The effect of butylated hydroxyanisole (BHA) administration on the hepatic components of the monooxygenase system and lipid peroxidation in microsomal and nuclear fractions was investigated in male Swiss mice. Addition of BHA to the diet for 8 days increased significantly the content of cytochrome P-450 (by 50%) and two times the specific activities of NADH- and NADPH-cytochrome c reductases in liver microsomes and lowered the concentration of cytochrome P-450 in liver nuclei. Lipid peroxidation of liver microsomes obtained from BHA fed mice was higher (by 70%) as compared with the control. The inhibition of peroxidation was shown when BHA was added to the incubation mixture containing control microsomal fraction or liver homogenate. When benzo(a)pyrene (BP) was incubated with liver microsomes from BHA fed mice the binding of BP metabolites to microsomal macromolecules increased 5.5-fold compared with control. However, there was no such effect in case of liver nuclei. In view of these results it has been postulated that BHA can play not only preventive role in chemical carcinogenesis.