Comparative effects of dietary administration of antioxidants and inducers on the activities of several hepatic enzymes in mice.

Feeding mice with anticarcinogenic antioxidants, 2 (3)-tert-butyl-4-hydroxyanisole (BHA), ethoxyquin (EQ), disulfiram (DSF), and selenite (SE) resulted in selective changes in hepatic microsomal mixed function oxidases and in other enzymatic activities which were different from those obtained by feeding phenobarbital (PB), 3-methyl cholanthrene (MC), and Aroclor (ARO). While the hepatic microsomal oxidation of benzo(a)pyrene was markedly elevated by MC and ARO, it was decreased by BHA, EQ, and SE, and unchanged by PB and DSF. In addition, differential effects on cytochrome P-450, aminopyrine demethylase, and aniline hydroxylase were observed. In marked contrast to the large increases produced by BHA, EQ, and ARO, the feeding of PB, MC, or SE resulted in little or no increase in epoxide hydrolase, UDP-glucuronyl transferase, UDP-glucose dehydrogenase, glutathione reductase, glutathione S-transferase, and glutathione levels. These results suggest that protective effects of anticarcinogens may be produced by both the decrease of metabolic activation (BHA, EQ, SE) and the enhancement of metabolic deactivation processes (BHA, EQ, DSF, SE).