EFFECTS OF 2-TERT-BUTYL-4-HYDROXYANISOLE AND 3-TERT-BUTYL-4-HYDROXYANISOLE ON GLUTATHIONE S-TRANSFERASE AND EPOXIDE HYDROLASE ACTIVITIES AND SULFHYDRYL LEVELS IN LIVER AND FORESTOMACH OF MICE

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (10) , 3940-3943
Abstract
Butylated hydroxyanisole, a food additive, has been found to inhibit the neoplastic effects of a wide variety of chemical carcinogens. The commercially available preparations of butylated hydroxyanisole contain 2 isomers, 2-tert-butyl-4-hydroxyanisole (2-BHA) and 3-tert-butyl-4-hydroxyanisole (3-BHA). Both isomers induce increased activities of glutathione (GSH) S-transferase and epoxide hydrolase and increase acid-soluble sulfhydryl concentration in hepatic and forestomach tissues of A/HeJ mice. The inductions were assayed after 2 wk of feeding diets containing the 2 isomers. 3-BHA induced an increase in the activity of hepatic microsomal epoxide hydrolase by 1.4 times that of the control. The activity of cytosolic GSH S-transferase was enhanced by both isomers. In the liver, the 3-BHA induction was more than 3 times higher than that of 2-BHA. In the forestomach, however, the induction effect of the 2 isomers was reversed. The overall magnitude of the induction was much lower in the forestomach than in the liver. Synergistic effects on the induction of GSH S-transferase activity were observed in the forestomach cytosol when mixtures of different proportions of the 2 isomers were added to the diet. Maximum enzyme activity was obtained at a ratio of 75% 2-BHA and 25% 3-BHA. No synergistic effect was observed with the corresponding hepatic cytosolic enzyme. The relative inductive effects of 2- and 3-BHA on the acid-soluble sulfhydryl level of liver and forestomach tissues followed closely those on GSH S-transferase activity. The 2 isomers of butylated hydroxyanisole apparently differ in the magnitude of their effects on carcinogen-metabolizing systems of the liver and forestomach.