Effect of butylated hydroxytoluene on alpha-tocopherol content in liver and adipose tissue of rats.

Female rats were fed an antioxidant supplemented diet containing butylated hydroxytoluene (BHT; 0.5% and 1.0%) with or without vitamin E acetate (0.4%) for 4 weeks, after which the contents of BHT and alpha-tocopherol in the liver and abdominal adipose tissue were analysed. The body weight gain was similar in all groups independent of the diet after the first week of treatment. At the end of the experiment the liver weights of the BHT-supplemented rats were increased compared to the liver weights of the control groups, and this difference was unaffected by vitamin E treatment. The liver concentration of alpha-tocopherol was decreased and inversely proportional to the BHT concentration in the diet. This attenuating effect of BHT on the hepatic alpha-tocopherol concentration was present both in animals with and without vitamin E supplementation. In contrast, BHT treatment did not alter the concentration of alpha-tocopherol in abdominal adipose tissue. The results show that BHT has adverse effects in the liver. BHT is metabolized by the cytochrome P450 system in the liver and may be converted to prooxidative compounds during this process. Adipose tissue lacks the cytochrome P450 system. Therefore, the decreased hepatic concentration of alpha-tocopherol may be a consequence of a BHT-induced, free oxygen radical mediated, depletion of this antioxidant.