Effects of Long-Term Vitamin E and Butylated Hydroxytoluene Supplemented Diets on Murine Intestinal and Hepatic Antioxidant Enzyme Activities

The present study was designed to determine long-term feeding effects of vitamin E and BHT (butylated hydroxytoluene) on serum biochemical profiles, organ weight, and intestinal and hepatic antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and glutathione-S-transferase (GST) in ICR mice. Four wk old ICR mice (n=8 per group) were fed the diets supplemented with vitamin E (I ; 0.03% and II ; 0.3%) and BHT (I ; 0.05% and II ; 0.5%) for 12 months. Feeding the diets containing vitamin E and BHT had no effects on growth and serum biochemical profiles. However, feeding the diets supplemented with 0.5% BHT for 12 months significantly increased liver weight of the mice. In the small intestine, there were no effects of vitamin E or BHT on SOD and GSH-PX activities in the mucosa. However, the activity of intestinal GST of the mice that received 0.5% BHT was almost twice as high as that of control mice. In the liver, the activity of SOD was not affected by feeding antioxidants for 12 months, whereas GSH-PX activity was significantly increased in mice that received the diets containing BHT (0.05%, 0.5%) and vitamin E (0.03%, 0.3%). In addition, supplementation of 0.5% BHT markedly enhanced hepatic GST activity compared with other groups. Enhanced activity of GSH-PX in response to feeding vitamin E or BHT might aid hepatic enzymes to eliminate active oxygen in organs from mice. However, we could not exclude the possibility of increased lipid peroxidation by high dosage of BHT supplementation. More detailed study is necessary for assessment of preventive or toxicological effects of high dosage of BHT supplementation.