Comparative effects of BHA and ascorbic acid on the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats.

1. The abilities of BHA and ascorbic acid to prevent the toxic manifestations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were examined in female Sprague-Dawley rats. 2. Rats treated with BHA were partially protected from TCDD-induced lipid peroxidation, inhibition of glutathione peroxidase activity, and losses in liver, thymus and body weights. 3. Ascorbic acid had no effect on TCDD-induced alterations in glutathione peroxidase and aryl hydrocarbon hydroxylase activities, or body, liver and thymus weight changes. Ascorbic acid was unable to protect against the lethality of TCDD. 4. Some of the toxic manifestations of TCDD may be mediated by reactive oxygen species and free radical processes.