Dietary selenium protects against acute toxicity of T-2 toxin in rats.

The efficacy of dietary selenium (Se) supplementation on acute toxicity of T-2 toxin was investigated. Wistar male rats were divided into six groups with 15 rats in each and fed for 6 weeks ad libitum a semi-synthetic diet containing either 0.03 (groups 1 and 2), 0.5 (groups 3 and 4) or 2.5 mg Se/kg (groups 5 and 6). By the end of the experiment the rats in groups 2, 4 and 6 were administered once per os 3.8 mg/kg body weight T-2 toxin, while the animals in groups 1, 3 and 5 received equal doses of the solvent. Twenty-four hours after administration of the toxin the surviving rats were sacrificed and the liver microsomes isolated and determined for activities of enzymes relating to xenobiotics metabolism and Se. The results showed that feeding the rats 2.5 mg Se/kg diet increased the deethylation rate of 7-ethoxycoumarin by 42% and slightly decreased (20%) glutathione-S-transferase activity. Twenty-four hours after the administration of T-2 toxin the lethality percentages in groups 2, 4 and 6 were 47%, 27% and 20%, respectively. Furthermore, administration of T-2 toxin to group 6 rats resulted in a significant decrease in the level of cytochrome P-450 and 7-ethoxycoumarin deethylase activity (to 78% and 51%, respectively) compared to the control group. At the same time a 72% increase in the UDP-glucuronosyltransferase activity and of 61% in epoxide hydrolase activity compared to the control group was found. Similarly, although somewhat smaller, changes were seen in the group 4 rats receiving 0.5 mg Se/kg diet.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of aspartame on the activity of rat liver xenobiotic-metabolizing enzymes.

Male, Wistar rats were administered aspartame (40 or 4000 mg/kg body weight) in their diet for 90 days. By 45 days, the activities of three microsomal enzymes, epoxide hydrolase, carboxylesterase, and p-nitrophenyl-UDP-glucuronosyltransferase, were significantly increased in rats consuming 4000 mg/kg of aspartame. By 90 days, however, the activity of the xenobiotic-metabolizing enzymes of the rats given aspartame did not differ significantly from the activity of control animals. From these results, we conclude that the consumption of aspartame does not substantially alter the function of the hepatic microsomal enzymes which protect the organism from foreign compounds found in its environment and food.