Preventive treatment with vitamin E alleviates the poisoning effects of carbon tetrachloride in cattle.

Fifteen yearling steers were used to study the preventive effect of vitamin E on the protection against free radicals produced by carbon tetrachloride (CCl4). The animals were randomly divided in three equal groups and treated as follows: group A--previously injected (i.m.) with 15 IU/kg BW on the 15th and second day before the trial and drenched with 0.05 ml/kg BW CCl4; group B--only drenched with the same dose of CCl4; group C--drenched with a placebo. Food intake was recorded and blood samples collected daily for 8 days after the CCl4 drenching to compare the activity of aspartate aminotransferase (AST), gamma-glutamyltransferase (gamma-GT) and the levels of erythrocyte reduced glutathione (GSH) and serum malonyldialdehyde (MDA). Food intake was reduced in group B for the first 3 days (P < 0.05); higher activities of AST and gamma-GT were observed in the poisoned groups, nevertheless the overall values were lower in the group A than B (P < 0.02); only the group A reached the basal values of AST at the seventh day; higher levels of GSH and MDA were recorded in the poisoned cattle indicating the generation of free radicals. It was concluded that the preventive use of Vitamin E lessened the damage in hepatic tissue caused by the free radicals and prevented the anorexia caused by CCl4.