EFFECT OF DIETARY ANTIOXIDANTS ON THE SUSCEPTIBILITY TO HEPATIC-MICROSOMAL LIPID-PEROXIDATION IN THE RAT

The inhibitory effect of probucol on ferrous-iron-induced microsomal l ipid peroxidation was compared to that of alpha-tocopherol and butylat ed hydroxytoluene (BHT). Male Wistar rats were fed with diets containi ng 1% probucol, 0.2% BHT or 0.1% alpha-tocopherol for 30 days. There w ere no effects of dietary antioxidants on growth parameters, although liver weight was significantly higher in the BHT-fed rats. Probucol re duced serum levels of total and free cholesterol, while BHT feeding in creased the concentrations of serum thiobarbituric-acid-reactive subst ances, HDL cholesterol and hepatic phospholipid. alpha-Tocopherol had no effect on these parameters. Incorporation of both, probucol and alp ha-tocopherol, decreased the susceptibility of microsomes to lipid per oxidation in vitro, while BHT incorporation increased hepatic microsom al lipid peroxidation. These results suggest the possible usefulness o f probucol for treatment of both hypercholesterolemia and elevated hep atic microsomal lipid peroxidation, while alpha-tocopherol decreases o nly an elevated lipid peroxidation. BHT works as a prooxidant.