The antioxidant effect of eugenol on CCl4-induced erythrocyte damage in rats

Simultaneous administration of eugenol (10.7 mg/kg of body weight/day) with carbon tetrachloride (CCl4) (1.195 g/kg of body weight, i.p. 3 times a week for 2 weeks) to mts protected the loss of functional integrity and membrane lipid alterations in red blood cells (RBCs) induced by oxidative stress. Eugenol, an allyl benzene that is the major ingredient of cloves, Osimum, and nutmeg, inhibits the accumulation of lipid peroxidation products in red blood cells and maintains the activities of the antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase(s), glutathione reductase, and glucose-6-phosphate dehydrogenase at normal levels. The CCl4-induced increase in membrane fluidity was decreased by eugenol, and the altered activities of membrane-bound enzymes Na+, K+-ATPase, NADH-dehydrogenase, and Ca2+-ATPase were normalized. Eugenol exhibited a concentration-dependent binding into RBC membranes in vitro, and it also inhibited the hemolysis of RBCs induced by liver S9 fraction-treated CCl4. Hence, it is suggested that eugenol, by incorporating into the membrane protects it from free radical attack and by maintaining the activities of the antioxidant enzymes at normal levels removes the oxidative stress imposed by CCl4.