Effects of caffeic acid phenethyl ester on lipid peroxidation and antioxidant enzymes in diabetic rat heart.

OBJECTIVES: The risk for cardiovascular disease is significantly high in diabetes mellitus. Experimental evidence suggests that oxidative stress plays a dominant role in the pathogenesis of diabetes mellitus. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has several biological and pharmacological properties, including antioxidant, anti-inflammatory, anti-carcinogenic, antiviral, and immunomodulatory activities. In light of the antioxidant ability of CAPE, the effects of CAPE on the antioxidative status of cardiac tissue were investigated in streptozotocin (STZ)-induced diabetic rats.

DESIGN AND METHODS: Twenty-six rats were randomly divided into three groups: group I, control, nondiabetic rats (n = 9); group II, STZ-induced, untreated diabetic rats (n = 7); and group III, STZ-induced, CAPE-treated diabetic rats (n = 10). In groups II and III, diabetes developed 3 days after intraperitoneal (ip) administration of a single 35 mg kg(-1) dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mumol kg(-1) ip dose of CAPE per day. After 8 weeks, the levels of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the cardiac tissues of all groups were analyzed.

RESULTS: In untreated diabetic rats, MDA markedly increased in the cardiac tissue compared with the control rats (P < 0.05). However, MDA levels were reduced to the control level by CAPE. The activities of SOD and CAT in the untreated diabetic group and the CAPE-treated diabetic group were higher than those of the control group (P < 0.05). Rats in the CAPE-treated diabetic group had reduced activities of SOD and CAT in comparison with the rats in the untreated diabetic group (P < 0.05). There were no significant differences in the activity of GSH-Px between the rats in the untreated diabetic group and the control group. However, the activity of GSH-Px was increased in CAPE-treated diabetic rats compared with the control and untreated diabetic rats (P < 0.05).

CONCLUSION: These results reveal that diabetes mellitus increases oxidative stress in cardiac tissue and CAPE has an ameliorating effect on the oxidative stress via its antioxidant property.