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 pet-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. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved.