Protective effect of cinnamic acid on orthophenylphenol-induced oxidative stress in rats

This study aimed to evaluate the protective effect of cinnamic acid (CA) on orthophenyl-phenol (OPP)-induced oxidative stress in rats. Thirty-two Sprague-Dawley male rats were divided into four groups as control, OPP, CA and OPP + CA groups. The animals in control, OPP and CA groups were received corn oil, OPP (700 mg kg^-1 dissolved in corn oil) and CA (200 mg kg^-1) by gavage for 21 days, respectively. The animals in OPP + CA group were received CA for 3 days and from day 4; OPP and CA were applied together daily until day 25. Blood and liver samples were collected at the end of experiment for measurement of aminotransferases, creatinine (CREA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), reduced glutathione (GSH) and malondialdehyde (MDA). The OPP-induced high serum activities of aminotransferases and level of CREA were reduced significantly by CA administration. The OPP induced significant increases of CAT activities and MDA levels in serum and liver tissue samples. Moreover, OPP significantly decreased GSH levels as well as GSH-Px and SOD activities. Pre-treatment with CA ameliorated the GSH levels along with GSH-Px and SOD activities compared to OPP-receiving rats. On the other hand, CAT activities and MDA levels significantly decreased following the pre-treatment with CA compared to OPP-receiving rats. It has been determined that OPP causes oxidative stress and lipid peroxidation in blood and liver tissues and creates changes in anti-oxidant defense enzymes. Pre-treatment with CA reduces lipid peroxidation and provides protective effect against oxidative stress.