Protective effects of caffeic acid phenethyl ester on radiation induced lung injury in rats

Purpose: The prevention of radiation-induced pulmonary toxicity may help to improve radiation therapy in the cancer patient. The aim of this study was to investigate the pulmonary protective effects of caffeic acid phenethyl ester (CAPE), an antioxidant, on radiation-induced lung injury in rats. Methods: 30 Wistar albino rats were divided into three groups and treated with saline, Radiation (RT) and RT + CAPE respectively. All rats were treated with CAPE (50 mu mol/kg i.p.) or saline. The first dose of CAPE was injected 24 h before radiation and application continued daily, with radiation in second day and 2 days more after the radiation treatment. Radiation dose was 800 cGy for total body. At 72 hr after the last radiation application, under general anesthesia using ip ketamine, the lungs were removed immediately after decapitation. After sacrification, antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) activities and malondiadehyde (MDA) levels were evaluated in lung tissue. Results: The level of malondialdehyde (MDA) was higher in the RT group (233.4 +/- 1.5 nmol/g protein) than in both the control (131.8 +/- 0.92) and the RT + CAPE (151.4 +/- 1.8) groups (P < 0.001). However, CAT activity was decreased in the RT group (7.26 +/- 0.27 Umg protein) compared with control (8.49 +/- 0.51) and increased again in the RT + CAPE group (8.31 +/- 0.56; P < 0.001). In accord with CAT activity, SOD activity in the RT group (0.42 +/- 0.07 nmol MDA/g wet tissue) was different from the control (0.78 +/- 0.02) and RT + CAPE (0.86 +/- 0.06) groups (P < 0.001). Conclusion: CAPE aplication with radiation therapy attenuated radiation induced pulmonary injury in vivo, possibly by its antioxidant effect.