[Effect of propolis against radiation-induced oral mucositis in rats].

OBJECTIVES This study aims to investigate whether propolis has a protective role in oral mucosal damage induced by radiotherapy applied to head-neck region, using quantitative, biochemical and histopathological approaches. MATERIALS AND METHODS Forty eight Wistar-Albino adult female rats at eight weeks of age and weighing 213±27 grams were included in this study and randomly divided into six groups: Group 1: control, group 2: only irradiated rats, group 3: irradiated rats with propolis administration at 50 mg/kg/day, group 4: irradiated rats with propolis administration at 100 mg/kg/day, group 5: only propolis administration at 50 mg/kg/day, group 6: only propolis administration at 100 mg/kg/day. The first dose of propolis was administered before 30 minutes irradiation and the other doses after irradiation once daily for seven days by topical application. Radiotherapy was applied to the total cranium by single fraction at a dose of 18 Gy. The mucositis degrees and body weights of the animals were measured throughout the experiment. On the 7th day of study, blood samples were taken from the rats under ketamine anesthesia and then the rats were sacrificed and tongue tissues samples were taken. Complete blood count and biochemical and antioxidant activities were analysed in the blood samples. The tongue samples were microscopically examined. RESULTS Radiotherapy group had a decrease in body weight and neutrophil count, and an increase in oral mucositis as compared with the control group (p<0.001). Moreover, an increase in plasma malondialdehyde concentrations (p<0.001) and significant decreases in catalase and superoxide dismutase activities (p<0.001) were observed in irradiation-alone group when compared to the control group. Propolis administered irradiated rat groups showed a dose-dependent normalization in quantitative, biochemical and histopathological parameters when compared with the irradiation-alone group. CONCLUSION The results showed that propolis is effective in reducing the severity of oral mucositis induced by head-and-neck irradiation.