Effects of Ginkgo biloba on plasma oxidant injury induced by bleomycin in rats.

Bleomycin is an anti-neoplastic agent and its clinical usage is limited by its toxicity, which is mostly induced by oxygen radicals. The aim of this study was to investigate the effect of Ginkgo biloba on plasma indices of oxidants induced by bleomycin in rats. Male Sprague-Dawley rats were divided into five groups: none medicated or 0.9% NaCl injected or only Ginkgo biloba (orally, 100 mg/kg per day for 14 days) or only a single dose of bleomycin (intratracheal, 2.5 U/kg) or Gingko biloba and bleomycin-treated groups. After 14 days, blood was taken before the rats were sacrificed. The plasma was removed and stored at -85 degrees C until the study day. Plasma superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) enzyme activities with malondialdehyde and nitric oxide (NO) levels were studied. The levels of malondialdehyde and NO with activity of XO were higher in plasma of bleomycin group than the other groups (P <0.05). The activities of SOD and GSH-Px were increased in the bleomycin plus Gingko biloba group in comparison with the bleomycin group (P <0.05). There was a positive correlation between malondialdehyde and NO levels in the bleomycin group (r =0.859, P <0.05). There were positive correlations between SOD and GSH-Px activities (r =0.760, P <0.05) and between XO activity and malondialdehyde level (r =0.822, P <0.05) in the bleomycin plus Gingko biloba group. In conclusion, it was thought that bleomycin induced oxidative stress can be prevented by Gingko biloba treatment via high anti-oxidant enzyme activity together with decreased radical production from XO.