EVALUATION OF THE RADIOPROTECTIVE ACTION OF RUTIN IN MICE EXPOSED TO GAMMA-RADIATION
Rutin, a bioflavonoid is known to be a potent antioxidant. To explore its possible role as a radioprotector, the effect of orally administered of rutin on radiation induced mortality in mice and in vitro free radical scavenging activity was studied. Toxicity studies showed that rutin was non-toxic up to a dose of 4250 mg/kg, where no drug-induced mortality was observed. The LD50 dose of rutin was found to be 4750 mg/kg b. wt. In the present study, the effect of rutin was studied on the radiation induced mortality in mice exposed to 10 Gy of gamma-radiation. Maximal protection was observed at dose of 10 mg/kg rutin, where highest survival was reported by 30 days post-irradiation. Further experiments were carried out using this dose of rutin. Mice were treated with 10 mg/kg b. wt. rutin or carboxy methyl cellulose (carrier) and exposed to 7, 8, 9, 10 and 11 Gy of gamma radiation following the induction of symptoms of radiation sickness and mortality up to 30 days post-irradiation were observed. Rutin treatment protected mice against the gastro intestinal death as well as bone marrow deaths. Dose reduction factor (DRF) was found to be 1.14. To understand the possible mechanism of action of rutin, free radical scavenging activity of the drug was evaluated. Rutin produced a dose-dependent increase in free radical scavenging ability against various free radicals viz., 2, 2-diphenyl-2-picrylhydrazyl (DPPH), 2, 2-azinobis (3-ethylbenzothiazoline–6–sulfonic acid) (ABTS), superoxide (O2.-), hydroxyl radical (OH.) and nitric oxide radical (NO.) generated in vitro. Our results demonstrate that rutin acts as a radioprotector agent and has potent free radical scavenging capacity.