Evaluation of the radioprotective action of geriforte in mice exposed to different doses of γ-radiation

The effect of 5, 10, 20, 40 and 80 mg/kg b. wt. of hydroalcoholic extract of geriforte (an Ayurvedic herbal medicine) administered intraperitoneally was studied on the radiation-induced mortality in mice exposed to 10 Gy of γ-radiation. Treatment of mice with different doses of geriforte consecutively for 5 days before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls. A maximum protection was observed for 10 mg/kg geriforte, where a highest number of survivors were reported by 30 days post-irradiation and further experiments were carried out using this dose of geriforte. The mice were treated with 10 mg/kg b. wt. geriforte or double distilled water (DDW) and exposed to 7, 8, 9, 10 and 11 Gy of gamma radiation and observed for the induction of symptoms of radiation sickness and mortality up to 30 days post-irradiation. The geriforte treatment protected the mice against the GI death as well as bone marrow deaths and the dose reduction factor (DRF) was found to be 1.14. Toxicity study showed that geriforte was non-toxic up to a dose of 4250 mg/kg, where no drug-induced mortality was observed. The LD₅₀ dose of geriforte was found to be 4750 mg/kg b. wt. To understand the mechanism of action of geriforte, free radical scavenging activity of the drug was evaluated. Geriforte was found to scavenge ^•OH, O₂^•- ABTS^•+ and NO^• in a dose-dependent manner. Our study demonstrates that geriforte is a good radioprotective agent and the optimum protective dose of 10 mg/kg was 1/475th of the LD₅₀ dose.