RESUMO
Effects of 20 mg/kg body weight of abana (ABE) on radiation-induced sickness and mortality in mice exposed to 7 Gy to 12 Gy of gamma irradiation were studied. Treatment of mice with abana 1 h before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls (double distilled water, DDW). Abana provided protection against both the gastrointestinal and haemopoietic deaths. However, animals of both the ABE+irradiation and DDW+irradiation groups did not survive up to 30 days post-irradiation beyond 11 Gy irradiation. The LD(50/30) was found to be 8.5 Gy for the DDW+irradiation group and 10.3 Gy for ABE+irradiation group. The administration of abana resulted in an increase in radiation tolerance by 1.8 Gy, and the dose modification factor (DMF) was found to be 1.2. The irradiation of animals resulted in a dose dependent elevation in lipid peroxidation, and a reduction in glutathione (GSH) concentration on day 31 post-irradiation. Treatment of mice with abana before irradiation caused a significant depletion in lipid peroxidation followed by a significant elevation in GSH concentration in the liver of mice at day 31 post-irradiation. Abana scavenged (*)OH, DPPH, ABTS(*+) and NO(*) in a concentration dependent manner in vitro. Our results indicate that the radioprotective activity of abana may be due to free radical scavenging and increased GSH level in irradiated mice.
