Radioprotective potential of Rosemarinus officinalis against lethal effects of gamma radiation : a preliminary study.

The radioprotective effect of Rosemarinus officinalis extract (ROE) was studied in mice exposed to 8 Gy of gamma radiation. The optimum dose for radioprotection was determined by administering 100, 200, 400, 800, 1000, 1500, and 2000 mg/kg body weight of ROE orally once daily, consecutively for five days before irradiation. Treatment of mice with ROE, delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug-treated irradiated controls. The dose of ROE found to be most effective against radiation was 1000 mg/kg body weight because this dose increased the survival time and reduced the mortality rate of mice significantly. Body weight loss in ROE administered irradiated animals was significantly less in comparison with animals who were given radiation treatment alone. Furthermore, irradiation of animals resulted in an elevation in lipid peroxidation (LPx) and a significant decrease in glutathione (GSH) in blood and liver. Conversely, administration of animals with ROE before irradiation caused a significant decline in LPx accompanied by a significant increase in GSH concentration. The present study demonstrates that Rosemarinus officinalis leave extract is a good radioprotector.