The modulatory influence of Rosmarinus officinalis
(rosemary) leaves extract was investigated in Swiss albino mice at a dose of 3 Gy gamma radiation. For this purpose, adult Swiss albino mice were irradiated with 3 Gy gamma rays in the presence (experimental) or absence (control) of rosemary (1000 mg/kg body wt.). These animals were necropsied and their blood was collected at days 1, 3, 5, 10, 20 and 30 post-irradiation. A decrease in the number of erythrocyte and leucocyte counts, hemoglobin content and hematocrit percentage was scored in the control group; whereas a recovery pattern was recorded in experimental animals and a normal value of hematological parameters were regained by day 30 post-treatment. In irradiated group, glutathione level was registered low in the blood, whereas a significant elevation was estimated in rosemary pre-treated animals. An increase in lipid peroxidation level above normal was evident in serum of irradiated mice, while a significant decrease in such values was noted in rosemary pretreated group. The present study suggests the possible radioprotective ability of rosemary extract.