Protection of swiss albino mice against whole-body gamma irradiation by Mentha piperita (Linn.)

The radioprotective effects of Mentha oil (Mentha piperita Linn.) against radiation induced haematological alterations in peripheral blood and the survival of Swiss albino mice were studied. Mentha oil 40 muL/animal/ day for 3 consecutive days when fed orally prior to whole-body gamma irradiation (8 Gy) showed protection of the animals in terms of the survival percentage and haematological parameters in mice. Fifty per cent of the animals died within 20 days and 100% mortality was observed up to 30 days post-irradiation in the control irradiated group. Whereas only 17% of the mice died within 30 days in the experimental group (Mentha oil pretreated irradiated). The total RBC count decreased maximally at 24 h (3.45 +/- 0.20 x 10(12)/L, p < 0.001), similar observations were obtained for the WBC count, haemoglobin content and haematocrit percentage in the irradiated control animals. However, in irradiated animals pretreated with Mentha oil, although the initial values of haematological components were lower they later showed a remarkable recovery reaching normal at 30 days post-irradiation compared with the irradiated control animals. In general, the recovery of the blood cell number in irradiated animals depends on the survival of stem cells and their derivatives. The results from the present study suggest that the oil of Mentha piperita (Linn.) has a radioprotective role in stimulating/ protecting the haematopoietic system. Hence, enhanced survival and an increase in the haematological constituents of peripheral blood of mice against lethal gamma radiation was observed. Copyright (C) 2004 John Wiley Sons, Ltd.