Abstract
Nigella sativa ascribed to have many medicinal properties. The study aimed to investigate whether N. sativa oil could decrease the side effects induced by the antibiotic, chloramphenicol. Rats were assigned into the following: The control group (first group); the second and the third groups which were orally administrated chloramphenicol for 21 days at a dose of 86 mg/kg body weight. Then the third group was treated with N. sativa oil for 30 days at a dose of 13.5 mg/150 g; the forth group was synergistically administrated both chloramphenicol and N. sativa for 21 days. Administration of N. sativa oil was extended to 30 days more in this group. There was a decrease in erythrocyte, hemoglobin and hematocrit with a progressive increase of leukocyte count in drug treated group. A decrease in neutrophils and lymphocyte with an increase in nucleated immature red cells as well as myeloblasts and myelocytes. On the other hand, N. sativa showed a time dependent improvement in blood parameters. A gradual decrease in the counts of immature stages was realized with the administration of N. sativa. Pathological changes in spleen included splenomegaly, lymphocytic depletion, enlargement of the marginal zone, wide trabeculae, reticular cells, pyknotic nuclei and cells in different stages of megakaryopoiesis. A marked depletion in cortical lymphocytes, disturbed lobular pattern, increased reticuloepithelial cells and dilated blood vessels in the thymus of group 2. N. sativa showed only a slight improvement of the damaged spleen tissues, while a time dependent repair in thymic tissue and both the cellular and humoral immunity was observed. In conclusion, N. sativa had an obvious protective effect and decreased the side effects of chloramphenicol.