Abstract
Introduction: In recent years, the growing research towards new drugs has been targeted on plant-based drugs, and Neem (Azadirachta indica) is one of the plants that have been extensively researched for its diverse medicinal properties. The study aimed to determine the effects of neem on the hematological parameters (total white blood cells, neutrophil, monocyte and eosinophil counts) and histology of some organs of rats. Methods: Fifteen healthy male Wister rats divided into control (Nm0) and experimental groups (Nm11 and Nm22). Control group 1 (Nm0) was given 100mg/200g body weight of normal saline orally twice daily; experimental group 2 (Nm11), 100mg/200g body weight neem extract twice daily for 11 days and experimental group 3 (Nm22), 100mg/200g neem leaf extract twice daily for 22 days. Total number of white blood cells (WBC), lymphocytes, neutrophils, monocytes and eosinophils, packed cell volumes (PCV) and histological changes in the spleen, liver and kidneys were evaluated. Results: There were no significant differences in mean values of the hematological parameters (total WBC; PCV; neutrophils, lymphocytes, monocytes and eosinophils). We observed the central vacuolation and accumulation of lymphocytes in the spleen, hypertrophy of the central vein in the liver and shrinking of the glomeruli and accumulation of the lymphocytes in the kidney using hematoxylin and eosin staining following prolonged administration of neem extract (Nm22). Conclusion: Prolonged administration of neem affected the histology of some organs of the rats more than the hematological parameters.