Acute toxicity and effects of methanolic extract of <i>Moringa oleifera</i> flower on haematological parameters of Wistar rats

Abstract

Methanolic extract of Moringa oleifera flowers was investigated for its acute toxicity and effects on haematological parameters of Wistar rats. The acute toxicity study to determine the LD50 was evaluated using Lorke’s method. It involves first and second phases with six rats each phase. The rats were divided into three groups of two rats each of the phase. In the first, they were administered 10, 100 and 1000 mg/kg of the extract intraperitonially while in the second phase, they were administered 1600, 2900 and 5000 mg/kg and then observed for 24 hours. The haematological study was carried out according to standard procedures. Twenty (20) rats were divided into 4 groups with five rats in each group. The rats in groups B, C and D were treated orally with the methanolic extract of Moringa oleifera flowers using 200 mg/kg, 400 mg/kg, and 800 mg/kg respectively for 21 days while group A that served as control were administered sterile water for injection at 0.5 ml/kg. Blood sample was taken from all the rats and used to establish the baseline values prior to treatments with the extract. Blood samples were collected at the end of every week and analyzed for haematological values. The administration of the extract at the dose of 5000 mg/kg intraperitoneally to the rats resulted in death but was safe at the dose of 2900 mg/kg. This indicated that the LD₅₀ is below 5000 mg/kg. There were significant increases (p<0.05) in red blood cells, haemoglobin concentration and the packed cell volume values in all treated groups when compared to the baseline values (control group). There were also significant (p<0.05) decrease and variation in the neutrophilic values and an increase in the lymphocytic values of the differential leukocytes counts. This research has revealed that the methanolic extract of Moringa oleifera flowers increased significantly the red blood cells, packed cell volume, haemoglobin concentration and lymphocytosis in Wistar rats.