Effect of Ethanol Extract of Moringa oleifera Leaf on Nissl Granules, Immunohistochemistry of Inferior Colliculus and Oxidative System Following Quinine Toxicity in Wistar Rats

Abstract

The metabolite of Quinine, 3-hydroxyquinine is the active substance and more toxic than quinine hence, it can exert pro-oxidant effect in the body. In this study, the effect of ethanol leaf extract of Moringa oleifera was evaluated against quinine toxicity on nissl granules, immunohistochemistry of inferior colliculus and oxidative system of Wistar rats. Fifty Wistar rats weighing 180 – 200g were alloted into 10 groups of 5 rats each. Group 1 served as control while Groups 2 to 10 were the treatment groups. Groups 2 – 4 received 10, 20 and 30 mg/kg body weight of quinine hypochloride injection intramuscularly eight hourly for 7 days. Groups 5 – 7 were orally administered 250, 500 and 750 mg/kg body weight of M. oleifera leaf extract daily for 7 days respectively. Group 8 received 250mg/kg of leaf extract orally and intramuscular (IM) 10mg/kg of quinine; Group 9 was treated with oral 500mg/kg of the extract and IM 20mg/kg of quinine while Group 10 received 750mg/kg of the extract orally and IM 30mg/kg of quinine for 7 days. Results revealed that quinine significantly (p < 0.05) decreased the activities of anti-oxidative enzymes (superoxide dismutase and catalase) and increased lipid peroxidation (malondialdehyde, MDA) in treated rats. However, Moringa oleifera leaf extract showed significant increase in the activities of anti-oxidant enzymes and decreased lipid peroxidation. Histomorphological and immunohistochemical observations revealed that quinine caused neuronal distortions, nuclear degenerations, and depletion of Nissl granules, vascular congestions and vacuolations and increased astrogliosis in the inferior colliculus. Incorporation of the extract to the quinine treated groups revealed neuronal regenerations, increased staining intensity and density of the Nissl granules, reduced astrogliosis and restoration in the inferior colliculuscyto-architectures. In conclusion, Moringa oleifera leaf extract can be used to ameliorate the adverse effects of quinine toxicity on inferior colliculus.