Phytochemical and neurotoxicity evaluation of methanolic leaf-extract of Moringa oleifera

Objective: As a plant with a host of medicinal properties used for treating various ailments, the research set out to investigate the neurotoxic effect of methanol leaf-extract of Moringa oleifera, as well as explore its phytochemical constituents. The amphiphylic property of methanol as a solvent was exploited to extract non-polar and medium polar phytoconstituents. Methods: Forty (40) male Swiss white mice were randomly grouped into four (n=10 per group). The control animals receive normal saline (p.o.) while two other groups received low dose (500mg/kg) and high dose (2500mg/kg) of the leaf-extract of M. oleifera for 21 days. The forth group received a low dose (500mg/kg) of the extract thirty minutes before the animals were sacrificed for histological studies. Results: The phytochemical screening and quantitative analysis showed that the methanol leaf-extract of M. oleifera contains alkaloids (1.80±0.2%), glycosides (1.37±0.1%), saponins (1.47±0.3%), tannins (0.48±0.01%), flavonoids (8.23±0.2%), polyphenols (20.47±0.3%) and reducing compounds (7.05±1.0%). Acute toxicity evaluation using Lorke’s method showed the LD50 to be 5,477.226mg/kg. Histopathological evaluation shows no toxicity at 2500mg/kg in the hippocampus, amygdala, cerebral cortex and the cerebellum. Conclusion: The methanol leaf-extract of M. oleifera has no neurotoxic effect even at high doses; and so, it very safe for use in the treatment regimes.