Noxious effect of Moringa oleifera leave extract on the developing brain, morphology and behaviour of Wistar rat

Abstract

The effects of Moringa oleifera leave extracts on the morphology and behaviour of the postnatal developing rat brain was studied. Twenty pregnant rats of Wistar strain weighing between 160 g and 180 g were used in the study. The pregnant rats were divided into two groups of ten animals per group. Group I animals received distilled water and served as control animals, while group II animals received 200 mg/kg body weight of Moringa oleifera leave extract orally. All the animals were provided with rat cubes and water ad libitum during pregnancy and lactation. After birth, five pups of day 21 were weighed and subjected to behavioural study. Animals of days 1, 7, 14, 21 and 28 of age were sacrificed by cervical dislocation, the brain dissected out, weighed and fixed in 10% formol-saline for microscopic studies. Some congenital malformations such as meromelia, phocomelia and amelia were observed in the Moringa oleifera group only. There was a significant increase in body weight of the Moringa oleifera animals on days 7, 14 and 21, in brain weight on days 1 and 7, and in cerebral weight on days 1, 7 and 21 (p<0.05). The behaviour of the rats was significantly worse in the Moringa oleifera group, especially in the area of motor function. Microscopically, there was significant reduction in the cerebral cortical thickness of Moringa oleifera group on days 21 and 28. Immunohistochemical studies revealed poor myelination in the Moringa oleifera group. The results indicate that maternal consumption of Moringa oleifera significantly affected the general morphology as well as behaviour of their pups, therefore it should be consumed with caution in pregnancy until better knowledge on humans is available.