Effect of Ethanolic Extract of Psidium Guajava Leaves on the Cerebellar cortex of Adult Male Wistar Rats Treated with Mercuric Chloride

Mercury toxicity has been reported to cause distortion of gait and motor co-ordination due to deficit in the activity of cerebellum. Chelation therapy used in heavy metal toxicity is expensive and has been associated with adverse side effects. Therefore, the present study was aimed at evaluating the effect of ethanolic extract of Psidium guajava leaves on the Cerebellar cortex of adult male Wistar rats treated with Mercuric Chloride. Twenty adult Wistar rats were divided into four groups of five rats each. Group 1 served as control and received 1 ml/kg of distilled water, Group 2 received 41.5 mg/kg of Mercuric chloride and 1ml/kg of distilled water, Group 3 received 41.5 mg/kg of Mercuric chloride and 500mg/kg body weight of ethanolic extract of Psidium guajava leaves and Group 4 received 41.5 mg/kg of Mercuric chloride and 1000 mg/kg of ethanolic extract of Psidium guajava leaves. Motor coordination was evaluated in experimental animals using beam walking test. At the end of the experiment, brain tissues were carefully harvested and fixed in Bouin's fluid, processed and stained for histological studies. The result revealed a significant increase (p<0.05) in the meantime taken by the rats to cross the beam, neuronal degeneration and depletion of Nissl substance in the cerebellar cortex of Wistar rats exposed to Mercuric chloride when compared to the control and groups treated with ethanolic extract of Psidium guajava leaves. Ethanolic extract of Psidium guajava leaves reversed motor deficits, neurodegeneration and neurotoxicity induced by Mercuric Chloride in adult male Wistar rats.

Key Words: Psidium guajava, Mercuric Chloride, Cerebellar cortex, Motor co-ordination, Neurotoxicity