DOSE-DEPENDENT EFFECT OF WITHANIA SOMNIFERA ON THE CHOLINERGIC SYSTEM IN SCOPOLAMINE-INDUCED ALZHEIMER’S DISEASE IN RATS

The present study was aimed to determine whether the methanol and aqueous extracts from the medicinal plant, Withania somnifera (root), could inhibit acetylcholinesterase (AChE) in scopolamine-induced Alzheimer’s rats. The rats were randomly divided into different groups of 5 each: normal control rats treated with saline; Scopolamine (2mg/Kg b.w. i.p.) – induced Alzheimer’s rats treated with saline; Scopolamine-induced Alzheimer’s rats post-treated with methanol extract of three different concentrations (100, 200 and 300mg/Kg b.w. oral); Scopolamine-induced Alzheimer’s rat post-treated with aqueous extract of three different concentrations (100, 200 and 300mg/Kg b.w. oral); and scopolamine-induced Alzheimer’s rat post-treated with donepezil, a reference control (5mg/Kg b.w. oral) for 10 successive days. Increased AChE activity and decreased Acetylcholine content were recorded in different brain regions in scopolamine-induced Alzheimer’s rats. Post-treatment with W. somnifera extracts caused recovery of the levels of AChE and acetylcholine (ACh) in a dose-dependent manner. These findings suggest that W. somnifera causes perceptible changes in the cholinergic system as one of the facets of its anti-alzheimeric activity.