Ocimum sanctum Linn. Leaf Extracts Inhibit Acetylcholinesterase and Improve Cognition in Rats with Experimentally Induced Dementia

Cognitive disorders such as dementia, attention deficits, and Alzheimer's disease (AD) have been well investigated. However, effective interventions for the promotion and progression of AD are unavailable to date. The present work was undertaken to investigate the effects of the aqueous (300 and 500 mg/kg) and alcoholic (300 and 500 mg/kg) extracts of Ocimum sanctum Linn. leaves as an antidementic and anticholinesterase agent and also as an immunostimulant in rats. Maximal electroshock, atropine, and cyclosporine were used to induce dementia. The passive avoidance task was used for assessing memory. Acetylcholinesterase (AChE) activity was estimated in different parts of the brain, and immune status was studied using dinitrochlorobenzene (DNCB) skin sensitivity tests. In all the three models both aqueous and alcoholic O. sanctum extracts decreased the time taken to reach the shock-free zone and the number of mistakes and significantly decreased the AChE activity in rats. O. sanctum treatment significantly increased the induration in the DNCB skin test. Therefore, O. sanctum was shown to be useful for the management of experimentally induced cognitive dysfunctions in rats.