Role of Ocimum sanctum in the experimental model of Alzheimer’s disease in rats

M. Raghavendra, Rituparna Maiti, Shafalika Kumar, S. B. Acharya


Alzheimer’s disease (AD), a neurodegenerative disorder incapacitating elderly people towards the end of their life, accounts for approximately 70% of dementia. It affects 17-25 million elderly people worldwide. In spite of the remarkable increase in scientific knowledge about the pathobiology of AD, attempts other than modifying the cholinergic neurotransmission have proved futile. In Ayurveda a number of agents are in use, since ancient times, for chronic debilitating disorders. One such preparation, Ocimum sanctum (OS) has been found to possess anti-ulcerogenic, anti-inflammatory and neuroprotective activities. Because of the nonavailability of proper curative therapy for AD, the present study has been undertaken to evaluate the possible role of OS in experimental AD in rats.
Experimental AD in rats was produced by a nucleus basalis magnacellularis lesion with ibotenic acid (IB) and intracerebroventricular (i.c.v) administration of colchicine (Col). Various behavioural tests and biochemical analysis were performed to explore the possible role of OS in AD. OS exhibited anxiolytic activity in an open field test. In an elevated plus maze test, OS significantly alleviated IB, and Col induced anxiety and depression in the Porsolt’s swim test. In Morris’ water maze test, OS pretreatments improved reference memory, working memory and spatial learning. Both IB and Col induced deficits in active avoidance learning and retention of learned
behaviour, which were significantly reversed by OS. IB and Col induced increased lipid peroxidase activity, which was significantly reversed by OS (as seen from the reductions in the malondialdehyde level) and stabilized the rise in superoxide dismutase activity, but it had no effect on the acetylcholinesterase activity. OS might be effective in clinical AD by virtue of its cognition enhancement, antidepressant and antianxiety properties, which are the primary needs to be addressed in AD.
Key words: Alzheimer’s disease, eugenol, Ocimum sanctum

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