Indian Journal of Experimental Biology Vol. 48, May 2010, pp. 479-485 Effect of Convolvulus pluricaulis Choisy. and Asparagus racemosus Willd on learning and memory in young and old mice: A comparative evaluation Komal Sharma a , Maheep Bhatnagar * , & S K Kulkarni b a B.N. PG College of Pharmacy, Udaipur 313 001, India * Department of Zoology, University College of Science, M.L. Sukhadia University, Udaipur 313 001, India and b Pharmacology Division, University Institute of Pharmaceutical Sciences, Punjab University, Chandigarh 160 014, India Received 21 April 2009; revised 19 January 2010 A dose dependent enhancement of memory was observed with A. racemosus and C. pluricaulis treatment as compared to control group when tested on second day. A. racemosus and C. pluricaulis at the dose of 200 mg/kg, po showed significantly higher percent retentions, than piracetam. Multiple treatment with A. racemosus and C. pluricaulis for three days also demonstrated significant dose dependent increase in percent retentions as compared to control group. The effect was more prominent with C. pluricaulis as compared with piracetam and A. racemosus. A significantly lower percent retention in aged mice was observed as compared to young mice. Aged mice (18-20 months) showed higher transfer latency (TL) values on first and second day (after 24 h) as compared to young mice, indicating impairment in learning and memory. Pretreatment with A. racemosus and C. pluricaulis for 7 days enhanced memory in aged mice, as significant increase in percent retention was observed. Significantly higher retention was observed with C. pluricaulis (200 mg/kg; po) as compared with piracetam (10 mg/kg/; po). Post-trial administration of C.pluricaulis and A. racemosus extract demonstrated significant decrease in latency time during retention trials. Hippocampal regions associated with the learning and memory functions showed dose dependent increase in AChE activity in CA 1 with A. reacemosus and CA3 area with C. pluracaulis treatment. The underlying mechanism of these actions of A. racemosus and C. pluricaulis may be attributed to their antioxidant, neuroprotective and cholinergic properties. Keywords: Asparagus racemosus, Convolvulus pluricaulis, Elevated plus maze, Learning, Memory A wide variety of clinical syndromes like head trauma, convulsive disorders and neurodegenerative diseases manifest cognitive or memory dysfunctions 1 . Cognitive and behavioural impairments are also shown by most common dementia in elderly. Although primary cause of these remains unclear, recent studies have suggested that free radicals produced during oxidative stress or inflammatory processes are pathologically important 2-4 . Currently the mainstays of pharmacological treatment for the cognitive deficits are donepezil, galantamine, rivastigmine and memantine-4, which are being primarily used to improve memory, mood and behavior 5 . However, the resulting adverse effects associated with these agents have limited their use 5,6 . Therefore, it is worthwhile to explore the utility of traditional medicines for the treatment of various cognitive disorders. Medhya rasayana are Ayurvedic preparations known to improve memory, intelligence 7,8 . Some of these rasayanas Withania somnifera 9 , Asparagus racemosus 10 , Convolvulus pluricaulis 11 , Tinospora cordifolia 12 and Centella asiatica 13 are commonly prescribed by the Ayurvedic practitioners for treatment of cognitive disorders or improving learning and memory. However, there has not been sufficient investigation to establish the biological effects of these plants in improving cognitive deficits or memory disorders. Therefore it is necessary to evaluate the beneficial effects of these plants on learning and memory by means of proper animal learning model with various sample treatments. In present study, A. racemosus Willd. and C. pluricaulis Choisy were selected for evaluation of their effects on learning and memory in mice. Both plants possess antioxidant, free radical scavenging activity and neuroprotective activities 14,15 . Free radical reactions are implicated in memory deficit, neurodegenerative diseases and also in aging 2-4,16 . —————— *Correspondent author Telephone: +91-0294-2441250 Fax: 91-0294-245010 E-mail: mbhatnagar@yahoo.com