Evaluation of learning and memory enhancing activities of protein extract of Withania somnifera (Ashwagandha) in Wistar albino rats

Shwetha Shivamurthy, Ravi Shankar Manchukonda, Dinesha Ramadas


Background: Learning may be defined as the ability to alter behavior on the basis of experience. Memory is the process of remembering what has been learnt. Memory loss is the first symptom to manifest in Alzheimer’s disease (AD). Currently, the drugs used in Alzheimer’s are either associated with side effects or they lack disease modifying effect. Ashwagandha is a rasayana (rejuvenative) and possesses antioxidant and free radical scavenging activity (free radicals are produced during the initiation and progression of AD). Hence, the present study was undertaken to evaluate the learning and memory enhancing effect of protein extract of Withania somnifera in Wistar albino rats.

Methods: In the present study, Wistar albino rats were given 200mg/kg dose of protein extracts of Withania somnifera orally along with scopolamine (i.p) for 14 days. Rats were subjected to elevate plus maze and passive avoidance testing on 14th day to evaluate learning. Same models were repeated on 15th day to evaluate retention (memory). The results were compared with the negative control group treated with scopolamine only and positive control group treated with scopolamine and piracetam.

Results: Significant learning and memory enhancement was observed with the protein extract of Withania somnifera as compared to negative and positive control groups with p value <0.05.

Conclusions: We conclude that the protein extract of Withania somnifera is having learning and memory enhancing activity in Wistar albino rats.


Withania somnifera, Learning, Memory, Alzheimer’s disease, Elevated plus maze, Passive avoidance test, Wistar albino rats

Full Text:



Buss DM, Greiling H. Adaptive individual differences. Journal of Personality. 1999;67:209-43.

Vijayalakshmi, Adiga S, Bhat P, Chaturvedi A, Bairy KL, Kamath S. Evaluation of the effect of Ferula asafoetida Linn.gum extract on learning and memory in Wistar rats. Indian J Pharmacol. 2012;44(1):82-7.

Okano H, Hirano T, Balaban E. Learning and memory, PNAS. 2000;97(23):12403-4.

Shah RS, Lee HG, Xiongwei Z, Perry G, Smith MA, Castellani RJ. Current approaches in the treatment of Alzheimer's disease. Biomed Pharmacothe. 2008;62(4):199-207.

Alzheimer’s association. Alzheimer’s disease facts and figures. Alzheimers Dement. 2015;11(3):332-84.

Rao VR, Descamps V, John V, Bredesen DE. Ayurvedic medicinal plants for Alzheimer’s disease:a review. Alzheimer’s Research & Therapy. 2012;4:22.

Kuboyama T, Tohda C, Zhao J, Nakamura N, Hattori M, Komatsu K: Axon- or dendrite-predominant outgrowth induced by constituents from Ashwagandha. Neuro report. 2002;13:1715-20.

Kuboyama T, Tohda C, Komatsu K: Neuritic regeneration and synaptic reconstruction induced by withanolide A. Br J Pharmacol. 2005;144:961-71.

Hock FJ, Huger FP, Vogel WH, Brioni JD, McGaugh JL, Dere E. Drug effects on learning and memory. In: Hans Gerhard Vogel editor. Drug discovery and evaluation: pharmacological assay. Vol-1. 3rd edn. Berlin: Springer. 2008:903-04.

Bartus RT, Dean RL, Beer B, Lippa AS. The cholinergic hypothesis of geriatric memory dysfunction.Science. 1982;217:408-14.

Dhingra D, Kumar V. Memory-enhancing activity of palmatine in mice using elevated plus maze and Morris water maze. Adv Pharmacol Sci. 2012:357368.

Agarwal A, Malin S, Bairy KL, Rao MS. Effect of tinospora cordifolia on learning and memory in normal and memory deficit rats. Indian J Pharmacol. 2002;34:339-49.