Received: February 9, 2006.

Accepted: May 11, 2006.

Abstract published online: June 26, 2006.

Full paper published online: November 30, 2006.

EVALUATION OF THE EFFECTS OF PHOTOOXIDIZED Echis carinatus VENOM ON LEARNING, MEMORY AND STRESS

REDDY C. M. (1), GAWADE S. P. (2)

(1) Manipal AcuNova, Manipal, Karnataka, India; (2) Department of Pharmacology, Al Ameen College of Pharmacy, Bangalore, India.

ABSTRACT: Snake venoms are a mixture of complex proteins, which have many physical and pharmacological properties. Photochemical detoxification has been suggested to generate photooxidized Echis carinatus venom product (POECVP). Antigenically-active photooxidized species of Echis carinatus venom could be obtained by exposing the venom to ultraviolet radiation (UVR) in the presence of methylene blue. The aim of the present study was to evaluate the effects of POECVP on learning, memory and stress in rats. Detoxification of the photooxidized venom was evident since the POECVP-treated group had longer survival time than the group of mice treated with Echis carinatus venom product (ECVP) following intraperitoneal and intracerebral injections. Photooxidized Echis carinatus venom product showed antidepressant activity by prolonging sleep onset and shortening the duration of pentobarbitone-induced hypnosis in mice. In single and chronic dose studies with rats, we observed that POECVP significantly decreased the time needed to reach food in T-maze, shortened transfer latency in elevated plus-maze, and decreased immobility time in forced swim test. We concluded that although there is a possibility of employing POECVP in the treatment of depressive and chronic degenerative illnesses as a nonherbal and nonsynthetic alternative for patients not responding to the available therapy, further investigation is still needed.

KEY WORDS: learning and memory, photooxidized Echis carinatus venom product, T-maze, forced swim test, elevated plus-maze.

CORRESPONDENCE TO:

CHANDRA MOHAN REDDY, Manipal AcuNova Ltd., Manipal, Udupi dist., Karnataka, India. Phone: +91 820 2922677. Fax: +91 820 2571999. Email: mohancra@gmail.com or chandra.mohan@acunovalife.com.