Title: The evaluation of the analgesic activity of the methanolic leaf extract of Jatropha curcas (Linn) in experimental animals

Authors: Omeh S. Yusuf, Ezeja I. Maxwell

Addresses: Department of Biochemistry, College of Natural and Applied Sciences, Micheal Okpara University of Agriculture, Umudike, Abia State, Nigeria. ' Department of Veterinary Physiology, Pharmacology and Biochemistry, College of Veterinary Medicine, Micheal Okpara University of Agriculture, Umudike, Abia State, Nigeria

Abstract: This study evaluated the analgesic activity of the methanolic leaf extract of Jatropha curcas (Linn) in-vivo using analgesic models viz. hot plate method in mice, tail flick or immersion method in rats and the acetic acid-induced writhing reflex model in mice. In all the models, Acetylsalicylic Acid (ASA) was used as the reference drug. In the hot plate and tail flick models, the oral administration of J. curcas extract at the doses of 100, 200 and 400 mg/kg and the reference drug ASA (400 mg/kg) showed potent analgesic effects by significantly (P < 0.001) increasing the Pain Reaction Time (PRT) dose dependently in mice and rats. Also the reference drug and the extract of J. curcas significantly (P < 0.0001) decreased the number of the abdominal contortions in the acetic acid-induced writhing reflex in mice and increased the percentage protection in a dose dependent manner. In conclusion, this study indicates that the methanolic leaf extract of Jatropha curcas has significant analgesic properties and may be acting through both peripheral and central pain mechanisms.

Keywords: Jatropha curcas; hot plate; tail flick; writhing reflex; ASA; acetylsalicylic acid; analgesia; methanolic leaf extract; mice; rats; pain reaction time; abdominal contortions; dose dependence.

DOI: 10.1504/IJBET.2011.041124

International Journal of Biomedical Engineering and Technology, 2011 Vol.6 No.2, pp.200 - 207

Published online: 21 Jan 2015 *

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