International Journal of Medicinal Plants Research

ISSN 2169-303X

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 9 (12), pp. 001-004, December, 2020. © International Scholars Journals

Full Length Research Paper

Antinociceptive activity of methanol extract and aqueous fraction of the stem bark of Pentaclethra macrophylla Benth (Mimosaceae)

Okunrobo L. O.1*, Ching F. P.2 and Ifijeh F.1

1Department of Pharmaceutical Chemistry, University of Benin, Benin city, Nigeria.

2Department Pharmacology, Niger-Delta University, Wilberforce Island, Yenagoa, Nigeria.

Accepted 12 July, 2020

Abstract

The antinociceptive activity of the methanol extract and the aqueous fraction of the bark of Pentaclethra macrophylla, family: (mimosaceae) was evaluated using the acetic acid induced mouse writhing assay and tail immersion assay in mice. The methanol extract and the aqueous fraction at a dose of 50 and 100 mg/kg body weight administered orally exhibited significant inhibition of the acetic acid induced writhing assay in a dose dependent manner (p < 0.001) with 100 mg/kg dose giving a higher inhibition. The methanol extract and the aqueous fraction also showed significant increase in the heat tolerance capacity in mice in a dose dependent manner (p < 0.001) in the tail immersion assay. These findings therefore justify the ethnomedicinal use of P. macrophylla stem bark as an antinociceptive agent.

Key words: Antinociceptive activity, Pentaclethra macrophylla, tail immersion assay, mouse writhing assay, stem bark.