Abstract

The root of Palisota hirsuta is used in Ghana and other West African countries for the treatment of various disease conditions such as rheumatoid arthritis (other painful and inflammatory conditions), infertility in females, anaemia, and dysentery. The current study seeks to evaluate the anti-nociceptive effect of the hydroethanolic root extract and compounds isolated from Palisota hirsuta. Mice were used for studying the antinociceptive activity of P. hirsuta extracts and isolates at doses of 10-300 mgkg-1, p.o and (phase 1: 10 mgkg-1 and phase 30 mgkg-1) respectively using the Formalin Induced paw licking model. The total crude extract, methanolic and petroleum ether fractions showed analgesic activity in a dose-dependent manner for both the early and late phases. Three isolates, a fatty acid mixture, 20-hydroxyecdysone and an uncharacterized ecdysteroid were obtained from the methanol fractions. 20-hydroxyecdysone exhibited a dose-dependent inhibition of the nociception for both the early and late phases; 71.39±9.19% and 89.19±3.81% respectively. PH V showed significant activity between the early and late phases of inhibition as compared to the standard control drug. The present results validates that the root extracts of P. hirsuta contains pharmacologically active constituents which possess antinociceptive activity. Thus, justifying its therapeutic use in treating conditions associated with painful conditions.

Key words: Formalin, Nociceptive, Inhibition, Isolates, ecdysteroids