Abstract

Oxyanthus unilocularis is a Rubiaceae used in traditional medicine for the treatment of arthritis and pain. The purpose of this study was to evaluate the antinociceptive and anti-inflammatory properties of O. unilocularis.Antinociceptive properties of both the leaf and stem bark extracts of this plant were studied using the pressure-induced pain, writhing, tail flick and formalin test methods. Carrageenan-induced hyperalgesia was used to further evaluate the analgesic properties of the plant extracts while the anti-inflammatory properties were studied using the carrageenan-induced acute inflammatory method. Oral pretreatment with the leaf and bark extracts of O. unilocularis significantly increased pain threshold in all nociceptive models used as well as inhibited carrageenan-induced paw oedema in the rat. These results confirm that O. unilocularis has both analgesic and anti-inflammatory properties thus validating its ethnomedicinal uses.

Key words: Oxyanthus unilocularis, analgesic, hyperalgesia, anti-inflammatory, pain.