Analgesic and anti-inflammatory activities of Cnestis ferruginea Vahl ex DC (Connaraceae) methanolic root extract

Abstract

Ethnopharmacological relevance: Cnestis ferruginea Vahl ex DC (Connaraceae) is a shrub widely used in traditional African Medicine (TAM) for the treatment of various painful and inflammatory conditions.

Aim of the study: The objective of this study was to investigate the analgesic and anti-inflammatory properties of the methanolic root extract of Cnestis ferruginea.

Materials and methods: Analgesic activity was evaluated using the acetic acid-induced writhing, formalin, tail clip, and hot plate tests in mice. The carrageenan- and egg albumin-induced rat paw oedema, formaldehyde-induced arthritis inflammation, and xylene-induced ear oedema tests were used to investigate the anti-inflammatory actions of Cnestis ferruginea.

Results: The methanolic root extract of Cnestis ferruginea (100, 200, and 400mg/kg; p.o.) produced significant (P<0.05) dose-dependent inhibition of pain response elicited by acetic acid and formalin while also increasing the nociceptive reaction latency in the tail clip and hot plate tests. In respect of anti-inflammatory activity, Cnestis ferruginea caused significant (P<0.05) dose-dependent inhibition of oedema development in the carrageenan, egg albumin, formaldehyde, and xylene-induced inflammation tests. The effects of the extract in the various models were generally comparable to those of the standard drugs used.

Conclusion: The findings in this study suggest that the methanolic root extract of Cnestis ferruginea possesses analgesic and anti-inflammatory activities possibly mediated through peripheral and central mechanisms involving inhibition of release and/or actions of vasoactive substances (histamine, serotonin and kinins) and prostaglandins. The results justify the use of the extract in TAM for the treatment of painful and inflammatory conditions.