Analgesic and anti-inflammatory studies of methanol stem bark extract of Burkea Africana hook (Fabaceae)

Abstract

Burkea africana Hook (Fabaceae) is a plant used in traditional medicine for the treatment of pain and inflammation in Africa. The methanol stem bark extract was evaluated for analgesic property using acetic acid induced writhing and hot plate test in mice while the anti-inflammatory property was evaluated using carrageenan-induced paw oedema. Acute toxicity studies and phytochemical screening using standard protocol was also conducted. Preliminary phytochemical screening of the extract revealed the presence of flavonoids, tannins, steroids and triterpenes, cardiac glycosides and saponins. The intraperitoneal median lethal dose (LD50) in mice was found to be 471.17 mg/kg body weight. The extract at all tested doses (20, 40 and 80 mg/kg) significantly (P≤ 0.001) decreased abdominal contractions induced by acetic acid and also significantly (P≤ 0.01) delayed the mean reaction time of the mice. The extract at all doses showed no significant anti-inflammatory activity. The results obtained from this study showed that the methanol stem bark extract of Burkea africana possesses both central and peripheral analgesic activities. This provides a rationale for its traditional use against pain.