Evaluation Of The Anti-Inflammatory, Analgesic And Antimicrobial Activities Of Bark Of Afzelia africana

Abstract

Afzelia africana Smith (Caesalpiniaceae) is a perennial tree which occurs in many parts of Africa where it is used as food and widely employed in traditional
medicine practice. Acute toxicity studies in mice established an oral LD50 greater than 5,000 mg/kg for bark methanolic extract. The extract and fractions (5 and 10 mg/ear; 200 and 400 mg/kg) inhibited topical edema induced by xylene in the mouse ear and significantly (P<0.05) suppressed the development of paw edema induced by egg albumin in rats. They also inhibited the global response to formaldehyde arthritis in rats and reduced abdominal writhing induced by acetic acid as well as the duration of paw licking induced by formalin in mice. Antimicrobial activity tests showed that the extract and fractions inhibited the growth of the strains of the Gram positive bacteria Staphylococcus aureus and Bacillus subtilis while they lacked activity against the Gram negative organisms (Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi), fungus (Aspergillus niger) and yeast (Candida albicans). B. subtilis was more susceptible than Staph. aureus. These findings suggest that the bark of this plant possess anti-inflammatory, analgesic and antibacterial properties which justify the ethnomedicinal uses of the plant in the treatment of inflammatory conditions, pain and infections.

Keywords: Afzelia africana, bark, anti-inflammatory, analgesic, antimicrobial

Nigerian Journal of Natural Products and Medicine Vol. 11 2007 pp. 48-52