Anti-inflammatory and Analgesic Effects of an Aqueous Extract of Lannea acida Stem Bark

Background: Different parts of Lannea acida A. Rich (fam: Anarcadiaceae) are used traditionally to treat various ailments including inflammation, facial pain, schistosomiasis, haemorrhoids and toothache.

Objective: This study was carried out to investigate the anti-inflammatory and analgesic effects of an aqueous extract of the stem bark of Lannea acida.

Methodology: Rats were given sub-plantar injection of prostaglandin E2 to induce oedema, which was measured using calipers over 2½ hours at 30 min interval. In the acetic acid–induced abdominal writhing test, mice were given intraperitoneal injection of acetic acid and writhing movements were recorded. Oedema test was run for both prophylactic and curative protocols. In both paw oedema and writhing test models, inhibitory effects of the plant extract were compared with diclofenac.

Results: Aqueous extract (30 – 300 mg/kg) of Lannea acida stem bark significantly reduced prostaglandin E2–induced paw oedema in both prophylactic and curative protocols. The extract also significantly inhibited acetic acid–induced abdominal writhing movement in Imprint Control Region (ICR) mice.

Conclusion: The aqueous extract of Lannea acida stem bark inhibited prostaglandin E2–induced paw oedema in rats and acetic acid–induced writhing behaviour in ICR mice; indicating a possible anti-inflammatory and analgesic activities.