Anti-Inflammatory Activities of Methanol Leaf Extract of Bridelia micrantha (Hochst) Baill. (Euphorbiaceae) in Wistar Rats

Aerial parts of Bridelia micrantha, a semi-deciduous tree are widely used in African traditional medical practice in the treatment of painful inflammatory conditions of the joints. This study evaluated the anti-inflammatory activities of the methanol leaf extract of Bridelia micrantha using acute, sub-acute and chronic models of inflammation in Wistar rats. In the carrageenan-induced acute inflammation model, 400 mg/kg of extract produced 71.79 % edema inhibition while 200 mg/kg of the extract produced 55.13 % inhibition relative to 56.41 % inhibition of the rat paw edema with 200 mg/kg of Acetylsalicylic Acid (ASA) within 5 h. In the histamine-induced rat paw edema model, the extract exhibited 72.97 % protection at 400 mg/kg compared to 83.33 % edema inhibition with phenylbutazone (100 mg/kg) after 6 h. In the sub-acute model using formaldehyde-induced paw edema, 400 mg/kg of extract showed 59.77 % (0.35±0.03) inhibition after 24 h, while 54.02 % inhibition was produced by 200 mg/kg of extract and 200 mg/kg of ASA produced 56.32 % (0.38±0.04) inhibition when compared with the negative control group (0.87±0.05). In the cotton pellet-induced granuloma test, 400 mg/kg of extract gave 52.55 % (40.57±1.3) protection, while 200 mg/kg extract gave 47.25 % protection and 200 mg/kg ASA gave 49.38 % (43.25±1.8) when compared with normal saline treated group (85.5±3.2) after 7 days. The results obtained in this study showed that Bridelia micrantha leaf extract exhibited potent anti-inflammatory activities thus authenticating its acclaimed anti-inflammatory efficacy. It was concluded that the extract of Bridelia micrantha may be a potential anti-inflammatory agent in alleviating edema associated with arthritis and musculo-skeletal pains in humans.