In Vivo Anti-Inflammatory, Analgesic And Antipyretic Effects Of Dichloromethane Stem Bark Extract Of Acacia Mellifera In Mice And Rat Models

ABSTRACT 

Inflammation is a reaction to irritants that causes an injury to the body. Pain is a physical discomfort caused by injury or illness while pyrexia is an increase in body temperature above the normal range (36.5°C–37.5°C). Commonly used conventional drugs against inflammation, pain and pyrexia are effective but due to long term use, these drugs tend to be costly and are associated with adverse side effects. Traditional medicine has been used as an alternative and complementary drug. This is because it is safe, has a good efficacy and fewer side effects. This study was designed to assess the in vivo anti-inflammatory, analgesic and antipyretic effects of Acacia mellifera as well as their phytochemical composition. Samples of the plant were sourced from Siakago division, Embu County in Kenya. Its bioactive components were extracted using dichloromethane. Inflammation, pain and pyrexia were induced using carrageenan, formalin and turpentine respectively in animal models. Adult Wistar rats and Swiss albino mice were placed into six groups of five animals each; three control groups (normal, negative and positive) and three experimental groups (50, 100 and 150mg/kg body weight). The anti-inflammatory and analgesic activities of the stem herbal extract were compared to diclofenac (reference drug), while the antipyretic activity was compared to aspirin. The stem bark extract of A. mellifera and the reference drugs showed anti-inflammatory, analgesic and antipyretic activities. For anti-inflammatory effect, the extract reduced inflamed hind paw diameter when compared to the control group. The inhibitory rates of paw edema ranged between 1.59% and 11.05%, while diclofenac reduced edema by between 0.1% and 8.78%. For the anti-nociceptive study, the A. mellifera extract inhibited paw licking time with inhibitory rates ranging between 1.38% and 48.26% (in the early phase) and by between 28.45% and 83.90% (in the late phase) while diclofenac reduced pain by 12.20% and 80.20% in the early and late phases respectively. The stem bark extract of A. mellifera lowered the elevated rectal temperature by between 0.16% and 3.95% while aspirin reduced it by between 1.52% and 3.60%. The phytochemical analysis showed the presence of alkaloids, cardiac glycosides, flavonoid, saponins, steroids, terpenoids, tannins and phenolics associated with anti-inflammatory, analgesic and antipyretic activities. The stem bark extract from A. mellifera may be used as an alternative bioresource in development of antiinflammatory, analgesic and antipyretic agent. This study, therefore, confirms the folklore use of A. mellifera by Ameru and Embu communities in the management of inflammation, pain and fever.