Anti-inflammatory effects of aqueous extract of Azadirachta indica A. Juss (Meliceae) on histamine and egg albuminn-induced paw edema in Wistar rats
Inflammation is a response to infections, injury, stress or trauma. Several medicinal plants were reported to be useful in the management of inflammation in traditional medicine. This study was aimed at investigating the effect of aqueous extract of Azadirachta indica on two models of acute inflammation; Histamine-induced inflammation and fresh egg albumin-induced inflammation in rats. Five (5) groups of rats containing five (5) animals per group were used for the study. Rats in group 1 were administered 1 mL/kg normal saline intraperitoneally that served as control for comparison with the test group. Groups 2, 3 and 4 rats were administered with aqueous extract of Azadirachta indica at a dose of 500, 1000 and 1500 mg/kg respectively while group 5 was administered diclofenac 20 mg/kg all of which were easily administered via intraperitoneal route. In the egg-albumin induced inflammation study, five (5) groups of five (5) rats each were administered different doses of drugs. Group 1 received 1 mL/kg normal saline, while groups 2-4 were given 20, 40 and 60 mg/kg of extract respectively. The fifth group received 20 mg/kg diclofenac. All drugs for this study were administered intraperitoneally. Data was analyzed using one-way analysis of variance ANOVA and presented as Mean ± Standard Deviation. The median lethal dose (LD50) was found to be greater than 5000 mg/kg. The histamine-induced rat paw edema significantly decreased at 3 hours in groups 3-4 given 20, 40 and 60 mg/kg of extract p < 0.01, p < 0.001, p < 0.001) respectively compared to normal saline control group. Both the aqueous extract of Azadirachta indica at 20, 40 and 60 mg/kg and diclofenac at 20 mg/kg were not able to significantly alter rat paw size. Therefore, we conclude that aqueous extract of Azadirachta indica produce dose dependent anti-inflammatory effect in histamine-induced paw edema model of Wistar rats.
Keywords: Azadirachta indica, Acute inflammation, edema, extract, diclofenac, paw size
*Correspondence: mahdi.mohammed30@yahoo.com; 2348103617554, 2349014208402
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