Study of anti-inflammatory effect of neem seed oil (Azadirachta indica) on infected albino rats

Objective: To study the anti-inflammatory effect of neem seed oil (NSO) on albino rats using carrageenan-induced hind paw edema. Materials and Methods: The study sample was divided into six groups with each group consisting of six rats as follows: Group I: Control (distilled water 0.5 ml/rat); Group II: Standard (aspirin 200 mg/kg body weight orally); Groups III, IV, V, and VI (NSO 0.25 ml, 0.5 ml, 1 ml, and 2 ml/kg body weight, respectively, i.p.). The inflammation induced in the form of hind paw edema was produced by injection of 0.1 ml of 1% suspension of carrageenan in normal saline below the plantar aponeurosis of right hind paw of rats; the left hind paw served as control. The volume of edema was measured by water displacement method in microburette. Volumes of both the hind paws were measured before and after 1, 2, 3, 4, 6, 12, and 24 h of carrageenan injection. Results: NSO in the dose of 0.25 ml/kg body weight did not show any significant anti-inflammatory activity. NSO showed increased inhibition of paw edema with the progressive increase in dose from 0.25 ml to 2 ml/kg body weight. At the dose of 2 ml/kg body weight, NSO showed maximum (53.14%) inhibition of edema at 4 th hour of carrageenan injection. Aspirin in the dose of 200 mg/kg body weight showed maximum inhibition of hind paw edema. Conclusion: The present study concludes that NSO exhibits significant anti-inflammatory action.