Analgesic and anti-inflammatory activity of Tectona grandis Linn. stem extract

Abstract Background: The objective of this work was to study the analgesic and anti-inflammatory activity of Tectona grandis Linn. (TG) stem extract. Methods: Healthy albino rats (150–200 g) and mice (25–50 g) were arranged and divided into five groups. Group 1 received distilled water and served as control, groups 2, 3, 4 were treated with TG stem extract (100, 200, 400 mg/kg) and group 5 received standard drug. For analgesic activity, the radiant heat method and writhing test were used, and for anti-inflammatory activity, the paw oedema model and granuloma pouch method were used. Statistical analysis was done by one-way analysis of variance followed by the t-test. Results: In the radiant heat method, there was a dose-dependent increase in reaction time in TG stem extract (100, 200, 400 mg/kg) and standard drug (buprenorphine). In the writhing test, TG stem extract (200, 400 mg/kg) and aspirin decreased the number of writhes which was significant (p<0.01, p<0.001) as compared to controls. The percentage protection was 8.88%, 15.55%, 22.22% and 35.55% in groups 2, 3, 4 and 5, respectively. In the rat paw oedema test, TG stem extract (200, 400 mg/kg) and aspirin showed 20%, 40% and 54% inhibition of oedema which was statistically significant (p<0.05, p<0.01, p<0.001), respectively, as compared to control at the end of 4 h. In the granuloma pouch method, TG stem extract (100, 200, 400 mg/kg) and aspirin showed 13.33%, 22.22%, 33.33% and 66.66% inhibition of granuloma, respectively, which was significant (p<0.05, p<0.01, p<0.001). Conclusions: TG stem extract possesses significant anti-inflammatory and analgesic activity.