Evaluation of the Anti-Inflammatory Activity of Methanolic and n-Hexane Root Extracts of Terminalia paniculata Roth in Formalin-Induced Paw Oedema Rats

Abstract

Inflammation is a complex biological response associated with various pathological disorders. The present study was designed to evaluate the anti-inflammatory potential of methanolic extract (METP) and n-hexane extract (HETP) obtained from the roots of Terminalia paniculata Roth using a formalin-induced paw oedema model in rats. The roots were collected, authenticated, and extracted successively using methanol and n-hexane solvents. Acute toxicity studies were conducted according to OECD guideline 425 and both extracts were found to be safe up to 2000 mg/kg body weight. Anti-inflammatory activity was assessed in female Wistar rats by measuring paw oedema volume at different time intervals following formalin administration. Diclofenac sodium (10 mg/kg) served as the standard drug. Both extracts exhibited significant and dose-dependent inhibition of paw oedema compared to the control group. At the 5th hour, METP at doses of 200, 400, and 600 mg/kg showed 69.53%, 77.34%, and 82.03% inhibition, respectively, while HETP at doses of 200, 400, and 600 mg/kg produced 62.50%, 71.09%, and 76.56% inhibition, respectively. The highest activity was observed with METP at 600 mg/kg, which was comparable to diclofenac sodium (84.38%). These findings suggest that Terminalia paniculata root extracts possess significant anti-inflammatory activity and may serve as a promising natural source for the development of anti-inflammatory agents.

Keywords: Terminalia paniculata, Anti-inflammatory activity, Formalin-induced paw oedema, Methanolic extract, Diclofenac sodium