Comparative Evaluation of the Anti-inflammatory Activity of Methanolic Leaf Extracts of Alstonia scholaris and Mallotus philippensis in Carrageenan-Induced Rat Paw Edema Model

Abstract

Inflammation is a protective biological response against tissue injury; however, chronic inflammation contributes to the progression of numerous diseases. Medicinal plants have been extensively explored as alternative therapeutic agents because of their rich phytochemical composition and reduced adverse effects. The present study evaluated the anti-inflammatory potential of methanolic leaf extracts of Alstonia scholaris and Mallotus philippensis using the carrageenan-induced rat paw edema model. Leaves of both plants were collected, authenticated, and extracted using Soxhlet extraction with 95% methanol. Acute oral toxicity was evaluated according to OECD Guideline 423. Anti-inflammatory activity was assessed in Wistar rats by measuring paw edema at different time intervals following carrageenan administration. Indomethacin (10 mg/kg) was used as the reference drug, while plant extracts were administered orally at doses of 200 and 400 mg/kg. Both extracts were found to be safe up to 2000 mg/kg body weight. In the carrageenan-induced paw edema model, both plant extracts significantly reduced paw swelling in a dose-dependent manner. The 400 mg/kg dose of both extracts exhibited greater inhibition of inflammation and showed activity comparable to indomethacin during the later phase of inflammation. The findings suggest that methanolic leaf extracts of Alstonia scholaris and Mallotus philippensis possess significant anti-inflammatory activity and may serve as potential sources for the development of plant-based anti-inflammatory agents.

Keywords: Alstonia scholaris, Mallotus philippensis, Anti-inflammatory activity, Carrageenan-induced paw edema, Methanolic extract.