Evaluation of the Anti-Inflammatory Activity of Ethanolic Rhizome Extract of Curcuma Longa in Wistar Albino Rats Using the Formalin-Induced Paw Edema Model

Research Article

Abstract

Acute and sub-acute inflammatory conditions present substantial clinical challenges, driving the scientific search for safer phytotherapeutic alternatives to conventional non-steroidal anti-inflammatory agents. Rhizomes of Curcuma longa contain bioactive polyphenols with potent therapeutic actions. This research evaluates the anti-inflammatory activity of an ethanolic extract of Curcuma longa rhizomes compared to the standard cyclooxygenase inhibitor, ibuprofen, in healthy adult Wistar albino rats. Subplantar injection of 1% formalin successfully establishes localized, acute inflammatory edema in the hind paw of experimental animals. Prior oral administration of the ethanolic extract at a high dose of 100 mg/kg results in a highly significant, time-dependent reduction in paw thickness, presenting a peak edema inhibition of 83.0% at the fifth hour. This therapeutic effect is close to the 94.3% edema inhibition shown by ibuprofen at 40 mg/kg. In contrast, a lower extract dose of 50 mg/kg produces a moderate anti-inflammatory effect, achieving 12.2% edema inhibition by the end of the monitoring period. Phytochemical screening of the crude ethanolic extract confirms the presence of abundant curcuminoids, phenolic compounds, terpenoids, tannins, and steroidal structures. These bioactive components act synergistically to suppress the cascade of inflammatory mediators, particularly during the late phase of formalin-induced edema. The evidence confirms the traditional application of turmeric in managing inflammatory conditions and establishes its potential as a highly effective, dose-dependent natural therapeutic agent