EVALUATION OF COX AND LOX INHIBITORY ACTIVITY OF COMBRETUM INDICUM LEAF EXTRACT IN RAW 264.7 CELLS

Abstract

Background Inflammation is a protective biological response initiated by the body against harmful stimuli such as pathogens, tissue injury, and toxic substances. Cyclooxygenase (COX) and lipoxygenase (LOX) are key enzymes involved in the biosynthesis of inflammatory mediators, including prostaglandins and leukotrienes. Medicinal plants rich in bioactive phytochemicals are increasingly investigated as alternative sources of anti-inflammatory agents. Combretum indicum (syn. Quisqualis indica L.) is traditionally used for various medicinal purposes, including the treatment of inflammatory disorders. Objective To evaluate the in vitro anti-inflammatory activity of ethanolic leaf extract of Combretum indicum using COX and LOX inhibitory assays in RAW 264.7 murine macrophage cells. Materials and Methods Fresh leaves of Combretum indicum were shade-dried, powdered, and extracted with ethanol using the maceration method. Preliminary phytochemical screening was performed using standard qualitative methods. Anti-inflammatory activity was assessed in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells by determining the inhibitory effects on COX and LOX enzymes. Diclofenac sodium was used as the reference standard. Percentage inhibition and IC₅₀ values were calculated. Results Phytochemical screening revealed the presence of carbohydrates, alkaloids, flavonoids, cardiac glycosides, tannins, phenolic compounds, and saponins. In the COX assay, the extract demonstrated concentration-dependent inhibition with a maximum inhibition of 51.19% at 100 µg/mL and an IC₅₀ value of 93.41 µg/mL. In the LOX assay, the extract exhibited 50.70% inhibition at 100 µg/mL with an IC₅₀ value of 96.10 µg/mL. Diclofenac showed superior inhibitory activity in both assays, with maximum inhibitions of 70.06% (COX) and 69.14% (LOX). Conclusion The ethanolic leaf extract of Combretum indicum exhibited significant in vitro anti-inflammatory activity through inhibition of both COX and LOX pathways. The observed activity may be attributed to the presence of flavonoids, phenolics, and other bioactive phytoconstituents. These findings support the traditional medicinal use of Combretum indicum and suggest its potential as a natural source of antiinflammatory agents.