Antiinflammatory Constituents from Eclipta prostrata using RAW264.7 Macrophage Cells

The whole plant extract of Eclipta prostrata and its isolated compounds were tested for their antiinflammatory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2 ) and tumor necrosis factor-alpha (TNF-α) release in RAW264.7 cells, as well as for the antiinflammatory mechanism of the active compound on mRNA expression. Among the isolated compounds, orobol (5) exhibited the highest activity against NO release with an IC50 value of 4.6 μm, followed by compounds 1, 2 and 4 with IC50 values of 12.7, 14.9 and 19.1 μm, respectively. The IC50 value of compound 5 against PGE2 release was found to be 49.6 μm, whereas it was inactive towards TNF-α (IC50 > 100 μm). The mechanism of orobol (5) was found to down-regulate iNOS and COX-2 mRNA expression in a concentration-dependent manner. The present study may support the traditional use of Eclipta prostrata for the treatment of inflammatory-related diseases.