RESUMO
OBJECTIVE To investigate the anti-inflammatory activity and potential mechanism of Clematis ranunculoides extract. METHODS The ear swelling was induced by xylene to establish an acute inflammation model of mice； using aspirin （0.25 g/kg） as a positive control， the effects of 1.25， 2.5， 5 g/kg C. ranunculoides extract on the degree of ear swelling were investigated. The chronic inflammation model of rats was also established by implanting cotton balls； using aspirin （0.17 g/kg） as a positive control， the effects of 0.88， 1.75， 3.5 g/kg C. ranunculoides extract on the net weight of granulomas were investigated. Furthermore， RAW264.7 cells were induced by lipopolysaccharide to establish an inflammatory injury model； the effects of 12.5， 25， 50 μg/mL C. ranunculoides extract on the contents of nitric oxide（NO）， prostaglandin E2（PGE2）， tumor necrosis factor-α （TNF-α）， interleukin-6（IL-6） and monocyte chemotactic protein-1（MCP-1） in the cell supernatant， the protein expressions of inducible nitric oxide synthase（iNOS）， cyclooxygenase-2（COX-2）， p65 and phosphorylated p65（p-p65） in cells as well as nuclear translocation of p65 protein were assessed. RESULTS C. ranunculoides extract with 5 g/kg significantly relieved ear swelling in mice， and C. ranunculoides extract with 1.75， 3.5 g/kg significantly decreased the net weight of granulomas in rats （P＜0.05）. C. ranunculoides extract with 12.5， 25， 50 μg/mL significantly reduced the contents of NO （except for 12.5 μg/mL C. ranunculoides extract）， PGE2， TNF-α， IL-6 and MCP-1 in the cell supernatant， as well as the relative expressions of iNOS and COX-2 protein， and relative expression ratio of p-p65 and p65 protein （P＜0.05 or P＜0.01）； C. ranunculoides extract with 25， 50 μg/mL inhibited the translocation of p65 protein to the cell nucleus. CONCLUSIONS C. ranunculoides extract exhibits significant anti- inflammatory activity， the mechanism of which may be attributed to the inhibition of the activation of nuclear factor-κB signaling pathway， down-regulation of COX-2 and iNOS protein expression， and the reduction of inflammatory cytokines release.