OBJECTIVETo evaluate the anti-inflammatory effects of icariin, from aspects of pro-inflammatory cytokines, inflammatory mediators and adhesion molecules.

METHODSMouse inflammation model in vitro was established by stimulating macrophage cell line RAW264. 7 with lipopolysaccharide (LPS); and the inflammation model in vivo was established by stimulating C57BL/6J mouse with LPS. Taking dexamethasone as the positive control, both models were treated with icariin, and the cell viability in model mice was detected with CCK-8 kit; tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) in cell culture medium and serum were detected by ELISA; nitric oxide (NO) in cell culture medium by Griess Reagent method; CD11b expression on the surface of neutrophil in mice by flow cytometry, and pulmonary inflammatory cell infiltration in mice by pathological section as well.

RESULTSin vitro studies showed that icariin at the doses of 1 microg/mL, 10 microg/mL and 100 microg/mL, all displayed no cytotoxicity (P < 0.01); 10 microg/mL and 100 microg/mL icariin effectively lowered the levels of TNF-alpha and IL-6 (P < 0.01) in medium; and 100 microg/mL icariin significantly reduced level of NO (P < 0.01) in medium. in vivo studies showed that icariin at the dose of 20 mg/kg significantly lowered serum TNF-alpha and IL-6 levels (P < 0.01), reduced the average fluorescence intensity of adhesion molecules CD11b (P < 0.01), and alleviated pulmonary inflammatory cell infiltration.

CONCLUSIONIcariin is a safe and effective natural anti-inflammatory drug, its partial mechanism is possible the multiple links intervention on pro-inflammatory cytokines (TNF-alpha, IL-6), inflammatory mediators (NO) and adhesion molecules (CD11b).