Effects of forsythia suspense on TLR4 protein in macrophage induced by LPS

Objective To observe the effects of Forsythia suspense the expression of TLR4 in macrophage RAW264.7 induced by LPS and to explore the anti-endotoxin and immunity modulation function of AFS and its possible mechanisms.Methods Cultured RAW264.7 cells have been randomly divided into six groups:control group: without any treatment;LPS group:adding LPS at final concentration of 10ng/ml for 16h;high concentration of Forsythia suspense、median concentration of Forsythia suspense、low concentration of Forsythia suspense group:30mins preconditioning of Forsythia suspense(50mg/ml、25mg/ml、12.5mg/ml in final concentration) before adding LPS;polymyxin B group:30mins preconditioning of Ploy B(10ug/ml in final concentration) before adding LPS.The expression of TLR4 protein on RAW264.7 were measured by western blot.Results It was found that TLR4 protein had a basic expression in RAW264.7 cells under normal condition;and it was increased significantly after LPS acted on RAW264.7 cells than that of control group at 16h(P0.01);adding Forsythia suspense before the presence of LPS,the expressions of TLR4 protein in high concentration of Forsythia suspense、median concentration of Forsythia suspense、low concentration of Forsythia suspense group decreased remarkably than that of LPS group(P0.01),which was dose-dependent.There was no significant difference between high concentration of Forsythia suspense group and polymyxin B group(P0.05).Conclusion It was verified that Forsythia suspensa had the effect of anti-endotoxin probably by inhabiting the up-regulation of TLR4 protein in macrophage induced by LPS.