ABSTRACT
Objective: The effect of Xiexintang on Toll like receptor 9 (TLR9) signaling pathway in macrophage derived foam cells was studied by in vitro cell experiments. Method: The fifty SPF male SD rats were randomly divided into low, medium and high dose groups (1.4,4.2,12.6 g·kg-1·d -1) and normal groups. Except 20 rats in the normal group, 10 rats in each group were given equal volume of pure water gavage in the blank group. After the last Administration for 7 days, serum was separated,and the serum containing drugs in the low, medium and high dose groups of Xiexintang was prepared. Oxidized low density lipoprotein (ox-LDL) was used to intervene the differentiation of RAW264.7 macrophages into foam cells. The cell foam was identified by oil red O staining. After observing the effect of drug containing serum on the proliferation of macrophage derived foam cells by methye thiazolye telrazlium(MTT) method,the serum containing 20%concentration of each drug was selected to act on the foam cell model. The expression of interleukin(IL) -1β and interferon (INF) -γ was determined by enzyme-linked immunosorbent assay (ELISA) and real-time fluorescence quantitative PCR (Real-time PCR). TLR9, myeloid differentiation factor 88(MyD88)and nuclear factor(NF) -κB were detected by Western blot. Result: Oil red O staining showed that the red particles were obvious after ox-LDL intervention. The foam cell model was successfully prepared. MTT results showed that there was no significant difference in cell proliferation between the high dose group of Xiexintang in the 10%~30%concentration range and the normal group serum. Follow up selection of the serum containing 20%concentration of each dose intervened the foam cells induced by ox-LDL. Compared with the normal group,the model group after ox-LDL intervention induced the high expression of TLR9,MyD88,NF-κB p65,IL-1β,INF-γ (PPκB p65,IL-1β,INF-γ(PPConclusion: Xiexintang containing serum can inhibit ox-LDL-induced RAW264.7 macrophage foaming,and its mechanism may involve regulation of TLR9/MyD88/NF-κB p65 signaling pathway and inhibition of IL-1β and INF-γ overexpression. This may be one of its mechanisms of against atherosclerosis.