Study On The Protecting Effect And Mechanism Of Effective Fraction Of Bletilla Striata On RAW264.7 Cells Injured By PM2.5

Objective The PM2.5 suspension extracted by water and dichloromethane respectively was used to establish the cell injury model and to study the Effective Fraction of Bletilla striata(EFB)on RAW264.7 cell injured by PM2.5,as well as its mechanisms.Methods 1.Different concentrations of PM2.5 suspension were added to RAW264.7 cells.RT-PCR was used to detect the m RNA expression of IL-6 and TNF-α.The levels of IL-6 and ROS in RAW264.7 cells were detected by ELISA and DCFH-DA fluorescent probe method.The optimal concentration and optimal time of PM2.5-injured cells were determined based on the levels of IL-6,TNF-α and ROS.The expression of related proteins in the NF-κB and MAPK pathway were detected by Western Blot and the mechanism of PM2.5-injured cells was investigated.2.The PM2.5 injured cells were treated with different concentrations of EFB(2.5,5,10,20 μg/m L).The levels of IL-6,TNF-α and MCP-1 in RAW264.7 cells were detected by flow cytometry.q PCR was used to detect the m RNA expression of IL-6 and TNF-α.After the treatment with EFB(2.5,5,10,20 μg/m L),the expression of related proreins in the NF-κB and MAPK pathway were detected by Western Blot.Results 1.With the increase of PM2.5 concentrations,the inhibitory effects on cell proliferation of RAW264.7 were increased.Compared with control group,different concentrations of PM2.5 increased the m RNA expression of TNF-α and IL-6.The levels of TNF-α and ROS in RAW264.7 cells were higher than the control group.These results indicated that PM2.5 could significantly injury the RAW264.7 cells.The results of Western blot showed that PM2.5 could significantly increase the phosphorylation levels of IKK,IκBα,NF-κB p65,JNK,ERK and p38.2.EFB could significantly decrease the levels of TNF-α,IL-6 and MCP-1 in PM2.5-injured RAW264.7 cells.Meanwhile,EFB also decreased the m RNA expression of TNF-α and IL-6,and downregulated the phosphorylation levels IκBα,NF-κB p65,JNK,ERK and p38.These results showed that EFB could alleviate the inflammation of the PM2.5-injured RAW264.7 cells.Conclusion EFB significantly alleviate the inflammation of RAW264.7 cells induced by PM2.5,and its mechanism may be related to the inhibitory effects on the activities of NF-κB and MAPK pathway.