Inhibitory Effects Of Total Ginsenoside On Bleomycin-induced Pulmonary Fibrosis In Mice

Objective:To observe the protective effect and mechanism of total ginsenoside（TG）on pulmonary fibrosis（PF）induced by bleomycin（BLM）in mice.Methods:The PF model of C57BL/6J mice were established by single intratracheal infusion of BLM（5 mg/kg）.The animals were divided into sham,model,TG（14 days and28 days）and prednisone group（28 days）.The therapeutic effect of TG in different stages of PF was determined by pulmonary indexes,pathomorphological and protein expression ofα-SMA.The expressions of E-cadherin,collagenIII,TGF-β1,TIMP-1,MMP-2,MMP-9,CX3CL1 and CX3CR1 protein were detected in the lung tissue of 14-day mice.For analyzing whether the effect of TG on PF mice is related to CX3CL1,CX3CL1 knockout(CX3CL1^-/-)model mouse was established.Wild-type（WT）mice of the same sex and month were used as control.The animals were divided into sham,model and TG 80 mg/kg group.After 14 days,the general state of mice in each group was observed.The pulmonary indexes,and the pathomorphological changes were observed,the protein expressions ofα-SMA and collagenIII were detected.The expressions of TGF-β1,smad2,smad3,smad7,TIMP-1,MMP-2,MMP-9 mRNA and protein were detected by molecular biology technique of lung tissue in 28-day mice.Results:After molding 14 days,the general condition was worse in the model mice,and the pulmonary indexes was significantly higher,pulmonary alveolitis become obvious,the levels ofα-SMA,collagenIII,MMP-2,MMP-9,CX3CL1 and CX3CR1 protein were up-regulated,and the levels of E-cadherin and TIMP-1 were decreased.The level of TGF-β1 had trend of up-regulation,but no statistical difference.Administration of TG 80mg/kg for 14 days,the general condition of model mice was improved,and the pulmonary indexes was decreased.Pulmonary alveolitis and collagen deposition were inhibited.The levels ofα-SMA,collagenIII,MMP-2,MMP-9,CX3CL1 and CX3CR1 were significantly down-regulated,and the levels of E-cadherin and TIMP-1 were significantly up-regulated.After 14 days of modeling,the BLM could induce PF in the CX3CL1^-/-mice,but the degree of lesion was significantly lighter compared with WT mice.The effect of TG on PF in CX3CL1^-/-mice was less than WT mice.Comparison with sham group,the general condition was worse,and pulmonary indexes was significantly higher,and alveolitis and fibrosis become obvious,and the levels ofα-SMA,TGF-β1,smad2,smad3,TIMP-1,MMP-2,and MMP-9 levels were significantly up-regulated,the level of smad7 was significantly down-regulated in model mice induced by BLM after 28 days.Compared with the model group,TG（80,160 mg/kg）and prednisone can significantly improve general condition of model mice,and decreased pulmonary indexes.TG（80,160mg/kg）can improve the alveolitis and fibrosis of model mice,and the levels ofα-SMA,TGF-β1,smad2,smad3,TIMP-1,MMP-2 and MMP-9 were significantly down-regulated,and the level of smad7 was up-regulated.Conclusion:The results suggest that the protective effect of TG on 14d and 28d PF mice induced by BLM.The mechanism is related to FKN（CX3CL1）in 14d and the regulation of TGF-β1/smad signaling pathway and matrix metalloproteinases system in 28d.