The Effect And Mechanism Of Heat-clearing Herbs On Bleomycin-induced Pulmonary Fibrosis In Rats

Objective：To observe the effect of heat-clearing herbs（Huangqin、Shuanghua、Lianqiao）on bleomycin-induced pulmonary fibrosis in rats,and discuss its anti-fibrosismechanism.Methods:32male SD rats,and randomly divided into four groups (N group:controlgroup,M group:model group,Z group:heat-clearing herbs treatment group,P group:prednisone treatment group),with8animals in each group.N group of normal feedingwithout any processing,free to water under the same indoor environment;M groupdropping bleomycin solution A5(5mg/ml) in trachea5mg/kg;Z group establishing withHuangqin (1.08g/kg),Shuanghua (2.16g/kg),Lianqiao (1.35g/kg) of decoction lavageafter daily;P group establishing prednisone (3mg/kg) to fill the stomach after daily.On the28thday rats in each group to be executed to get lung tissue and serum,rat lung tissuespecimens were observed pathological changes under light microscope,and RT-PCR wasused to detect the expression of VEGF mRNA,and ELISA method was used to detect thelevels of TNF-α、IL-8and TGF-β1,and observe the level change of serum SOD and GSHby fluorescence method,and the expression of PDGF in lung tissue was detected byimmunohistochemistry.Results:①M group compared with the other three groups was severe alveolitis,alveolar septum broadening, inflammatory cellular infiltration, part of the alveolar rupture、fusion and occlusion,and alveolar structure was obviously destroyed, after treatmentalveolitis and pulmonary fibrosis in Z and P groups significantly alleviated in Mgroup(p<0.01).②The levels of TNF-α、IL-8and TGF-β1in Z and P groups were muchlower than that in M group(p<0.01),then the levels of TNF-α and TGF-β1in Z group were much lower than that in P group(p<0.01),showing that heat-clearing herbs and prednisonehad a good effect of anti-inflammation,and anti-inflammatory effects of heat-clearing herbsin alveolitis period were better than prednisone.③Pulmonary capillary proliferation of Zgroup significantly alleviated in M group(p<0.01); and VEGF-mRNA expression of lungtissue in Z group had significant differences in P group(p<0.01), Showing that to a certainextent heat-clearing herbs treatment effect was superior to prednisone.④Serum SOD andGSH expression in M group was much lower than that in Z and P groups(p<0.01), SODand GSH expression in Z and P groups was much lower than that in N group(p<0.05).⑤PDGF expression in Z and P groups was much lower than that in Mgroup(p<0.01),expression in Z group was lower than that in P group(p<0.05).Conclusion: heat-clearing herbs on bleomycin-induced pulmonary fibrosis in rats hasa certain therapeutic effect, and in some ways effect is superior to prednisone, itsmechanism may reduce inflammation reaction、inhibition hyperplasia and repair ofalveolar capillary endothelial cell、anti-oxidative damage、to reduce the formation anddeposition of collagen and other measures.