Effects Of Diammonium Glycyrrhizinate On Rats With BLM-induced Pulmonary Fibrosis And Its Mechanism In Rats

Objective：To explore the effects of diammonium glycyrrhizinate onbleomycin (BLM)-induced pulmonary fibrosis (PF) and to further clarifythe underlying fibrotic mechanisms.Methods：30Wistar rats were randomly divided into normal controlgroup(control group), BLM-induced pulmonary fibrosis group(modelgroup) and glycyrrhizinate group. Pulmonary fibrosis models of rats wereestablished by injected of BLM via trachea (5mg·kg-1once). From the2nd day after injection, the rats in glycyrrhizinate group wereintraperitoneally injected with glycyrrhizinate(75mg·kg-1·d-1), while therats in other two groups with normal saline injection instead. On the28thday, all rats were sacrificed, Their left lung lobe tissues were removedand used for pathological section examination. the blood samples wereobstained to measure laminin（LN）、hyaluronic acid（HA）、SuperoxideDismutase（SOD）、scavenger enzymes（CAT）、inducible nitric oxidesynthase (iNOS)、nitric oxide (NO)levels.Results：(1) The pulmonary tissue of control group was normal，and thepulmonary fibrosis in glycyrrhizin group was significantiy lighter, and thepulmonary fibrosis in model group was severe through paraffin section. (2) compared with control group,the serum LN and HA levels ofrats in model group were significantly increased（P <0.01）, the serum LNlevel of rats in glycyrrhizinate group was increased（P<0.01）, but theserum HA level had no changes（P>0.05）；the serum LN and HA levelsof the rats in glycyrrhizinate group were lower than these in modelgroup（P<0.01；P<0.01）.(3) compared with control group,the serum SOD、CAT levels of rats inmodel group were lower（P<0.01, P<0.01）, but the serum SOD、CATlevels of rats in glycyrrhizinate group had no changes（P>0.05）；theserum SOD、CAT levels of the rats in glycyrrhizinate group were higherthan these in model group（P<0.01；P<0.01）.(4) compared with control group,the serum iNOS and NO levels ofrats in model group were significantly increased（P<0.01）, but the serumiNOS and NO levels of rats in glycyrrhizinate group had no changes（P>0.05）；the serum iNOS and NO levels of the rats in glycyrrhizinategroup were lower than these in model group（P<0.05，P<0.01）.Conclusion：Diammonium glycyrrhizinate can significantly increasethe levels of SOD、CAT，and reduce the serum levels of LN、HA、iNOS、NO in BLM-induced pulmonary fibrosis rats, and to alleviate pulmonaryfibrosis.