The Therapeutic Effects And Mechanism Ofsaikosaponin-D On Mice With Bleomycin-Induced Pulmonary Fribrosis

Objective Saikosaponin(SS) is the main effective ingredient of inradix bupleuri,which has the sex hormone-like effects,anti-platelet activating factor and immune regulation effects. This study is to investigate the therapeutic effects and mechanisms of saikosaponin-d(SSd) on Bleomycin-induced pulmonary fibrosis in mice.Methods According to the random number table,all 180 mice were randomly divided into 5 groups,of which there were four model groups of pulmonary fibrosis.Fibrosis model was established by intratracheal injection of bleomycin(5mg·kg^-1 0.1ml).Theses four goups were respectively BLM group,DXM group,SSd group,SSd+DXM group,each of which contains 40 mice.After molding an hour,the 3 groups ranked behind were administered dexamethasone(DXM,5mg·kg^-1·d^-1 0.1ml),SSd(1.8mg·kg^-1·d^-1 0.18ml),DXM+SSd(0.28ml) respectively by intraperitoneal injection(ip) once daily up to the 28^th day.BLM group were administered normal saline(ip).In addition,20 mice in the normal control group(NC group) was administered normal saline also by intraperitoneal injection at the same time in the same way.The mice were anesthetized and sacrificed at the 3^th,7^th,14^th,28^th day for blood serum and lung tissue,and we observated the conventional histopathological change of the lung tissue.The indexes such as superoxide dismutase(SOD),malonaldehyde(MDA), plasminogen activator inhibitor-1(PAI-1) were examined in both serum and lung tissue samples,and hydroxyproline(HYP),laminin(LN),transforming growth factor-β₁(TGF-β₁) were tested only in lung tissue.Results(1) The survival rate of SSd group are significantly increased higher compared with the BLM group.And the early alveolitis and late pulmonary fibrosis on the pathological morphology in SSd group was all alleviated.(2) The index HYP of BLM group in lung tissue begin to ascend on the 7^th day,ascend the most on the 14^th day,and get peak value on the 28^th day;on the 14^th and 28^th day, compaired with BLM group,there was a significant difference in DXM group,SSd group and SSd+DXM group,but of no significance among the three therapeutic groups. (3) LN only has a small amount in normal lung tissue.LN in lung tissue of modled mice began to ascend on the 3^th day,on the 14^th day increased and got the peak on the 28^th day,which expressed in alveolar septa and epithelial cells.Compaired with BLM group,LN of DXM group,SSd group and SSd+DXM group decreased significantly.But there is of no significance of MDA in lung tissue between the three therapeutic groups.(4) Compaired with NC group,SOD in lung tissue and serum of BLM group decreased significantly on the 3^th day,got the nadir on the 7^th day,after that ascend gradually till the 28^th day recured normal.Compaired with BLM group,the SOD of DXM group,SSd group and SSd+DXM group ascended significantly on the 3^th and 7^th day.There is of no significance of SOD in lung tissue between SSd group and DXM group.Compaired with DXM group,the SOD of SSd group and SSd+DXM group in serum ascended significantly. on the 7^th day.(5) Compaired with NC group,the MDA in lung tissue and serum began to ascend on day 3,got the peak on the 14^th day and descended on the 28^th day.Compaired with BLM group,the MDA of DXM group,SSd group and SSd+DXM group decreased significantly. There is of no significance of MDA in lung tissue and serum between the three therapeutic groups.(6) Compaired with NC group,the TGF-β₁ in lung tissue had no change on the 3^th day, which began to ascend on the 7^th day and ascended gradually till the 28^th day.Compaired with BLM group,the TGF-β₁ of DXM group,SSd group and SSd+DXM group decreased significantly.There is of no significance of TGF-β₁ in lung tissue between the three therapeutic groups.(7) Compaired with NC group,the PAI-1 of BLM group in lung tissue and serum began to ascend on the 7^th day,got the peak on the 28^th day.The PAI-1 of DXM group,SSd group and SSd+DXM group decreased significantly.Compaired with DXM group, SSd+DXM group decreased significantly on the 28^th day.Conclusion SSd could have obvious therapeutic effects on Bleomycin-induced pulmonary fibrosis in mice,and the mechanism may be associated with its effects of anti-lipid pemxidation,anticoagulant,anti-angiogenesis,improving fibrinolysis and inhibiting the expression of TGF-β₁ mRNA.