摘要Liver fibrosis is a vital cause of morbidity in patients with liver diseases and developing novel anti-fibrotic drugs is imperative.Isovalerylspiramycin Ⅰ(ISP Ⅰ)as a major component of carrimycin applied to upper respiratory infections,was first found to possess anti-fibrotic potential.The present study aims to evaluate the functions and mechanisms of ISP Ⅰ in protecting against liver fibrosis.According to our results,ISP Ⅰ not only reduced the expressions of fibrogenic markers in LX-2 cells but also appeared great protective effects on liver injury and liver fibrosis in bile duct ligation(BDL)rats and carbon tetrachloride(CCl4)mice.We proved that nucleotide-binding protein 2(NUBP2)was the direct target of ISP Ⅰ.ISP Ⅰ through targeting NUBP2,increased the amount of vascular non-inflammatory molecule-1(VNN1)on the cell membrane,which will inhibit oxidative stress and fibrosis.Simultaneously,the original carri-mycin's protective effect on liver damage and fibrosis was verified.Therefore,our study provides po-tential agents for patients with liver fibrosis-related diseases,and the clear mechanism supports wide application in the clinic.