丹参多酚酸盐通过TGF-β1/Smad和PI3K/AKT/mTOR信号通路抑制大鼠肝纤维化的进展

目的：探索丹参多酚酸盐对四氯化碳诱导的大鼠肝纤维化的防治作用及其作用机制。方法：将雄性SD大鼠随机分为正常对照组（空白组）、CCl₄模型组（模型组）、丹参多酚酸盐低剂量组（低剂量组）和丹参多酚酸盐高剂量组（高剂量组），每组12只。采用1 mL·kg^-1每周2次的剂量给予大鼠灌胃CCl₄-橄榄油（1：1）溶液诱导建立肝纤维化模型，治疗组大鼠在建模的同时分别每日1次腹腔注射丹参多酚酸盐15，30 mg·kg^-1。7周处死大鼠，观察大鼠肝脏大体形态；HE和Masson三色染色检测肝组织病理学变化；全自动生化分析仪检测大鼠肝功能指标，包括总胆红素（TBIL）、谷草转氨酶（AST）及谷丙转氨酶（ALT）；放射免疫法测定四项肝纤维化指标，包括透明质酸（HA）、层黏蛋白（LN）、Ⅲ型前胶原肽（PⅢP）和Ⅳ型胶原（CIV）；实时定量PCR法测定肝组织中α-SMA、MMP-1、TIMP-1、Collagen Ⅰ和Collagen Ⅲ基因表达的水平；Western blot检测肝脏组织中TGF-β1、Smad2/3、Smad7、p-PI3K、p-AKT、p-mTOR等蛋白的表达。结果：与模型组相比，丹参多酚酸盐能够显著降低大鼠肝功能和肝纤维化指标，并改善大鼠肝纤维化程度；与此同时，丹参多酚酸盐能够抑制肝组织中TGF-β1/Smad和PI3K/AKT/mTOR信号通路，且能够通过调节细胞外基质的合成和降解来抑制肝纤维化的进展。结论：丹参多酚酸盐可通过调节TGF-β1/Smad和PI3K/AKT/mTOR信号通路发挥抗肝纤维化的作用。

Anti-fibrotic effects of salvianolate on hepatic fibrosis in rats by regulating TGF-β1/Smad and PI3K/AKT/mTOR signaling pathway

OBJECTIVE To explore the preventive and therapeutic effects of salvianolate on CCl₄-induced hepatic fibrosis and its molecular mechanisms. METHODS Male SD rats were randomly divided into four groups including control group (n=12), CCl₄ model group (n=12), salvianolate low dose group (n=12) and salvianolate high dose group (n=12). Hepatic fibrosis model was induced by treatment with CCl₄-olive oil (1:1; 1 mL·kg^-1) twice a week for 7 weeks. In addition, rats in low dose and high dose groups were intraperitoneally injected with salvianolate 15 and 30 mg·kg^-1 respectively once daily over 7 weeks. The rats were executed at 7 weeks to observe the gross morphology of the liver; HE and Masson trichrome staining were used to detect the histopathological changes of the liver; an automatic biochemical analyzer was used to detect the liver function parameters of the rats, including total bilirubin (TBIL), aspartate aminotransferase (AST) and alanine aminotransferase (ALT); four liver fibrosis markers were measured by radioimmunoassay, including hyaluronic acid (HA), laminin (LN), type Ⅲ procollagen peptide (PⅢP) and type IV collagen (CIV); the levels of α-SMA, MMP-1, TIMP-1, collagen Ⅰ and collagen Ⅲ gene expression in the liver tissues were determined by real-time quantitative PCR; and the expression of TGF-β1, Smad2/3, Smad7, p-PI3K, p-AKT, p-mTOR and other proteins in the liver tissues were detected by Western blot. RESULTS Compared with model group, salvianolate can significantly reduce the liver function, liver fibrosis index, while improve the degree of liver fibrosis in rats. Furthermore, we demonstrated that salvianolate can inhibit TGF-β1/Smad and PI3K/AKT/mTOR signaling pathway as well as regulate extra cellular matrix (ECM) synthesis and degradation. CONCLUSION Salvianolate can prevent the progression of liver fibrosis by targeting TGF-β1/Smad and PI3K/AKT/mTOR signaling pathway.