基于TGF-β1/Notch信号通路研究杠板归对二甲基亚硝胺诱导大鼠肝纤维化的作用机制

目的：从TGF-β₁/Notch信号通路探讨杠板归对二甲基亚硝胺（DMN）诱导HF大鼠的保护作用机制。方法：按1.6 mL·kg^-1剂量腹腔注射0.5% DMN溶液，每周3次，共42 d建立大鼠肝纤维化（HF）模型。造模同时灌胃秋水仙碱（0.1 g·kg^-1）和杠板归高、中、低（10，5，2.5 g·kg^-1）干预，每天1次，末次给药后，禁食不禁水16 h，眼球取血，收集血清和肝组织。生化法检测血清中ALT和AST活性，Elisa法测定血清中HA、LN、PCⅢ和Ⅳ-C含量；Western-blot法检测肝组织中TGF-β₁、Notch-1、α-SMA和E-cadherin蛋白表达情况；HE染色观察肝组织病理学变化。结果：与模型组相比，杠板归各剂量组大鼠血清中ALT和AST活性显著降低（P<0.05或P<0.01）；高、中剂量组大鼠血清中的PCⅢ、Ⅳ-C、LN和HA含量呈下降趋势（P<0.05或P<0.01），肝组织中TGF-β₁、Notch-1和α-SMA蛋白表达下降，而E-cadherin蛋白表达升高（P<0.05或P<0.01）；HE染色结果显示，杠板归各剂量组大鼠HF程度得到不同程度改善。结论：杠板归对HF大鼠具有显著的保护作用，其作用机制可能与调控TGF-β₁/Notch信号通路有关。

Action mechanism of Polygonum perfoliatum on hepatic fibrosis induced by DMN in rats based on TGF-β1/Notch signaling pathway

OBJECTIVE To study the protective effects of Polygonum perfoliatum on hepatic fibrosis induced by DMN in rats based on TGF-β₁/Notch signaling pathway. METHODS Rats were injected intraperitoneally with 0.5% DMN solution at 1.6 mL·kg^-1, three times a week for 42 days to establish rat liver fibrosis models. At the same time, colchicines (0.1 g·kg^-1) and Polygonum perfoliatum (10,5,2.5 g·kg^-1) were administered for intervention once daily. After the last administration, rats were fast for 16 h, and then the serum and liver tissues were collected. ALT and AST in serum were measured by biochemical method. ELISA was used to measure the contents of PC Ⅲ, Ⅳ-C, LN and HA in liver tissues. Western-blot was used to detect the expressions of α-SMA, TGF-β₁, Notch-1 and E-cadherin in liver tissues. Histopathological changes of liver were observed by HE staining. RESULTS Compared with the model group, the levels of ALT and AST in the rat serum of Polygonum perfoliatum groups were significantly decreased (P<0.05 or P<0.01). The levels of PC Ⅲ, Ⅳ-C, LN and HA in liver tissues of Polygonum perfoliatum groups (10,5 g·kg^-1) were decreased (P<0.05 or P<0.01). The expressions of TGF-β₁, Notch-1 and α-SMA protein in liver tissues were decreased, while the expression of E-cadherin protein was increased (P<0.05 or P<0.01). The results of HE staining showed that the hepatic fibrosis of the rats of Polygonum perfoliatum groups was improved to different degrees. CONCLUSION Polygonum perfoliatum has significant protective effects on hepatic fibrosis rats, and its mechanism may be related with the regulation of TGF-β₁/Notch signaling pathway.