摘要
目的 观察银杏叶提取物(EGB)对大鼠肝纤维化的防治效果，探讨 EGB 抗肝纤维化的机 制。方法 采用四氯化碳诱导大鼠肝纤维化。EGB 各组四氯化碳处理同模型组，另分别给予0．25、0．5、 1．0g/kg EGB 灌胃。8周末检测其肝功能以及血清透明质酸和层黏连蛋白。取肝组织进行氧化应激测定，免 疫组织化学法检测核因子-kB(NF-kB)P65和α-平滑肌肌动蛋白的表达，逆转录聚合酶链反应法检 测转化生长因子β1(TGF β1)和Ⅰ型胶原 mRNA 的表达，凝胶电泳迁移率分析检测 NF-kB 的活性，并 进行病理组织学检查。结果 EGB 组肝纤维化分级评分、肝功能以及血清透明质酸和层黏连蛋白较模型组 明显改善；EGB 能抑制氧化应激、肝星状细胞的活化、NF-kB P65的表达以及 NF-kB 活性。此外，EGB 还可减低 TGF β1和Ⅰ型胶原 mRNA 的表达。结论 ECB 可能通过抑制氧化应激和 TGF β1的表达，减弱 NF-kB 诱导的肝星状细胞活化，从而阻止四氯化碳诱导的大鼠肝纤维化的发生发展。
Objective To evaluate the effects of Ginkgo biloba extract （EGB） on CCl4-induced liver fibrosis and to investigate the underlying mechanisms. Methods Rats were divided into the following groups： normal control group, CCl4 model group, low dose EGB group, moderate dose EGB group and high dose EGB group. The rat liver fibrosis model was induced by intraperitoneal injection of CCl4 twice a week for 8 weeks. The rats of the three EGB treated groups were given 0.25 g/kg, 0.5 g/kg, 1.0 g/kg of EGB through stomach tubes every day. At the end of the eighth week, blood and liver specimens were obtained. The expressions of nuclear factor kappaB （NF- kB） P65, and α-smooth muscle actin （α- SMA） were detected by immunohistochemistry. Radioimmunoassay was used to evaluate serum hyaluronic acid （HA） and laminin （LN） levels. Electrophoretic mobility shift assay （EMSA） was used to confirm the nuclear translocation activity of NF- kB in liver tissues. The mRNA expression of transforming growth factor- β1 （TGFβ1） and collagen Ⅰ were determined by RT-PCR. Malondialdehyde （MDA）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） in liver tissues and alanine aminotransferase （ALT） and aspartate aminotransferase （AST） in the sera were also examined. Results CCl4 administration induced liver fibrosis, which was inhibited by EGB in a dose-dependent manner. The histopathologic scores of liver fibrosis, the levels of serum ALT, AST, HA and LN were significantly lower in the rats treated with EGB compared with those of the model group （P 〈0.01 or P 〈0.05）. SOD and GSH-Px activites were notably elevated and MDA content was significantly lower in the rats treated with EGB （P 〈0.01 or P 〈0.05）, indicating reduced oxidative stress. Immunohistochemical staining demonstrated inhibition of hepatic stellate cell （HSC） activation （in terms of α -SMA expression） and NF- kB P65 expression in the livers of the EGB-treated rats. As determined by EMSA and RT-PCR, activation of NF- kB, the mRNA expression of TGFβ1 and collagen Ⅰ were significantly higher in model group rats, but obviously lower in EGB treated rats. Conclusion from CCl4-induced liver fibrosis by suppressing oxidative stress of TGFβ1 and the induction of NF- kB on HSC activation. EGB is able to ameliorate liver injury and prevent rats This process may be related to inhibiting the expression of TGFβ1 and the induction of NF-kB on HSC activation.
出处
《中华肝脏病杂志》
CAS
CSCD
北大核心
2005年第12期903-907,共5页
Chinese Journal of Hepatology
