疏肝祛瘀通络降浊法对大鼠非酒精性脂肪性肝炎的保护作用

Traditional Chinese medicine protects rats with nonalcoholic steatohepatitis from endotoxin-induced liver injury

目的探讨非酒精性脂肪性肝炎大鼠内毒素性肝损伤机制及中药对其影响。方法用喂饲高脂饮食的方法建立非酒精性脂肪性肝炎大鼠模型。4周后用疏肝祛瘀通络降浊法分小、中、大剂量进行治疗,12周后处死测定血脂、ALT、内毒素(ET)、肿瘤坏死因子(TNF-α)和白细胞介素(IL-1β)的含量;免疫组化法观察肝组织CD14和核转录因子(NF-κB)的表达;RT-PCR检测脂多糖结合蛋白(LBP)和4型Toll样受体(TLR-4)mRNA的表达。同期正常饮食饲养大鼠作对照。结果第12周时,模型组大鼠腹主动脉血清内毒素水平较正常组明显升高,有显著性差异;中剂量治疗组大鼠血清ET、TNF-α、IL-1β水平明显低于模型组,差异有显著意义。模型组大鼠肝组织CD14阳性细胞数量明显增多,主要分布于肝窦内,部分呈灶型聚集;与模型组相比,中剂量治疗组大鼠肝组织CD14阳性细胞数量明显减少。模型组可见少量细胞核染色的NF-κB阳性细胞散在分布于汇管区。模型组肝组织LBPmRNA和TLR-4mRNA表达均明显上调,与正常组比较差异均有显著意义;中剂量治疗组大鼠肝组织LBPmRNA和TLR-4mRNA表达均较模型组明显下调,且有显著性差异。结论疏肝祛瘀通络降浊法对非酒精性脂肪肝有疗效,可能与其降低血清内毒素水平和下调肝组织内毒素相关受体表达继而减轻炎症性肝损害有关。

Objective To study the pathogenesis of hepatic injury induced by endotoxin （ET） in rats with nonalcoholic steatohepatitis （NASH） and the effects of traditional Chinese medicine. Methods NASH rats were induced by high fat diet and treated by low,medium and high dose of traditional Chinese medicine for smoothing liver,removing stagnation,dredging collaterals,and descending turbid substance four weeks later. These rats were sacrificed at the end of 12 weeks. Serum lipoid,ALT,ET,TNF-α and IL-1β were measured. The expressions of CD14 and NF-κB in liver were observed by immunohistochemistry. The expression of LBP and TLR-4 mRNA in liver were detected by RT-PCR. Results After 12 wk,Serum ET levels in model group rats increased significantly compared with those in control group. The levels of ET,TNF-α and IL-1β in medium-dose group were lower than those of rats in control group,the differences were significant. The quantity of CD14 positive staining cells in the liver of model group increased obviously compared with those of control group,and all of them were situated in the sinusoidal lining,meanwhile they were also located around central veins of hepatic lobules. CD14 positive staining cells in the liver of medium-dose group were less than those of model group evidently. On high fatty diet,a few positive staining cells with NF-κB were situated diffusedly in the portal area of liver of model group. The mRNA levels of LBP and TLR-4 in the liver of model group were higher than those of control group,but they decreased in medium-dose group comparison with those of model group,the difference was significant. Conclusion Traditional Chinese medicine therapy is an effective treatment for NASH. Its mechanism of action maybe related to decreasing the level of serum ET,and down regulating endotoxin receptors of the liver and relieving inflammatory hepatic injury.