基于逍遥散及其拆方研究“肝病实脾法”对肝纤维化大鼠肠道菌群的影响

Effect of “treating liver by nourishing spleen”on gut microbiota in rats with liver fibrosis based on Xiaoyao powder and its separated recipe

目的通过逍遥散及其拆方对肝纤维化大鼠肠道菌群结构、门静脉内毒素水平的变化,探讨"肝病实脾法"抗肝纤维化的可能作用机制。方法将健康Wistar大鼠70只随机分为空白组10只,模型组、实验组和对照组各20只,采用牛血清白蛋白尾静脉注射8周建立免疫性肝纤维化大鼠模型。实验组予逍遥散中药颗粒剂进行灌胃治疗,对照组予逍遥散去健脾类中药颗粒剂灌胃。观察各组血清转氨酶、肝组织病理学、门静脉内毒素及肠道菌群指纹图谱分析(ERIC-PCR)。满足方差齐性条件的计量资料多组间比较采用方差分析,进一步2组间比较采用LSD-t检验,方差不齐时用Tamhane's法。相关性检验采用Pearson相关分析。结果与空白组比较,模型组大鼠肠道菌群多样性及其构成发生改变,门静脉内毒素水平升高[(0.421±0.170)EU/ml vs(0.784±0.180)EU/ml],差异有统计学意义(P<0.01),且门静脉内毒素与肝组织胶原纤维面积百分比呈正相关(r=0.736,P<0.01);与模型组比较,实验组ALT、AST、门静脉内毒素水平有所下降[(73.25±10.90)U/L vs(59.84±9.60)U/L,(135.36±31.41)U/L vs(107.43±17.71)U/L,(0.784±0.180)EU/ml vs(0.576±0.220)EU/ml],差异均有统计学意义(P<0.01或P<0.05),且肠道菌群多样性及构成与正常大鼠相似;对照组与模型组、实验组在ALT、AST、门静脉内毒素水平方面比较,差异均无统计学意义(P值均>0.05)。结论肝纤维化大鼠出现肠道菌群失调,并引起门静脉内毒素的升高,是慢性肝损伤病理过程中"肝病传脾"的发生机制之一。而逍遥散能够改善肝纤维化,部分恢复肠道菌群正常结构,降低内毒素;而去掉健脾药物将减弱逍遥散对肝脏的保护作用,说明恢复肠道菌群,降低门静脉内毒素可能是"肝病实脾法"抗肝纤维化的重要作用机制之一。

Objective To investigate the possible mechanism of＂treating liver by nourishing spleen＂in the treatment of liver fibrosis with reference to the effect of Xiaoyao powder and its separated recipe on gut microbiota and the level of portal endotoxins. Methods A total of70 healthy Wistar rats were randomly divided into blank group（ 10 rats）,model group（ 20 rats）,experimental group（ 20 rats）,and control group（ 20 rats）,and tail vein injection of bovine serum albumin was performed for 8 weeks to establish a rat model of immune liver fibrosis.The rats in the experimental group were given Xiaoyao granules by gavage,and those in the control group were given Xiaoyao granules without the spleen- strengthening traditional Chinese medicines Atractylodes macrocephala Koidz.,Poria cocos,ginger,and Radix Glycyrrhizae Preparata by gavage. Serum aminotransferases,liver pathology,portal endotoxins,and the enterobacterial repetitive intergenic consensus（ ERIC）- PCR fingerprint of gut microbiota were observed in each group. The analysis of variance was applied for comparison of continuous data with homogeneity of variance between multiple groups,and the least significant difference t- test was used for further comparison between any two groups; the Tamhane＇s method was applied for data with heterogeneity of variance; the Pearson correlation analysis was used for correlation analysis. Results Compared with the blank group,the model group showed changes in the diversity and structure of gut microbiota and an increase in the level of portal endotoxins（ 0. 421 ± 0. 170 EU / ml vs 0. 784 ± 0. 180 EU / ml）,which showed significant differences between these two groups（ P〈0. 01）,and the level of portal endotoxins was positively correlated with collagen area percentage in liver tissue（ r = 0. 736,P〈0. 01）. Compared with the model group,the experimental group had significantly reduced levels of alanine aminotransferase（ ALT）,aspartate aminotransferase（ AST）,and portal endotoxins（ 73. 25 ± 10. 90 U / L vs 59. 84 ± 9. 60 U / L,135. 36 ±31. 41 U / L vs 107. 43 ± 17. 71 U / L,0. 784 ± 0. 180 EU / ml vs 0. 576 ± 0. 220 EU / ml,P〈0. 01 or P〈0. 05）,and the rats in the experimental group had similar diversity and structure of gut microbiota as normal rats. The levels of ALT,AST,and portal endotoxins showed no significant differences between the experimental group and the control group（ P〈0. 05）. Conclusion The rats with liver fibrosis experience intestinal dysbacteriosis which causes the increase in portal endotoxins,and it is one of the mechanisms for the pathogenesis of ＂liver disease affecting spleen＂during the pathological process of chronic liver injury. Xiaoyao powder can relieve liver fibrosis,partially restore the normal structure of gut microbiota,and reduce endotoxins,while the removal of the spleen- strengthening drugs will weaken the protective effect of Xiaoyao powder on the liver. This suggests that restoration of gut microbiota and reduction of portal endotoxins may be an important mechanism of ＂treating liver by nourishing spleen＂in the treatment of liver fibrosis.