目的 从肠道菌群与肝脏代谢物角度，研究蒲公英甾醇对酒精性肝病（alcoholic liver disease，ALD）的保护作用及作用机制。方法 C57BL/6J小鼠随机分为对照组、模型组、水飞蓟宾（100 mg/kg）组和蒲公英甾醇高、低剂量（10、5 mg/kg）组，每组8只。连续给药4周，每日给药4 h后，小鼠ig 53°红星二锅头诱导ALD模型。检测血清中肝功能、肝脏组织氧化应激和炎症反应相关指标；采用苏木素-伊红（hematoxylin-eosin，HE）染色观察肝脏组织病理变化；Western blotting检测小肠组织闭锁小带蛋白-1（zonula occludens-1，ZO-1）和闭合蛋白（Occludin）蛋白表达；代谢组学和16S rRNA测序检测肝脏代谢物和肠道菌群的变化。结果 与模型组比较，蒲公英甾醇显著降低ALD小鼠肝脏指数及血清中天冬氨酸氨基转移酶（aspartate aminotransferase，AST）、丙氨酸氨基转移酶（alanine aminotransferase，ALT）、三酰甘油（triglyceride，TG）水平（P＜0.05、0.01），升高肝脏组织中超氧化物歧化酶（superoxide dismutase，SOD）活性（P＜0.05、0.01），降低肝脏组织中丙二醛（malondialdehyde，MDA）、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）和白细胞介素-6（interleukin-6，IL-6）水平（P＜0.05、0.01），改善肝脏病理变化，上调小肠组织ZO-1和Occludin的表达（P＜0.05、0.01）。16S rRNA测序分析表明，蒲公英甾醇有效调节ALD小鼠肠道菌群多样性，改善肠道微生态结构紊乱，拟杆菌属Bacteroides、双歧杆菌属Bifidobacterium和副拟杆菌属Parabacteroides等有益菌群丰度升高，埃希氏菌志贺氏菌属Escherichia Schigella、链球菌属Streptococcus等致病菌群丰度降低。代谢组学分析表明蒲公英甾醇逆转了酒精引起的肝脏代谢物紊乱，尤其是鞘脂和亚油酸代谢途径，并提高乙酸、丁酸和戊酸的水平。结论 蒲公英甾醇通过调节肠道菌群和代谢物的变化，减轻肝脏炎症反应，缓解ALD。

Objective To study the protective effect and mechanism of taraxasterol on alcoholic liver disease (ALD) from the perspective of gut microbiota and liver metabolites. Methods C57BL/6J mice were randomly divided into control group, model group, silibinin (100 mg/kg) group, taraxasterol high- and low-dose (10, 5 mg/kg) groups, with eight mice in each group. After continuous administration for four weeks and daily administration for 4 h, the ALD model was induced in mice by ig 53° red star erguotou. Liver function, liver tissue oxidative stress and inflammation related indicators in serum were detected. Hematoxylin-eosin (HE) staining was used to observe pathological changes in liver tissue. Western blotting was used to detect the expressions of zonula occludin-1 (ZO-1) and Occludin proteins in small intestine tissue. Metabolomics and 16S rRNA sequencing were used to detect changes in liver metabolites and gut microbiota. Results Compared with model group, taraxasterol significantly reduced the liver index and levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TG) in serum of ALD mice (P < 0.05, 0.01), increased the activity of superoxide dismutase (SOD) in liver tissue (P < 0.05, 0.01), reduced the levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in liver tissue (P < 0.05, 0.01), improved liver pathological changes, and upregulated the expressions of ZO-1 and Occludin in small intestine tissue (P < 0.05, 0.01). 16S rRNA sequencing analysis showed that taraxasterol effectively regulated the diversity of gut microbiota in ALD mice, improved the disorder of gut microbiota structure, and increased the abundance of beneficial bacteria such as Bacteroides, Bifidobacterium and Parabacteroides, decreased the abundance of pathogenic bacteria such as Escherichia Schilla and Streptococcus. Metabolomics analysis showed that taraxasterol reversed alcohol induced liver metabolic disorders, particularly in the sphingolipid and linoleic acid metabolic pathways, and increased levels of acetic acid, butyric acid and valeric acid. Conclusion Taraxasterol alleviates liver inflammation and alleviates ALD by regulating changes in gut microbiota and metabolites.

R285.5

温州医科大学企业横向课题（KJHX2206）