目的 研究菊苣酸对小鼠溃疡性结肠炎（ulcerative colitis，UC）继发肝损伤的改善作用及作用机制。方法 35只C57BL/6J雄性小鼠随机分为对照组、模型组及菊苣酸低、高剂量（10、30 mg/kg）组和5-氨基水杨酸（150 mg/kg）组，每组7只。采用3.5%葡聚糖硫酸钠（dextran sulfate sodium，DSS）诱导UC继发性肝损伤小鼠模型，并按10 mL/kg剂量ig不同药物治疗，1次/d，连续11 d。末次给药24 h后收集各组小鼠血清、结肠、脾脏和肝脏组织。采用苏木素-伊红（hematoxylin- eosin，HE）染色法和天狼星红（sirius red）染色法观察肝脏组织病理变化及纤维化情况；采用试剂盒检测小鼠肝脏组织中丙氨酸氨基转移酶（alanine aminotransferase，ALT）、天冬氨酸氨基转移酶（aspartate aminotransferase，AST）、过氧化物歧化酶（superoxide dismutase，SOD）活性和丙二醛（malondialdehyde，MDA）含量；采用试剂盒检测血清中肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）、白细胞介素-6（interleukin-6，IL-6）和IL-1β水平；使用Liperfluo试剂盒及FerroOrange试剂盒检测肝脏组织中脂质过氧化物（lipid peroxidation，LPO）及游离Fe²⁺水平；采用qRT-PCR法检测肝脏组织中TNF-α、IL-6和IL-1β mRNA表达；采用Western blotting检测肝组织谷胱甘肽过氧化物酶4（glutathione peroxidase 4，GPX4）和磷酸化核因子-κB p65（phosphorylated nuclear factor-κB p65，p-NF-κB p65）蛋白表达。结果 与对照组比较，模型组小鼠脾脏和肝脏指数显著升高（P＜0.001），肝脏细胞肿胀、纤维化面积显著增加（P＜0.01、0.001），血清中TNF-α、IL-6、IL-1β水平显著升高（P＜0.001），肝脏组织中AST、ALT、MDA、ROS含量显著升高（P＜0.01、0.001），SOD活性显著降低（P＜0.01），肝脏组织中LPO及Fe²⁺积累增多、凋亡细胞增多，TNF-α、IL-6、IL-1β mRNA表达显著升高（P＜0.001），肝组织中铁死亡通路关键蛋白GPX4表达显著下降（P＜0.001）、炎症通路p-p65蛋白表达显著上调（P＜0.001）。与模型组比较，菊苣酸组小鼠肝脏组织病理损伤明显改善，血清中TNF-α、IL-6、IL-1β水平显著降低（P＜0.05、0.01、0.001），AST、ALT、MDA、ROS含量显著降低（P＜0.05、0.01、0.001），SOD活性显著升高（P＜0.05、0.01），肝脏组织中LPO及Fe²⁺积累减少、凋亡细胞减少，TNF-α、IL-6和IL-1β mRNA表达显著降低（P＜0.001），肝脏组织中GPX4表达显著上调（P＜0.05、0.01）、p-p65蛋白表达显著下降（P＜0.05、0.01）。结论 菊苣酸可以缓解DSS诱导的UC继发性肝脏炎症，通过抑制铁死亡和炎症途径发挥保肝作用。

Objective To investigate the improvement effect and mechanism of chicolic acid (CA) on secondary liver injury in mice with ulcerative colitis (UC). Methods A total of 35 male c57BL/6J mice were randomly divided into control group, DSS group, CA-L (10 mg/kg) group, CA-H (30 mg/kg) group, and 5-ASA (150 mg/kg) group, with seven mice in each group. A mouse model of secondary liver injury in UC using 3.5% dextran sulfate sodium (DSS) was constructed and administered different drug by gavage at a dose of 10 mL/kg once a day for 11 days. After the last administration for 24 h, serum, colon, spleen and liver tissues were collected. Hematoxylin eosin (HE) staining and sirius red staining were used to observe the pathological changes and fibrosis of liver tissue. The activities of alanine aminotransferase (ALT), aspartate transaminase (AST), superoxide dismutase (SOD) and content of malondialdehyde (MDA) in mouse liver tissue were detected by kits; The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β in serum were detected by kits; The lipid peroxides (LPO) and free Fe²⁺in liver tissue were detected by Liperfluo assay kit and FerroOrange assay kit, qRT-PCR was performed to measure the mRNA expression of TNF-α, IL-6 and IL-1β in liver tissue; Western blotting was performed to determine the protein expression of glutathione peroxidase 4 (GPX4) and phosphorylated nuclear factor kappa B p65 (p-NF-κB p65) in liver tissue.Results Compared with the control group, the DSS group showed an significantly increase in spleen and liver indices (P< 0.001), swelling of liver cells, and an significantly increase in fibrosis area (P< 0.01, 0.001). The levels of TNF-α, IL-6, and IL-1β in serum were significantly increased (P< 0.001), and the contents of AST, ALT, MDA, and ROS in liver tissue were significantly increased (P< 0.01, 0.001). The activity of SOD was significantly decreased (P< 0.01), and the accumulation of lipid peroxides (LPO) and Fe²⁺in liver tissue increased, as well as an increase in apoptotic cells. The expression of TNF-α, IL-6 and IL-1β mRNA was also significantly increased (P< 0.001). The expression of GPX4, a key protein in the iron death pathway, was significantly decreased (P< 0.001), and the expression of p-p65 protein in the inflammatory pathway was significantly increased (P< 0.001). Compared with the DSS group, the pathological damage of liver tissue in CA group mice was significantly improved, and the levels of TNF-α, IL-6, and IL-1β in serum were significantly reduced (P< 0.05, 0.01, 0.001). The contents of AST, ALT, MDA, and ROS were significantly reduced (P< 0.05, 0.01, 0.001), and the activity of SOD was significantly increased (P< 0.05, 0.01). The accumulation of lipid peroxides (LPO) and Fe²⁺ in liver tissue was reduced, and the number of apoptotic cells was decreased. The expression of TNF-α, IL-6 and IL-1β mRNA was significantly reduced (P< 0.001). The expression of GPX4 was significantly upregulated (P< 0.05, 0.01), and the expression of p-p65 protein was significantly decreased (P< 0.05, 0.01). Conclusion CA can alleviate DSS induced secondary liver inflammation in colitis, and its mechanism of action may be to exert its hepatoprotective effect by inhibiting iron death and inflammatory pathways.

R285.5

国家自然科学基金资助项目（82170424，82370364，81700364，82300414）;无锡市软科学研究课题项目（KX-24-C009，KX-24-C160）;西藏藏医药大学重点学科建设-藏医基础理论方向（BSDJS-XKJS-24-01）;西藏日喀则市科技项目（RKZ2024ZR-005）