毛冬青三萜皂苷调控氧化应激-炎症通路对LPS诱导的急性肝损伤小鼠的保护作用与机制研究

Study on the Protective Effect and Mechanism of Ilex pubescens triterpenoid saponins on LPS-induced Acute Liver Injury in Mice by Regulating Oxidative Stress-Inflammation Pathway

关键词:  毛冬青三萜皂苷  急性肝损伤  转录组学分析  氧化应激  炎症

Key words:  Ilex saponin  Acute liver injury  Transcriptome analysis  Oxidative stress  Inflammation

摘要:

目的：探讨毛冬青三萜皂苷对脂多糖（lipopolysaccharide, LPS）诱导的急性肝损伤小鼠的保护作用及分子机制。方法：选取6～8周龄雄性C57BL/6小鼠36只，随机分为正常组、模型组、水飞蓟素阳性对照组（50 mg/kg）和毛冬青三萜皂苷低、中、高剂量组（30、60、120 mg/kg），每组6只。通过腹腔注射LPS（10 mg/kg）建立急性肝损伤模型；采用苏木精-伊红（HE）染色观察肝脏组织病理学变化；ELISA法检测血清中谷丙转氨酶（ALT）、谷草转氨酶（AST）、髓过氧化物酶（MPO）、诱导型一氧化氮合酶（iNOS）、超氧化物歧化酶（SOD）及炎症因子水平；结合转录组学探究毛冬青三萜皂苷的潜在作用机制。结果：与模型组相比，毛冬青三萜皂苷治疗组肝脏组织病理损伤显著改善，表现为肝细胞排列规则、炎性细胞浸润减少；血清ALT、AST水平显著降低（P<0.05），氧化应激指标（MPO、iNOS、SOD）和炎症因子（TNF-α, IL-10, IL-1β）水平明显改善。转录组分析显示，毛冬青三萜皂苷高剂量组共鉴定出175个差异表达基因，这些基因主要富集于花生四烯酸代谢通路、TRP通道炎症调控通路和B细胞受体信号通路等与氧化应激和炎症反应密切相关的通路。结论：毛冬青三萜皂苷可通过调控氧化应激与炎症反应核心通路，显著减轻LPS诱导的小鼠急性肝损伤，该作用与其直接抑制 TNF-α、IL-1β、IL-6 等炎症因子释放，下调 iNOS、MPO 活性并恢复 SOD 抗氧化酶活性密切相关；同时可通过调控 C2H2 锌指蛋白、TRAF 家族转录因子网络，靶向干预脂质代谢、肠道免疫及TRP通道介导的炎症调控等关键通路，发挥肝保护效应。

Abstract:

Objective: To explore the protective effect and molecular mechanism of Ilex pubescens triterpenoid saponins (IPTS) on acute liver injury induced by lipopolysaccharide (LPS) in mice based on transcriptomics. Methods: Thirty-six 6-8-week-old male C57BL/6 mice were randomly divided into normal group, model group, silymarin positive control group (50 mg/kg), and low-, medium-, and high-dose IPTS groups (30, 60, and 120 mg/kg), with 6 mice in each group. An acute liver injury model was established by intraperitoneal injection of LPS (10 mg/kg). Hematoxylin-eosin (HE) staining was used to observe the histopathological changes of liver tissues. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD), and inflammatory factors (TNF-α, IL-10, IL-1β) in serum were detected by ELISA. The potential mechanism of IPTS was explored by combining transcriptome sequencing technology. Results: Compared with the model group, the liver histopathological damage in the IPTS treatment groups was significantly improved, characterized by regular arrangement of hepatocytes and reduced infiltration of inflammatory cells. The levels of serum ALT and AST were significantly decreased (P < 0.05), and the levels of oxidative stress indicators (MPO, iNOS, SOD) and inflammatory factors (TNF-α, IL-1β, IL-10) were significantly improved. Transcriptome analysis showed that a total of 175 differentially expressed genes were identified in the high-dose IPTS group, which were mainly enriched in pathways closely related to oxidative stress and inflammation, such as arachidonic acid metabolism, TRP channel inflammatory regulation, and B-cell receptor signaling. Conclusion: IPTS can significantly alleviate LPS-induced acute liver injury in mice by regulating the core pathways of oxidative stress and inflammatory response. This effect is closely related to its direct inhibition of the release of inflammatory factors such as TNF-α, IL-1β, and IL-6, down-regulation of iNOS and MPO activities, and restoration of SOD antioxidant enzyme activity. At the same time, it can exert hepatoprotective effects by regulating the C2H2 zinc finger protein and TRAF family transcription factor network, and targeting the key pathways of lipid metabolism, intestinal immunity, and TRP channel-mediated inflammatory regulation.