Li Jin, Huang Yuechen, Han Yue, Wang Jiafu, Zhang Chun, Jiang Jiuyang
Department of Traditional Chinese Medicine, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
Boli County Hospital of Traditional Chinese Medicine, Qitaihe, China.
Ann Transl Med. 2021 Oct;9(20):1534. doi: 10.21037/atm-21-4561.
This study aimed to investigate whether lupeol could inhibit the inflammatory mediators associated with the regulation of macrophage phenotypes and functions in rats with diet-induced metabolic syndrome (MS).
Forty specific-pathogen-free Sprague Dawley rats were fed a high-fat diet (HFD) for 10 weeks to establish an MS model. Lupeol was prepared and administered to the rats intraperitoneally at 20, 50, or 100 mg/kg (the lupeol 20 mg/kg, lupeol 50 mg/kg, and lupeol 100 mg/kg groups respectively). After 28 days of continuous intraperitoneal administration, rats were anesthesia and euthanasia. The obesity index, blood glucose and lipid metabolism indexes of rats in each group were measured. The levels of insulin and inflammatory factors in each group were detected by enzyme-linked immunosorbent assay (ELISA) kits. The pathological changes of liver tissue in rats were observed by hematoxylin and eosin (HE) and oil red O staining. The polarization levels of M1 and M2 macrophages in peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry. The transcription levels of M1 and M2 macrophages markers were detected by qRT-PCR. The expressions of inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1) proteins in heart tissues of rats in each group were analyzed by Western blotting.
Lupeol significantly recovered fasting blood glucose and serum insulin levels, and reduced the production of proinflammatory cytokines, including interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), and monocyte chemoattractant protein-1 (MCP-1), in the liver. It also elevated the expression of anti-inflammatory cytokines, including IL-4 and IL-10, in the MS model. Further, after treatment with lupeol, the levels of total cholesterol, triacylglycerol and low-density lipoprotein (LDL) were decreased, and high-density lipoprotein (HDL) were increased. Importantly, in the MS model group, lupeol remarkably inhibited M1 macrophages polarization (F4/80iNOS) while elevating M2 macrophages polarization (F4/80CD206) remarkably. At the same time, the levels of M1 markers, including inducible nitric oxide synthase, IL-1β, IL-6, and TNF-α, were markedly inhibited, while those of M2 markers, such as arginase-1, IL-10, CD206, and TGF-β, were markedly elevated in the MS model rats.
Lupeol might promote M2 polarization of macrophages to relieve damage caused by MS.
本研究旨在探讨羽扇豆醇是否能抑制与饮食诱导的代谢综合征（MS）大鼠巨噬细胞表型和功能调节相关的炎症介质。
40只无特定病原体的Sprague Dawley大鼠喂食高脂饮食（HFD）10周以建立MS模型。制备羽扇豆醇并以20、50或100mg/kg的剂量腹腔注射给大鼠（分别为羽扇豆醇20mg/kg组、羽扇豆醇50mg/kg组和羽扇豆醇100mg/kg组）。连续腹腔注射28天后，将大鼠麻醉并处死。测量每组大鼠的肥胖指数、血糖和脂质代谢指标。通过酶联免疫吸附测定（ELISA）试剂盒检测每组中的胰岛素和炎症因子水平。用苏木精和伊红（HE）染色及油红O染色观察大鼠肝组织的病理变化。通过流式细胞术分析外周血单核细胞（PBMC）中M1和M2巨噬细胞的极化水平。通过qRT-PCR检测M1和M2巨噬细胞标志物的转录水平。通过蛋白质印迹法分析每组大鼠心脏组织中诱导型一氧化氮合酶（iNOS）和精氨酸酶-1（Arg-1）蛋白的表达。
羽扇豆醇显著恢复空腹血糖和血清胰岛素水平，并减少肝脏中促炎细胞因子的产生，包括白细胞介素（IL）-6、肿瘤坏死因子-α（TNF-α）和单核细胞趋化蛋白-1（MCP-1）。它还提高了MS模型中抗炎细胞因子的表达，包括IL-4和IL-10。此外，用羽扇豆醇治疗后，总胆固醇、三酰甘油和低密度脂蛋白（LDL）水平降低，高密度脂蛋白（HDL）水平升高。重要的是，在MS模型组中，羽扇豆醇显著抑制M1巨噬细胞极化（F4/80iNOS），同时显著提高M2巨噬细胞极化（F4/80CD206）。同时，MS模型大鼠中M1标志物水平，包括诱导型一氧化氮合酶、IL-1β、IL-6和TNF-α，受到显著抑制，而M2标志物水平，如精氨酸酶-1、IL-10、CD206和转化生长因子-β，则显著升高。
羽扇豆醇可能促进巨噬细胞的M2极化，以减轻MS造成的损伤。
