目的 探討熊果酸對(duì)大鼠頸動(dòng)脈粥樣硬化(CAS)易損斑塊的影響及相關(guān)機(jī)制。方法 采用隨機(jī)數(shù)字表法將144只雄性SD大鼠分為對(duì)照組、模型組、熊果酸(10、20、40 mg·kg^-1)組和阿托伐他汀(ATO,2 mg·kg^-1)組,每組24只。采用高脂飲食2周+ip維生素D₃+液氮冷凍損傷血管+免疫刺激的方法制備CAS易損斑塊大鼠模型,繼續(xù)高脂飲食10周。造模第3周開(kāi)始,各組ig給藥,每天1次,連續(xù)10周。通過(guò)蘇丹IV染色觀察頸動(dòng)脈斑塊分布,計(jì)算斑塊面積與管腔面積比值(PA/LA);通過(guò)HE染色、Movat五色染色觀察頸動(dòng)脈組織病理學(xué)改變和斑塊形態(tài),計(jì)算頸動(dòng)脈斑塊泡沫細(xì)胞容積分?jǐn)?shù)(FVF)和膠原容積分?jǐn)?shù)(CVF);生化分析法檢測(cè)血清低密度脂蛋白膽固醇(LDL-C)、高密度脂蛋白膽固醇(HDL-C)水平;分光光度法檢測(cè)血清丙二醛(MDA)、氧化修飾型低密度脂蛋白膽固醇(ox-LDL-C)水平;ELISA法檢測(cè)血清腫瘤壞死因子-α(TNF-α)、白細(xì)胞介素-1β(IL-1β)、細(xì)胞間黏附分子1(ICAM-1)、單核細(xì)胞趨化蛋白1(MCP-1)水平;Western blotting法檢測(cè)頸動(dòng)脈Toll樣受體4(TLR4)、核因子-κB(NF-κB)蛋白表達(dá)。結(jié)果 與對(duì)照組比較,模型組頸動(dòng)脈斑塊數(shù)量明顯增多,PA/LA顯著升高(P<0.01);頸動(dòng)脈可見(jiàn)平滑肌細(xì)胞增多、排列紊亂、內(nèi)膜增厚、大量泡沫細(xì)胞聚集等病理學(xué)改變;LDL-C、MDA、ox-LDL-C、TNF-α、IL-1β、ICAM-1、MCP-1水平顯著升高而HDL-C水平顯著降低(P<0.01);TLR4、NF-κB蛋白表達(dá)量顯著升高(P<0.01)。與模型組比較,熊果酸20、40 mg·kg^-1組和ATO組頸動(dòng)脈斑塊數(shù)量明顯減少,PA/LA顯著降低(P<0.01);頸動(dòng)脈病理學(xué)改變明顯改善,FVF顯著降低、CVF顯著升高(P<0.01);LDL-C、MDA、ox-LDL-C、TNF-α、IL-1β、ICAM-1、MCP-1水平顯著降低且HDL-C水平顯著升高(P<0.01);TLR4、NF-κB蛋白表達(dá)量顯著降低(P<0.01)。結(jié)論 熊果酸具有減少和穩(wěn)定大鼠CAS易損斑塊的作用,其機(jī)制可能與抑制TLR4/NF-κB通路,進(jìn)而抑制炎癥反應(yīng)和氧化應(yīng)激有關(guān)。

Objective To investigate the effect of ursolic acid (UA) on vulnerable plaques in rats with carotid atherosclerosis (CAS) and related mechanisms. Methods Totally 144 male SD rats were randomly divided into control group, model group, UA (10, 20, 40 mg·kg^-1) group and atorvastatin (ATO) 2 mg·kg^-1 group. The CAS vulnerable plaque rat models were prepared by high-fat diet for two weeks + ip injection of vitamin D₃ + liquid nitrogen to freeze blood vessels + immune stimulation, and after continuing high-fat diet for 10 weeks. Starting from the 3rd week of modeling, the drugs were given by intragastric administration, once a day. The plaque distribution was observed through Sudan IV staining, and the ratio of plaque area to lumen area (PA/LA). The histopathological changes and plaque morphology of the aorta were observed by HE staining and Movat five-color staining. The level of low density lipoprotein (LDL-C) and high density lipoprotein (HDL-C) in serum were detected by biochemical analysis method; the level of malondialdehyde (MDA), oxidatively modified low-density lipoprotein (ox-LDL-C) were detected by spectrophotometric. The level of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), intercellular adhesion molecule 1 (ICAM-1), monocyte chemotactic protein 1 (MCP-1) were detected by ELISA method; the expression of aortic toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB) were detected by Western blotting. Results Compared with control group, the number of aortic plaques in the model group increased, and the PA/LA significantly increased (P<0.01). The physiological changes of aorta showed increased smooth muscle cells, disordered arrangement, intimal thickening, large number of foam cell accumulations. The level of LDL-C, MDA , ox-LDL-C, TNF-α, IL-1β, ICAM-1, MCP-1 significantly increased while the level of HDL-C significantly decreased (P<0.01). The expression of TLR4, NF-κB were significantly increased (P<0.01). Compared with model group, the number of aortic plaques in the UA 20, 40 mg·kg^-1 group and ATO 2 mg·kg^-1 group was significantly decreased, and the PA/LA was significantly reduced (P<0.01). The pathological changes of the aorta were significantly improved, the FVF was significantly decreased and the CVF was significantly increased (P<0.01). The level of LDL-C, MDA, ox-LDL-C, TNF-α, IL-1β, ICAM-1, MCP-1 significantly decreased and the level of HDL-C significantly increased (P<0.01). The expression of TLR4, NF-κB were significantly decreased (P<0.01). Conclusion UA has the effect of reducing and stabilizing vulnerable plaques of CAS in rats, which mechanism may be related to inhibiting the TLR4/NF-κB pathway, and then inhibiting inflammation and oxidative stress.

R285.5

河北省邯鄲市科學(xué)技術(shù)研究與發(fā)展計(jì)劃項(xiàng)目(1823208043ZC)