黄芩苷对脂多糖诱导巨噬细胞一氧化氮和一氧化氮合酶表达的影响

Baicalin inhibits LPS-induced iNOS expression in macrophages

目的研究黄芩苷对小鼠巨噬细胞一氧化氮(NO)生成和诱导型一氧化氮合酶(iNOS)表达的影响。方法体外培养小鼠巨噬细胞RAW264.7,取生长良好的细胞分别加入LPS(终浓度1μg/mL)和不同浓度黄芩苷(终浓度10、50、100μmol/L)进行干预,并设空白对照组。取培养24 h细胞上清,用Griess法检测NO生成量;取培养8 h和24 h细胞,分别提取细胞总RNA和蛋白,用RT-PCR法和Western Blot法检测iNOS基因和蛋白水平表达情况。结果与空白对照组相比,LPS明显促进了RAW 264.7细胞iNOS表达和NO的生成;加入黄芩苷可抑制LPS诱导的RAW264.7细胞iNOS mRNA和蛋白表达,减少NO的生成,与LPS组差异有统计学意义。结论黄芩苷可明显降低LPS诱导的巨噬细胞iNOS表达和NO生成,这可能是其抗动脉粥样硬化斑块形成的作用机制之一。

Objective To investigate the effects of baicalin on LPS-induced iNOS expression and NO secretion in macrophages.Methods Macrophage cell line RAW264.7 cells were cultured and incubated with LPS and different concentrations of baicalin（10,50,100 μmol/L）.The production of inflammatory factor NO in the supernatant was measured by Griess reagent.The mRNA expression and protein levels of inducible NOS（iNOS） were determined by RT-PCR and Western Blot,respectively.Results Incubated in LPS,the concentration of NO and the expression level of iNOS were significantly higher than those in control group（P0.05）.Baicalin significantly inhibited LPS-induced NO production in a concentration-dependent manner.Baicalin also significantly inhibited LPS-induced iNOS expression at both mRNA and protein levels comparing with LPS group（P0.05）.Conclusion Baicalin effectively block LPS-induced production of NO via inhibiting expression of iNOS in macrophages.This is likely the mechanism of baicalin in ameliorating atherosclerotic lesions.