黄芩提取物抑制金黄色葡萄球菌α-溶血素溶血活性的研究

The effect of Scutellaria baicalensis Georgi extract on inactivation to Staphylococcus aureus α-hemolysin

α-溶血素(αHL)是金黄色葡萄球菌(S.aureus)重要的毒力因子,为研究黄芩醇提物对αHL溶血活性的抑制作用,本研究通过乙醇回流提取法获得黄芩醇提取物,测定其对S.aureus的最小抑菌浓度(MIC)、对αHL表达和生物学活性的影响以及对αHL介导的A549细胞损伤的保护性作用。试验结果显示,黄芩醇提取物对所测试的S.aureus的MIC均高于2 048μg/mL;黄芩醇提取物能够抑制S.aureus培养物上清中的αHL的溶血活性,并呈浓度依赖关系,但对αHL的表达并无抑制作用;而且黄芩醇提取物也能够呈剂量依赖关系缓解S.aureusαHL介导的对A549细胞损伤作用。该结果表明黄芩醇提取物能够以某种形式导致αHL丧失生物活性,并提示黄芩醇提取物是一种潜在的抗S.aureus感染的复合物。

The α-hemolysin, a vital virulence factor of Staphylococcus aureus, plays a key role in the bacteria pathogenesis. To evaluate the inactivity of the ethanol extract from Scutellaria baicalensis Georgi （SBG） to the S.aureus α-hemolysin, the effect of the SBG extract on S.aureus α-hemolysin was assessed by determination of minimal inhibitory concentrations （MICs）, inactivation of hemolytic activity of the a-hemolysin and cytotoxicity assay. The results showed MICs of the SBG extract for 8 S.aureus strains were ≥2 048 μg/mL and the SBG extract was able to efficiently reduce the hemolytic activity of α-hemolysin in culture medium secreted from S.aureus. However, the expression of α-hemolysin by the bacteria was not inhibited by the SBG extract. Furthermore, the A549 cells damage by S.aureus α-hemolysin was alleviated with treatment of the SBG extract in a dose-dependent manner, which suggests that the SBG extract had the ability to inactivate the hemolytic activity of α-hemolysin and it could be used as a potential drug against S.aureus infections.