胡椒碱抑制金黄色葡萄球菌α溶血素的表达研究

Piperine inhibits the expression of alpha hemolysin in Staphylococcus aureus

为了测定胡椒碱对金黄色葡萄球菌USA300α溶血素(α-Hemolysin, Hla)溶血活性的抑制作用并初步阐明其机制,为胡椒碱治疗金黄色葡萄球菌感染提供依据,试验选择Hla为靶标,通过溶血活性试验测定不同浓度胡椒碱对金黄色葡萄球菌USA300共培养物上清液溶血活性的影响,通过最低抑菌浓度(MIC)试验及生长曲线试验考察胡椒碱对金黄色葡萄球菌生长的影响,通过免疫印迹分析试验初步阐明胡椒碱抑制金黄色葡萄球菌USA300溶血活性的机制,通过乳酸脱氢酶(LDH)试验考察胡椒碱对共培养物上清液介导的细胞损伤的抑制作用。结果表明:胡椒碱可显著降低金黄色葡萄球菌Hla的表达,抑制金黄色葡萄球菌USA300培养物上清液的溶血活性,不同浓度胡椒碱均不影响金黄色葡萄球菌USA300生长,且可保护A549细胞免于培养物上清液介导的细胞损伤。说明胡椒碱能够通过抑制Hla的表达而缓解培养物上清液介导的A549细胞损伤,可用于治疗金黄色葡萄球菌感染。

The objective of this study is to determine the inhibitory effect of piperine on Hla expression in Staphylococcus aureus and provide the theoretical basis for the application of tested compound in the treatment of S.aureus infection by clarifying its mechanism.Hemolysis assay was performed to investigate the influence of piperine on hemolytic activity of culture supernatants by S.aureus USA300.The MIC and growth curves assays were employed to elucidate the influence of piperine on S.aureus growth.Western blot assay was used to detect the mechanism of piperine affecting the hemolytic activity in the S.aureus culture supernatants.And then,we assessed the effects of piperine in S.aureus culture supernatants-mediated injury of A549 cell death by determining the release of LDH.We discovered that piperine could decrease the production of Hla in culture supernatants with little anti-S.aureus activity.And our cytotoxicity data suggested that such inhibition provides significant protection against culture supernatants-mediated cells injury.In this study,we identified that piperine could alleviate the S.aureus culture supernatants-mediated cells injury by inhibiting Hla production,suggesting that piperine may be a promising candidate for use in the treatment of S.aureus infection.