姜黄素与根皮素联合作用对大肠杆菌的抑菌效果

Inhibition of Curcumin Combined with Phloretin against Escherichia coli

为研究姜黄素和根皮素联合使用对大肠杆菌的抑菌作用,采用微量肉汤稀释法测定姜黄素、根皮素的亚抑菌浓度;细菌培养测定各药物在亚抑菌浓度剂量下,对大肠杆菌的生长曲线、胞外核酸蛋白、乳酸脱氢酶(LDH)、碱性磷酸酶(AKP)以及总蛋白含量的影响;牛津杯法分析各药物亚抑菌浓度剂量下,姜黄素与根皮素的联合抑菌效果。结果表明:1)姜黄素与根皮素在质量浓度均为250μg/mL时,对大肠杆菌的生长具有显著的抑制作用,此质量浓度确定为姜黄素与根皮素的亚抑菌浓度;2)亚抑菌浓度的姜黄素和根皮素联合作用,能够有效抑制大肠杆菌的生长,抑菌效果优于姜黄素与根皮素单独处理组(P<0.05);3)亚抑菌浓度的姜黄素和根皮素联合使用对大肠杆菌的细胞壁和细胞膜有很强的破坏性,导致菌液上清中核酸、蛋白质以及AKP指数均升高。同时,亚抑菌浓度的姜黄素和根皮素联合使用减少了菌体内总蛋白(包括LDH)的表达量,效果显著优于姜黄素与根皮素单独处理组(P<0.05)。由此可见,姜黄素和根皮素联合作用大肠杆菌时,抑菌效果优于姜黄素与根皮素单独使用。

In order to study the antibacterial effect of curcumin combined with phloretin against Escherichia coli and explore the antibacterial mechanism,the sub-inhibitory concentrations of curcumin and phloretin were determined by the micro broth dilution method.The effects of each drug on the growth curve,extracellular nucleic acid protein,lactate dehydrogenase(LDH),alkaline phosphatase(AKP)and total protein content of Escherichia coli were determined by bacterial culture at sub-inhibitory concentration doses.The Oxford cup method was used to analyze the combined antibacterial effect of curcumin and phloretin at the sub-inhibitory concentration of each drug.These results showed that:1)Curcumin and phloretin had a significant inhibitory effect on the growth of Escherichia coli when both concentrations were 250μg/mL,and this concentration was determined as the sub-inhibitory concentration of curcumin and phloretin.2)The combined action of curcumin and phloretin at sub-inhibitory concentrations could effectively inhibit the growth of Escherichia coli,and the antibacterial effect was better than that of curcumin and phloretin alone(P<0.05).3)The combined use of curcumin and phloretin at sub-inhibitory concentrations has a strong destructive effect on the cell wall and cell membrane of Escherichia coli,resulting in the increase of nucleic acid,protein and AKP index in the supernatant of bacterial liquid.At the same time,the combined use of sub-inhibitory concentrations of curcumin and phloretin reduced the expression of total proteins(including LDH)in bacteria,and the effect was significantly better than that of curcumin and phloretin alone(P<0.05).It can be seen that the antibacterial effect of curcumin and phloretin is better than that of curcumin and phloretin alone.