大黄等5味中药及单体成分对临床多重耐药菌的抑制作用

Antibacterial Activities of Five Chinese Medicines of Rhei Radiset Rhizoma and Their Chemical Constituents Against Multidrug-resistant Clinical Bacteria Isolates

摘要:

目的: 研究大黄、丁香、蒲公英、姜黄、金银花5味中药及大黄素、芦荟大黄素、丁香酚、咖啡酸、绿原酸和姜黄素对临床多重耐药菌的抑制作用.方法: 用微量稀释法测定各药物的最小抑菌浓度(MIC).记录细菌连续24 h的吸光度A₅₉₅,绘制生长曲线,用聚丙烯酰胺凝胶电泳(SDS-PAGE)分析细菌可溶性蛋白质.结果: 大黄的抑菌效果显著,MIC在6.25~12.50 g ·L^-1; 丁香的抑菌谱最广,对所有实验菌株均有抑菌作用,MIC在3.13~25.00 g ·L^-1,蒲公英、金银花和姜黄在本实验中未见抑菌活性;6种单体药物在实验中对铜绿假单胞菌均没有抑菌效果;大黄素、芦荟大黄素和丁香酚对金黄色葡萄球菌的抑菌效果优于其他临床耐药菌株;大黄素的抑菌效果显著,MIC在1.95~15.63 mg ·L^-1;芦荟大黄素的抑菌效果稍弱,MIC在2.34~75.00 mg ·L^-1;丁香酚是唯一对鲍曼不动杆菌有抑菌活性的单体化合物,MIC在5.32~10.64 mg ·L^-1;姜黄素、咖啡酸、绿原酸在实验中未显示抑菌活性.大黄素作用下,金黄色葡萄球菌的生长及可溶性蛋白表达发生明显改变.结论: 大黄和丁香以及大黄素和芦荟大黄素、丁香酚对金黄色葡萄球菌等多种临床多重耐药菌具有显著的抑制效果.大黄素、芦荟大黄素和丁香酚分别是大黄和丁香发挥抑菌作用的主要成分,其具体作用机制有待于深入研究.

Abstract:

Objective:To evaluate the antibacterial activities of five Chinese medicines and their chemical constituents against five multidrug-resistant clinical bacteria isolates. Method: A micro-twofold dilution method was performed to detect the minimum inhibitory concentration (MIC). The growth curve of bacteria was recorded by measuring A₅₉₅ successively and the protein expression profile was mapped by SDS-PAGE. Result: Rhei Radix et Rhizoma was effective against the strains of Staphylococcus aureus and Enterococcus faecalis with the MIC of 6.25-12.50 g · L^-1. Caryophylli Flos exhibited a broad spectrum actibity and suppressed all the tested bacteria isolates to grow with the MIC of 3.13-25.00 g · L^-1. The rest medicines, namely Taraxaci Herba, Lonicerae Japonicae Flos and Curcumae Longae Rhizoma appeared no antibacterial activities.No monomer constituents show antibacterial activities against pseudomonas aeruginosa. Emodin, aloe-emodin and eugenol showed better antibacterial activities against G-negative bacteria than other bacterial isolates. Emodin was observed with the MIC of 1.95-15.63 mg · L^-1and aloe-emodin with the MIC of 2.34-75.00 mg · L^-1. Eugenol was the only constituent that could suppress Acinetobacter baumanii with the MIC of 5.32-10.64 mg · L^-1. No antibacterial activity of curcumin, caffeic acid and chlorogenic acid was found. Growth suppression and changes of protein expression were observed with strains of S. aureus in the presence of emodin. Conclusion: Rhei Radix et Rhizoma and Caryophylli Flos, as well as their chemical constituents, emodin, aloe-emodin and eugenol, can significantly inhibit some multidrug-resistant clinical bacteria strains. Emodin, aloe-emodin and eugenol play an important role in the antibacterial activities of these two Chinese medicines, respectively. The further researches would be carried out to elucidate their exact functional mechanism.