芍药苷对白色念珠菌生物膜的作用

Paeoniflorin effects on Candida albicans biofilms

背景:研究证实中药赤芍有效成分对白色念珠菌有较好的抑制作用,但其单体芍药苷对白色念珠菌生物膜是否有抑制作用未见报道。目的:观察芍药苷对体外白色念珠菌生物膜的影响。方法:用RPMI-1640分别按2倍稀释法制备5个浓度梯度(4,2,1,0.5,0.25 g/L)的芍药苷溶液。用RPMI-1640稀释洗必泰为5个浓度梯度(2%,1%,0.5%,0.25%,0.125%)。采用琼脂扩散法检测不同浓度梯度芍药苷或洗必泰对白色念珠菌的抑菌直径。MTT法检测不同浓度洗必泰或芍药苷对白色念珠菌细胞黏附的作用,以及对白色念珠菌生物膜的抑制作用,并且利用激光共聚焦扫描显微镜和死菌活菌荧光染色技术相结合方法观察常态及药物作用下的白色念珠菌生物膜。结果与结论:洗必泰与芍药苷均有抑菌能力,抑菌环直径与药物浓度呈正相关;除2 g/L芍药苷组与1%,2%洗必泰组抑菌环直径无差异外,其余组间两两比较差异均有显著性意义。不同质量浓度芍药苷对白色念珠菌的细胞黏附都具有抑制作用,对白色念珠菌生物膜也具有抑制作用,且抑制率与药物质量浓度呈正相关。观察48 h时常态生物膜结构中大部分是活菌,有少量死菌存在;随芍药苷质量浓度改变白色念珠菌生物膜中死菌比例不断增高,其抑菌活性相对弱于洗必泰。表明芍药苷对体外白色念珠菌生物膜有较明显的抑制作用。

BACKGROUND：Studies have confirmed that the active ingredients ofPaeonia lactiflora Pal. have better inhibitory effects onCandida albicans, but its monomer paeoniflorin has not been reported whether it can inhibit Candida albicans biofilm. OBJECTIVE：To observe the effect of paeoniflorin onCandida albicans biofilm in vitro. METHODS：Paeoniflorin solution at different concentrations of 4, 2, 1, 0.5, 0.25 g/L was prepared using RPMI-1640 according to 2-fold dilution method. Chlorhexidine was diluted with RPMI-1640 to different concentrations, including 2%, 1%, 0.5%, 0.25%, 0.125%. We compared the effects of different concentrations of chlorhexidine and paeoniflorin on diameter ofCandida albicans by agar diffusion method. MTT assay was used to detect the effect of different concentrations of chlorhexidine or paeoniflorin on the celladhesion of Candida albicans as wel as their inhibitory effects onCandida albicans biofilms. Confocal laser scanning microscope and LIVE/DEAD BacLight Bacterial Viability Kits were combined to observe the changes ofCandida albicans biofilms under normal or intervention conditions. RESULTS AND CONCLUSION：Both chlorhexidine and paeoniflorin possessed bacteriostatic ability, and their bacteriostatic ring diameters were positively correlated with drug concentrations. Significant differences in the bacteriostatic ring diameter were observed between chlorhexidine and paeoniflorin, except between 2 g/L paeoniflorin and 1%, 2% chlorhexidine. Paeoniflorin at different concentration could inhibit celladhesion of Candida albicans as wel as inhibitCandida albicans biofilm. The inhibition rate was also positively correlated with drug concentrations. Under normal conditions, most of bacteria in the biofilms were alive, and there was a smal amount of dead bacteria after 48 hours. After intervention with paeoniflorin, the proportion of dead bacteria in thebiofilms was increasing along with the concentrations of paeoniflorin. Compared with the chlorhexidine, paeoniflorin showed a lower bacteriostatic activity. These findings indicate that paeoniflorin has an obvious inhibitory action in Candida albicans biofilms in vitro.