桔梗皂苷D防御口腔黏膜上皮细胞感染白色念珠菌的作用

Platycodin D protects oral epithelial cells against infection of Candida albicans

目的:探讨桔梗皂苷D对白色念珠菌黏附口腔黏膜上皮细胞的影响。方法:MTT法检测不同桔梗皂苷D对口腔上皮KB细胞存活率的影响;将白色念珠菌、KB细胞以及不同浓度的桔梗皂苷D共同培养,革兰染色检测白色念珠菌黏附数,台盼蓝排斥实验检测念珠菌活力和菌丝转换率;ELISA法检测上清液中IL-18与人β-防御素2(HBD-2)的蛋白含量;实时荧光定量PCR和Western blot法分别检测KB细胞中HBD-2 mRNA与蛋白表达的变化。结果:桔梗皂苷D对KB细胞存活率无影响;随着桔梗皂苷D浓度的增加,白色念珠菌的黏附数、菌活力和菌丝转换率逐渐下降,上清液中IL-18与HBD-2的蛋白含量以及KB细胞中HBD-2 mRNA表达与蛋白水平逐渐降低。结论:桔梗皂苷D具有抑菌作用,并参与了口腔黏膜上皮细胞防御白色念珠菌感染的免疫反应。

AIM：To investigate the effect of platycodin D on Candida albicans infection in oral epithelial cells. METHODS：The viability of the oral squamous carcinoma KB cells was detected by MTT assay after treated with different concentrations of platycodin D. The KB cells were infected with Candida albicans,and then were incubated with platycodin D at different concentrations. Adherent numbers of the Candida albicans were counted by Gram staining,and the bacterial activity and conversion were measured by Trypan blue staining. Furthermore,the protein levels of IL-18 and human β-defensin 2（HBD-2）were analyzed by ELISA,and the expression of HBD-2 at mRNA and protein levels was determined by RT-qPCR and Western blot,respectively. RESULTS：The viability of the KB cells was not affected by platycodin D at the concentrations used. The adherent numbers,bacterial activity and conversion were decreased by treatment with platycodin D in a dose-dependent manner. In addition,the protein level of IL-18 in the culture supernatant and the mRNA expression of HBD-2 in the KB cells were also reduced after platycodin D treatment. CONCLUSION：Platycodin D has a bacteriostasis effect and prevents oral epithelial cells from Candida albicans infection.