落叶松脂醇-4-β-D-吡喃葡糖苷抑制变异链球菌生长和生物膜形成的作用研究

Effect of lariciresinol-4-beta-D-glucopyranoside on the growth and biofilm formation of Streptococcus mutans

摘要:

[目的] 研究落叶松脂醇-4-β-D-吡喃葡糖苷对变异链球菌生长和生物膜形成的影响。[方法] 四甲基偶氮唑盐微量酶反应比色法（MTT法）用于分析落叶松脂醇-4-β-D-吡喃葡糖苷对变异链球菌生物膜形成的影响；用氧敏感性测试法检测落叶松脂醇-4-β-D-吡喃葡糖苷对变异链球菌氧敏感性的影响；用Real-time PCR方法检测基因的mRNA水平；采用人单核细胞检测了落叶松脂醇-4-β-D-吡喃葡糖苷的细胞毒性。[结果] 落叶松脂醇-4-β-D-吡喃葡糖苷能显著抑制变异链球菌的生长和生物膜形成，而这种抑制作用呈现浓度依赖性。Real-time PCR实验发现，50μg/mL落叶松脂醇-4-β-D-吡喃葡糖苷作用的生物膜中，brpA（transcriptional regulator）、recA（recombinase A）、nth（endonuclease III）、luxS（S-ribosylhomocysteinase）、ffh （fifty four homologue）、smx（sulfamethoxazole）、gtfB（glucosyltransferase-I）和gtfC（glucosyltransferase-SI）的mRNA表达水平均显著降低。同时研究发现，25、50、75μg/mL的落叶松脂醇-4-β-D-吡喃葡糖苷对人单核细胞的生长和LDH活性均无影响。[结论] 落叶松脂醇-4-β-D-吡喃葡糖苷具有抑制变异链球菌生长和生物膜形成的作用，分子水平可以下调brpA、recA、nth、luxS、ffh、smx、gtfB和gtfC等生物膜形成相关基因的mRNA表达水平，同时研究发现其无细胞毒性，因此有望成为抗菌治疗的潜在药物。

Abstract:

[Objective] To study the effects of lariciresinol-4-beta-D-glucopyranoside on the growth and biofilm formation of Streptococcus mutans.[Methods] MTT[3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was used to analyze the effects of lariciresinol-4-beta-D-glucopyranoside on the biofilm formation of Streptococcus mutans; oxygen sensitivity test was used to detect the effects of lariciresinol-4-beta-D-glucopyranoside on oxygen sensitivity of S. mutans; Realtime PCR was used to detect gene expression level. The cytotoxic of lariciresinol-4-beta-D-glucopyranoside was analyzed by using human monocytes. [Results] We found that lariciresinol-4-β-D-glucopyranoside could significantly inhibit the growth of S. mutans, and also suppress the biofilm formation of S. mutans in a concentration-dependent manner. And in lariciresinol-4-β-D-glucopyranoside-treated biofilms, we also found that the mRNA expression levels of brpA (transcriptional regulator), recA (recombinase A), nth (endonuclease III), luxS (S-ribosylhomocysteinase), ffh (fifty four homologue), smx (sulfamethoxazole), gtfB (glucosyltransferase-I) and gtfC (glucosyltransferase-SI) were all decreased. We further revealed that lariciresinol-4-β-D-glucopyranoside (50 μg/mL) had no effect on the growth and LDH activity of human monocytes. [Conclusion] Our findings suggested that lariciresinol-4-β-D-glucopyranoside inhibited the biofilm formation of S. mutans, and the decrease of luxS, brpA, ffh, recA, nth, smx, gtfB and gtfC might contribute to the antibacterial effects of lariciresinol-4-β-D-glucopyranoside.