昆仑雪菊挥发油化学成分及对新生隐球菌抗菌作用

Essential oil composition of Coreopsis tinctoria Nutt. and anti-Cryptococcus activity

【目的】探究昆仑雪菊挥发油对新生隐球菌抗菌活性及细胞膜的影响。【方法】采用水蒸气蒸馏法提取昆仑雪菊挥发油并用GC-MS分析挥发油中的化学成分,采用微量稀释法测定昆仑雪菊挥发油对新生隐球菌的最低抑菌浓度(MIC),研究昆仑雪菊挥发油对新生隐球菌生物量和芽管萌发的影响,以及昆仑雪菊挥发油对细胞膜中麦角固醇合成和细胞膜渗透性的作用。【结果】昆仑雪菊挥发油对隐球菌的最小抑菌浓度为0.781μL/m L,昆仑雪菊挥发油对新生隐球菌的生物量和芽管萌发都有一定的抑制作用,其抑制作用与浓度呈正相关的趋势。昆仑雪菊挥发油能减少新生隐球菌细胞膜中麦角固醇的合成,并使新生隐球菌细胞膜的渗透性发生改变。【结论】昆仑雪菊挥发油通过破坏新生隐球菌细胞膜而对其达到抑制作用。

[Objective] Essential oil（EO） composition of Coreopsis tinctoria Nutt., together with The their anti-Cryptococcus activity and influence on the cell membrane of Cryptococcus neoformans present study were evaluated in this study. [Methods] EO from Coreopsis tinctoria Nutt. was extracted team distillation and the main chemical components of it was identified by GC-MS. The micro-dilution method was used in acquiring the minimal inhibitory concentration（MIC）. The cell weight of C. neoformans and germ tube germination of C. neoformans were also determined to evaluate the anti-C. neoformans activity in vitro. The effect on membrane permeabilization was measured by monitoring the influx of Propidium iodide（PI） using flow cytometry and further verified through the inhibition of ergosterol synthesis in the cell membrane. [Results] The MIC value of EO against C. neoformans was 0.781 μL/m L. Cell weight and germ tube germination of C. neoformans were inhibited in a dose-dependent manner. As shown in the results ergosterol production was reduced and propidium iodide penetrated C. neoformans through a lesion in its cell membrane upon treatment with EO. [Conclusion] Inhibitory effect of EO against C. neoformans relying on the cell membrane lesion.