龙胆泻肝汤不同提取部位对白念珠菌生物膜的抑制作用研究

目的： 观察龙胆泻肝汤提取物体外对白念珠菌生物膜形成影响，探讨其可能的作用机制。方法：采用XTT法和微量稀释法筛选龙胆泻肝汤各提取部位的抗菌活性并检测各提取物对白念珠菌生物膜的抑制作用。采用实时荧光定量PCR法检测其黏附相关基因ALS1和菌丝形成基因SUN41的表达量。结果：龙胆泻肝汤用石油醚、水、正丁醇、甲醇及乙酸乙酯提取部位对白念珠菌浮游菌的MIC分别为>1 000，>1 000，>1 000，125，125 mg·L^-1；对白念珠菌生物膜的SMIC₅₀分别为>1 000，>1 000，>1 000，500，500 mg·L^-1；SMIC₈₀分别为>1 000，>1 000，>1 000，>1 000，1 000 mg·L^-1；1 000 mg·L^-1的乙酸乙酯提取物能明显抑制黏附相关基因ALS1和菌丝形成基因SUN41的表达。结论：龙胆泻肝汤抗白念珠菌生物膜的活性部位为乙酸乙酯提取部位。

Study on inhibitory effect of different extract fractions from Longdan Xiegan decoction on biofilms of Candida albicans

Objective: To observe the inhibitory effect of different extract fractions from Longdan Xiegan decoction on biofilms of Candida albicans, and discuss its possible mechanism. Method: The micro-dilution method and the XTT reduction assay were adopted to explore the antifungal activity of different extract fractions from Longdan Xiegan decoction and detect the inhibitory effect of different extracts on biofilms of C. albicans. The expression quantity of the adhesion related gene ALS1 and hypha formation SUN41 were detected by qRT-PCR. Result: The MICs of extracts from Longdan Xiegan decoction, including petroleum ether, water, butanol, methanol and ethyl acetate, against C. albicans were >1 000, >1 000, >1 000, 125, 125 mg·L^-1. The SMIC₅₀ against biofilms of C. albicans were >1 000, >1 000, >1 000, 500, 500 mg·L^-1. The SMIC₈₀ were >1 000, >1 000, >1 000, >1 000 and 1 000 mg·L^-1. 1 000 mg·L^-1 ethyl acetate extracts could considerably inhibit the expression of the adhesion related gene ALS1 and hypha formation SUN41. Conclusion: The ethyl acetate extract showed the greatest activity against Candida albicans biofilms.