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 x L(-1). The SMIC50 against biofilms of C. albicanswere > 1 000, > 1000, > 1 000, 500, 500 mg x L(-1). The SMIC50 were > 1 000, > 1 000, > 1 000, > 1 000 and 1 000 mg x L(-1). 1 000 mg x 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.