Activity of Matrine Against Candida albicans Adhesion and Biofilm Formation

Objectives: To establish a model of Candida albicans biofilms in vitro and to examine the effect of matrine on C. albicans biofilms and ultrastructure. To investigate the influence of matrine on the adhesion of C. albicans to human buccal epithelial cells (BEC) and the agglutinin-like sequence (ALS) gene expression. Methods: C. albicans collection strain ATCC76615 was obtained and propagated. Biofilms were formed in 96-well microtiter plates. Antifungal susceptibility testing of C. albicans biofilms were assessed with the tetrazolium salt(XTT)reduction assay. Confocal laser scanning microscopy (CLSM) and dead/live fluorescent stainning technique were combined to detect the effects of matrine on preformed C. albican biofilms' composition and ultrastructure. C. albicans were co-cultured with human BEC after following brief exposure to different concentrations of matrine in vitro. The numbers of adherent C. albicans were counted in 50 BECs after Gram stain. Real time polymerase chain reaction (RT-PCR) was used to investigate ALS1 and ALS4 genes expression. Results: Over 80% inhibition of biofilm was observed at matrine concentrations between 18mg/ml and 20mg/ml. Minimal inhibitory concentration (MIC) of matrine for planktonic C. albicans was 3.0mg/ml. CLSM indicated that matrine affected morphology and metabolic status of cells within the biofilm. Adhesion to BECs assay showed lower levels of ability to adhere to BECs in the matrine-treated groups compared with the control group. RT-PCR results showed that matrine-treated cells expressed lower levels of ALS1 and ALS4 mRNA than untreated cells. Conclusion: This study demonstrated that matrine has potent activity against C. albicans biofilm in vitro and might be a compound useful to treat biofilm-associated candidal infections. Supported by the Doctorate Innovation Foundation of Shanghai Jiao Tong University School of Medicine (Grant No.BXJ0822) .