In vitro synergism between berberine and miconazole against planktonic and biofilm Candida cultures.

To investigate the antimycotic activity of the plant alkaloid berberine (BBR), alone and in combination with antifungal azoles, against planktonic and biofilm Candida cultures. The minimum inhibitory concentrations (MICs) of BBR, miconazole (MCZ), and fluconazole (FLC) towards Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis were determined by a microdilution method. For C. albicans, the synergistic effects of BBR combined with MCZ or FLC were examined in a paper disc agar diffusion assay and checkerboard microdilution assay. The effect of the BBR/MCZ combination was further investigated in a C. albicans biofilm formation model with a dual-chamber flow cell. The effect on metabolic activity of biofilm cells was established using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)/menadione. Berberine inhibited the growth of various Candida species (MICs 0.98-31.25mg/L) in the following order of susceptibility: C. krusei > C. kefyr > C. glabrata > C. tropicalis > C. parapsilosis and C. albicans. Synergism between BBR and MCZ or FLC was observed in the disc diffusion assay as well as in suspension showing an FIC index <0.5 (∑FIC=0.19). Whilst neither BBR (16 mg/L) nor MCZ (0.8 mg/L) alone significantly inhibited biofilm formation of C. albicans, their combination reduced biofilm formation by >91% after 24 h, as established from the reduction in surface area coverage (P<0.01). The BBR/MCZ combination also exhibited synergy against the metabolic activity of pre-formed C. albicans biofilms in polystyrene microtiter plates (∑FIC=0.25). Berberine exhibits synergistic effects with commonly used antimycotic drugs against C. albicans, either in planktonic or in biofilm growth phases.

Wei GX ，Xu X ，Wu CD 《-》

Synergistic effects of tea catechin epigallocatechin gallate and antimycotics against oral Candida species.

Epigallocatechin gallate (EGCG), the major antimicrobial tea polyphenol, has been reported to inhibit the growth of Candida albicans planktonic cells and enhance the antifungal activity of antimycotics. We hypothesised that synergism exists between EGCG and conventional antimycotics against biofilms of Candida species. The minimal inhibitory concentrations (MIC) of EGCG, miconazole, fluconazole and amphotericin B against planktonic cells and the sessile MIC (SMIC) against biofilms of Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata, Candida kefyr and Candida krusei were determined by a microdilution method. For assessment of biofilm metabolic activity, the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay was used. The interactions between EGCG and antimycotics were evaluated by checkerboard microdilution assay and determined by fractional inhibitory concentration index (FIC). Synergism was observed between EGCG and miconazole, fluconazole or amphotericin B against most test planktonic and biofilm cells of Candida species (FIC≤0.5). All biofilm cells were significantly more resistant to EGCG and antimycotics (20-3200 times higher) compared with their planktonic counterparts. We conclude that EGCG enhances the antifungal effects of miconazole, fluconazole and amphotericin B. Combined treatment with EGCG may lower the dosages of antimycotics, thus preventing adverse effects and the emergence of drug-resistant oral Candida species.

Ning Y ，Ling J ，Wu CD 《-》

Synergistic antifungal activity of berberine derivative B-7b and fluconazole.

Li LP ，Liu W ，Liu H ，Zhu F ，Zhang DZ ，Shen H ，Xu Z ，Qi YP ，Zhang SQ ，Chen SM ，He LJ ，Cao XJ ，Huang X ，Zhang JD ，Yan L ，An MM ，Jiang YY ... -  《PLoS One》

Proteomic analysis reveals a synergistic mechanism of fluconazole and berberine against fluconazole-resistant Candida albicans: endogenous ROS augmentation.

Xu Y ，Wang Y ，Yan L ，Liang RM ，Dai BD ，Tang RJ ，Gao PH ，Jiang YY ... -  《-》

Miconazole activity against Candida biofilms developed on acrylic discs.

Gebremedhin S ，Dorocka-Bobkowska B ，Prylinski M ，Konopka K ，Duzgunes N ... -  《-》