Department of Restorative Sciences, Faculty of Dentistry, Health Sciences Center, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
Department of Bioclinical Sciences, Faculty of Dentistry, Health Sciences Center, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
J Mycol Med. 2019 Jun;29(2):158-167. doi: 10.1016/j.mycmed.2019.01.011. Epub 2019 Feb 20.
The antifungal drug resistance has become an emerging problem in the management of candida infections worldwide. The objective of this study was to examine the efficacy of epigallocatechin 3-O-gallate (EGCG) alone and in combination with fluconazole/ketoconazole drugs against oral Candida isolates.
Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) of EGCG against 60 oral Candida isolates and 4 ATCC strains were determined. Synergism of EGCG with azole drugs was evaluated by checkerboard micro-dilution method and calculated fractional inhibitory concentration index (FICI). Candida cells' ultrastructure was studied by electron microscopy.
MIC and MFC values of EGCG were in the range of 3.91-15.63 and 15.63-31.25μg/mL, respectively. Minimum biofilm inhibitory concentration (MBIC) range of EGCG (62.5-125μg/mL), was less than the ketoconazole (64-256μg/mL) and fluconazole (128-512μg/mL). The combination of EGCG with fluconazole/ketoconazole exhibited synergistic effects (ΣFICI≤0.50). EGCG with azole drugs showed high sensitivity against the tested isolates in growth curve assays. Against the biofilm, the susceptibility of fluconazole/ketoconazole significantly increased (3 to 5 fold), after combination with EGCG (MBIC/4) (P≤0.001). Electron microscopy of EGCG treated cells showed deformation of cell structure, ruptured cell wall and release of intracellular content. In molecular docking experiments, a strong interaction was observed between EGCG and fungal cell membrane molecule ergosterol.
We conclude that EGCG synergistically enhanced the antifungal potential of azole drugs. The synergistic potential of EGCG might be helpful in preventing the development of drug resistance, in lowering the drug dosage, and thus minimizing adverse effects.
抗真菌药物耐药性已成为全球念珠菌感染管理中的一个新问题。本研究旨在研究表没食子儿茶素没食子酸酯（EGCG）单独及与氟康唑/酮康唑药物联合应用对口腔念珠菌分离株的疗效。
测定 EGCG 对 60 株口腔念珠菌分离株和 4 株 ATCC 株的最低抑菌浓度（MIC）和最低杀菌浓度（MFC）。用棋盘微量稀释法和计算的部分抑菌浓度指数（FICI）评估 EGCG 与唑类药物的协同作用。通过电子显微镜研究念珠菌细胞的超微结构。
EGCG 的 MIC 和 MFC 值分别为 3.91-15.63μg/mL 和 15.63-31.25μg/mL。EGCG 的最小生物膜抑制浓度（MBIC）范围（62.5-125μg/mL）小于酮康唑（64-256μg/mL）和氟康唑（128-512μg/mL）。EGCG 与氟康唑/酮康唑联合使用表现出协同作用（ΣFICI≤0.50）。在生长曲线测定中，EGCG 与唑类药物联合使用对测试分离株具有高敏感性。对于生物膜，与 EGCG（MBIC/4）联合使用后，氟康唑/酮康唑的敏感性显著增加（3 至 5 倍）（P≤0.001）。用 EGCG 处理的细胞的电子显微镜显示细胞结构变形，细胞壁破裂和细胞内内容物释放。在分子对接实验中，观察到 EGCG 与真菌细胞膜分子麦角固醇之间存在强烈相互作用。
我们得出结论，EGCG 协同增强了唑类药物的抗真菌作用。EGCG 的协同作用潜力有助于防止耐药性的发展，降低药物剂量，从而最大程度地减少不良反应。
