PDF(Pubmed)
Abstract：
The limited arsenal of antifungal drugs have prompted the search for novel molecules with biological activity. This study aimed to characterize the antifungal mechanism of action of Eugenia uniflora extract and its synergistic activity with commercially available antifungal drugs on the following Candida species: C. albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. dubliniensis. In silico analysis was performed to predict antifungal activity of the major compounds present in the extract. Minimal inhibitory concentrations (MICs) were determined in the presence of exogenous ergosterol and sorbitol. Yeast cells were grown in the presence of stressors. The loss of membrane integrity was assessed using propidium iodide staining (fluorescence emission). Synergism between the extract and antifungal compounds (in addition to time kill-curves) was determined. Molecular docking revealed possible interactions between myricitrin and acid gallic and enzymes involved in ergosterol and cell wall biosynthesis. Candida cells grown in the presence of the extract with addition of exogenous ergosterol and sorbitol showed 2 to 8-fold increased MICs. Strains treated with the extract revealed greater loss of membrane integrity when compared to their Fluconazole counterparts, but this effect was less pronounced than the membrane damage caused by Amphotericin B. The extract also made the strains more susceptible to Congo red and Calcofluor white. A synergistic action of the extract with Fluconazole and Micafungin was observed. The E. uniflora extract may be a viable option for the treatment of Candida infections.
摘要：
有限的抗真菌药物库促使人们寻找具有生物活性的新型分子。本研究旨在表征Eugeniauniflora提取物的抗真菌作用机制及其与市售抗真菌药物对以下念珠菌的协同作用：白色念珠菌，C.热带，C.光滑，拟态梭菌和都柏林梭菌。进行计算机模拟分析以预测提取物中存在的主要化合物的抗真菌活性。在外源麦角甾醇和山梨糖醇存在下测定最小抑制浓度(MIC)。酵母细胞在应激源的存在下生长。使用碘化丙啶染色(荧光发射)评估膜完整性的损失。测定提取物和抗真菌化合物之间的协同作用(除了时间杀死曲线之外)。分子对接揭示了杨梅苷和酸性没食子酸与麦角甾醇和细胞壁生物合成中涉及的酶之间可能的相互作用。在添加外源麦角甾醇和山梨糖醇的提取物存在下生长的念珠菌细胞显示出增加2至8倍的MIC。与氟康唑对应物相比，用提取物处理的菌株显示出膜完整性损失更大。但这种作用不如两性霉素B引起的膜损伤明显。提取物还使菌株对刚果红和Calcofluor白色更敏感。观察到提取物与氟康唑和米卡芬净的协同作用。该E.uniflora提取物可能是治疗念珠菌感染的可行选择。
