Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; College of Biological Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China.
Key Laboratory of Functional Molecules for Biomedical Research, Zhengzhou, Henan University of Technology, 450001 Zhengzhou, Henan, PR China; College of Information Science and Engineering, Henan University of Technology, 450001 Zhengzhou, Henan, PR China.
Life Sci. 2024 Aug 1;350:122767. doi: 10.1016/j.lfs.2024.122767. Epub 2024 Jun 4.
Candida albicans is the most prevalent pathogenic fungus, exhibiting escalating multidrug resistance (MDR). Antimicrobial peptides (AMPs) represent promising candidates for addressing this issue. In this research, five antimicrobial peptides, ACP1 to ACP5 which named ACPs were studied as alternative fungicidal molecules.
CD assay was used to analyze the 2D structures, Absorbance method was used to test the antimicrobial activity, haemolytic activity, time-kill kinetics, biofilm inhibition and reduction activity, resistance induction activity and assessment against fluconazole-resistant C. albicans. SEM, TEM, CLSM, flow cytometer and FM were carried out to provide insight into the mechanisms of anti-Candida action.
ACPs possessed an α-helical structure and strong anti-Candida activities, with minimum inhibitory concentrations (MICs) from 3.9 to 15.6 μg/mL. In addition, ACPs did not produce hemolysis at concentrations lower than 10 or 62 × MIC, indicating their low cytotoxicity. Fungicidal kinetics showed that they completely killed C. albicans within 8 h at 2 to 4 × MIC. Notably, ACPs were highly fungicidal against fluconazole-resistant C. albicans and showed low resistance. In addition, they were effective in inhibiting mycelium and biofilm formation. Fluorescence microscopy revealed that while fluconazole had minimal to no inhibitory effect on biofilm-forming cells, ACPs induced apoptosis in all of them. The research on mechanism of action revealed that ACPs disrupted the cell membranes, with ROS increasing and cellular mitochondrial membrane potential decreasing.
ACPs could be promising candidates for combating fluconazole-resistant C. albicans infections.
白色念珠菌是最常见的致病性真菌，表现出不断加剧的多药耐药性（MDR）。抗菌肽（AMPs）是解决这一问题的有前途的候选者。在这项研究中，研究了五种抗菌肽，即命名为 ACP 的 ACP1 至 ACP5，作为替代杀菌分子。
使用 CD 分析测定 2D 结构，使用吸光度法测试抗菌活性、溶血活性、时间杀伤动力学、生物膜抑制和减少活性、耐药诱导活性以及对氟康唑耐药白色念珠菌的评估。SEM、TEM、CLSM、流式细胞仪和 FM 用于提供抗真菌作用机制的见解。
ACP 具有α-螺旋结构和强大的抗白色念珠菌活性，最小抑菌浓度（MIC）为 3.9 至 15.6μg/ml。此外，ACP 在低于 10 或 62×MIC 的浓度下不会产生溶血，表明其细胞毒性低。杀菌动力学表明，它们在 2 至 4×MIC 下 8 小时内即可完全杀死白色念珠菌。值得注意的是，ACP 对氟康唑耐药白色念珠菌具有高度杀菌作用，且耐药性低。此外，它们对菌丝和生物膜形成具有抑制作用。荧光显微镜显示，虽然氟康唑对生物膜形成细胞几乎没有抑制作用，但 ACP 诱导所有细胞凋亡。作用机制的研究表明，ACP 破坏细胞膜，导致 ROS 增加和细胞线粒体膜电位降低。
ACP 可能是对抗氟康唑耐药白色念珠菌感染的有前途的候选者。
