Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
Arch Microbiol. 2024 May 11;206(6):257. doi: 10.1007/s00203-024-03993-7.
There is a growing imperative for research into alternative compounds for the treatment of the fungal infections. Thus, many studies have focused on the analysis of antifungal proteins and peptides from different plant sources. Among these molecules are protease inhibitors (PIs). Previously, PIs present in the peptide-rich fractions called PEF1, PEF2 and PEF3 were identified from Capsicum chinense seeds, which have strong activity against phytopathogenic fungi. The aim of this study was to evaluate the mechanism of action and antimicrobial activity of PIs from PEF2 and PEF3 on the growth of yeasts of the genus Candida. In this work, analyses of their antimicrobial activity and cell viability were carried out. Subsequently, the mechanism of action by which the PIs cause the death of the yeasts was evaluated. Cytotoxicity was assessed in vitro by erythrocytes lysis and in vivo in Galleria mellonella larvae. PEF2 and PEF3 caused 100% of the growth inhibition of C. tropicalis and C. buinensis. For C. albicans inhibition was approximately 60% for both fractions. The PEF2 and PEF3 caused a reduction in mitochondrial functionality of 54% and 46% for C. albicans, 26% and 30% for C. tropicalis, and 71% and 68% for C. buinensis, respectively. These fractions induced morphological alterations, led to membrane permeabilization, elevated ROS levels, and resulted in necrotic cell death in C. tropicalis, whilst demonstrating low toxicity toward host cells. From the results obtained here, we intend to contribute to the understanding of the action of PIs in the control of fungal diseases of medical importance.
研究替代化合物治疗真菌感染的需求日益迫切。因此，许多研究集中在分析来自不同植物来源的抗真菌蛋白和肽。这些分子包括蛋白酶抑制剂（PIs）。此前，从辣椒种子中分离出富含肽的 PEF1、PEF2 和 PEF3 中存在的 PIs，对植物病原真菌具有很强的活性。本研究旨在评估来自 PEF2 和 PEF3 的 PIs 对念珠菌属酵母生长的作用机制和抗菌活性。在这项工作中，对它们的抗菌活性和细胞活力进行了分析。随后，评估了 PIs 导致酵母死亡的作用机制。通过红细胞溶解和在大蜡螟幼虫体内进行体外细胞毒性评估。PEF2 和 PEF3 导致热带念珠菌和布因念珠菌的生长抑制率达到 100%。对于白色念珠菌，两种分数的抑制率约为 60%。PEF2 和 PEF3 分别导致白色念珠菌的线粒体功能降低 54%和 46%，热带念珠菌降低 26%和 30%，布因念珠菌降低 71%和 68%。这些分数导致形态改变，导致膜通透性增加，ROS 水平升高，并导致热带念珠菌发生坏死性细胞死亡，而对宿主细胞的毒性较低。从这里获得的结果，我们旨在有助于理解 PIs 在控制具有医学重要性的真菌感染中的作用。
