Abstract：
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.
摘要：
研究用于治疗真菌感染的替代化合物的必要性日益增加。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。这些分子是蛋白酶抑制剂(PI)。以前,从辣椒种子中鉴定出富含肽的部分中存在的PIs，称为PEF1，PEF2和PEF3，对植物病原真菌有很强的活性。这项研究的目的是评估PEF2和PEF3的PI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,对其抗菌活性和细胞活力进行了分析。随后，评估了PI导致酵母死亡的作用机制。通过红细胞裂解在体外评估细胞毒性，并在Galleriamelonella幼虫体内评估细胞毒性。PEF2和PEF3引起100%的热带梭菌和布inensis的生长抑制。对于白色念珠菌,两种级分的抑制为约60%。PEF2和PEF3导致白色念珠菌线粒体功能降低54%和46%,26%和30%为热带梭菌，和71%和68%的C.buinensis，分别。这些部分诱导了形态学改变，导致膜透化，ROS水平升高，导致热带梭菌坏死细胞死亡，同时显示对宿主细胞的低毒性。从这里获得的结果，我们打算有助于理解PIs在控制具有医学重要性的真菌疾病中的作用。
