Center of Research in Medicinal Plants - NPPM, Federal University of Piauí - UFPI, Teresina, Piauí, Brazil.
Biotechnology and Biodiversity Center Research - BIOTEC, Federal University of Delta do Parnaíba - UFDPar, Parnaíba, Piauí, Brazil; Center for Research in Applied Morphology and Immunology, NuPMIA, University of Brasilia, Brasilia, Brazil.
Microb Pathog. 2020 Dec;149:104513. doi: 10.1016/j.micpath.2020.104513. Epub 2020 Sep 17.
Resistance to antimicrobials is a challenging issue that complicates the treatment of infections caused by bacteria and fungi, thus requiring new therapeutic options. Oncocalyxone A, a benzoquinone obtained from Auxemma oncocalyx (Allem) Taub has several biological effects; however, there is no data on its antimicrobial action. In this study, its antimicrobial and antibiofilm activities were evaluated against bacteria and fungi of clinical interest. Strains of Gram-positive and Gram-negative bacteria, and filamentous fungi and yeasts were selected to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of oncocalyxone A. The antibacterial effect of oncocalyxone A was studied using survival curves, atomic force microscopy (AFM), and the involvement of oxidative stress. We examined the inhibitory action of the molecule on biofilm formation and its hemolytic activity against human erythrocytes. Our results showed that among the strains tested, Staphylococcus epidermidis was highly sensitive to the action of oncocalyxone A, with an MIC of 9.43 μg/mL. In most bacterial strains analyzed, a bacteriostatic effect was observed, though the molecule showed no antifungal activity. Antibiofilm activity was observed against the methicillin-resistant S. aureus bacteria. Additionally, results from atomic force microscopy imaging showed that oncocalyxone A significantly altered bacterial morphology. Further, oncocalyxone A showed no hemolytic activity at concentrations ≥151 μg/mL. Together, our results demonstrate the antibacterial and antibiofilm potential of oncocalyxone A, indicating its therapeutic potential against bacterial resistance.
抗菌药物耐药性是一个棘手的问题，它使细菌和真菌引起的感染的治疗变得复杂，因此需要新的治疗选择。Oncocalyxone A 是从 Auxemma oncocalyx (Allem) Taub 中获得的一种苯醌，具有多种生物学效应；然而，其抗菌作用尚无数据。在这项研究中，评估了它对临床相关细菌和真菌的抗菌和抗生物膜活性。选择革兰氏阳性和革兰氏阴性细菌、丝状真菌和酵母的菌株来确定 oncocalyxone A 的最小抑菌浓度 (MIC) 和最小杀菌浓度 (MBC)。使用生存曲线、原子力显微镜 (AFM) 和氧化应激的参与来研究 oncocalyxone A 的抗菌作用。我们研究了该分子对生物膜形成的抑制作用及其对人红细胞的溶血活性。我们的结果表明，在所测试的菌株中，表皮葡萄球菌对 oncocalyxone A 的作用高度敏感，MIC 为 9.43 μg/mL。在大多数分析的细菌菌株中，观察到抑菌作用，尽管该分子对真菌没有活性。对耐甲氧西林金黄色葡萄球菌表现出抗生物膜活性。此外，原子力显微镜成像的结果表明 oncocalyxone A 显著改变了细菌形态。此外，oncocalyxone A 在浓度≥151 μg/mL 时没有溶血活性。总之，我们的结果表明 oncocalyxone A 具有抗菌和抗生物膜潜力，表明其在治疗细菌耐药性方面具有潜在的治疗价值。
