Surur Amanda Koberstain, Momesso Vinícius Medeiros, Lopes Pedro Monteiro, Ferrisse Túlio Morandin, Fontana Carla Raquel
São Paulo State University (UNESP), School of Pharmaceutical Sciences - Department of Clinical Analysis, Araraquara, São Paulo, Brazil.
São Paulo State University (UNESP), School of Dentistry - Department of Dental Materials and Prosthodontics, Araraquara, São Paulo, Brazil.
Photodiagnosis Photodyn Ther. 2023 Mar;41:103185. doi: 10.1016/j.pdpdt.2022.103185. Epub 2022 Nov 19.
Antimicrobial Photodynamic Therapy (aPDT) is a treatment based on the interaction between a photosensitizer (PS), oxygen and a light source, resulting in the production of reactive oxygen species (ROS). There are two main types of reactions that can be triggered by this interaction: type I reaction, which can result in the production of hydrogen peroxide, superoxide anion and hydroxyl radical, and type II reaction, which is the Photodynamic Reaction, which results in singlet oxygen production. Antioxidant enzymes (e.g., catalase and superoxide dismutase) are agents that help prevent the damage caused by ROS and, consequently, reduce the effectiveness of aPDT. The aim of this study was to evaluate a possible synergism of the combined inhibition therapy of the enzyme Cu/Zn-Superoxide dismutase (SOD) and the methylene blue- and curcumin-mediated aPDT against Escherichia coli ATCC 25922, in suspension and biofilm.
Kinetic assay of antimicrobial activity of diethydithiocarbamate (DDC) and Minimum Bactericidal Concentration (MIC) of DDC were performed to evaluate the behavior of the compound on bacterial suspension. Inhibition times of Cu/Zn-SOD, as well as DDC concentration, were evaluated via bacterial susceptibility to combined therapy in suspension and biofilm.
DDC did not present MIC at the evaluated concentrations. The inhibition time and Cu/Zn-SOD concentration with the highest bacterial reductions were 30 minutes and 1.2 μg/mL, respectively. Synergism occurred between DDC and MB-mediated aPDT, but not with CUR-mediated aPDT.
The synergism between Cu/Zn-SOD inhibition and aPDT has been confirmed, opening up a new field of study full of possibilities.
抗菌光动力疗法（aPDT）是一种基于光敏剂（PS）、氧气和光源之间相互作用的治疗方法，可产生活性氧（ROS）。这种相互作用可引发两种主要反应类型：I型反应，可产生过氧化氢、超氧阴离子和羟基自由基；II型反应，即光动力反应，可产生单线态氧。抗氧化酶（如过氧化氢酶和超氧化物歧化酶）有助于防止ROS造成的损伤，从而降低aPDT的有效性。本研究的目的是评估酶铜/锌超氧化物歧化酶（SOD）的联合抑制疗法与亚甲蓝和姜黄素介导的aPDT对悬浮液和生物膜中的大肠杆菌ATCC 25922的可能协同作用。
进行二乙基二硫代氨基甲酸盐（DDC）的抗菌活性动力学测定和DDC的最低杀菌浓度（MIC）测定，以评估该化合物在细菌悬浮液中的行为。通过细菌对悬浮液和生物膜联合治疗的敏感性评估Cu/Zn-SOD的抑制时间以及DDC浓度。
在所评估的浓度下，DDC未呈现MIC。细菌减少率最高时的抑制时间和Cu/Zn-SOD浓度分别为30分钟和1.2μg/mL。DDC与MB介导的aPDT之间发生了协同作用，但与CUR介导的aPDT未发生协同作用。
已证实Cu/Zn-SOD抑制与aPDT之间存在协同作用，开辟了一个充满可能性的新研究领域。
