São Paulo State University (UNESP), School of Dentistry, Araçatuba, Department of Preventive and Restorative Dentistry, Araçatuba, São Paulo, Brazil.
São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences (IBILCE), Department of Chemistry and Environmental Sciences, São José do Rio Preto, São Paulo, Brazil.
Photodiagnosis Photodyn Ther. 2021 Dec;36:102534. doi: 10.1016/j.pdpdt.2021.102534. Epub 2021 Sep 12.
Curcuminoids have been designed not only to improve chemical and metabolic stability of curcumin (CUR), but also to increase its antimicrobial activity, without effecting its ability as photosensitizer agent in antimicrobial photodynamic therapy (aPDT) with light emitting diode (LED). This study evaluated the antimicrobial and antibiofilm action of curcumin analog DHC (or 3,3'-dihydroxycurcumin), submitted or not to LED irradiation, on microorganisms of endodontic importance and its influence on fibroblasts viability.
DHC was synthetized by modified Pablon's methodology and the experiments were conducted under irradiation or not with indium gallium nitride-based LED (440-480nm, 100 mW/cm, 0.78 cm,60 s). The antimicrobial activity of CUR and DHC were determined by the Minimum Inhibitory and Bactericidal Concentration assays against Gram-positive and Gram-negative bacteria and the effect of both compounds on fibroblast viability was tested using colorimetric assays. They were also evaluated on 72h and 7days single-species biofilms and on 14 days multispecies biofilms formed inside dentin tubules by bacterial colonies counts and confocal microscopy, respectively. Data were analyzed statistically considering p<0.05.
DHC had bactericidal effect against all bacteria tested higher than CUR, in planktonic conditions. CUR and DHC (at 39 and 19 μg/mL, respectively) were cytocompatible and LED irradiation reduced fibroblast viability, regardless of compound. CUR and DHC reduced the growth of single-species biofilms and the effect of aPDT was bacteria dependent. DHC reduced more than 70% of microorganisms from multispecies biofilms, superior to CUR effect.
DHC showed low cytotoxicity and antibiofilm effect similar to curcumin, when submitted or not to aPDT, and could be further explored as a bioactive compound for endodontic purposes.
姜黄素类化合物的设计不仅旨在提高姜黄素 (CUR) 的化学和代谢稳定性，还旨在提高其抗菌活性，同时不影响其作为光动力抗菌治疗 (aPDT) 中光致发光二极管 (LED) 光敏剂的能力。本研究评估了姜黄素类似物 DHC（或 3,3'-二羟基姜黄素）在接受或不接受 LED 照射的情况下对牙髓学重要微生物的抗菌和抗生物膜作用及其对成纤维细胞活力的影响。
DHC 是通过改良的 Pablon 方法合成的，实验在照射或不照射基于铟镓氮化物的 LED（440-480nm，100mW/cm，0.78cm，60s）下进行。通过最低抑菌浓度和杀菌浓度测定法测定 CUR 和 DHC 对革兰氏阳性菌和革兰氏阴性菌的抗菌活性，并使用比色法测定这两种化合物对成纤维细胞活力的影响。还在 72 小时和 7 天的单种生物膜以及在 14 天的牙本质小管内细菌菌落计数和共聚焦显微镜形成的多物种生物膜上进行了评估。数据统计分析考虑 p<0.05。
DHC 在浮游状态下对所有测试的细菌均具有高于 CUR 的杀菌作用。CUR 和 DHC（分别为 39 和 19μg/mL）具有细胞相容性，并且无论化合物如何，LED 照射都会降低成纤维细胞活力。CUR 和 DHC 减少了单种生物膜的生长，aPDT 的作用取决于细菌。DHC 从多物种生物膜中减少了超过 70%的微生物，优于 CUR 的效果。
DHC 表现出低细胞毒性和类似于姜黄素的抗生物膜作用，无论是在接受或不接受 aPDT 的情况下，都可以进一步探索作为牙髓学目的的生物活性化合物。
