This study evaluated the cytocompatibility and antimicrobial/antibiofilm effects of epigallocatechin-3-gallate (EGCG) associated with peptide LL-37 and its analogue KR-12-a5 against oral pathogens. The effect of the compounds on metabolism of fibroblasts was evaluated by methyltetrazolium assays. Antimicrobial activity of the compounds was evaluated on Streptococcus mutans, Enterococcus faecalis, Actinomyces israelii, and Fusobacterium nucleatum under planktonic conditions, on single- and dual-species biofilms and E. faecalis biofilms in dentinal tubules and analyzed by bacterial counts and confocal microscopy. Data were statistically analyzed considering p < 0.05. EGCG and peptide combinations were not toxic to fibroblasts. KR-12-a5 showed synergistic or addictive effects with EGCG and LL-37 against all bacteria tested. However, EGCG associated with KR-12-a5 demonstrated the highest bactericidal activity on all bacteria tested, at lower concentrations. In single-species biofilms, EGCG + KR-12-a5 eliminated S. mutans and A. israelii and reduced E. faecalis and F. nucleatum counts around 5 log CFU/mL. EGCG + KR-12-a5 reduced E. faecalis (-3.93 log CFU/mL) and eliminated S. mutans in dual-species biofilms. No growth of E. faecalis and significant reduction in A. israelii (−6.24 log CFU/mL) and F. nucleatum (−4.62 log CFU/mL) counts were detected in dual-species biofilms. The combination of EGCG and KR-12-a5 led to 88% of E. faecalis dead cells inside dentin tubules. The association of EGCG and KR-12-a5 was cytocompatible and promoted synergistic effect against biofilms of bacteria associated with endodontic infections.

本研究评估了与肽 LL-37 及其类似物 KR-12-a5 相关的表没食子儿茶素-3-没食子酸酯 (EGCG) 对口腔病原体的细胞相容性和抗菌/抗菌作用。通过甲基四唑测定评估化合物对成纤维细胞代谢的影响。化合物的抗菌活性在浮游条件下对变形链球菌、粪肠球菌、以色列放线菌和具核梭杆菌、牙本质小管中的单种和双种生物膜和 粪肠球菌生物膜进行了评估，并通过细菌计数和共聚焦显微镜进行了分析。考虑到p 对数据进行统计分析 < 0.05。EGCG 和肽组合对成纤维细胞没有毒性。KR-12-a5 与 EGCG 和 LL-37 对所有测试的细菌都有协同作用或成瘾作用。然而，与 KR-12-a5 相关的 EGCG 在较低浓度下对所有测试的细菌表现出最高的杀菌活性。在单一物种生物膜中，EGCG + KR-12-a5 消除了变形链球菌和以色列曲霉，并将粪肠球菌和具核梭菌计数降低了约 5 log CFU/mL。EGCG + KR-12-a5 减少了粪肠球菌(-3.93 log CFU/mL) 并消除了双物种生物膜中的变形链球菌。E. faecalis没有生长，A. israelii显着减少在双物种生物膜中检测到(-6.24 log CFU/mL) 和F. nucleatum (-4.62 log CFU/mL) 计数。EGCG 和 KR-12-a5 的组合导致牙本质小管内88% 的粪肠球菌死亡细胞。EGCG 和 KR-12-a5 的结合是细胞相容的，并促进了对与牙髓感染相关的细菌生物膜的协同作用。