State Key Laboratory of Military Stomatology &National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
Ninth Hospital of Xi'an, Xi'an 710054,China.
Cell Mol Biol (Noisy-le-grand). 2022 Sep 30;68(9):21-27. doi: 10.14715/cmb/2022.68.9.3.
Dental caries and pulpal diseases are common oral bacterial infectious diseases, the prevention and treatment of these diseases require the control of the causative pathogens, such as Streptococcus mutans (S. mutans) and Enterococcus faecalis. As a cationic antimicrobial peptide, Chrysophsin-3 has broad-spectrum bactericidal activity against both Gram-positive and Gram-negative bacteria which may cause a variety of oral infectious diseases. The present study evaluated the potential of chrysophsin-3 against several oral pathogens and S.mutans biofilms. The cytotoxic activity of chrysophsin-3 against human gingival fibroblasts (HGFs) was investigated for potential oral application. We use minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and time-kill assay to evaluate the killing effect of chrysophsin-3. Then scanning electron microscopy (SEM) and Transmission Electron Microscope (TEM) were used to analyze the change of morphology and membrane of the pathogens, Live/Dead staining and confocal scanning laser microscopy (CSLM) was used to observe S. mutans biofilms. The results indicate that chrysophsin-3 has varying antimicrobial activities against different oral bacteria. Chrysophsin-3 did not cause obvious cytotoxicity in HGFs at concentrations of 32-128 μg/ml for 5 min or 8 μg/ml for 60 min. SEM revealed membranous blebs and pore formation on the bacterial cell surface, and TEM showed loss of the nucleoid and dissolution of the cytoplasmic space. Furthermore, the CSLM images indicate that chrysophsin-3 can reduce the viability of the cells within the biofilms significantly and had a comparatively lethal effect against S. mutans biofilms. Taken together, our finding suggests that chrysophsin-3 has potential clinical application in oral infectious disease, especially in preventing and treating dental caries.
龋齿和牙髓疾病是常见的口腔细菌性传染病，这些疾病的防治需要控制致病病原体，如变形链球菌（S. mutans）和粪肠球菌。作为一种阳离子抗菌肽，Chrysophsin-3 对革兰氏阳性和革兰氏阴性细菌具有广谱杀菌活性，这些细菌可能导致多种口腔传染病。本研究评估了 Chrysophsin-3 对几种口腔病原体和 S.mutans 生物膜的潜在作用。研究了 Chrysophsin-3 对人牙龈成纤维细胞（HGFs）的细胞毒性作用，以评估其在口腔应用中的潜力。我们使用最小抑菌浓度（MIC）、最小杀菌浓度（MBC）和时间杀伤试验来评估 Chrysophsin-3 的杀菌效果。然后使用扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析病原体形态和膜的变化，使用 Live/Dead 染色和共聚焦扫描激光显微镜（CSLM）观察 S. mutans 生物膜。结果表明，Chrysophsin-3 对不同的口腔细菌具有不同的抗菌活性。Chrysophsin-3 在浓度为 32-128 μg/ml 作用 5 分钟或 8 μg/ml 作用 60 分钟时，在 HGFs 中不会引起明显的细胞毒性。SEM 显示细菌细胞表面出现膜泡和孔形成，TEM 显示核质丢失和细胞质空间溶解。此外，CSLM 图像表明 Chrysophsin-3 可以显著降低生物膜内细胞的活力，对 S. mutans 生物膜具有较强的致死作用。综上所述，我们的研究结果表明，Chrysophsin-3 具有在口腔感染性疾病，特别是在预防和治疗龋齿方面的潜在临床应用价值。
