title: Effect of a novel antimicrobial peptide chrysophsin-1 on oral pathogens and Streptococcus mutans biofilms.
abstract: Dental caries and pulpal diseases are common oral bacterial infectious diseases. Controlling and reducing the causative pathogens, such as Streptococcus mutans and Enterococcus faecalis, is a key step toward prevention and treatment of the two diseases. Chrysophsin-1 is a cationic antimicrobial peptide having broad-spectrum bactericidal activity against both Gram-positive and Gram-negative bacteria. In this study, we investigated the antibacterial activity of chrysophsin-1 against several oral pathogens and S. mutans biofilms and performed a preliminary study of the antimicrobial mechanism. Cytotoxic activity of chrysophsin-1 against human gingival fibroblasts (HGFs) was investigated. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and time-kill assay were used to evaluate the killing effect of chrysophsin-1. Scanning electron microscopy (SEM) was used to analyze morphological and membrane change in oral pathogens. Live/Dead staining, in conjunction with confocal scanning laser microscopy (CSLM), was used to observe and analyze S. mutans biofilms. MIC and MBC results demonstrated that chrysophsin-1 had different antimicrobial activities against the tested oral microbes. Lysis and pore formation of the cytomembrane were observed following treatment of the bacteria with chrysophsin-1 for 4h or 24h by SEM. Furthermore, CLSM images showed that chrysophsin-1 remarkably reduced the viability of cells within biofilms and had a significantly lethal effect against S. mutans biofilms. Toxicity studies showed that chrysophsin-1 at concentration between 8 μg/ml and 32 μg/ml had little effect on viability of HGFs in 5 min. Our findings suggest that chrysophsin-1 may have potential clinical applications in the prevention and treatment of dental caries and pulpal diseases.
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Tao
authors.forename: Zhongchun
authors.initials: Z
authors.lastname: Tong
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Ding
authors.forename: Rong
authors.initials: R
authors.lastname: Kuang
authors.forename: Shafei
authors.initials: S
authors.lastname: Zhai
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Longxing
authors.initials: L
authors.lastname: Ni
mesh_terms: D000190:Actinomyces / Q000187:drug effects / Q000648:ultrastructure; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D013293:Enterococcus faecalis / Q000187:drug effects / Q000648:ultrastructure; D005347:Fibroblasts / Q000187:drug effects; D005881:Gingiva / Q000166:cytology; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; C472594:chrysophsin