title: Antibacterial activities of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) against planktonic and biofilm growing Streptococcus mutans.
abstract: The aim of this study was to evaluate the potential antibacterial activities of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) against planktonic and biofilm modes of Streptococcus mutans (S. mutans). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The effects on planktonic growth and biofilm metabolic activity were evaluated by growth curve determination and MTT assay, respectively. Then, colony forming unit (CFU) counting, scanning electron microscopy (SEM) and real-time PCR were performed to further investigate the actions of DHA and EPA on exponential phase-S. mutans. Confocal laser scanning microscopy (CLSM) was used to detect the influences on mature biofilms. The MICs of DHA and EPA against S. mutans were 100 μM and 50 μM, respectively; the MBC of both compounds was 100 μM. In the presence of 12.5 μM-100 μM DHA or EPA, the planktonic growth and biofilm metabolic activity were reduced in varying degrees. For exponential-phase S. mutans, the viable counts, the bacterial membranes and the biofilm-associated gene expression were damaged by 100 μM DHA or EPA treatment. For 1-day-old biofilms, the thickness was decreased and the proportion of membrane-damaged bacteria was increased in the presence of 100 μM DHA or EPA. These results indicated that, DHA and EPA possessed antibacterial activities against planktonic and biofilm growing S. mutans.
authors.affiliation: Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
authors.forename: Mengjun
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
authors.forename: Jiachen
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
authors.forename: Yiru
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. Electronic address: shurong123@hotmail.com.
authors.forename: Rong
authors.initials: R
authors.lastname: Shu
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D015169:Colony Count, Microbial; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000379:methods; D050296:Microbial Viability / Q000187:drug effects; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid
keywords: Biofilm; Docosahexaenoic acid; Eicosapentaenoic acid; Streptococcus mutans