title: Adjuvant Antibiotic Activity of Acidic Sophorolipids with Potential for Facilitating Wound Healing.
abstract: The sophorolipid class of biosurfactants is finding increasing use in personal care as well as pharmaceutical products and has the potential to disrupt biofilm formation and inhibit the growth of a variety of clinically relevant organisms. In order to investigate potential biomedical applications of sophorolipids derived from nonpathogenic organisms, we fractionated and purified glycolipid biosurfactant sophorolipids produced by the yeastStarmerella bombicola, which yielded nonacetylated acidic C18:1congeners that were essentially free from other contaminants (>95% purity). These acidic sophorolipids have antimicrobial activities against the nosocomial infective agentsEnterococcus faecalisandPseudomonas aeruginosa, with significant reductions in CFU at concentrations of as low as 5 mg ml-1In addition, the sophorolipid showed similar effects against the same two bacterial strains when combined with kanamycin or cefotaxime. As a potential use of these sophorolipids is as a component of topically applied creams for the treatment of wound infections, it is clear that they must have no demonstrable adverse effect on wound healing. To assess this, we evaluated mammalian cell toxicityin vitrousing viability tests, which revealed no adverse effect on either endothelial or keratinocyte-derived cell lines with sophorolipid concentrations of < 0.5 mg ml-1In addition,in vivoexperiments using a mouse skin wounding assay revealed that the time course of healing wounds was unaffected by the application of sophorolipid-containing creams, and histological examination of regenerated skin tissue confirmed that the healing process was similar to that observed for control animals, with no evidence of inflammation. These results are consistent with the suggestion that acidic sophorolipids can be used as a component of antimicrobial creams to reduce the risk of wound infection during healing.
authors.affiliation: School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, United Kingdom.
authors.forename: Helen L
authors.initials: HL
authors.lastname: Lydon
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, CNRS, Collège de France UMR 7574, Chimie de la Matière Condensée de Paris, UMR 7574, Paris, France.
authors.forename: Niki
authors.initials: N
authors.lastname: Baccile
authors.affiliation: School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, United Kingdom.
authors.forename: Breedge
authors.initials: B
authors.lastname: Callaghan
authors.affiliation: School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, United Kingdom.
authors.forename: Roger
authors.initials: R
authors.lastname: Marchant
authors.affiliation: School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, United Kingdom ca.mitchell@ulster.ac.uk.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Mitchell
authors.affiliation: School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, United Kingdom.
authors.forename: Ibrahim M
authors.initials: IM
authors.lastname: Banat
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000494:pharmacology; D002478:Cells, Cultured; D013293:Enterococcus faecalis / Q000254:growth & development*; D006017:Glycolipids / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007612:Kanamycin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011550:Pseudomonas aeruginosa / Q000254:growth & development*; D004718:Saccharomycetales / Q000378:metabolism; D013501:Surface-Active Agents / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000277:Adjuvants, Pharmaceutic; D000900:Anti-Bacterial Agents; D006017:Glycolipids; D013501:Surface-Active Agents; D007612:Kanamycin; D002439:Cefotaxime
keywords: Enterococcus; Pseudomonas aeruginosa; acidic sophorolipids; adjuvants; antimicrobial activity; endothelium; growth inhibition; in vivo; keratinocytes; microbial pathogens; wound healing