title: Rhamnolipids as emulsifying agents for essential oil formulations: antimicrobial effect against Candida albicans and methicillin-resistant Staphylococcus aureus.
abstract: This work examines the influence of essential oil composition on emulsification with rhamnolipids and their use as therapeutic antimicrobial agents against two opportunistic pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Rhamnolipids, produced by Pseudomonas aeruginosa, with waste frying oil as the carbon source, were composed of eight rhamnolipid homologues. The rhamnolipid mixture was used to produce emulsions containing essential oils (EOs) of Melaleuca alternifolia, Cinnamomum verum, Origanum compactum and Lavandula angustifolia using the titration method. Ternary phase diagrams were designed to evaluate emulsion stability, which differed depending on the essential oil. The in vitro antimicrobial activity of the EOs alone and the emulsions was evaluated. The antimicrobial activity presented by the essential oils alone increased with emulsification. The surface properties of rhamnolipids contribute to the positive dispersion of EOs and thus increase their availability and antimicrobial activity against C. albicans and S. aureus. Therefore, rhamnolipid-based emulsions represent a promising approach to the development of EO delivery systems.
authors.affiliation: Unitat de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: Ester
authors.initials: E
authors.lastname: Haba
authors.affiliation: Département de Phytologie, Institut National des Plantes Médicinales et Aromatiques, Université Sidi Mohamed Ben Abdellah-Fès, Morocco.
authors.forename: Samira
authors.initials: S
authors.lastname: Bouhdid
authors.affiliation: Unitat de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: Noelia
authors.initials: N
authors.lastname: Torrego-Solana
authors.affiliation: Unitat de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: A M
authors.initials: AM
authors.lastname: Marqués
authors.affiliation: Unitat de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: M José
authors.initials: MJ
authors.lastname: Espuny
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, R+D Associated Unit to CSIC, Faculty of Pharmacy, University of Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain.
authors.forename: M José
authors.initials: MJ
authors.lastname: García-Celma
authors.affiliation: Unitat de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Joan XXIII s/n, 08028 Barcelona, Spain. Electronic address: amanresa@ub.edu.
authors.forename: Angeles
authors.initials: A
authors.lastname: Manresa
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D016503:Drug Delivery Systems; D004355:Drug Stability; D045703:Emulsifying Agents / Q000737:chemistry; D004655:Emulsions; D006017:Glycolipids / Q000737:chemistry*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D045703:Emulsifying Agents; D004655:Emulsions; D006017:Glycolipids; D009822:Oils, Volatile; C418382:rhamnolipid
keywords: Emulsions; Essential oils; Methicillin-resistant; Phase behaviour; Rhamnolipids