title: Visible light enhances the antimicrobial effect of some essential oils.
abstract: The photodisinfection is a topical, broad spectrum antimicrobial technology, targeting bacteria, virus, fungi, and protozoa effective for single cells as for biofilms. Natural molecules have been studied less than synthetic agents in the process but they are currently receiving great interest. Therefore, the aim of this study is to evaluate for the first time if non-coherent blue and red light enhances the antimicrobial activity of some essential oils when standard strains for antibiotic or fungicide tests are enlightened in vitro. Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans collection strains were irradiated with monochromatic visible light from light emitting diodes in the presence of 5% and 0.5% eucalyptus (Eucalyptus globulus), clove (Eugenia caryophyllata), and thyme (Thymus vulgaris) essential oils. Microbial levels were measured by plate count on culture media. In this preliminary report, the results differ according to the kind and concentration of antimicrobial oils, the wavelength of light, and the prokaryotic or eukaryotic microorganism. The results support the idea that mainly blue light enhances the innate antimicrobial activity of the essential oils, especially phenols, and could offer a very efficient and natural way to combat microorganisms in several industries and medical applications (cutaneous and oral infections, medical textiles, foodstuffs and fruit surface, etc.).
authors.affiliation: Departament d'Òptica i Optometria, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla Sant Nebridi 22, 08222-Terrassa, Barcelona, Spain. Electronic address: marisol.marques@upc.edu.
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Marqués-Calvo
authors.affiliation: GenIUL, Rambla Sant Nebridi 22, 08222-Terrassa, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Codony
authors.affiliation: GenIUL, Rambla Sant Nebridi 22, 08222-Terrassa, Barcelona, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Agustí
authors.affiliation: Departament d'Òptica i Optometria, Universitat Politècnica de Catalunya-Barcelona Tech, Rambla Sant Nebridi 22, 08222-Terrassa, Barcelona, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Lahera
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005052:Eucalyptus; D006801:Humans; D008828:Microbiological Techniques; D009822:Oils, Volatile / Q000494:pharmacology*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013212:Staphylococcus epidermidis / Q000187:drug effects; D027842:Syzygium; D046930:Thymus Plant
chemical_list: D000890:Anti-Infective Agents; D009822:Oils, Volatile; D017319:Photosensitizing Agents
keywords: Candida albicans; Essential oils; Photodisinfection; Pseudomonas aeruginosa; Staphylococcus epidermidis; Visible light