title: Photo-oxidation of ergosterol: indirect detection of antioxidants photosensitizers or quenchers of singlet oxygen.
abstract: Consumption of antioxidant supplements is associated to prevention of several diseases. However, recent studies suggest that antioxidants, besides scavenge free radicals could lead development of tumors. Due to conflicting reports on the antioxidant benefits, the capacity to photosensitize the generation of singlet oxygen of seven natural antioxidants was evaluated through photo-oxidation of ergosterol which proved to be an efficient method of indirect detection of singlet oxygen. Our results showed that curcumin, resveratrol and quercetin have pro-oxidant activity due they act as photosensitizers in generation of singlet oxygen. In addition, we observed that genistein, naringenin, β-carotene and gallic acid besides their antioxidant activity against ROS radicals, are capable of quenching ROS non-radicals as singlet oxygen. Finally, our results allow us to propose a new approach in classification of natural antioxidants scavengers of free radicals, based on their activity as quenchers of singlet oxygen or as photosensitizers in singlet oxygen generation.
authors.affiliation: Doctorado en Ciencias Biomédicas, Universidad Veracruzana, Av. Luis Castelazo Ayala s/n, Col. Industrial Ánimas, C.P. 91190 Xalapa, Veracruz, Mexico.
authors.forename: Irene
authors.initials: I
authors.lastname: Lagunes
authors.affiliation: Laboratorio de Alta Tecnología de Xalapa (LATEX), Calle Médicos 5, Col. Unidad del Bosque, C.P. 91010 Xalapa, Veracruz, Mexico; Instituto de Ciencias Básicas, Universidad Veracruzana, Av. Luis Castelazo Ayala s/n, Col. Industrial Ánimas, C.P. 91190 Xalapa, Veracruz, Mexico. Electronic address: atrigos@uv.mx.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Trigos
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D004875:Ergosterol / Q000032:analysis* / Q000737:chemistry; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D017319:Photosensitizing Agents / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry*; D013696:Temperature
chemical_list: D000975:Antioxidants; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D026082:Singlet Oxygen; D004875:Ergosterol