title: The dual action of epigallocatechin gallate (EGCG), the main constituent of green tea, against the deleterious effects of visible light and singlet oxygen-generating conditions as seen in yeast cells.
abstract: Green tea extracts (GTEs) as well as their main component, the polyphenol epigallocatechin gallate (EGCG), are known for their versatile antioxidant, antimicrobial, antitumoral or anti-inflammatory effects. In spite of the huge beneficial action, there is increasing evidence that under certain conditions green tea and its components can be detrimental to living organisms. Using Saccharomyces cerevisiae strains with various defects in the response to oxidative stress, we found that GTEs or EGCG act in synergy with visible light, exhibiting either deleterious or protective effects depending on the solvent employed. Similar synergistic effects could be observed under singlet oxygen-generating conditions, such as light exposure in the presence of photosensitizers or UV-A irradiation, therefore solvent variance may represent a powerful tool to modulate the preparation of green tea extracts, depending on the intended target.
authors.affiliation: Postgraduate Department of Biochemistry, University of Medicine & Pharmacy "Carol Davila", Sos. Fundeni 258, Bucharest, Romania.
authors.forename: Radu
authors.initials: R
authors.lastname: Mitrica
authors.forename: Ioana
authors.initials: I
authors.lastname: Dumitru
authors.forename: Lavinia L
authors.initials: LL
authors.lastname: Ruta
authors.forename: Augustin M
authors.initials: AM
authors.lastname: Ofiteru
authors.forename: Ileana C
authors.initials: IC
authors.lastname: Farcasanu
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D008027:Light / Q000009:adverse effects; D018384:Oxidative Stress; D017319:Photosensitizing Agents / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism; D026082:Singlet Oxygen / Q000378:metabolism*; D012997:Solvents; D013662:Tea; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D012997:Solvents; D013662:Tea; D026082:Singlet Oxygen; D002392:Catechin; C045651:epigallocatechin gallate