title: The effect of quercetin on the mRNA expression of different antioxidant enzymes in hepatoma cells.
abstract: The flavonol quercetin shows a wide range of effects in biological systems. We investigated whether quercetin exerts its proposed antioxidant properties via the antioxidant enzyme system. Quercetin in a concentration range from 5 to 100 microM decreased manganese superoxide dismutase, glutathione peroxidase, and copper zinc superoxide dismutase mRNA expression levels each by 30-40% in rat hepatoma H4IIE cells. Catalase mRNA expression levels increased about 30% but only with the cytotoxic concentration of 100 microM. Despite the down-regulation of antioxidant enzyme mRNA expression quercetin treatment of cells induced only a mild oxidative stress. Pretreatment of H4IIE cells with quercetin even protected against an oxidative stress resulting from hydrogen peroxide exposure. In conclusion, the antioxidant capacity of quercetin was shown not to be due to the antioxidant enzyme system.
authors.affiliation: Bundesinstitut für Arzneimittel und Medizinprodukte, Kurt-Georg-Kiesinger Allee 3, 53175 Bonn, Germany. e.roehrdanz@bfarm.de
authors.forename: Elke
authors.initials: E
authors.lastname: Röhrdanz
authors.forename: Achim
authors.initials: A
authors.lastname: Bittner
authors.forename: Quynh-Hoa
authors.initials: QH
authors.lastname: Tran-Thi
authors.forename: Regine
authors.initials: R
authors.lastname: Kahl
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015152:Blotting, Northern; D002374:Catalase / Q000096:biosynthesis / Q000235:genetics; D015536:Down-Regulation; D005979:Glutathione Peroxidase; D015227:Lipid Peroxidation / Q000187:drug effects; D008114:Liver Neoplasms, Experimental; D011794:Quercetin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; D011794:Quercetin; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase