title: Hyperglycemia and Anthocyanin Inhibit Quercetin Metabolism in HepG2 Cells.
abstract: A high glucose (Glu) milieu promotes generation of reactive oxygen species, which may not only cause cellular damage, but also modulate phase II enzymes that are responsible for the metabolism of flavonoids. Thus, we examined the effect of a high Glu milieu on quercetin (Q) metabolism in HepG2 cells. HepG2 cells were grown for 3 days in Glu ranging from 5.5 to 50 mmol/L and/or cyanidin-3-glucoside (C3G) ranging from 0 to 25 μmol/L. Subsequently, the capacity of HepG2 cells to metabolize Q was assessed for up to 16 h. Q metabolites were analyzed by high-performance liquid chromatography. Four major Q metabolites were observed in the culture medium and inside the HepG2 cells. Three of these metabolites appear to be sulfated forms of Q or methylated Q, and one was a methylated Q. These metabolites and Q itself were reduced or tended to be reduced in cells grown in a high Glu compared to a normal Glu medium. Addition of C3G or superoxide dismutase plus catalase did not prevent or enhance reduction of Q metabolites. In vitro, a hyperglycemic milieu decreases the production of the principal Q metabolites in HepG2 cells, mediated through mechanisms independent of oxidative stress.
authors.affiliation: 1 Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University , Boston, Massachusetts, USA.|2 Koshi Headquarters, National Agricultural Research Center for Kyushu Okinawa Region , Koshi, Kumamoto, Japan .|3 Memuro Research Station, National Agriculture Research Center for Hokkaido Region , Kasai, Hokkaido, Japan .
authors.forename: Naoto
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: 1 Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University , Boston, Massachusetts, USA.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Blumberg
authors.affiliation: 1 Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University , Boston, Massachusetts, USA.
authors.forename: C-Y Oliver
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000872:Anthocyanins / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005960:Glucosides / Q000494:pharmacology*; D056945:Hep G2 Cells; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy*; D018384:Oxidative Stress / Q000187:drug effects; D011794:Quercetin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005960:Glucosides; D017382:Reactive Oxygen Species; C462279:cyanidin-3-O-beta-glucopyranoside; D011794:Quercetin; D002374:Catalase; D013482:Superoxide Dismutase
keywords: cyanidin-3-glucoside; human hepatoma; hyperglycemic milieu; quercetin metabolism