title: Effect of sulforaphane on glutathione-adduct formation and on glutathione_S_transferase-dependent detoxification of acrylamide in Caco-2 cells.
abstract: The toxicity of dietary acrylamide (AA) depends on its biotransformation pathways, in which phase I cytochrome P-450 enzymes transform AA into glycidamide. The phase II enzyme glutathione_S_transferase (GST) catalyses the conjugation of AA with glutathione (GSH). GST induction by phytochemicals like sulforaphane (SFN) plays a role in chemoprevention. Here, the effect of SFN on the detoxification of AA through GSH conjugation was studied in Caco-2 cells. GSH adducts with AA and SFN were synthesized, identified by NMR and quantified by LC-MS/MS. Caco-2 cells were treated with either 2.5 mM AA, 10 microM SFN or the combination of both for 24 h. Concentrations of GSH conjugates (GSH-AA, GSH-SFN, SFN-GSH-AA), AA and SFN were analysed by LC-MS/MS. GSH contents and GST activity were determined photometrically. GST activity was increased after treatment of the cells with SFN (38+/-6%, p< or =0.05) or AA (25+/-4%, p< or =0.05). GSH concentrations decreased after all treatments. Quantitative data of GSH adduct formation showed that the reaction between GSH and SFN is favoured over that between GSH and AA. The data suggest that SFN might impair the GSH-dependent detoxification of AA by SFN-GSH adduct formation and, thus, lower the GSH concentrations available for its reaction with AA.
authors.affiliation: University of Naples, Portici, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Pernice
authors.forename: Johanna
authors.initials: J
authors.lastname: Hauder
authors.forename: Peter
authors.initials: P
authors.lastname: Koehler
authors.forename: Paola
authors.initials: P
authors.lastname: Vitaglione
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Fogliano
authors.forename: Veronika
authors.initials: V
authors.lastname: Somoza
mesh_terms: D020106:Acrylamide / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D002273:Carcinogens / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004852:Epoxy Compounds / Q000032:analysis; D005506:Food Contamination / Q000517:prevention & control; D005978:Glutathione / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017879:Isothiocyanates; D009682:Magnetic Resonance Spectroscopy; D050217:Metabolic Detoxication, Phase II; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization; D013454:Sulfoxides; D053719:Tandem Mass Spectrometry; D013861:Thiocyanates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D016588:Anticarcinogenic Agents; D002273:Carcinogens; D004852:Epoxy Compounds; D017879:Isothiocyanates; D013454:Sulfoxides; D013861:Thiocyanates; D020106:Acrylamide; C071834:glycidamide; D005982:Glutathione Transferase; C016766:sulforaphane; D005978:Glutathione