title: Biomonitoring the intake of garlic via urinary excretion of allyl mercapturic acid.
abstract: Allium vegetables (onions, leeks, chives) and in particular garlic have been claimed to have health-promoting potential. This study was conducted to get insight into the perspectives for monitoring the intake of garlic by a biomarker approach. Chemically, the biomarker results from exposure to gamma-glutamyl-S-allyl-l-cysteine, which is first hydrolysed by gamma-glutamine-transpeptidase resulting in the formation of S-allyl-l-cysteine. The latter compound is subsequently N-acetylated by N-acetyltransferase into S-allyl-mercapturic acid (ALMA) and excreted into urine. The mercapturic acid was measured in urine using gaschromatography with mass spectrometry. Thus the intake of garlic was determined to check the compliance of garlic intake in a placebo-controlled intervention study. Results indicate that S-allyl-mercapturic acid could be detected in 15 out of 16 urine samples of garlic supplement takers, indicating good compliance. In addition, the intake of garlic was also monitored in a cross-section study of vegans versus controls in Finland, in which no differences in garlic consumption nor in ALMA output were recorded between vegans and controls. These data indicate good possibilities for further studies in the field of biomarkers to investigate the putative chemopreventive effects of garlic and garlic-containing products.
authors.affiliation: TNO Voeding, P.O. Box 360, Zeist, 3700 AJ, The Netherlands. hans.verhagen@unilever.com
authors.forename: H
authors.initials: H
authors.lastname: Verhagen
authors.forename: G J
authors.initials: GJ
authors.lastname: Hageman
authors.forename: A L
authors.initials: AL
authors.lastname: Rauma
authors.forename: G
authors.initials: G
authors.lastname: Versluis-de Haan
authors.forename: M H
authors.initials: MH
authors.lastname: van Herwijnen
authors.forename: J
authors.initials: J
authors.lastname: de Groot
authors.forename: R
authors.initials: R
authors.lastname: Törrönen
authors.forename: H
authors.initials: H
authors.lastname: Mykkänen
mesh_terms: D000111:Acetylcysteine / Q000652:urine*; D000975:Antioxidants / Q000008:administration & dosage; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D014676:Diet, Vegetarian; D004435:Eating; D005260:Female; D005737:Garlic; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010946:Plants, Medicinal; D012680:Sensitivity and Specificity
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D000111:Acetylcysteine