title: Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian women.
abstract: Hop-derived food supplements and beers contain the prenylflavonoids xanthohumol (X), isoxanthohumol (IX) and the very potent phyto-oestrogen (plant-derived oestrogen mimic) 8-prenylnaringenin (8-PN). The weakly oestrogenic IX can be bioactivated via O-demethylation to 8-PN. Since IX usually predominates over 8-PN, human subjects may be exposed to increased doses of 8-PN. A dietary intervention trial with fifty healthy post-menopausal Caucasian women was undertaken. After a 4 d washout period, participants delivered faeces, blank urine and breath samples. Next, they started a 5 d treatment with hop-based supplements that were administered three times per d and on the last day, a 24 h urine sample was collected. A semi-quantitative FFQ was used to estimate fat, fibre, alcohol, caffeine and theobromine intakes. The recoveries of IX, 8-PN and X in the urine were low and considerable inter-individual variations were observed. A five-fold increase in the dosage of IX without change in 8-PN concentration resulted in a significant lower IX recovery and a higher 8-PN recovery. Classification of the subjects into poor (60%), moderate (25%) and strong (15%) 8-PN producers based on either urinary excretion or microbial bioactivation capacity gave comparable results. Recent antibiotic therapy seemed to affect the 8-PN production negatively. A positive trend between methane excretion and 8-PN production was observed. Strong 8-PN producers consumed less alcohol and had a higher theobromine intake. From this study we conclude that in vivo O-demethylation of IX increases the oestrogenic potency of hop-derived products.
authors.affiliation: Laboratory of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium.
authors.forename: Selin
authors.initials: S
authors.lastname: Bolca
authors.forename: Sam
authors.initials: S
authors.lastname: Possemiers
authors.forename: Veerle
authors.initials: V
authors.lastname: Maervoet
authors.forename: Inge
authors.initials: I
authors.lastname: Huybrechts
authors.forename: Arne
authors.initials: A
authors.lastname: Heyerick
authors.forename: Stefaan
authors.initials: S
authors.lastname: Vervarcke
authors.forename: Herman
authors.initials: H
authors.lastname: Depypere
authors.forename: Denis
authors.initials: D
authors.lastname: De Keukeleire
authors.forename: Marc
authors.initials: M
authors.lastname: Bracke
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
authors.forename: Willy
authors.initials: W
authors.lastname: Verstraete
authors.forename: Tom
authors.initials: T
authors.lastname: Van de Wiele
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004032:Diet; D019587:Dietary Supplements; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D044950:Flavanones / Q000096:biosynthesis* / Q000652:urine; D005419:Flavonoids; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D027582:Humulus; D008697:Methane / Q000096:biosynthesis; D008875:Middle Aged; D010641:Phenotype; D048789:Phytoestrogens / Q000378:metabolism; D017698:Postmenopause / Q000502:physiology*; D011427:Propiophenones / Q000652:urine; D044004:Xanthones / Q000652:urine
chemical_list: C119737:8-prenylnaringenin; D000900:Anti-Bacterial Agents; D044950:Flavanones; D005419:Flavonoids; D048789:Phytoestrogens; D011427:Propiophenones; D044004:Xanthones; C512910:isoxanthohumol; D008697:Methane; C104536:xanthohumol