The bioavailability of non-nutrient plant factors: dietary flavonoids and phyto-oestrogens

Wiseman, Helen

doi:10.1079/pns19990019

Cited by 118 publications

(69 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These transformation products can subsequently be absorbed from the colon, as it is established for soy isoflavones (39), to exert biological activity inside the body. While 8-PN was only one out of a large number of liver transformation products of IX (21), the human intestinal microbiota selectively converted IX into 8-PN with high conversion efficiencies (>35%).…”

Section: Discussionmentioning

confidence: 99%

Activation of Proestrogens from Hops (Humulus lupulus L.) by Intestinal Microbiota; Conversion of Isoxanthohumol into 8-Prenylnaringenin

Possemiers

Heyerick

Robbens

et al. 2005

J. Agric. Food Chem.

165

161

View full text Add to dashboard Cite

Hop, an essential ingredient in most beers, contains a number of prenylflavonoids, among which 8-prenylnaringenin (8-PN) would be the most potent phytoestrogen currently known. Although a number of health effects are attributed to these compounds, only a few reports are available about the bioavailability of prenylflavonoids and the transformation potency of the intestinal microbial community. To test these transformations, four fecal samples were incubated with xanthohumol, isoxanthohumol (IX), and 8-PN. Upon incubation with IX, present in strong ales up to 4 mg/L, 36% was converted into 8-PN in one fecal sample and the estrogenic properties of the sample drastically increased. In an experiment with 12 fecal cultures, this conversion was observed in one-third of the samples, indicating the importance of interindividual variability in the intestinal microbial community. Eubacterium limosum was identified to be capable of this conversion (O-demethylation) of IX into 8-PN, and after strain selection, a conversion efficiency of 90% was achieved. Finally, strain supplementation to a nonconverting fecal sample led to rapid and high 8-PN production at only 1% (v/v) addition. Up to now, the concentration of 8-PN in beer was considered too low to affect human health. However, these results show that the activity of the intestinal microbial community could more than 10-fold increase the exposure concentration. Because prenylflavonoids are present in many beers with IX being the major constituent, the results raise the question whether moderate beer consumption might contribute to increased in vivo levels of 8-PN and even influence human health.

show abstract

Section: Discussionmentioning

confidence: 99%

Activation of Proestrogens from Hops (Humulus lupulus L.) by Intestinal Microbiota; Conversion of Isoxanthohumol into 8-Prenylnaringenin

Possemiers

Heyerick

Robbens

et al. 2005

J. Agric. Food Chem.

165

161

View full text Add to dashboard Cite

show abstract

“…The incidence of endometrial hyperplasia, complex, or simple was not increased in the groups treated with isoflavones. Since isoflavones are known to possess both estrogenic and anti-estrogenic properties, 40) the result that only anti-estrogenic effects on endometrial carcinogenesis were found is considered to be related to the dose used in this study.…”

Section: Discussionmentioning

confidence: 99%

“…39) Free genistein or daidzein as well as the corresponding glucuronidated products are absorbed, and the compounds are excreted in free form or as metabolites. 39,40) In this study, genistein and daidzein were given subcutaneously, as has been done in a number of previous studies. 14,15,41) It is thought that such isoflavones administered s.c. can be directly absorbed into the blood.…”

Section: Discussionmentioning

confidence: 99%

Preventive Effects of Isoflavones, Genistein and Daidzein, on Estradiol‐17β‐related Endometrial Carcinogenesis in Mice

Zhou

Niwa

Tagami

et al. 2001

Japanese Journal of Cancer Research

View full text Add to dashboard Cite

The effects of isoflavones (genistein and daidzein) on endometrial carcinogenesis in mice were investigated in two experiments. In the short-term experiment (2 weeks), single subcutaneous (s.c.) administration of genistein [1 mg/30 g body weight (b.w.)] significantly decreased the levels of estradiol-17β β β β (E 2 ) (5 ppm in diet)-induced expression of c-jun, interleukin-1α α α α (IL-1α α α α) and tumor necrosis factor-α α α α (TNF-α α α α) mRNAs in the uteri of ovariectomized mice (P < < < <0.005, P < < < <0.05 and P < < < <0.01, respectively). Daidzein significantly inhibited E 2 -induced expression of c-fos and IL-1α α α α (P < < < <0.01, P < < < <0.01 respectively). In the long-term experiment (30 weeks), 140 female ICR mice were given N-methyl-N-nitrosourea-containing solution (1 mg/100 g b.w.) and normal saline (as controls) into their left and right uterine corpora, respectively. They were divided into six groups; group 1 was given E 2 (in diet) alone. Group 2 was given E 2 and genistein (1 mg/30 g b.w., s.c., every four weeks). Group 3 was exposed to E 2 and daidzein (1 mg/30 g b.w., s.c., every four weeks). Groups 4 and 5 respectively received genistein and daidzein, and were kept on the basal diet. Group 6 was kept on the basal diet and served as a control. At the termination of the experiment, incidences of endometrial adenocarcinoma and atypical endometrial hyperplasia of the group given E 2 and genistein or daidzein were significantly lower than of the group with E 2 alone (P < < < <0.01 and P < < < <0.05, respectively). It is suggested that both genistein and daidzein have an inhibitory effect on estrogen-related endometrial carcinogenesis in mice, possibly by suppressing expression of estrogen-induced estrogen-related genes c-fos and c-jun, and internal cytokines IL-1α α α α and TNF-α α α α through a cytokine and estrogen receptor-mediated pathway.

show abstract

“…No entanto, a absorção deste flavonóide é pequena. Genisteína e daidzeína têm efeitos antioxidantes menos eficazes que a quercetina in vitromas, como são melhores absorvidas, poderiam ser suficientemente biodisponíveis para agir in vivo (58). O efeito inibidor de formação de peroxidase poderia ter implicações na DCV, na tumorigênese e também em relação ao funcionamento da tireóide (43).…”

Section: Efeitos Em Doença Cardiovascular E Trombofiliaunclassified

Fitoestrogênios: posicionamento do Departamento de Endocrinologia Feminina da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM)

Clapauch

Meirelles

Julião

et al. 2002

Arq Bras Endocrinol Metab

View full text Add to dashboard Cite

Para avaliar a utilidade dos fitoestrogênios (FE) na terapia de reposição hormonal da menopausa (TRHM), o Departamento de Endocrinologia Feminina da SBEM reuniu um grupo de especialistas para fazer uma revisão bibliográfica e selecionar trabalhos nos quais a metodologia adotada demonstrasse rigor científico. Os FE têm ações estrogênicas e antiestrogênicas, predominantemente sobre os receptores de estrogênios (E) beta, com potência estrogênica muito inferior à do estradiol. O conteúdo de FE nas suas fontes vegetais é variável, dependendo da forma de cultivo, safra, armazenamento e industrialização. Também a conversão dos precursores em fitormônios ativos no organismo humano tem grande variabilidade individual. A maior parte das pesquisas com FE é realizada in vitro ou com animais de laboratório, nem sempre podendo ser extrapoladas para humanos. Com relação à síndrome do climatério, alguns estudos sugerem discreta melhora dos fogachos, sem modificação do ressecamento vaginal ou das alterações do humor. No metabolismo lipídico, alimentação rica em soja, mas não isoflavonas isoladamente, promove redução do colesterol total, do LDL-col e dos triglicerídeos, mas não elevam o HDL-col, como os E, e podem causar aumento da lipoproteína (a), que os E contribuem para diminuir. Embora alguns estudos de curta duração sugiram aumento da densidade mineral óssea com uso de isoflavonas, não há demonstração de redução de fraturas. Conclui-se que não há evidências convincentes que justifiquem o uso de FE ou alimentação rica em soja como alternativa para a TRHM.

show abstract

The bioavailability of non-nutrient plant factors: dietary flavonoids and phyto-oestrogens

Cited by 118 publications

References 48 publications

Activation of Proestrogens from Hops (Humulus lupulus L.) by Intestinal Microbiota; Conversion of Isoxanthohumol into 8-Prenylnaringenin

Activation of Proestrogens from Hops (Humulus lupulus L.) by Intestinal Microbiota; Conversion of Isoxanthohumol into 8-Prenylnaringenin

Preventive Effects of Isoflavones, Genistein and Daidzein, on Estradiol‐17β‐related Endometrial Carcinogenesis in Mice

Fitoestrogênios: posicionamento do Departamento de Endocrinologia Feminina da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM)

Contact Info

Product

Resources

About