Search results for "genistein"
showing 10 items of 61 documents
Estrogenic effects of food wrap packaging xenoestrogens and flavonoids in female Wistar rats : a comparative study
2003
International audience; The objective of this study was to compare the estrogenicity of xenoestrogens found in food wrap packaging and phytoestrogen flavonoids. Uterotrophic and vaginal cornification assays were performed on immature and ovariectomized rats. Genistein, bisphenol F, and octylphenol were identified as estrogenic only in immature rats. Using vaginal cornification as a more specific estrogenic parameter, all tested compounds except tangeretin were active in immature rats. While apigenin and kaempferol appeared to have low estrogenic activity, they potentialized the uterotrophic effect of 17β-estradiol in immature rats. These data showed that (i) phytoestrogens like genistein ca…
Isoflavonoid-based bone-sparing treatments exert a low activity on reproductive organs and on hepatic metabolism of estradiol in ovariectomized rats
2007
International audience; The use of soy isoflavones is a potential alternative to hormone replacement therapy in post-menopausal bone-loss prevention. Nevertheless, phytoestrogens can target other organs and may disrupt cell proliferation, or could modify endogenous steroid hormone metabolism. These mechanisms could be linked to an increased risk of developing cancer. We therefore studied the possible side effects of such treatments in an experimental model of menopause. Forty adult female Wistar rats were ovariectomized and fed with a genistein-, daidzein- or equol-supplemented diet at bone-sparing levels (10 mg/kg BW/day) for 3 months. The estrogenic effects were assessed by histological a…
Molecular analysis on the chemopreventive properties of resveratrol, a plant polyphenol microcomponent.
2002
As a plant microcomponent, resveratrol is a polyphenolic compound produced by several species and found especially in Polygonum roots, peanuts seeds, berries and also grape and therefore can be present in human diet or beverages (red wine, for instance). Traditional chinese medicine and more recent epidemiological studies strongly suggested that resveratrol may act as a cancer chemopreventive compound. The biochemical mechanism by which resveratrol inhibits cell proliferation was provided by studies in numerous human cell lines including our work in hepatoblastoma HepG2 and colorectal tumor SW480 cells. The results show that resveratrol strongly inhibits cell proliferation at the micromolar…
Signal transduction pathways involved in the mechanical responses to protease-activated receptors in rat colon.
2002
Recording simultaneously in vitro the changes of endoluminal pressure (index of circular muscle activity) and isometric tension (index of longitudinal muscle activity), we examined the mechanisms responsible for the apamin-sensitive relaxant and contractile responses induced by protease-activated receptor (PAR)-1 and PAR-2 activating peptides, SFLLRN-NH2 and SLIGRL-NH2, respectively, in rat colon. In the circular muscle, the inhibitory effects of SFLLRN-NH2 and SLIGRL-NH2 were significantly reduced by ryanodine, an inhibitor of Ca2+ release from the sarcoplasmic reticulum, but unaffected by 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U73122), a phosph…
Oestradiol or genistein rescues neurons from amyloid beta-induced cell death by inhibiting activation of p38.
2007
Oestrogenic compounds have been postulated as neuroprotective agents. This prompted us to investigate their mechanism action in neurons in primary culture. Cells were pretreated with physiological concentrations of 17-beta estradiol (0.2 nm) or with nutritionally relevant concentrations of genistein (0.5 microm), and 48 h later treated with 5 microm of amyloid beta (Abeta) for 24 h. We found that Abeta increased oxidative stress, measured as peroxide levels or oxidized glutathione/reduced glutathione ratio, which in turn, caused phosphorylation of p38 MAP kinase. Amyloid beta subsequently induced neuronal death. Inhibiting the MAP kinase pathway prevented cell death, confirming the role of …
Modulation of longevity-associated genes by estrogens or phytoestrogens.
2008
Abstract Females live longer than males. We have shown that the higher levels of estrogens in females protect them against aging, by up-regulating the expression of antioxidant, longevity-related genes, such as that of selenium-dependent glutathione peroxidase (GPx) and Mn-superoxide dismutase (Mn-SOD). Both estradiol and genistein (the most abundant phytoestrogen in soybeans) share chemical properties which confer antioxidant features to these compounds. However, the low concentration of estrogens and phytoestrogens make it unlikely that they exhibit significant antioxidant capacity in the organism. Physiological concentrations of estrogens and nutritionally relevant concentrations of geni…
Garcinoic acid prevents β-amyloid (Aβ) deposition in the mouse brain
2020
Garcinoic acid (GA or δ-T3-13'COOH), is a natural vitamin E metabolite that has preliminarily been identified as a modulator of nuclear receptors involved in β-amyloid (Aβ) metabolism and progression of Alzheimer's disease (AD). In this study, we investigated GA's effects on Aβ oligomer formation and deposition. Specifically, we compared them with those of other vitamin E analogs and the soy isoflavone genistein, a natural agonist of peroxisome proliferator–activated receptor γ (PPARγ) that has therapeutic potential for managing AD. GA significantly reduced Aβ aggregation and accumulation in mouse cortical astrocytes. Similarly to genistein, GA up-regulated PPARγ expression and apolipoprote…
Direct antioxidant and protective effect of estradiol on isolated mitochondria
2009
AbstractEstrogens have antioxidant properties which are due to their ability to bind to estrogen receptors and to up-regulate the expression of antioxidant enzymes via intracellular signalling pathways. Mitochondria are key organelles in the development of age-associated cellular damage. Recently, estrogen receptors were identified in mitochondria. The aim of this paper was to test whether estradiol directly affects mitochondria by preventing oxidative stress and protecting frail mitochondria. Incubation with estradiol at normal intracellular concentrations prevents the formation of reactive oxygen species by mitochondria in a saturable manner. Moreover, estradiol protects mitochondrial int…
Dietary soy isoflavone induced increases in antioxidant and eNOS gene expression lead to improved endothelial function and reduced blood pressure in …
2005
Epidemiological evidence suggests that populations consuming large amounts of soy protein have a reduced incidence of coronary heart disease (1-5). The cardiovascular risks associated with conventional hormone replacement therapy in postmenopausal women (5-7) have precipitated a search for alternative estrogen receptor modulators. Here we report that long-term feeding of rats with a soy protein-rich (SP) diet during gestation and adult life results in decreased oxidative stress, improved endothelial function, and reduced blood pressure in vivo measured by radiotelemetry in aged male offspring. Improved vascular reactivity in animals fed an SP diet was paralleled by increased mitochondrial g…
Blocking signaling through the gp130 receptor chain by interleukin-6 and oncostatin M inhibits PC-3 cell growth and sensitizes the tumor cells to eto…
1999
BACKGROUND The mechanisms of drug resistance associated with advanced, hormone-independent prostate carcinoma are poorly understood. The human prostate carcinoma PC-3 cell line, derived from a metastatic tumor and lacking androgen receptors, represents a useful model to investigate drug resistance. METHODS The effects of oncostatin M (OM), antiinterleukin-6 (IL-6) treatment, or interference with the gp130-mediated signaling on etoposide- or cisplatin-mediated cytotoxicity were investigated. RESULTS Both endogenous and exogenous IL-6 and exogenous OM up-regulated cell growth and enhanced resistance of PC-3 tumor cells to both etoposide and cisplatin. The influence of IL-6 is controlled by tr…