Search results for "Phytoestrogens"

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…

ERa dimerization: a key factor for the weak estrogenic activity of an ERa modulator unable to compete with estradiol in binding assays

2016

PMID: 27400858; International audience; AbstractEstrothiazine (ESTZ) is a weak estrogen sharing structural similarities with coumestrol. ESTZ failed to compete with [3H]17β-estradiol ([3H]17β-E2) for binding to the estrogen receptor α (ERα), questioning its ability to interact with the receptor. However, detection by atomic force spectroscopy (AFS) of an ESTZ-induced ERα dimerization has eliminated any remaining doubts. The effect of the compound on the proliferation of ERα-positive and negative breast cancer cells confirmed the requirement of the receptor. The efficiency of ESTZ in MCF-7 cells was weak without any potency to modify the proliferation profile of estradiol and coumestrol. Gro…

Dietary phytoestrogens improve stroke outcome after transient focal cerebral ischemia in rats.

2006

As phytoestrogens are postulated as being neuroprotectants, we assessed the hypothesis that dietary isoflavone-type phytoestrogens are neuroprotective against ischemic stroke. Transient focal cerebral ischemia (90 min) was induced by middle cerebral artery occlusion (MCAO) following the intraluminal thread technique, both in rats fed with soy-based diet and in rats fed with isoflavone-free diet. Cerebro-cortical laser-Doppler flow (cortical perfusion, CP), arterial blood pressure, core temperature, PaO2, PaCO2, pH and glycemia were measured before, during and after MCAO. Neurological examination and infarct volume measurements were carried out 3 days after the ischemic insult. Dietary isofl…

Phytoestrogens Up-regulate Antioxidant Genes

2009

Mitochondrial oxidant generation is involved in determining why females live longer than males

2006

Females live longer than males in many mammalian species, including humans. This natural phenomenon can be explained on the basis of the mitochondrial theory of aging. Mitochondria are a major source of free radicals in cells. Mitochondria from female rats generate half the amount of hydrogen peroxide than those of males and have higher levels of mitochondrial reduced glutathione. The latter is due to females behaving as double transgenic in over-expressing antioxidant enzymes. Estrogens bind to the estrogen receptors and subsequently activate the mitogen activated protein (MAP) kinase and nuclear factor kappa B (NFkappaB) signalling pathways, resulting in an upregulation of antioxidant enz…

Women Live Longer than Men: Understanding Molecular Mechanisms Offers Opportunities to Intervene by Using Estrogenic Compounds

2010

Abstract Women live longer than men. Moreover, females live longer than males in some, but not all, experimental animals. The differences in longevity between genders are related to free radical production. Indeed, females produce less radicals only in animal species in which they live longer than males. This is because estrogens upregulate antioxidant longevity-related genes. These considerations have led us to postulate an extended concept of antioxidant in biology: an antioxidant is any nutritional, physiological, or pharmacological manipulation that increases the expression and activity of antioxidant genes or proteins. Phytoestrogens or other selective estrogen receptor modulators lowe…

Nutritional prevention of cognitive decline and dementia.

2018

Cognitive impairment results from a complex interplay of many factors. The most important independent predictor of cognitive decline is age but other contributing factors include demographic, genetic, socio-economic, and environmental parameters, including nutrition. The number of persons with cognitive decline and dementia will increase in the next decades in parallel with aging of the world population. Effective pharmaceutical treatments for age-related cognitive decline are lacking, emphasizing the importance of prevention strategies. There is extensive evidence supporting a relationship between diet and cognitive functions. Thus, nutritional approaches to prevent or slow cognitive decli…

New findings on the bioactivity of lignans

2002

Abstract This chapter reviews the lignans with biological and pharmacological activity, and includes new natural products and some synthetic or semisynthetic compounds. Lignans are widespread in plants and in many cases are their effective principles. They play an important role as phytoestrogens in preventing menopausial symptoms, osteoporosis, cancer and heart diseases. Lignans possess anticancer and antiviral properties and specifically inhibit certain enzymes and mediators involved in inflammation and immunity processes. They affect the cardiovascular system by different mechanisms including the modification of phosphodiesterase activity and platelet activating factor function. Lignans …

Genistein effect on cognition in prodromal Alzheimer's disease patients : the GENIAL clinical trial

2022

Background: Delaying the transition from minimal cognitive impairment to Alzheimer’s dementia is a major concern in Alzheimer’s disease (AD) therapeutics. Pathological signs of AD occur years before the onset of clinical dementia. Thus, long-term therapeutic approaches, with safe, minimally invasive, and yet efective substances are recommended. There is a need to develop new drugs to delay Alzheimer’s dementia. We have taken a nutritional supplement approach with genistein, a chemically defned polyphenol that acts by multimodal specifc mechanisms. Our group previously showed that genistein supplementation is efective to treat the double transgenic (APP/PS1) AD animal model. Methods: In this…

Nonhormonal management of postmenopausal women: Effects of a red clover based isoflavones supplementation on climacteric syndrome and cardiovascular …

2013

The aim of this prospective randomized study was to evaluate a red clover based isoflavones supplementation in the treatment of climacteric syndrome and its effects on cardiovascular risk serum profile. Materials and Methods: The study included 150 healthy postmenopausal women that were randomly assigned to receive phytoestrogens tablets, amounting in a total daily intake of 60.8 mg red clover isoflavones plus 19.2 mg soy isoflavones (n = 75), or placebo (n = 75). The authors evaluated teh following: daily number of hot flushes and Kupperman Index at baseline and after one and three months; serum total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglyceri…