phytoestrogens and zearalenol

Humans and animals are exposed to multiple substances in their food and feed that might have a negative health impact. Among these substances, the Fusarium mycoestrogen zearalenone (ZEN) and its metabolites α-zearalenol (α-ZEL) and α-zearalanol (α-ZAL) are known to possess endocrine disruptive properties. In a mixed diet or especially animal feed, these potential contaminants might be ingested together with naturally occurring phytoestrogens such as soy isoflavones. So far, risk assessment of potential endocrine disruptors is usually based on adverse effects of single compounds whereas studies investigating combinatorial effects are scarce. In the present study, we investigated the estrogenic potential of mycoestrogens and the isoflavones genistein (GEN), daidzein (DAI) and glycitein (GLY) as well as equol (EQ), the gut microbial metabolite of DAI, in vitro alone or in combination, using the alkaline phosphatase (ALP) assay in Ishikawa cells. In the case of mycoestrogens, the tested concentration range included 0.001 to 10 nM with multiplication steps of 10 in between, while for the isoflavones 1000 times higher concentrations were investigated. For the individual substances the following order of estrogenicity was obtained: α-ZEL > α-ZAL > ZEN > GEN > EQ > DAI > GLY. Most combinations of isoflavones with mycoestrogens enhanced the estrogenic response in the investigated concentrations. Especially lower concentrations of ZEN, α-ZEL and α-ZAL (0.001-0.01 nM) in combination with low concentrations of GEN, DAI and EQ (0.001-0.1 µM) strongly increased the estrogenic response compared to the single substances.

Topics: Alkaline Phosphatase; Animals; Endocrine Disruptors; Equol; Estrone; Genistein; Humans; Isoflavones; Phytoestrogens; Zearalenone; Zeranol

Our previous studies demonstrated both phytoestrogen α-zearalanol (α-ZAL) and estrogen is effective decrease Alzheimer's disease (AD)-like apoptotic neuron death, but α-ZAL showed significantly less side-effect on breast and endometrial tissue compared to estrogen, it suggested that α-ZAL can be used as a potential substitute for estrogen. However, the molecular mechanism by which α-ZAL prevents neuron damage remains unclear. Growing evidence suggests that endoplasmic reticulum (ER) stress plays an important role in the process of cell apoptosis in AD; in addition, our published data indicated that α-ZAL possessed the potential ability to stabilize ER function. We therefore hypothesized that ER-stress mechanism maybe involved in the antiapoptotic effect of α-ZAL in this study.. Primary rat hippocampal neurons have been cultured and subsequently followed exposed to β-peptide fragment 25-35(Aβ25-35) with or without α-ZAL pre-treatment, and then western blot and flow cytometry techniques has been used to evaluate the intracellular calcium balance, ER stress and apoptotic cell death.. The results showed that Aβ25-35 treatment for 24h induced dramatic neuronal apoptosis, accompanied by an increase in calpain2 expression, a marker of intracellular calcium overload. On the other hand, ER stress sensitive hallmarks, glucose-regulated protein 78 (GRP78), double-stranded RNA-dependent protein kinase (PKR)-like ER-resident kinase (PERK) and C/EBP homologous protein-10 (CHOP10) expressions were up-regulated after Aβ25-35 administration. Importantly, α-ZAL pre-treatment effectively attenuated above changes.. These results demonstrated that α-ZAL protects cells against AD-like apoptosis and the effects at least partially by attenuating severely ER stress.

Topics: Amyloid beta-Peptides; Animals; Apoptosis; Endoplasmic Reticulum Stress; Hippocampus; Neurons; Peptide Fragments; Phytoestrogens; Rats; Zeranol

Hyperhomocysteinemia is strongly associated with cardiovascular diseases. Previous studies have shown that phytoestrogen α-zearalanol can protect cardiovascular system from hyperhomocysteinemia and ameliorate the level of plasma total homocysteine; however, the underlying mechanisms remain to be clarified. The aim of this research is to investigate the possible molecular mechanisms involved in ameliorating the level of plasma homocysteine by α-zearalanol. By the successfully established diet-induced hyperhomocysteinemia rat models, we found that, after α-zearalanol treatment, the activity of cystathionine β-synthase, the key enzyme in homocysteine metabolism, was significantly elevated and level of nitrative stress in liver was significantly reduced. In correlation with this, results also showed a decreased nitration level of cystathionine β-synthase in liver. Together data implied that alleviation of plasma homocysteine level by phytoestrogen α-zearalanol might be related to the reduction of cystathionine β-synthase nitration.

Topics: Animals; Cystathionine beta-Synthase; Dose-Response Relationship, Drug; Down-Regulation; Enzyme Activation; Female; Homocysteine; Hyperhomocysteinemia; Liver; Nitrates; Oxidation-Reduction; Phytoestrogens; Rats; Rats, Wistar; Treatment Outcome; Tyrosine; Zeranol

The aim of this study was to evaluate the effect of a novel phytoestrogen, α-Zearalanol, on Alzheimer's disease-related memory impairment and neuronal oxidation in ovariectomized mice.. Female C57/BL6 mice were ovariectomized or received sham operations and treatment with equivalent doses of 17β-estradiol or α-Zearalanol for 8 weeks. Their spatial learning and memory were analyzed using the Morris water maze test. The antioxidant enzyme activities and reactive oxygen species generation, neuronal DNA oxidation, and MutT homolog 1 expression in the hippocampus were measured.. Treatment with 17β-estradiol or α-Zearalanol significantly improved spatial learning and memory performance in ovariectomized mice. In addition, 17β-estradiol and α-Zearalanol attenuated the decrease in antioxidant enzyme activities and increased reactive oxygen species production in ovariectomized mice. The findings indicated a significant elevation in hippocampi neuronal DNA oxidation and reduction in MutT homolog 1 expression in estrogen-deficient mice, but supplementation with 17β-estradiol or α-Zearalanol efficaciously ameliorated this situation.. These results demonstrate that α-Zearalanol is potentially beneficial for improving memory impairments and neuronal oxidation damage in a manner similar to that of 17β-estradiol. Therefore, the compound may be a potential therapeutic agent that can ameliorate neurodegenerative disorders related to estrogen deficiency.

Topics: Alzheimer Disease; Animals; Blotting, Western; DNA Damage; DNA Repair Enzymes; Estradiol; Female; Hippocampus; Immunohistochemistry; Memory Disorders; Mice; Mice, Inbred C57BL; Ovariectomy; Oxidative Stress; Phosphoric Monoester Hydrolases; Phytoestrogens; Reproducibility of Results; Time Factors; Treatment Outcome; Zeranol

The aim of this research is to investigate the vasorelaxing effects and mechanisms involved in the phytoestrogen alpha-zearalanol (alpha-ZAL) in rat thoracic aortas rings. Intact or endothelium denuded rat thoracic aortas rings were put in individual organ chamber to observe the endothelium-dependent or independent vasorelaxing effects of alpha-ZAL (10(-10)-10(-5) M). The thoracic aortas rings were pre-contracted with phenylephrine. The relaxing effects of alpha-ZAL were observed and the influence of N(omega)-nitro-L-arginine methylester (L-NAME, NOS inhibitor), methylene blue (MB, guanylate cyclase inhibitor), charybdotoxin (ChTX, Ca(2+)-activated K+ channel blocker), glibenclamide (ATP-sensitive K+ channel blocker), (-) BayK8644 (L-type Ca2+ channel agonist) and ICI182,780 (estrogen receptor antagonist) were pre-incubated with alpha-ZAL, respectively, to explore the possible mechanisms involved in this vasorelaxation. Furthermore, the Phospho-eNOS expression and cGMP level in the aortas tissue were detected by Western blot and radioimmunity, respectively; the NO level in perfusate was assaied by chromatometry. Our result showed that alpha-ZAL (10(-10)-10(-5) M) induced both endothelium-dependent and -independent relaxation of rat thoracic aortas rings. The vasorelaxing effects of alpha-ZAL were dose-dependent whether the endothelium was intact or not. In endothelium-intact aortas rings, alpha-ZAL-induced vasorelaxation might be inhibited by L-NAME, MB, charybdotoxin, glibenclamide and (-) BayK8644, but not ICI182,780. (-) BayK8644 could also inhibit alpha-ZAL-induced vasorelaxation in endothelium-denuded aortas rings.10(-7)-10(-5) M alpha-ZAL might induce the Phospho-eNOS expression in thoracic aorta tissue, increase the NO level in perfusate and cGMP content in thoracic aorta tissue. Meanwhile, L-NAME might decrease both NO and its downstream cGMP level. Methylene blue might decrease the level of cGMP. These results suggest that alpha-ZAL induces a partly endothelium-dependent relaxation of rat thoracic aortas rings; the possible mechanisms involved in this rapid vasorelaxation include activation of eNOS/NO/cGMP pathway, opening of VSMCs ATP-sensitive and Ca(2+)-activated K+ channels through secretion of EDHF from endothelium. Furthermore, this relaxation also appears to be mediated by both direct and indirect inhibition of voltage-dependent Ca2+ channel of VSMCs, while it is not concerned with activation of estrogen receptor.

Topics: 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; Animals; Aorta, Thoracic; Calcium Channel Blockers; Calcium Channels; Charybdotoxin; Cyclic GMP; Enzyme Inhibitors; Estradiol; Estrogen Antagonists; Female; Fulvestrant; In Vitro Techniques; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Phytoestrogens; Potassium Channel Blockers; Potassium Channels; Rats; Rats, Wistar; Receptors, Estrogen; Vasodilation; Zeranol

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).\ \ This article has been retracted at the request of the Editor-in-Chief.\ \ After an institutional investigation into the work of Dr. Jun Ren, University of Wyoming subsequently conducted an examination of other selected publications of Dr. Ren's under the direction of the HHS Office of Research Integrity. Based on the findings of this examination, the University of Wyoming recommended this article be retracted due to data irregularities in Figures 3 and 5 that significantly affect the results and conclusions reported in the manuscript.

Topics: Cells, Cultured; Endothelial Cells; Endothelin-1; Gene Expression Regulation; Homocysteine; Humans; Mitogen-Activated Protein Kinases; Oxidative Stress; Phytoestrogens; Reactive Oxygen Species; Signal Transduction; Transcription Factor AP-1; Transcriptional Activation; Umbilical Veins; Up-Regulation; Zeranol

Although experimental evidence has shown that the neuroprotective effect from estrogen may benefit postmenopausal women, but the clinical use of estrogen was limited by the risk of increasing the cases of mammary and endometrial cancer. This study was designed to evaluate the neuroprotective effects of a novel phytoestrogen alpha-zearalanol (alpha-ZAL), on the cultured rat hippocampal neurons. Following a 24-h exposure of the cells to amyloid beta-peptide fragment 25-35 (A beta 25-35), a significant reduction in cell survival and activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as increased of malondialdehyde (MDA) were observed. Preincubation of the cells with alpha-ZAL or 17 beta-estradiol(17 beta-E2) prior to A beta 25-35 exposure elevated the cell survival and SOD and GSH-Px activities, and decreased the level of MDA. These data suggested that the phytoestrogen alpha-ZAL, like estrogen, may effectively antagonize A beta 25-35-induced cell toxicity, which might be beneficial for neurons.

Topics: Amyloid beta-Peptides; Animals; Antioxidants; Cell Death; Cell Survival; Cells, Cultured; Estradiol; Estrogens; Glutathione Peroxidase; Hippocampus; Malondialdehyde; Neurodegenerative Diseases; Neurons; Oxidative Stress; Peptide Fragments; Phytoestrogens; Rats; Rats, Sprague-Dawley; Superoxide Dismutase; Zeranol

Although the issue of estrogen replacement therapy on cardiovascular health is debatable, it has presumable benefits for endothelial function in postmenopausal women. However, the fear of breast cancer has intimidated women contemplating estrogen treatment and limited its long-term application. An effective alternative remedy not associated with breast carcinoma is in serious demand. This study was designed to examine the effect of phytoestrogen alpha-zearalanol (alpha-ZAL) and 17beta-estradiol (E2) on nitric oxide (NO) and endothelin (ET)-1 levels, apoptosis, and apoptotic enzymes in human umbilical vein endothelial cells (HUVEC). HUVEC cells were challenged for 24 h with homocysteine (10-3 M), an independent risk factor for a variety of vascular diseases, in the presence of alpha-ZAL or E2 (10-9 to 10-6 M). Release of NO and ET-1 were measured with enzyme immunoassay. Apoptosis was evaluated by fluorescence-activated cell sorter analysis. Expression of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), Bax, and Bcl-2 were determined using Western blot. NOS activity was evaluated with 3H-arginine to 3H-citrulline conversion. Our results indicated that Hcy significantly reduced NO production, NOS activity, enhanced ET-1/NO ratio and apoptosis, upregulated iNOS, Bax, and downregulated eNOS, Bcl-2 expression. These effects were significantly attenuated by alpha-ZAL and E2. ZAL displayed a similar potency compared with E2 in antagonizing Hcy-induced effects. In summary, these results suggested that alpha-ZAL may effectively preserve Hcy-induced decrease in NO, increase in ET-1/NO ratio and apoptosis, which contributes to protective effects of phytoestrogens on endothelial function.

Topics: Apoptosis; Arginine; bcl-2-Associated X Protein; Blotting, Western; Cells, Cultured; Citrulline; Endothelin-1; Endothelium, Vascular; Estradiol; Female; Gene Expression Regulation; Homocysteine; Humans; Nitric Oxide; Nitric Oxide Synthase; Phytoestrogens; Umbilical Veins; Zeranol

Although neuroprotective effects of estrogen on postmenopausal women have been recognized, an associated increased incidence of uterine and breast tumors has jeopardized the clinical use of estrogen. This study was designed to evaluate the neuroprotective effects of a novel phytoestrogen alpha-zearalanol (alpha-ZAL), on ovariectomized (OVX) rats. Adult Wistar rats were ovariectomized or sham-operated and treatment with equivalent doses of 17beta-estradiol or alpha-ZAL for 5 wk. Uteruses have been weighted and stained by hematoxylin and eosin for morphology analysis. The expression of synaptophysin and parvalbumin in hippocampus were evaluated by immunohistochemistry assays. Our experiments indicated that the synaptophysin and parvalbumin-positive areas were significantly decreased in the OVX group compared to the sham group, alpha-ZAL or 17beta-estradiol administration can reverse the effects. Although alpha-ZAL and 17beta-estradiol treatments reconciled uterus weight loss which was induced by ovariectomy, the effect of alpha-ZAL was less than 17beta-estradiol. This result suggests that alpha-ZAL may effectively abate neurons loss in the hippocampus while slightly promoting weight gain of the uterus.

Topics: Animals; Estrogens; Female; Hippocampus; Humans; Neurons; Neuroprotective Agents; Organ Size; Ovariectomy; Parvalbumins; Phytoestrogens; Rats; Rats, Wistar; Synaptophysin; Uterus; Zeranol

To investigate the effect of alpha-zearalenol on angiotensin II-induced beta3 integrin mRNA expression in human umbilical vein endothelial cells (HUVECs).. The mRNA level in integrin beta3 was determined by reverse transcription-polymerase chain reaction. Endothelial NF-kappaB activity was determined by the luciferase activity assay of plasmid NF-kappaB-LUC.. The angiotensin II-induced beta3 integrin mRNA expression was inhibited by alpha-zearalenol and 17beta-estradiol (10 nmol/L -1 micromol/L), but not influenced by ICI 182, 780, a pure competitive antagonist for estrogen receptor or a nitric oxide inhibitor Nomega-Nitro-L-arginine methyl ester hydrochloride. Alpha-zearalenol and 17beta-estradiol suppressed the angiotensin II-induced activation of NF-kappaB in endothelial cells.. Alpha-zearalenol inhibits angiotensin II-induced integrin beta3 mRNA expression by suppressing NF-kappaB activation in endothelial cells.

Topics: Angiotensin II; Cells, Cultured; Endothelial Cells; Endothelium, Vascular; Estradiol; Female; Gene Expression Regulation; Humans; Integrin beta3; NF-kappa B; Nitric Oxide; Phytoestrogens; Receptors, Estrogen; RNA, Messenger; Zeranol

Estrogen replacement therapy (ERT) is one of the most challenging issues women and their physicians have to face. Clinical and epidemiological studies have provided conflicting data regarding the cardiovascular benefit versus risk in women using ERT. Although ERT may improve several risk factors of coronary heart disease such as favorable changes in lipid profile, an associated increased incidence of uterine and breast tumors has jeopardized the clinical use of ERT. We reported here that the phytoestrogen alpha-zearalanol is effective against atherosclerotic development without overt growth-promoting effects in the uterus compared to estrogen. These results suggest clinical potential of this phytoestrogen as a "safe estrogen" with less risk of tumorogenesis.

Topics: Arteriosclerosis; Estrogen Replacement Therapy; Female; Humans; Phytoestrogens; Zeranol

Although favorable effects of estrogen replacement therapy on atherosclerosis have been recognized, the benefit versus risk of estrogen replacement on overall cardio- vascular health remains controversial. The main adverse effect jeopardizing the clinical usage of estrogen is the increased risk of breast and endometrial cancer. Zearalenone (ZEN) is a universal endogenous hormone possessing estrogen-like effects and facilitating plant growth. alpha-Zearalanol (alpha-ZAL), a new phytoestrogen, is a reductive product of ZEN. Our preliminary evidence suggested that alpha-ZAL is anti-atherosclerotic. The aim of this study was to examine the effect of alpha-ZAL on atherosclerotic formation and serum lipid profile. Adult female nulliparous rabbits were ovariectomized or sham-operated and fed a high-cholesterol diet with different doses of alpha-ZAL or 17beta-estradiol for 12 wk. The aortic intimal atherosclerotic plaque was significantly larger in the cholesterol-fed group compared to control and sham groups. alpha-ZAL and 17beta-estradiol treatments significantly reduced plaque formation and improved serum profile of lipid (TC, TG, HDL-C, and LDL-C) and lipoprotein (ApoAl and ApoB). Both alpha-ZAL and 17beta-estradiol reconciled ovariectomy-induced uterine atrophy, although alpha-ZAL was significantly less potent than 17beta-estradiol in stimulating uterine growth. Our findings indicate that the phytoestrogen alpha-ZAL has an important anti-atherogenic property, analogous to that of estrogen.

Topics: Animals; Aorta; Apolipoprotein A-I; Apolipoproteins B; Arteriosclerosis; Cholesterol; Diet, Atherogenic; Estradiol; Estrogens; Female; Histocytochemistry; Lipids; Organ Size; Ovariectomy; Phytoestrogens; Rabbits; Triglycerides; Uterus; Zeranol

It has been shown recently that alpha-zearalenol, a resorcyclic acid lactone, prevents bone loss in a rat model of postmenopausal bone loss. We have therefore investigated the effects of this phytoestrogen on endothelial dysfunction induced by estrogen deficiency in rats. Female mature Sprague-Dawley rats underwent a bilateral oophorectomy (OVX rats). Sham-operated animals (sham OVX rats) were used as controls. Three weeks after surgery, animals were randomized to the following treatments: alpha-zearalenol (1 mg/kg/day, i.m., for 4 weeks), 17beta-estradiol (20 microg/kg/day, i.m., for 4 weeks), or their vehicle (100 microl, i.m., of cottonseed oil). Two other groups of rats were treated with alpha-zearalenol or 17beta-estradiol plus the pure estrogen receptor antagonist ICI 182780 (2.5 mg/kg/day, i.m., for 4 weeks). Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, and plasma alpha-zearalenol were studied. We also investigated endothelial-dependent (acetylcholine, 10 nM to 10 microM) and endothelial-independent (sodium nitroprusside, 15 nM to 30 nM) relaxation of aortic rings, as well as N(G)-methyl-L-arginine (L-NMA: 10 to 100 microM)-induced vasoconstriction and calcium-dependent nitric oxide synthase (cNOS) activity in homogenates of lungs taken from both sham OVX rats and OVX rats. Untreated OVX rats had, compared with sham OVX animals, unchanged body weight, MAP, HR, and plasma cholesterol. In contrast oophorectomy reduced plasma estradiol levels (OVX, 2 +/- 0.5 pg/ml; sham OVX, 35 +/- 6 pg/ml), impaired endothelial-dependent relaxation and blunted L-NMA-induced contraction (L-NMA 100 microM: sham OVX, 2.7 +/- 0.3 g/mg tissue; OVX, 1.3 +/- 0.1 g/mg tissue). Moreover OVX rats showed a reduced calcium-dependent NO synthase (cNOS) activity. Treatment with alpha-zearalenol or with 17beta-estradiol reverted the endothelial dysfunction and increased cNOS activity in lung homogenates. These effects were abolished by the pure estrogen receptor antagonist ICI 182780. Our data suggest that alpha-zearalenol improves endothelial-dependent relaxation in OVX rats through an estrogen receptor-mediated effect.

Topics: Acetylcholine; Animals; Aorta; Blood Pressure; Body Weight; Endothelium, Vascular; Estradiol; Estrogen Antagonists; Estrogens, Non-Steroidal; Female; Fulvestrant; Heart Rate; In Vitro Techniques; Isoflavones; Lung; Muscle Contraction; Muscle, Smooth, Vascular; Nitric Oxide Synthase; Nitric Oxide Synthase Type III; Nitroprusside; Organ Size; Ovariectomy; Phytoestrogens; Plant Preparations; Rats; Rats, Sprague-Dawley; Reference Values; Uterus; Zeranol