Phytoestrogens Act as Estrogen Agonists in an Estrogen-Responsive Pituitary Cell Line

Stahl, Sarah T.; Chun, Tae-Yon; Gray, Wesley

doi:10.1006/taap.1998.8500

Cited by 121 publications

(71 citation statements)

References 33 publications

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“…Because ISF act as antioxidant (Jiang et al, 2007), it is possible that the higher dosages of ISF could prevent from the initial increase in reactive oxidant species necessary to stimulate lymphocytes; whereby diminish lymphocytes' responses. On the other hand, it has been shown that genistein is an inhibitor of protein tyrosine kinases at high concentrations, while acting as an estrogenic compound at low levels (Stahl et al, 1998). Trevillyan et al (1990) showed that genistein, a selective protein tyrosine kinase inhibitor, blocked the activity of p56lck in a concentration-dependent manner.…”

Section: Discussionmentioning

confidence: 99%

Improved performance and immunological responses as the result of dietary genistein supplementation of broiler chicks

Rasouli

Jahanian

2015

Animal

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The present study aimed to investigate the effect of supplemental genistein (an isoflavonoid) on performance, lymphoid organs' development, and cellular and humoral immune responses in broiler chicks. A total of 675-day-old male broiler chicks (Ross 308) were randomly assigned to the five replicate pens (15 chicks each) of nine experimental diets. Dietary treatments included a negative (not-supplemented) control diet, two positive control groups (virginiamycin or zinc-bacitracin, 20 mg/kg), and diets containing 10, 20, 40, 80, 160 and 320 mg/kg of genistein. The cutaneous basophil hypersensivity (CBH) test was measured at day 10 of age after toe web injection with phytohemagglutinin-P. In addition, sera samples were collected after different antigen inoculations to investigate antibody responses. At day 28 of age, three randomly selected birds from each pen were euthanized to evaluate the relative weights of lymphoid organs. Results showed that dietary supplementation of both antibiotics increased ( P < 0.01) feed intake during 1 to 42 days of age. Furthermore, daily weight gain was influenced ( P < 0.01) by dietary treatments throughout the trial, so that the birds fed on antibiotics and 20 to 80 mg/kg genistein diets revealed the greater weight gains compared with other experimental groups. The best ( P < 0.05) feed conversion ratio assigned to the birds fed on diets containing antibiotics and moderate levels (40 to 80 mg/kg) of genistein. Although the relative weights of thymus ( P < 0.05) and bursa of Fabricius ( P < 0.01) were greater in birds fed on genistein-supplemented diets compared with antibiotics-supplemented birds, the spleen weight was not affected by experimental diets. Similarly, CBH response and antibody titers against Newcastle and infectious bronchitis disease viruses were markedly ( P < 0.05) greater in chicks fed on diets supplemented with 20 to 80 mg/kg of genistein. Interestingly, the higher dosages of genistein suppressed CBH and antibody responses to the levels seen by control and antibiotics chicks. Dietary inclusion of genistein increased ( P < 0.05) lymphocytes and subsequently reduced ( P < 0.01) heterophil to lymphocyte ratio. The present findings indicate that dietary genistein supplementation at the levels of 20 to 80 mg/kg not only improves growth performance, but also could beneficially affect immunological responses in broiler chicks.Keywords: broiler chicks, genistein, humoral immunity, isoflavonoids, leukocyte subpopulations ImplicationsComparative effects of two antibiotics (virginiamycin or zincbacitracin) and supplemental genistein were assessed in broiler chicks. Results showed that the birds fed on diets containing antibiotics and 20 to 80 mg/kg of genistein had the greater weight gains. Dietary genistein supplementation increased the relative weights of thymus and bursa of Fabricius. In addition, antibody responses against viral antigens were greater in genistein-supplemented chicks compared with those on antibiotics diets. Dietary inclusion of genistein increased lymp...

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Section: Discussionmentioning

confidence: 99%

Improved performance and immunological responses as the result of dietary genistein supplementation of broiler chicks

Rasouli

Jahanian

2015

Animal

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“…As matter of fact, some reports suggest that resveratrol has estrogenic activity, while others show antiestrogenic effects. 12,13,[43][44][45][46][47][48][49] The first report on this theme has been published in 1997. Gehm et al reported that resveratrol hampered the binding of estradiol to the ER and activated transcription of estrogen-responsive reporter genes transfected into human breast cancer cells.…”

Section: © 2 0 0 7 L a N D E S B I O S C I E N C E D O N O T D I S mentioning

confidence: 99%

Resveratrol: From Basic Science to the Clinic

Cucciolla¹,

Borriello²,

Oliva³

et al. 2007

Cell Cycle

162

102

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Plants produce an extraordinary array of low molecular mass natural products endowed with biological activity. Among these molecules, resveratrol (3,5,4'-trihydroxystilbene) has been identified as an inhibitor of carcinogenesis with a pleiotropic mode of action. Extensive literature on its anticancer activity, performed in cellular models, suggests a potential antiproliferative and apoptogenic use of the stilbene. Similarly, studies on implanted cancers and chemical-induced tumors confirm a potential chemotherapeutical interest of the compound. Moreover, recent intriguing studies have demonstrated, in mice, that the negative effects (insulin resistance and hyperglycemia) of a high-fat diet might be prevented by resveratrol treatment. Despite these promising observations, only few clinical trials have been performed on the compound due to the scarce interest of pharmaceutical industry. We suggest that resveratrol might be considered an interesting anticancer compound in association with more specific target-oriented drugs.

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“…This is supported by the observation that certain phytoestrogens, such as genistein, coumestrol, or zearalenol, are able to bind to the estrogen receptors and modulate a variety of estrogendependent processes (Stahl et al, 1998). Furthermore it has been suggested that ␣-zearalenol shows interesting bioactivity in preventing bone loss in a wellrecognized model of postmenopausal osteoporosis in the rat (Draper et al, 1997).…”

Section: Discussionmentioning

confidence: 91%

The Phytoestrogen α-Zearalenol Reverses Endothelial Dysfunction Induced by Oophorectomy in Rats

Altavilla

Saitta

Galeano

et al. 2001

Laboratory Investigation

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SUMMARY:It has been shown recently that ␣-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). Shamoperated animals (sham OVX rats) were used as controls. Three weeks after surgery, animals were randomized to the following treatments: ␣-zearalenol (1 mg/kg/day, im, for 4 weeks), 17␤-estradiol (20 g/kg/day, im, for 4 weeks), or their vehicle (100 l, im, of cottonseed oil). Two other groups of rats were treated with ␣-zearalenol or 17␤-estradiol plus the pure estrogen receptor antagonist ICI 182780 (2.5 mg/kg/day, im, for 4 weeks). Mean arterial blood pressure (MAP), heart rate (HR), total plasma cholesterol, plasma estradiol, and plasma ␣-zearalenol were studied. We also investigated endothelial-dependent (acetylcholine, 10 nM to 10 M) 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 M)-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 Ϯ 0.5 pg/ml; sham OVX, 35 Ϯ 6 pg/ml), impaired endothelial-dependent relaxation and blunted L-NMA-induced contraction (L-NMA 100 M: sham OVX, 2.7 Ϯ 0.3 g/mg tissue; OVX, 1.3 Ϯ 0.1 g/mg tissue). Moreover OVX rats showed a reduced calcium-dependent NO synthase (cNOS) activity. Treatment with ␣-zearalenol or with 17␤-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 ␣-zearalenol improves endothelial-dependent relaxation in OVX rats through an estrogen receptor-mediated effect. (Lab Invest 2001, 81:125-132).

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Phytoestrogens Act as Estrogen Agonists in an Estrogen-Responsive Pituitary Cell Line

Cited by 121 publications

References 33 publications

Improved performance and immunological responses as the result of dietary genistein supplementation of broiler chicks

Improved performance and immunological responses as the result of dietary genistein supplementation of broiler chicks

Resveratrol: From Basic Science to the Clinic

The Phytoestrogen α-Zearalenol Reverses Endothelial Dysfunction Induced by Oophorectomy in Rats

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