Isoflavone metabolites and their in vitro dual functions: They can act as an estrogenic agonist or antagonist depending on the estrogen concentration

Phytoestrogens could be a useful tool in swine husbandry practices because of their structural and functional similarities to estradiol. The goal of this study was to compare various routes and doses of administration of the phytoestrogen genistein in sows of two different physiological statuses. Circulating concentrations of isoflavones, estradiol and IGF-I were determined. In experiment 1, 65 sows were equally divided into the five following groups, between days 3 and 5 of the first or second estrous cycle post weaning: (1) controls (CTL); (2) 1 g of genistein fed daily (OR1); (3) 2 g of genistein fed daily (OR2); (4) two daily i.m. injections of 200 mg of genistein (IM400); and (5) two daily i.m. injections of 400 mg of genistein (IM800). Treatments were carried out for 10 days. In experiment 2, 10 sows were equally divided into two groups on day 90 of gestation, namely, controls (CTL) or 2 g of genistein fed daily for 10 days (OR2). In both trials, jugular blood samples were collected on days 1 (before treatment), 5 and 10 at 0730 h. In experiment 1, a blood sample was also collected at 1730 h on day 10 for CTL, IM400 and IM800 sows. In experiment 1, circulating concentrations of genistein on days 5 and 10 were greater in OR2, IM400 and IM800 than in CTL and OR1 group sows (P < 0.01). Daily dietary supplementation with 2 g of genistein resulted in blood concentrations that were similar to those in animals given daily two i.m. injections of 200 mg. Values of all isoflavones, except equol, which was not detectable, were greater in PM than in AM on day 10 (P < 0.01). In experiment 2, genistein concentrations were greater in OR2 compared with CTL on days 5 and 10 (P ⩽ 0.05). There was no difference in the genistein response to OR2 because of physiological status (i.e. weaned v. gestating, P > 0.1). Estradiol and IGF-I concentrations were not altered by any of the treatments (P > 0.1). Providing genistein either per os or via i.m. injections increased circulating concentrations of genistein in female swine within 5 days of the onset of treatment. The genistein response to i.m. injections of genistein was similar in weaned and late-pregnant sows, even though endogenous concentrations of estradiol differed. This response was specific in that estradiol, IGF-I and isoflavones other than genistein were not affected by treatments.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of dose and route of administration of genistein on isoflavone concentrations in post-weaned and gestating sows

Farmer

Robertson

Gilani

2013

“…Phytoestrogens have gained increasing interest in recent years because of their potential health benefits in prevention of mammary cancer (review by Warri et al, 2008) and other benefits such as alleviation of bone loss in postmenopausal women -E-mail:Chantal.Farmer@agr.gc.ca (review by Lister et al, 2007). These naturally occurring plant compounds with estrogenic or anti-estrogenic activities (depending on the concentration of endogenous estrogens present; Sun Hwang et al, 2006) comprise three major classes. They are isoflavones (comprising genistein), lignans and coumestans, and isoflavones are present in large amounts in soya, which is a major component of swine feed.…”

Section: Introductionmentioning

confidence: 99%

Dietary genistein stimulates mammary hyperplasia in gilts

Farmer

Palin

Gilani

et al. 2010

The possible role of the phytoestrogen genistein on prepubertal development of mammary glands, hormonal status and bone resorption was investigated in gilts. Forty-five gilts were fed a control diet containing soya (CTLS, n 5 15), a control diet without soya (CTL0, n 5 15) or the CTLS diet supplemented with 2.3 g of genistein daily (GEN, n 5 15) from 90 days of age until slaughter (day 183 6 1). Both basal diets were isonitrogenous and isocaloric. Jugular blood samples were obtained on days 89 and 176 to determine concentrations of isoflavone metabolites (on day 176 only), prolactin, estradiol, progesterone, insulin-like growth factor 1 (IGF1), and N-telopeptide of type I collagen (NTx; on day 176 only). At slaughter, mammary glands were excised, parenchymal and extraparenchymal tissues were dissected, and composition of parenchymal tissue (protein, fat, dry matter (DM), DNA) was determined. Histochemical analyses of mammary parenchyma were performed. Dietary genistein increased parenchymal protein (P , 0.05) while decreasing DM (P , 0.05) and tending to lower fat content compared with the CTLS, but not the CTL0, diet. There was more parenchymal DNA (1.26 v. 0.92 mg/g, P , 0.05) in GEN than CTLS gilts, likely reflecting an increase in the quantity of mammary epithelial cells. Circulating concentrations of genistein were increased in GEN gilts (P , 0.001) but concentrations of hormones or NTx (indicator of bone collagen resorption) were not affected by GEN (P . 0.1). Percentage of estradiol receptor alpha (ERa)-positive epithelial cells was lower (P , 0.05) in GEN than CTLS gilts, whereas 5-bromo-2 0 -deoxyuridine labeling index was unaltered (P . 0.1). Transcript levels for ERa, ERb, IGF1, epidermal growth factor (EGF), epidermal growth factor receptor and transforming growth factor alpha were not altered by treatments. Supplementation of the diet with genistein during the growing phase in gilts, therefore, led to hyperplasia of mammary parenchymal tissue after puberty; yet, even though circulating genistein was increased, this was not accompanied by changes in mammary expression of selected genes or circulating hormone levels.

“…anti-estrogenic bioactivity (Hwang et al, 2006), or through other non-estrogen receptor pathways, such as via adipogenic transcription factors, as has been suggested in rodents (Ørgaard and Jensen, 2008). With respect to the cholesterol metabolism, dietary supplementation with soy isoflavones in quail significantly reduced the levels of cholesterol in the liver and muscles (Yilmaz et al, 2008).…”

Section: Discussionmentioning

confidence: 95%

“…Cederroth et al (2007) reported that male CD-1 mice fed from conception to adulthood a high soy-containing diet significantly increased energy expenditure and decreased adiposity (Cederroth et al, 2007). Daidzein is a major isoflavonic phytoestrogen and has a variety of biological functions (Cassidy, 2003;Hwang et al, 2006). As a metabolite of daidzein, equol (Eq) possesses more biological activities than its precursor (Matthies et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

The effect of equol injection in ovo on lipid metabolism and hepatic lipogenic gene expression in broilers

Wei

Zhang

et al. 2012

This study investigated the effects of in ovo administration of equol (Eq) on post-hatch growth and hepatic lipid metabolism in broiler chickens. Fertilized eggs (146 eggs/group) were injected with 0 mg (control, Con), 20 mg (low dose, L) and 100 mg (high dose, H) Eq in the albumen on the 7th day of incubation. Except a trend increase in the weight of total fat (P 5 0.09), Eq had no effect on growth or liver weight in broilers at 49 days of age. Males presented higher liver and BWs and lower total fat and relative liver weights than females (P , 0.01). However, there were no significant effects of Eq or Eq-gender interactions on growth performance or tissues weight (P . 0.05). With respect to lipid parameters in the serum, the results showed that female broilers presented higher triacyglycerol (TG) and low-density lipoprotein cholesterol concentrations than males, whereas there was no gender difference in serum total cholesterol (TC) or high-density lipoprotein cholesterol (HDLC) concentration (P . 0.05). Eq administration significantly decreased serum TG and TC but increased HDLC concentrations in serum of broilers at 49 days of age (P , 0.05), whereas there were no interactions between gender and Eq (P . 0.05). To elucidate the mechanism behind the significant changes of serum TG and TC levels, the expression of genes involved in lipid metabolism in the liver was investigated in female chickens using reverse transcription-PCR. Carnitine palmitoyl transferase I (CPTI) messenger RNA (mRNA) was significantly upregulated by 20 and 100 mg Eq (P , 0.05). High-dose Eq significantly decreased fatty acid synthase (FAS) and enhanced cholesterol-7alpha-hydroxylase (CYP7A1) mRNA levels in the liver (P , 0.05). Eq had no significant effects on acetyl-CoA carboxylase, sterol regulatory element binding protein-1c, malic enzyme, low-density lipoprotein receptor or 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA in the liver (P . 0.05). These results in female broilers suggest that Eq decreased blood TG by upregulating CPTI and downregulating FAS mRNA expression in the liver, and that high serum cholesterol levels stimulated CYP7A1 gene transcription in the liver.