Browsing by Subject "Genistein"

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    Flavonoids inhibit platelet function through binding to the thromboxane A2 receptor
    (Elsevier, 2005) Lozano Almela, María Luisa; Castillo, J.; Benavente-García, O.; Vicente, Vincente; Rivera Pozo, José; Guerrero López, José Antonio; Medicina Interna; Facultad de Medicina
    Background: Dietary flavonoids are known for their antiplatelet activity resulting in cardiovascular protection, although the specific mechanisms by which this inhibition occurs has not been fully established. Objective: The aim of this study was to Investigate the interaction of nine flavonoids representative of various chemical classes, with platelet responses dependent on thromboxane A2 (TxA2) generation and on receptor antagonism, and to analyze the structural requirements for such effects. Methods: The effect of several types of flavonoids on platelet aggregation, serotonin release, andTxA2generationwasinvestigated. Competitive radioligand binding assays were used to screen for affinity of these compounds to TxA2 receptors. Results: Flavones (apigeninand luteolin) and isoflavones (genistein) abrogated arachidonic acid and collagen-induced platelet responses, such as aggregation and secretion, with a less substantial effect on TxA2 synthesis. These compounds were identified as specific ligands of the TxA2 receptor in the lmol L)1 range, this effect accounting for antiplatelet effects related to stimulation with those agonists. Tight binding of flavonoids to the human TxA2 receptor relies on structural features such as the presence of the double bond in C2–C3, and a keto group in C4. Conclusions: The inhibition by specific flavonoids of in vitro platelet responses induced by collagen or arachidonic acid seems to be related, to a great extent, to their ability to compete for binding to the TxA2receptor. Therefore, antagonism of this TxA2 receptor may represent an additional mechanism for the inhibitory effect of these compounds in platelet function.
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    Genistein attenuates monocrotaline-induced pulmonary arterial hypertension in rats by activating PI3K/Akt/eNOS signaling
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Zheng, Zeqi; Yu, Songping; Zhang, Wan; Peng, Yongchao; Pu, Mingyu; Kang, Ting; Zeng, Junyi; Yu, Yuefei; Li, Guorong
    Introduction: Phytoestrogen genistein may be useful to treat pulmonary arterial hypertension (PAH). However, its mechanism is still not clear. The aim of the present study was to confirm the therapeutic effects of phytoestrogen genistein on PAH in monocrotalineinduced rat model and to explore its mechanism. Materials and Methods: Sprague-Dawley male rats were randomly divided into 4 groups: control group (n=8), PAH group (n=8), genistein treament group with three different doses (n=8 in each dose group) and group of PI3K inhibitor LY294002. The rat model of PAH was induced by monocrotaline (MCT). The situation of survival of rats was observed. Pathological studies of lung and heart tissues were performed. Western-blot detection of P-Akt and P-eNOS expression levels in lung tissue was carried out. Nitrate reductase analysis was used to measure nitric oxide (NO) in lung tissue. Results: Genistein treatment resulted in significant improvement in the speed of tricuspid regurgitation, diameter of pulmonary artery, mean pulmonary artery pressure and right ventricular hypertrophy index. Genistein treatment also resulted in significant improvement in the stenosis of pulmonary artery, proliferation of smooth muscle, right ventricular hypertrophy and myocardial hypertrophy. These therapeutic effects were more obvious with increasing dose of genistein. After genistein treatment, amelioration
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    Genistein stimulates the hypothalamo-pituitary-adrenal axis in adult rats: morphological and hormonal study
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2012) Trifunović, Svetlana L.; Manojlović-Stojanoski, Milica; Ajdžanović, Vladimir Z.; Nestorović, Nataša; Ristić, Nataša; Medigović, Ivana; Milošević, Verica Lj.
    Genistein, the soy isoflavone structurally similar to estradiol, is widely consumed for putative beneficial health effects. However, there is a lack of data about the genisteins’ effects in adult males, especially its effects on the hipothalamo-pituitary-adrenal (HPA) axis. Therefore, the present study was carried out to investigate the effects of genistein on the HPA axis in orchidectomized adult rats, and to create a parallel with those of estradiol. Changes in the hypothalamic corticotrophin-releasing hormone (CRH) neurons and pituitary corticotrophs (ACTH cells) were evaluated stereologically, while corticosterone and ACTH levels were determined biochemically. Orchidectomy (Orx) provoked the enlargement (p<0.05) of: hypothalamic paraventricular nucleus volume (60%), percentage of CRH neurons (23%), percentage of activated CRH neurons (45%); pituitary weight (15%) and ACTH level (57%). In comparison with Orx, estradiol treatment provoked the enlargement (p<0.05) of: percentage of CRH neurons (28%), percentage of activated CRH neurons (2.7-fold), pituitary weight (131%) and volume (82%), ACTH level (69%), the serum (103%) and adrenal tissue (4.8 fold) level of corticosterone. Clearly, Orx has induced the increase in HPA axis activity, which even augments after estradiol treatment. Also, compared to Orx, genistein treatment provoked the enhancement (p<0.05) of: percentage of activated CRH neurons (2.3-fold), pituitary weight (28%) and volume (21%), total number of ACTH cells (22%) ACTH level (45%), the serum (2.6-fold) and adrenal tissue (2.8 fold) level of corticosterone. It can be concluded that an identical tendency, concerning the HPA axis parameters, follows estradiol and genistein administration to the orchidectomized adult rats