Chronic administration of genistein improves endothelial dysfunction in spontaneously hypertensive rats: involvement of eNOS, caveolin and calmodulin expression and NADPH oxidase activity.

The soya-derived phytoestrogen genistein has been suggested to be protective in cardiovascular diseases. In the present study, we have analysed whether chronic oral genistein might influence endothelial function in male SHRs (spontaneously hypertensive rats) via ERs (oestrogen receptors), changes in eNOS (endothelial NO synthase) activity and vascular O(2)(-) (superoxide) production. Rats (23-weeks old) were divided into the following groups: WKY (Wistar-Kyoto)-vehicle, SHR-vehicle, WKY-genistein (10 mg.

Endothelial nitric oxide production stimulated by the bioflavonoid chrysin in rat isolated aorta.

In the present study, the effects of the bioflavonoid chrysin (5,7-dihydroxyflavone) were analysed on nitric oxide (NO) production from vascular endothelium. In aortic rings, incubation with chrysin or acetylcholine (both at 10 microM) increased L-NAME-sensitive endothelial NO release as measured using the fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2 DA). Moreover, chrysin increased cGMP accumulation only in aortic rings with endothelium.

Soy isoflavones improve endothelial function in spontaneously hypertensive rats in an estrogen-independent manner: role of nitric-oxide synthase, superoxide, and cyclooxygenase metabolites.

The aim of this study was to analyze the effects of the isoflavones genistein and daidzein, and the mammalian estrogen 17beta-estradiol on endothelial function in isolated aortic rings from male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Relaxation to acetylcholine on precontracted rings was impaired and endothelium-dependent contraction to acetylcholine in aortic rings was increased in SHR compared with WKY. Aortic NADPH-stimulated O(2)(-) release and prostaglandin (PG)H(2) production evoked by acetylcholine were increased, whereas nitric-oxide synthase activity was reduced in SHR versus WKY.

Effects of chronic quercetin treatment in experimental renovascular hypertension.

The aims of the present study were to analyse the effects of an oral daily dose (10 mg/kg) of the dietary flavonoid quercetin for five weeks in two-kidney, one-clip (2K1C) Goldblatt (GB) hypertensive rats. The evolution of systolic blood pressure was followed by weekly measurements, and morphological variables, proteinuria, plasma nitrates plus nitrites (NOx) and thiobarbituric acid reactive substances (TBARS), liver oxidative stress markers and endothelial function were determined at the end of the experimental period. Quercetin treatment reduced systolic blood pressure of GB rats, producing no effect in control animals.

Effects of the dietary flavonoid chrysin in isolated rat mesenteric vascular bed.

In the present study, the effects of the bioflavonoid chrysin (5,7-dihydroxyflavone) were analyzed on the perfusion pressure of isolated mesenteric vascular bed. The vasorelaxant effects of chrysin were more potent on intact endothelium than on denuded vessels. This endothelium-dependent response induced by chrysin was inhibited in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME), KCl, tetraethylammonium (TEA), BaCl(2), TEA plus L-NAME, and ouabain plus BaCl(2), while incubations with indomethacin and glibenclamide did not modify the response induced by this bioflavonoid.

Effects of chronic quercetin treatment on antioxidant defence system and oxidative status of deoxycorticosterone acetate-salt-hypertensive rats.

We investigated the potential of chronic administration of an oral daily dose (10 mg/kg) of the dietary flavonoid quercetin to prevent hypertension and oxidative stress induced by deoxycorticosterone acetate (DOCA)-salt in rats. We have compared its effects to those produced by the well-known anti-hypertensive drug verapamil, administered orally (20 mg/kg/day). Quercetin and verapamil treatments reduced systolic blood pressure of DOCA-salt rats in approximately 67.

Effects of quercetin treatment on vascular function in deoxycorticosterone acetate-salt hypertensive rats. Comparative study with verapamil.

This study analysed and compared the effects of chronic oral treatment with quercetin or verapamil on systolic blood pressure and vascular function in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Quercetin and verapamil inhibited the development of DOCA-salt-induced hypertension in a similar manner. DOCA-salt-hypertensive rats showed potassium depletion and oxidative stress, prevented only by concomitant quercetin administration.

Effects of chronic chrysin treatment in spontaneously hypertensive rats.

The effects of an oral daily dose (20 mg kg(-1)) of the flavonoid chrysin for 6 weeks in spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rats (WKY) were analysed. Chrysin reduces SHR elevated blood pressure, cardiac hypertrophy and functional vascular changes, but is without effect in WKY. These protective effects were associated with a reduced oxidative status due to the antioxidant properties of the drug.