Paradoxical Effect of Nonalcoholic Red Wine Polyphenol Extract, Provinols™, in the Regulation of Cyclooxygenases in Vessels from Zucker Fatty Rats (fa/fa)

The aim of this work was to study the vascular effects of dietary supplementation of a nonalcoholic red wine polyphenol extract, Provinols, in Zucker fatty (ZF) obese rats. ZF or lean rats received diet supplemented or not with Provinols for 8 weeks. Vasoconstriction in response to phenylephrine (Phe) was then assessed in small mesenteric arteries (SMA) and the aorta with emphasis on the contribution of cyclooxygenases (COX). Although no difference in vasoconstriction was observed between ZF and lean rats both in SMA and the aorta, Provinols affected the contribution of COX-derived vasoconstrictor agents. The nonselective COX inhibitor, indomethacin, reduced vasoconstriction in vessels from both groups; however, lower efficacy was observed in Provinols-treated rats. This was associated with a reduction in thromboxane-A2 and 8-isoprostane release. The selective COX-2 inhibitor, NS398, reduced to the same extent vasoconstriction in aortas from ZF and Provinols-treated ZF rats. However, NS398 reduced response to Phe only in SMA from ZF rats. This was associated with a reduction in 8-isoprostane and prostaglandin-E release. Paradoxically, Provinols decreased COX-2 expression in the aorta, while it increased its expression in SMA. We provide here evidence of a subtle and paradoxical regulation of COX pathway by Provinols vessels from obese rats to maintain vascular tone within a physiological range

Red wine polyphenols prevent metabolic and cardiovascular alterations associated with obesity in Zucker fatty rats (Fa/Fa)

Peer reviewedPublisher PD

Interaction in endothelium of non-muscular myosin light-chain kinase and the NF-κB pathway is critical to lipopolysaccharide-induced vascular hyporeactivity

During sepsis, endothelial barrier dysfunction contributes to cardiovascular failure, mainly through the release of oxidative metabolites by penetrant leukocytes. We reported the non-muscular isoform of myosin light chain kinase (nmMLCK) playing a pivotal role in endotoxin shock injury associated with oxidative and nitrative stresses, and vascular hyporeactivity. The present study was aimed at understanding the molecular mechanism of lipopolysaccharide (LPS)-induced vascular alterations as well as studying a probable functional association of nmMLCK with nuclear factor κ-light-chain enhancer of activated B cells (NF-κB). Aortic rings from mice were exposed in vitro to LPS and, then, vascular reactivity was measured. Human aortic endothelial cells (HAoECs) were incubated with LPS, and interaction of nmMLCK with NF-κB was analysed. We provide evidence that nmMLCK deletion prevents vascular hyporeactivity induced by in vitro LPS treatment but not endothelial dysfunction in the aorta. Deletion of nmMLCK inhibits LPS-induced NF-κB activation and increases nitric oxide (NO) release via induction of inducible NO synthase (iNOS) within the vascular wall. Also, removal of endothelium prevented both NF-κB and iNOS expression in aortic rings. Among the proinflammatory factors released by LPS-treated endothelial cells, interleukin-6 accounts for the induction of iNOS on smooth muscle cells in response to LPS. Of particular interest is the demonstration that, in HAoECs, LPS-induced NF-κB activation occurs via increased MLCK activity sensitive to the MLCK inhibitor, ML-7, and physical interactions between nmMLCK and NF-κB. We report for the first time on NF-κB as a novel partner of nmMLCK within endothelial cells. The present study demonstrates a pivotal role of nmMLCK in vascular inflammatory pathologies

Provinols™ improve cardiac function in ZF rats.

<p>Echocardiography measurements of diastolic left ventricular dimension (LVDd), systolic left ventricular dimension (LVDs), cardiac output and fraction of ejection (A–D). Systolic blood pressure was evaluated using tail-cuff technique (E). Total arterial peripheral resistances were calculated from blood pressure and cardiac output (F). Values are means±SEM (<i>n</i> = 6). *<i>P</i><0.05 Zucker fatty (ZF) rats <i>vs.</i> lean rats; #<i>P</i><0.05 ZF+Provinols™ rats <i>vs.</i> ZF rats.</p

Provinols™ improve endothelial function in ZF rats.

<p>Acetylcholine (Ach)-induced relaxation in rat aorta (A), small mesenteric arteries (SMA) (B), SMA in the presence of inhibitors of EDHF and COX components (C) (apamine, APA; charybdotoxin, CTX; indomethacin, INDO), SMA in the presence of inhibitors of NO and COX components (D) (INDO, L-NAME). Results are expressed as a percentage of relaxation. Values are means±SEM (<i>n</i> = 6). *<i>P</i><0.05, ***<i>P</i><0.001 Zucker fatty (ZF) rats <i>vs.</i> lean rats; #<i>P</i><0.05, ###<i>P</i><0.001 ZF+Provinols™ rats <i>vs.</i> ZF rats.</p

Provinols™ improve metabolic parameters in ZF rats.

<p>Circulating levels of glucose (A), fructosamine (B), total cholesterol (C), ratio between LDL- and HDL-cholesterol (D), triglygerides (E), creatinin (F) and uric acid (G) were evaluated in fasting plasma of rats. Values are means±SEM (<i>n</i> = 11–12). *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 Zucker fatty (ZF) rats <i>vs.</i> lean rats; #<i>P</i><0.05, ###<i>P</i><0.001 ZF+Provinols™ rats <i>vs.</i> ZF rats.</p

Provinols™ increase NO vascular release in vessels from ZF rats.

<p>NO production in aorta (A), carotid arteries (B) and small mesenteric arteries (C) from Zucker fatty (ZF) and ZF+Provinols™ rats. Values are expressed as units of amplitude (A)/mg weight of dried tissue (dw). Western blots revealing expression of eNOS (D), phosphorylation of eNOS at Thr495 (E), and NOS Ser1177 (F) and expression of caveolin-1 (G) in aorta expressed as arbitrary units (A.U.). (<i>n</i> = 6). *<i>P</i><0.05, **<i>P</i><0.01 <i>vs.</i> ZF rats.</p

Provinols™ reduce O₂⁻ vascular release in vessels from ZF rats.

<p>O₂⁻ production in aorta (A), carotid arteries (B) and small mesenteric arteries (C) from Zucker fatty (ZF) and ZF+Provinols™ rats. Values are expressed as units of amplitude (A)/mg weight of dried tissue (dw). Western blots revealing expression of Nox-1 (D), Nox-2 (E), Nox-4 (F), Mn-SOD (G), Cu/Zn-SOD (H) and Ec-SOD (I) in aorta expressed as arbitrary units (A.U.). (<i>n</i> = 6). *<i>P</i><0.05, **<i>P</i><0.01 <i>vs.</i> ZF rats.</p