Differential effects of resveratrol on the dilator responses of femoral arteries, ex vivo

Sex, Endothelial Cell Functions, and Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD.

The Effect of a Single Bout of Resistance Exercise with Blood Flow Restriction on Arterial Stiffness in Older People with Slow Gait Speed: A Pilot Randomized Study

Purpose: Low-intensity resistance exercise with moderate blood-flow restriction (LIRE-BFR) is a new trending form of exercises worldwide. The purpose of this study was to compare the acute effect of a single bout of traditional resistance exercise (TRE) and LIRE-BFR on arterial stiffness in older people with slow gait speeds. Methods: This was a randomized, controlled clinical study. Seventeen older adults (3 men; 14 women; 82 ± 5 years old) completed a session of TRE (n = 7) or LIRE-BFR (n = 10). At baseline and after 60 min post-exercise, participants were subject to blood pressure measurement, heart rate measurements and a determination of arterial stiffness parameters. Results: There was no significant difference between the TRE and LIRE-BFR group at baseline. Pulse-wave velocity increased in both groups (p < 0.05) post-exercise with no between-group differences. Both exercise modalities did not produce any adverse events. The increase in systolic blood pressure, pulse pressure, augmentation pressure and pulse wave velocity (all p > 0.05) were similar after both TRE and LIRE-BFR. Conclusion: TRE and LIRE-BFR had similar responses regarding hemodynamic parameters and pulse-wave velocity in older people with slow gait speed. Long-term studies should assess the cardiovascular risk and safety of LIRE-BFR training in this population.

Nanostructured Lipid Carriers Deliver Resveratrol, Restoring Attenuated Dilation in Small Coronary Arteries, via the AMPK Pathway

Nanostructured lipid carriers (NLCs) are an emerging drug delivery platform for improved drug stability and the bioavailability of antihypertensive drugs and vasoprotective nutraceutical compounds, such as resveratrol (RV). The objective of this study was to ascertain NLCs’ potential to deliver RV and restore attenuated dilator function, using an ex vivo model of acute hypertension. Trimyristin–triolein NLCs were synthesized and loaded with RV. The uptake of RV-NLCs by human coronary artery endothelial cells (HCAECs) maintained their viability and reduced both mitochondrial and cytosolic superoxide levels. Acute pressure elevation in isolated coronary arteries significantly attenuated endothelial-dependent dilator responses, which were reversed following incubation in RV-NLCs, superoxide dismutase or apocynin (p < 0.0001). RV-NLCs demonstrated a five-fold increase in potency in comparison to RV solution. At elevated pressure, in the presence of RV-NLCs, incubation with Nω-nitro-l-arginine (L-NNA) or indomethacin resulted in a significant reduction in the restored dilator component (p < 0.0001), whereas apamin and TRAM-34 had no overall effect. Incubation with the adenosine monophosphate-activated protein kinase (AMPK) inhibitor dorsomorphin significantly attenuated dilator responses (p < 0.001), whereas the SIRT-1 inhibitor EX-527 had no effect. RV-NLCs improved the impaired endothelial-dependent dilation of small coronary arteries, following acute pressure elevation, via NO and downstream COX elements, mediated by AMPK. We suggest that RV-NLCs are an effective delivery modality for improved potency and sustained drug release into the vasculature. Our findings have important implications for the future design and implementation of antihypertensive treatment strategies.

Cardioprotective Activity of Selected Polyphenols Based on Epithelial and Aortic Cell Lines. A Review

Polyphenols have recently gained popularity among the general public as products and diets classified as healthy and containing naturally occurring phenols. Many polyphenolic extracts are available on the market as dietary supplements, functional foods, or cosmetics, taking advantage of clients' desire to live a healthier and longer life. However, due to the difficulty of discovering the in vivo functions of polyphenols, most of the research focuses on in vitro studies. In this review, we focused on the cardioprotective activity of different polyphenols as possible candidates for use in cardiovascular disease therapy and for improving the quality of life of patients. Thus, the studies, which were mainly based on endothelial cells, aortic cells, and some in vivo studies, were analyzed. Based on the reviewed articles, polyphenols have a few points of action, including inhibition of acetylcholinesterase, decrease in reactive oxygen species production and endothelial tube formation, stimulation of acetylcholine-induced endothelium-derived mediator release, and others, which lead to their cardio- and/or vasoprotective effects on endothelial cells. The obtained results suggest positive effects of polyphenols, but more long-term in vivo studies demonstrating effects on mechanism of action, sensitivity, and specificity or efficacy are needed before legal health claims can be made.

Ginsenoside Rb1 attenuates cardiomyocyte apoptosis induced by myocardial ischemia reperfusion injury through mTOR signal pathway

OBJECTIVE

Ginsenoside Rb1 (GRb1) is known to play an effective protection on myocardial infarction, yet its therapeutic mechanism on myocardial ischemia/reperfusion (I/R) injury has remained obscure. Here we sought to investigate the protective mechanism of GRb1 preconditioning on myocardial I/R injury in rats.

METHODS AND RESULTS

We report here that GRb1 preconditioning could improve myocardial I/R injury induced-cardiac functions including LVDP, -dp/dt min and + dp/dt max; however, the heart rate (HR) was maintained at a level comparable to the I/R group. Additionally, in I/R injury group given GRb1 preconditioning, release of myocardial enzymes (CK-MB and Trop l) and CtsB was decreased. Moreover, GRb1 decreased the expression of apoptotic related proteins e.g. cleaved-caspase 3; however, the ratio of Bcl-2/Bax related to anti-apoptosis was decreased. The study was extended by injecting rapamycin intraperitoneally before GRb1 pretreatment. Thus, mTOR pathway was significantly upregulated after GRb1 pretreatment when compared with I/R. Remarkably, the anti-apoptosis protection of GRb1 pretreatment was attenuated by rapamycin. Furthermore, GRb1 effectively reduced the infarct size thus supporting its role in anti-myocardial I/R injury.

CONCLUSIONS

It is concluded that GRb1 preconditioning can ameliorate myocardial I/R injury as manifested by the improvement of cardiac function indices; moreover, release of myocardial enzymes, namely, CK-MB, Trop l and CtsB was reduced. More importantly, we have shown that the protective effect of GRb1 against I/R injury induced cardiomyocyte apoptosis is associated with the activation of mTOR signal pathway as evident by the use of rapamycin.

Acute resveratrol supplementation in coronary artery disease: towards patient stratification

Objective: Resveratrol (RV) is a polyphenol with antioxidant, anti-inflammatory and cardio-protective properties. Our objective was to investigate whether acute supplementation with high doses of RV would improve flow-mediated dilation (FMD) and oxygen consumption (VO₂) kinetics in older coronary artery disease (CAD) patients. Design: We employed a placebo-controlled, single-blind, crossover design in which ten participants (aged 66.6 ± 7.8 years) received either RV or placebo (330 mg, 3× day^-1) during three consecutive days plus additional 330 mg in the morning of the fourth day with a seven-day wash-out period in-between. On the fourth day, FMD of the brachial artery and VO₂ on-kinetics were determined. Results: RV improved FMD in patients who had undergone coronary artery bypass grafting (CABG; -1.4 vs. 5.0%; p = .004), but not in those who had undergone percutaneous coronary intervention (PCI; 4.2 vs. -0.2%; NS). Conclusion: Acute high dose supplementation with RV improved FMD in patients after CABG surgery but impaired FMD in patients who underwent PCI. The revascularization method-related differential effects of RV may be due to its direct effects on endothelial-dependent dilator responses. Our findings have important implications for personalized treatment and stratification of older CAD patients.