Resveratrol in cardiovascular disease: what is known from current research?

Cellular and molecular biology of sirtuins in cardiovascular disease

Sirtuins (SIRTs) are a nicotinic adenine dinucleotide (+) -dependent histone deacetylase that regulates critical signaling pathways in prokaryotes and eukaryotes. Studies have identified seven mammalian homologs of the yeast SIRT silencing message regulator 2, namely, SIRT1-SIRT7. Recent in vivo and in vitro studies have successfully demonstrated the involvement of SIRTs in key pathways for cell biological function in physiological and pathological processes of the cardiovascular system, including processes including cellular senescence, oxidative stress, apoptosis, DNA damage, and cellular metabolism. Emerging evidence has stimulated a significant evolution in preventing and treating cardiovascular disease (CVD). Here, we review the important roles of SIRTs for the regulatory pathways involved in the pathogenesis of cardiovascular diseases and their molecular targets, including novel protein post-translational modifications of succinylation. In addition, we summarize the agonists and inhibitors currently identified to target novel specific small molecules of SIRTs. A better understanding of the role of SIRTs in the biology of CVD opens new avenues for therapeutic intervention with great potential for preventing and treating CVD.

Regulation of Acetylation States by Nutrients in the Inhibition of Vascular Inflammation and Atherosclerosis

Atherosclerosis (AS) is a chronic metabolic disorder and primary cause of cardiovascular diseases, resulting in substantial morbidity and mortality worldwide. Initiated by endothelial cell stimulation, AS is characterized by arterial inflammation, lipid deposition, foam cell formation, and plaque development. Nutrients such as carotenoids, polyphenols, and vitamins can prevent the atherosclerotic process by modulating inflammation and metabolic disorders through the regulation of gene acetylation states mediated with histone deacetylases (HDACs). Nutrients can regulate AS-related epigenetic states via sirtuins (SIRTs) activation, specifically SIRT1 and SIRT3. Nutrient-driven alterations in the redox state and gene modulation in AS progression are linked to their protein deacetylating, anti-inflammatory, and antioxidant properties. Nutrients can also inhibit advanced oxidation protein product formation, reducing arterial intima-media thickness epigenetically. Nonetheless, knowledge gaps remain when it comes to understanding effective AS prevention through epigenetic regulation by nutrients. This work reviews and confirms the underlying mechanisms by which nutrients prevent arterial inflammation and AS, focusing on the epigenetic pathways that modify histones and non-histone proteins by regulating redox and acetylation states through HDACs such as SIRTs. These findings may serve as a foundation for developing potential therapeutic agents to prevent AS and cardiovascular diseases by employing nutrients based on epigenetic regulation.

Ameliorating age-dependent effects of resveratrol on VPA-induced social impairments and anxiety-like behaviors in a rat model of Neurodevelopmental Disorder

Although anxiety disorders, as well as difficulties in social interaction, are documented in children with autism spectrum disorder (ASD) as a neurodevelopmental disorder, the effectiveness of potential therapeutic procedures considering age and sex differences is under serious discussion. The present study aimed to investigate the effect of resveratrol (RSV) on anxiety-like behaviors and social interaction in juvenile and adult rats of both sex in a valproic acid (VPA)-induced autistic-like model. Prenatal exposure to VPA was associated with increased anxiety, also causing a significant reduction in social interaction in juvenile male subjects. Further administration of RSV attenuated VPA-induced anxiety symptoms in both sexes of adult animals and significantly increased the sociability index in male and female juvenile rats. Taken together, it can be concluded that treatment with RSV can attenuate some of the harsh effects of VPA. This treatment was especially effective on anxiety-like traits in adult subjects of both sexes regarding their performance in open field and EPM. We encourage future research to consider the sex and age-specific mechanisms behind the RSV treatment in the prenatal VPA model of autism.

Are South African Wild Foods the Answer to Rising Rates of Cardiovascular Disease?

The rising burden of cardiovascular disease in South Africa gives impetus to managerial changes, particularly to the available foods in the market. Since there are many economically disadvantaged groups in urban societies who are at the forefront of the CVD burden, initiatives to make healthier foods available should focus on affordability in conjunction with improved phytochemical diversity to incentivize change. The modern obesogenic diet is deficient in phytochemicals that are protective against the metabolic products of sugar metabolism, i.e., inflammation, reactive oxygen species and mitochondrial fatigue, whereas traditional southern African food species have high phytochemical diversity and are also higher in soluble dietary fibres that modulate the release of sugars from starches, nurture the microbiome and produce digestive artefacts that are prophylactic against cardiovascular disease. The examples of indigenous southern African food species with high horticultural potential that can be harvested sustainably to feed a large market of consumers include: Aloe marlothii, Acanthosicyos horridus, Adansonia digitata, Aloe ferox, Amaranthus hybridus, Annesorhiza nuda, Aponogeton distachyos, Bulbine frutescens, Carpobrotus edulis, Citrullus lanatus, Dioscorea bulbifera, Dovyalis caffra, Eleusine coracana, Lagenaria siceraria, Mentha longifolia, Momordica balsamina, Pelargonium crispum, Pelargonium sidoides, Pennisetum glaucum, Plectranthus esculentus, Schinziophyton rautanenii, Sclerocarya birrea, Solenostemon rotundifolius, Talinum caffrum, Tylosema esculentum, Vigna unguiculata and Vigna subterranea. The current review explains the importance of phytochemical diversity in the human diet, it gives a lucid explanation of phytochemical groups and links the phytochemical profiles of these indigenous southern African foods to their protective effects against cardiovascular disease.

Effect of resveratrol supplementation on hepatic steatosis and cardiovascular indices in overweight subjects with type 2 diabetes: a double-blind, randomized controlled trial

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) are prone to develop non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD). We aimed to investigate whether the resveratrol supplementation improves novel hepatic and cardiovascular indices in these patients.

METHODS

We conducted a double-blind, randomized controlled trial for 8 weeks. Seventy-six patients with T2DM were randomly assigned to receive 1000 mg/day resveratrol or placebo. Levels of lipid accumulation product (LAP), visceral adiposity index (VAI), Castelli risk index I (CRI-I), CRI-II and atherogenic coefficient (AC) were measured at the beginning and after intervention.

RESULTS

A total of 71 participants completed the trial. After adjusting for confounding factors including medications, diabetes duration, energy intake and physical activity, no significant difference was found between the intervention group and the control group in LAP (mean change: - 2.46 ± 23.3 vs. 1.43 ± 14.3; P = 0.43), VAI (mean change: - 0.25 ± 1.1 vs. - 0.02 ± 0.6; P = 0.47), CRI-I (mean change: - 0.25 ± 0.9 vs. - 0.09 ± 0.5; P = 0.79), CRI-II (mean change: - 0.23 ± 0.7 vs. - 0.06 ± 0.6; P = 0.38) and AC (mean change: - 0.25 ± 0.9 vs. - 0.09 ± 0.5; P = 0.79).

CONCLUSIONS

Resveratrol supplementation had no effect on hepatic steatosis and cardiovascular indices. Further clinical trials, especially among subjects with dyslipidemia are needed to reach a firm conclusion. In addition, taking all medications should be controlled in future studies. Trial registration The protocol was registered on 29/12/2017 at the Iranian clinical trials website (IRCT20171118037528N1) with URL: https://en.irct.ir/trial/27734 .

Resveratrol protects against atherosclerosis by downregulating the PI3K/AKT/mTOR signaling pathway in atherosclerosis model mice

Atherosclerosis is a cardiovascular disease, which is characterized by the interaction between carbohydrates, lipids, cells and various other molecules and genetic factors. Previous studies have demonstrated that resveratrol (RV) served protective roles in numerous types of human disease by regulating different signaling pathways. The aim of the present study was to investigate the therapeutic effects of RV and analyze the potential RV-mediated mechanism in umbilical vein endothelial cells (UVECS) in atherosclerosis model mice. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were used to analyze the therapeutic effects of RV both in vitro and in vivo. The results demonstrated that total cholesterol, triglycerides, low-density lipoprotein cholesterin and high-density lipoprotein cholesterin levels were significantly decreased in the RV group compared with the control group. RV demonstrated significant anti-atherosclerotic activity, which was determined through the atherogenic index, 3-hydroxy-3-methyl-glutaryl-Coa (HMG-CoA) reductase activity and marker enzymes, such as lactate dehydrogenase, creatine phosphokinase, aspartate transaminase, alanine transaminase and alkaline phosphatase. It was also observed that RV treatment significantly decreased the area of the arteriosclerotic lesion in the RV group compared with the control, as well as significantly decreasing the expression levels of matrix metalloproteinase-9 and CD40 ligand (CD40L) in arterial lesion tissue compared with the control group. Serum expression levels of tumor necrosis factor-α and C-reactive protein were also significantly decreased by RV treatment compared with the control group. Furthermore, RV treatment significantly decreased the expression levels of PI3K, AKT and mTOR in UVECS in vitro. In conclusion, these results suggested that the anti-atherosclerotic activity of RV may be due to its modulatory activity over the PI3K/AKT/mTOR signaling pathway. These findings suggested a potential novel treatment option for patients with atherosclerosis.

Potential role of resveratrol and its nano-formulation as anti-cancer agent

The uncontrolled and metastatic nature of cancer makes it worse and more unpredictable. Hence, many therapy and medication are used to control and treat cancer. However, apart from this, many medications cause various side effects. In America, nearly 8% of patients admitted to the hospital are due to side effects. Cancer is more seen in people residing in developed countries related of their lifestyle. There are various phytoconstituents molecules in which resveratrol (RSV) is the best-fitted molecule for cancer due to its significantly less adverse effect on the body. RSV inhibits the initiation and progression of cell proliferation due to the modulation of various pathways like the phosphoinositol 3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. RSV downgraded cell cycle-regulated proteins like cyclin E, cyclin D1, and proliferating cell nuclear antigen (PCNA) and induced the release of cytochrome c from the mitochondria, causing apoptosis or programmed cell death (PCD). A great benefit comes with some challenges, hence, RSV does suffer from poor solubility in water i.e. 0.05 mg/mL. It suffers from poor bioavailability due to being highly metabolized by the liver and intestine. Surprisingly, RSV metabolites also induce the metabolism of RSV. Hence, significantly less amount of RSV presented in the urine in the unchanged form. Due to some challenges like poor bioavailability, less aqueous solubility, and retention time in the body, researchers concluded to make the nanocarriers for better delivery. Adopting the technique of nano-formulations, increased topical penetration by up to 21%, improved nano-encapsulation and consequently improved bioavailability and permeability by many folds. Hence, the present review describes the complete profile of RSV and its nano-formulations for improving anti-cancer activity along with a patent survey.

Combating Ischemia-Reperfusion Injury with Micronutrients and Natural Compounds during Solid Organ Transplantation: Data of Clinical Trials and Lessons of Preclinical Findings

Although extended donor criteria grafts bear a higher risk of complications such as graft dysfunction, the exceeding demand requires to extent the pool of potential donors. The risk of complications is highly associated with ischemia-reperfusion injury, a condition characterized by high loads of oxidative stress exceeding antioxidative defense mechanisms. The antioxidative properties, along with other beneficial effects like anti-inflammatory, antiapoptotic or antiarrhythmic effects of several micronutrients and natural compounds, have recently emerged increasing research interest resulting in various preclinical and clinical studies. Preclinical studies reported about ameliorated oxidative stress and inflammatory status, resulting in improved graft survival. Although the majority of clinical studies confirmed these results, reporting about improved recovery and superior organ function, others failed to do so. Yet, only a limited number of micronutrients and natural compounds have been investigated in a (large) clinical trial. Despite some ambiguous clinical results and modest clinical data availability, the vast majority of convincing animal and in vitro data, along with low cost and easy availability, encourage the conductance of future clinical trials. These should implement insights gained from animal data.

Endothelial Progenitor Cells Dysfunctions and Cardiometabolic Disorders: From Mechanisms to Therapeutic Approaches

Metabolic syndrome (MetS) is a cluster of several disorders, such as hypertension, central obesity, dyslipidemia, hyperglycemia, insulin resistance and non-alcoholic fatty liver disease. Despite health policies based on the promotion of physical exercise, the reduction of calorie intake and the consumption of healthy food, there is still a global rise in the incidence and prevalence of MetS in the world. This phenomenon can partly be explained by the fact that adverse events in the perinatal period can increase the susceptibility to develop cardiometabolic diseases in adulthood. Individuals born after intrauterine growth restriction (IUGR) are particularly at risk of developing cardiovascular diseases (CVD) and metabolic disorders later in life. It has been shown that alterations in the structural and functional integrity of the endothelium can lead to the development of cardiometabolic diseases. The endothelial progenitor cells (EPCs) are circulating components of the endothelium playing a major role in vascular homeostasis. An association has been found between the maintenance of endothelial structure and function by EPCs and their ability to differentiate and repair damaged endothelial tissue. In this narrative review, we explore the alterations of EPCs observed in individuals with cardiometabolic disorders, describe some mechanisms related to such dysfunction and propose some therapeutical approaches to reverse the EPCs dysfunction.

Acute oral treatment with resveratrol and Lactococcus Lactis Subsp. Lactis decrease body weight and improve liver proinflammatory markers in C57BL/6 mice

The present study aimed to evaluate the effects of resveratrol, a nutraceutical polyphenol, and Lactococcus lactis (bacteria probiotic), on metabolic parameters and hepatic proinflammatory markers expression. C57BL/6 mice were divided into 4 groups: Standard (ST), Lactococcus lactis (LL), Resveratrol (RSV), and Lactococcus lactis plus resveratrol (LL + RSV). Lactococcus lactis and resveratrol were administered by orogastric gavage. Blood parameters were assessed (total cholesterol, triglycerides, ALT and AST). IL-6 mRNA expression was evaluated by Real-time PCR and TNF-α protein expression was assessed by immunohistochemistry. The main findings showed that resveratrol and Lactococcus lactis association decreased body weight, aspartate aminotransferase and total cholesterol levels. LL and LL + RSV decreased triglycerides levels and IL-6 and TNF-α expression. These results open a perspective of using resveratrol and Lactococcus lactis to improve metabolic parameters and Lactococcus lactis in preventing inflammation and the hepatic diseases development.

Resveratrol and Diabetic Cardiomyopathy: Focusing on the Protective Signaling Mechanisms

Diabetic cardiomyopathy (DCM) is a common cardiovascular complication of diabetic mellitus that is characterized by diastolic disorder in the early stage and clinical heart failure in the later stage. Presently, DCM is considered one of the major causes of death in diabetic patients. Resveratrol (RSV), a naturally occurring stilbene, is widely reported as a cardioprotective substance in many heart diseases. Thus far, the specific roles of RSV in DCM prevention and treatment have attracted great attention. Here, we discuss the roles of RSV in DCM by focusing its downstream targets from both in vivo and in vitro studies. Among such targets, Sirtuins 1/3 and AMP-activated kinase have been identified as key mediators that induce cardioprotection during hyperglycemia. In addition, many other signaling molecules (e.g., forkhead box-O3a and extracellular regulated protein kinases) are also regulated in the presence of RSV and exert beneficial effects such as opposing oxidative stress, inflammation, and apoptosis in cardiomyocytes exposed to high-glucose conditions. The beneficial potential of an RSV/stem cell cotherapy is also reviewed as a promising therapeutic strategy for preventing the development of DCM.

Neuroprotection with Natural Antioxidants and Nutraceuticals in the Context of Brain Cell Degeneration: The Epigenetic Connection

Bioactive antioxidant agents present in selected plants are known to provide the first line of biological defense against oxidative stress. In particular, soluble vitamin C, E, carotenoids and phenolic compounds have demonstrated crucial biological effects in cells against oxidative damage, preventing prevalent chronic diseases, such as diabetes, cancer and cardiovascular disease. The reported wide range of effects that included anti-aging, anti-atherosclerosis, anti-inflammatory and anticancer activity were studied against degenerative pathologies of the brain. Vitamins and different phytochemicals are important epigenetic modifiers that prevent neurodegeneration. In order to explore the potential antioxidant sources in functional foods and nutraceuticals against neurodegeneration, the present paper aims to show a comprehensive assessment of antioxidant activity at chemical and cellular levels. The effects of the different bioactive compounds available and their antioxidant activity through an epigenetic point of view are also discussed.

Liposomal Resveratrol and/or Carvedilol Attenuate Doxorubicin-Induced Cardiotoxicity by Modulating Inflammation, Oxidative Stress and S100A1 in Rats

Doxorubicin (DOX) is a cytotoxic anthracycline antibiotic and one of the important chemotherapeutic agents for different types of cancers. DOX treatment is associated with adverse effects, particularly cardiac dysfunction. This study examined the cardioprotective effects of carvedilol (CAR) and/or resveratrol (RES) and liposomal RES (LIPO-RES) against DOX-induced cardiomyopathy, pointing to their modulatory effect on oxidative stress, inflammation, S100A1 and sarco/endoplasmic reticulum calcium ATPase2a (SERCA2a). Rats received CAR (30 mg/kg) and/or RES (20 mg/kg) or LIPO-RES (20 mg/kg) for 6 weeks and were challenged with DOX (2 mg/kg) twice per week from week 2 to week 6. DOX-administered rats exhibited a significant increase in serum creatine kinase-MB (CK-MB), troponin-I and lactate dehydrogenase (LDH) along with histological alterations, reflecting cardiac cell injury. Cardiac toll-like receptor 4 (TLR-4), inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α and interleukin (IL)-6 protein expression were up-regulated, and lipid peroxidation was increased in DOX-administered rats. Treatment with CAR, RES or LIPO-RES as well as their alternative combinations ameliorated all observed biochemical and histological alterations with the most potent effect exerted by CAR/LIPO-RES. All treatments increased cardiac antioxidants, and the expression of S100A1 and SERCA2a. In conclusion, the present study conferred new evidence on the protective effects of CAR and its combination with either RES or LIPO-RES on DOX-induced inflammation, oxidative stress and calcium dysregulation.

Effects of Polyphenol Compounds and Nitrogen Oxide Donors on Lipid Oxidation, Membrane-Skeletal Proteins, and Erythrocyte Structure under Hypoxia

This study shows that membrane-associated cytoskeletal protein structures and the erythrocyte morphology undergo profound changes during hypoxia. Hypoxia also intensified oxidative processes in the lipid phase of the bilayer of red blood cell membranes. Sodium nitroprusside impaired the morphology of red blood cells and altered quantitative and qualitative composition of membrane-skeletal proteins. The findings suggest that hypoxia causes changes at all levels of red blood cell organization, which can cause the functional disorders of hemoglobin oxygen-transporting properties and, eventually, the complete degradation of red blood cells. The use of flavonoids has a protective effect against hypoxia.

Effect of oocyte vitrification on DNA damage in metaphase II oocytes and the resulting preimplantation embryos

As an assisted reproduction technology, vitrification has been widely used for oocyte and embryo cryopreservation. Many studies have indicated that vitrification affects ultrastructure, gene expression, and epigenetic status. However, it is still controversial whether oocyte vitrification could induce DNA damage in metaphase II (MII) oocytes and the resulting early embryos. This study determined whether mouse oocytes vitrification induce DNA damage in MII oocytes and the resulting preimplantation embryos, and causes for vitrification-induced DNA damage. The effects of oocyte vitrification on reactive oxygen species (ROS) levels, γ-H2AX accumulation, apoptosis, early embryonic development, and the expression of DNA damage-related genes in early embryos derived by in vitro fertilization were examined. The results indicated that vitrification significantly increased the number of γ-H2AX foci in zygotes and two-cell embryos. Trp53bp1 was upregulated in zygotes, two-cell embryos and four-cell embryos in the vitrified group, and Brca1 was increased in two-cell embryos after vitrification. Vitrification also increased the ROS levels in MII oocytes, zygotes, and two-cell embryos and the apoptotic rate in blastocysts. Resveratrol (3,5,4'-trihydroxystilbene) treatment decreased the ROS levels and the accumulation of γ-H2AX foci in zygotes and two-cell embryos and the apoptotic rate in blastocysts after vitrification. Overall, vitrification-induced abnormal ROS generation, γ-H2AX accumulation, an increase in the apoptotic rate and the disruption of early embryonic development. Resveratrol treatment could decrease ROS levels, γ-H2AX accumulation, and the apoptotic rate and improve early embryonic development. Vitrification-associated γ-H2AX accumulation is at least partially due to abnormal ROS generation.

The Influence of Oxidative Stress and Natural Antioxidants on Morphometric Parameters of Red Blood Cells, the Hemoglobin Oxygen Binding Capacity, and the Activity of Antioxidant Enzymes

Using a wide range of different physical and chemical methods, it was found that the oxidative stress caused by addition of hydrogen peroxide to the incubation medium has a significant effect on the conformation of haematoporphyrin, influencing the oxygen-binding properties of haemoglobin in red blood cells. Morphofunctional characteristics of red blood cells change; in particular, we have observed the transformation of erythrocytes, their transition into echinocytes. In erythrocytes, in response to increased lipid peroxidation (LPO) antioxidant enzymes become active. The use of natural antioxidants (β-carotene and resveratrol) works towards reducting the level of oxidative processes. Resveratrol has the greatest antioxidant effect.

Are the cardioprotective effects of the phytoestrogen resveratrol sex-dependent? 1

Cardiovascular disease (CVD) is the number one cause of death in both men and women. Younger women have a lower risk for CVD, but their risk increases considerably after menopause when estrogen levels decrease. The cardiovascular protective properties of estrogen are mediated through decreasing vascular inflammation and progression of atherosclerosis, decreasing endothelial cell damage by preventing apoptosis and anti-hypertrophic mechanisms. Estrogen also regulates glucose and lipid levels, which are 2 important risk factors for CVD. Resveratrol (RES), a cardioprotective polyphenolic compound, is classified as a phytoestrogen due its capacity to bind to and modulate estrogen receptor signalling. Due to its estrogen-like property, we speculate that the cardioprotective effects of RES treatment could be sex-dependent. Based on earlier reports and more recent data from our lab presented here, we found that RES treatment may have more favourable cardiovascular outcomes in females than in males. This review will discuss estrogen- and phytoestrogen-mediated cardioprotection, with a specific focus on sex-dependent effects reported in preclinical and clinical studies.

Resveratrol protects late endothelial progenitor cells from TNF-α-induced inflammatory damage by upregulating Krüppel-like factor-2

Cardiovascular risk factors can negatively influence late endothelial progenitor cell (EPCs) number and functions, thus EPCs biology is a clinical implications for cardiovascular diseases. The present study aimed to investigate the potential protective effects of resveratrol (RES) on tumor necrosis factor (TNF)-α-induced inflammatory damage in late endothelial progenitor cells (EPCs) and to elucidate the underlying mechanisms. Late EPCs at passages 3–5 were pretreated with RES at a concentration of 20 µmol/l for 12 h and subsequently incubated with TNF-α (10 ng/ml) for 24 h. The adhesion, migration, proliferation and vasculogenesis of EPCs were subsequently detected. Furthermore, the mRNA expression levels of intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1) were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Nitric oxide (NO) levels in the supernatant were determined using a colorimetric assay kit. Additionally, the mRNA and protein expression of Krüppel-like factor-2 (KLF2) was determined by RT-qPCR and western blot analysis, respectively. The results indicated that TNF-α markedly inhibited the proliferation, adhesion, migration and vasculogenesis of late EPCs. However, RES ameliorated the effects induced by TNF-α. Furthermore, exposure of EPCs to TNF-α decreased the levels of NO secretion and KLF2 expression at the mRNA and protein levels, but upregulated the levels of inflammatory factors, including ICAM-1 and MCP-1, compared with the control group. RES significantly inhibited TNF-α-induced inflammatory damage through upregulation of KLF2 expression and downregulation of the expression of ICAM-1 and MCP-1. In conclusion, RES may exert protective effects on the cardiovascular system, as demonstrated by the amelioration of TNF-α-induced inflammation in EPCs following RES treatment, and may therefore be used in the future for the prevention of cardiovascular disease.

Neuroprotection in Glaucoma: Old and New Promising Treatments

Glaucoma is a major global cause of blindness, but the molecular mechanisms responsible for the neurodegenerative damage are not clear. Undoubtedly, the high intraocular pressure (IOP) and the secondary ischemic and mechanical damage of the optic nerve have a crucial role in retinal ganglion cell (RGC) death. Several studies specifically analyzed the events that lead to nerve fiber layer thinning, showing the importance of both intra- and extracellular factors. In parallel, many neuroprotective substances have been tested for their efficacy and safety in hindering the negative effects that lead to RGC death. New formulations of these compounds, also suitable for chronic oral administration, are likely to be used in clinical practice in the future along with conventional therapies, in order to control the progression of the visual impairment due to primary open-angle glaucoma (POAG). This review illustrates some of these old and new promising agents for the adjuvant treatment of POAG, with particular emphasis on forskolin and melatonin.

Significance of Resveratrol in Clinical Management of Chronic Diseases

Resveratrol could be beneficial to health and provides protection against a wide array of pathologies and age-associated problems, as evident from preclinical studies. However, a comparison of animal and human studies reveals that this dietary polyphenol cannot protect against metabolic diseases and their associated complications. The clinical outcomes are affected by many factors such as sample size. This article not only presents a comprehensive review of the current advances concerning the dose, the extent of absorption, interaction and toxicity of resveratrol in human studies, but also describes its therapeutic effects against several chronic diseases such as diabetes mellitus, obesity, cardiovascular diseases, cancer and aging and the related diseases.

Dominant Carbons in trans- and cis-Resveratrol Isomerization

A comprehensive analysis for isomerization of geometric isomers in the case of resveratrol (R) has been presented. As an important red wine molecule, only one geometric isomer of resveratrol, i.e., trans-R rather than cis-R, is primarily associated with health benefit. In the present study, density function theory (DFT) provides accurate descriptions of isomerization of resveratrol. The nearly planar trans-R forms a relatively rigid and less flexible conjugate network, but the nonplanar cis-R favors a more flexible structure with steric through space interaction. The calculated carbon nuclear magnetic resonance (NMR) chemical shift indicates that all carbons are different in the isomers; it further reveals that four carbon sites, i.e., C₍₆₎, C₍₈₎═C₍₉₎, and C₍₁₁₎, have a significant response to the geometric isomerization. Here C₍₆₎ is related to the steric effect in cis-R, whereas C₍₁₁₎ may indicate the isomerization proton transfer on C₍₉₎ linking with the resorcinol ring. The excess orbital energy spectrum (EOES) confirms the NMR "bridge of interest" carbons and reveals that five valence orbitals of 34a, 35a, 46a, 55a, and 60a respond to the isomerization most significantly. The highest occupied molecular orbital (HOMO), 60a, of the isomer pair is further studied using dual space analysis (DSA) for its orbital momentum distributions, which exhibit p-electron dominance for trans-R but hybridized sp-electron dominance for cis-R. Finally, energy decomposition analysis (EDA) highlights that trans-R is preferred over cis-R by -4.35 kcal·mol^-1, due to small electrostatic energy enhancement of the attractive orbital energy with respect to the Pauli repulsive energy.

Resveratrol protects against oxidized low‑density lipoprotein‑induced human umbilical vein endothelial cell apoptosis via inhibition of mitochondrial‑derived oxidative stress

Resveratrol, a natural phytochemical found in grapes and red wine, has been found to possess protective effects against endothelial cell apoptosis and oxidative damage. Oxidized-low density lipoprotein (ox-LDL) can induce apoptosis of endothelial cells, which is an important initial event in several cardiovascular diseases. However, the effect of resveratrol on ox-LDL-induced apoptosis and oxidative damage, and the possible associated mechanisms remain to be elucidated. In the present study, following exposure to ox-LDL, human umbilical vein endothelial cells (HUVECs) were treated with or without resveratrol. Cell viability was examined using Cell Counting Kit-8 and 5-bromo-2′-deoxyuridine uptake assays, respectively. Cell apoptosis was determined by flow cytometry. Apoptosis-associated markers were detected using western blot analysis. Oxidative stress was analyzed using molecular and biochemical approaches. Resveratrol restored ox-LDL-induced HUVEC injury and apoptosis in a dose-dependent manner. In addition, compared with the control group, ox-LDL treatment decreased the B cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein ratio, mitochondrial membrane potential and activation of superoxide dismutase, and enhanced the release of mitochondrial cytochrome c into the cytoplasm, the activation of caspase and lipid peroxidation. All these alterations were significantly inhibited following treatment with resveratrol. The results demonstrated that resveratrol prevented HUVEC apoptosis through inhibiting mitochondria-derived oxidative damage. These findings may provide a novel mechanism by which resveratrol prevents against endothelial cell apoptosis.

Simulated microgravity affects some biological characteristics of Lactobacillus acidophilus

The effects of weightlessness on enteric microorganisms have been extensively studied, but have mainly been focused on pathogens. As a major component of the microbiome of the human intestinal tract, probiotics are important to keep the host healthy. Accordingly, understanding their changes under weightlessness conditions has substantial value. This study was carried out to investigate the characteristics of Lactobacillus acidophilus, a typical probiotic for humans, under simulated microgravity (SMG) conditions. The results revealed that SMG had no significant impact on the morphology of L. acidophilus, but markedly shortened its lag phase, enhanced its growth rate, acid tolerance ability up to pH < 2.5, and the bile resistance at the bile concentration of <0.05%. SMG also decreased the sensitivity of L. acidophilus to cefalexin, sulfur gentamicin, and sodium penicillin. No obvious effect of SMG was observed on the adhesion ability of L. acidophilus to Caco-2 cells. Moreover, after SMG treatment, both the culture of L. acidophilus and its liquid phase exhibited higher antibacterial activity against S. typhimurium and S. aureus in a time-dependent manner. The SMG treatment also increased the in vitro cholesterol-lowering ability of L. acidophilus by regulating the expression of the key cholesterol metabolism genes CYP7A1, ABCB11, LDLR, and HMGCR in the HepG2 cell line. Thus, the SMG treatment did have considerable influence on some biological activities and characteristics of L. acidophilus related to human health. These findings provided valuable information for understanding the influence of probiotics on human health under simulated microgravity conditions, at least.

Cholesterol-Lowering Effects and Mechanisms in View of Bile Acid Pathway of Resveratrol and Resveratrol Glucuronides

Resveratrol (Res) was previously reported to be capable of lowering plasma TC and LDL-C. The mechanism behind Res is not clearly understood, although it is presumed to have an effect on bile acid metabolism in the liver: a significant way in eliminating cholesterol from the body. As one of the major metabolites of Res in the liver, resveratrol glucuronides (Gres) is suspected to also contribute to the overall cholestrol-lowering activity of Res, which needs to be studied. In this research, when HepG2 steatosis hepatic cells were treated with Res and Gres at different concentration levels, Res and Gres showed similar activity in lowering cellular TC content. The presence of Res and Gres caused a significant increase in hepatic CYP7A1 and BSEP, indicating the increase in the synthesis and efflux of bile acids, respectively. The reduction of HMG-CoAR tied to a decrease in de novo synthesis of cholesterol and the increase of ABCG5 suggested the increase of direct efflux of cholesterol. All above variations reduced the hepatic cholesterol level, which triggered the significant enhancement of LDLR, illustrating the improvement of clearance of LDL-C from the plasma and prevention of atherosclerosis. Overall, this study demonstrated both Res and Gres might have capabilities in lowering hepatic cholesterol through increasing in the synthesis and efflux of bile acids, and decreasing in synthesis and increasing in the efflux of cholesterol. Gres would have preferred potential than Res because of its lower cytotoxicity, which indicated that the action of the metabolites should also be considered in the future studies.

Endothelium-dependent and-independent relaxation induced by resveratrol in rat superior mesenteric arteries

Resveratrol (Res) is a specific agonist of sirtuin 1, and has many cardioprotective effects. Although Res is able to relax various vascular beds, its pharmacological properties in rat superior mesenteric arteries and the underlying mechanism are not well clarified. The aim of present study was to investigate the vasorelaxant effects of Res on rat superior mesenteric arteries and the mechanisms involved. The isometric tension of rat superior mesenteric arterial rings was recorded in vitro using myography. It was found that Res concentration-dependently relaxed endothelium-intact superior mesenteric artery rings pre-contracted by phenylephrine hydrochloride (E_max, 97.66±0.79%; pD₂, 4.30±0.14) or KCl (E_max, 101.3±0.6%; pD₂, 4.12±0.03). The vasorelaxant effect of Res on the superior mesenteric artery rings was partially endothelium-dependent. N^G-nitro-L-arginine methyl ester (100 µM) significantly inhibited the Res-induced vasorelaxant effect. However, 1H-[1,2,4]oxadiazolo[4,3-a] quinoxalin-1-one (10 µM) and indomethacin (5 µM) each had no effect on the Res-induced vasorelaxation. In artery rings without endothelium, the vasorelaxation induced by Res was attenuated by 4-aminopyridine (100 µM) and glibenclamide (10 µM). However, barium chloride dehydrate (10 µM) and tetraethylammonium chloride (1 mM) did not affect the vasorelaxation induced by Res. Moreover, Res also inhibited the contraction induced by an increase in external calcium concentration in Ca²⁺-free medium plus KCl (60 mM). These results suggest that Res induces relaxation in superior mesenteric arterial rings through an endothelium-dependent pathway, involving nitric oxide release, and also through an endothelium-independent pathway, with opening of voltage-dependent K⁺ channels and ATP-sensitive K⁺ channels and blockade of extracellular Ca²⁺ influx.

Distinct metabolic effects of resveratrol on lipogenesis markers in mice adipose tissue treated with high-polyunsaturated fat and high-protein diets

OBJECTIVE

A healthy diet is essential for the prevention of metabolic syndrome. The present study evaluated the effect of resveratrol associated with high-polyunsaturated fat and high-protein diets on expression of adipogenic and lipogenic genes.

RESEARCH METHODS & PROCEDURES

FVB/N mice were divided into 6 groups (n=7 each) and fed with experimental diets for 60days: standard (ST), high-fat diet (HFD), and high-protein diet (HPD), with and without resveratrol (RSV) (4g/kg diet). The body weight, food intake, energy intake (kcal), and blood parameters (HDL-C, total cholesterol, glucose, and triglyceride levels) were assessed. Real-time PCR was performed to analyze the expression of adipogenesis and lipogenesis markers: PPARγ, SREBP-1c, ACC and FAS in samples from perigonadal adipose tissue.

RESULTS

In the HPD+RSV group, resveratrol decreased body weight, body adiposity, adipose tissue weight, adipocyte area, total cholesterol, ACC and FAS expression, and increased HDL-cholesterol in comparison to HPD. In the HPD group there was a decrease in adipocyte area, as well as PPARγ, SREBP-1c and ACC expression in comparison to ST. While in HFD+RSV, resveratrol decreased levels of total cholesterol in comparison to HFD. In the HFD group there was decrease in body weight, and PPARγ, SREBP-1c and ACC expression in comparison to ST.

CONCLUSIONS

The obtained results show that resveratrol decreases lipogenesis markers and metabolic parameters in the setting of a high-protein diet. Moreover, resveratrol decreased total cholesterol in both diets. These results point to the increased potential of resveratrol use in prevention of metabolic syndrome, acting on different dietary compositions.

SIRT1 improves VSMC functions in atherosclerosis

Despite advancements in diagnosis and treatment of cardiovascular diseases (CVDs), the morbidity and mortality of CVDs are still rising. Atherosclerosis is a chronic inflammatory disease contributing to multiple CVDs. Considering the complexity and severity of atherosclerosis, it is apparent that exploring the mechanisms of atherosclerotic formation and seeking new therapies for patients with atherosclerosis are required to overcome the heavy burden of CVDs on the quality and length of life of the global population. Vascular smooth muscle cells (VSMCs) play a dominant role in functional and structural changes of the arterial walls in response to atherogenic factors. Therefore, improvement of VSMC functions will slow down the development of atherosclerosis to a large extent. Given its protective performances on regulation of cholesterol metabolism and inflammatory responses, SIRT1 has long been known as an anti-atherosclerosis factor. In this review, we focus on the effects of SIRT1 on VSMC functions and thereby the development of atherosclerosis.

Evaluation of PPARα activation by known blueberry constituents

BACKGROUND

Anthocyanins are known to have hypolipidemic properties. It was deemed necessary to determine whether major blueberry anthocyanins and catechins are ligands for the transcription factor peroxisome proliferator activated receptor alpha isoform (PPARα), and compare activation with known PPARα agonistic constituents, pterostilbene and resveratrol. It was also considered important to investigate the effect of pterostilbene on PPARα gene expression, and relate results with hepatic mRNA PPARα expression up-regulation observed previously in hamsters fed a diet supplemented with blueberry peels extract (BBX).

RESULTS

The anthocyanins and catechins did not activate PPARα. Only pterostilbene exhibited a dose-dependent activation of PPARα in H4IIEC3 cells. The resveratrol responses were lower than those of pterostilbene. Pterostilbene significantly and dose-dependently (at 10, 20 and 50 µmol L(-1) ) increased PPARα gene expression and the effect at 10 µmol L(-1) was greater than 100 and 200 µmol L(-1) of fenofibrate. Analysis of BBX showed levels of pterostilbene and resveratrol at 418 and 2381 ng g(-1), respectively.

CONCLUSION

Anthocyanins and catechins do not appear to contribute to the up-regulation of hepatic PPARα expression observed in hamsters. While pterostilbene and resveratrol demonstrated PPARα activation, their levels in BBX do not seem to be at efficacious concentrations. These stilbenes may contribute to the up-regulation of PPARα expression by acting synergistically with each other or with other constituents in BBX.

Nrf2 signaling and redox homeostasis in the aging heart: A potential target to prevent cardiovascular diseases?

Aging process is often accompanied with a high incidence of cardiovascular diseases (CVD) due to the synergistic effects of age-related changes in heart morphology/function and prolonged exposure to injurious effects of CVD risk factors. Oxidative stress, considered a hallmark of aging, is also an important feature in pathologies that predispose to CVD development, like hypertension, diabetes and obesity. Approaches directed to prevent the occurrence of CVD during aging have been explored both in experimental models and in controlled clinical trials, in order to improve health span, reduce hospitalizations and increase life quality during elderly. In this review we discuss oxidative stress role as a main risk factor that relates CVD with aging. As well as interventions that aim to reduce oxidative stress by supplementing with exogenous antioxidants. In particular, strategies of improving the endogenous antioxidant defenses through activating the nuclear factor related-2 factor (Nrf2) pathway; one of the best studied molecules in cellular redox homeostasis and a master regulator of the antioxidant and phase II detoxification response.

Antioxidant potential of CORM-A1 and resveratrol during TNF-α/cycloheximide-induced oxidative stress and apoptosis in murine intestinal epithelial MODE-K cells

Targeting excessive production of reactive oxygen species (ROS) could be an effective therapeutic strategy to prevent oxidative stress-associated gastrointestinal inflammation. NADPH oxidase (NOX) and mitochondrial complexes (I and II) are the major sources of ROS production contributing to TNF-α/cycloheximide (CHX)-induced apoptosis in the mouse intestinal epithelial cell line, MODE-K. In the current study, the influence of a polyphenolic compound (resveratrol) and a water-soluble carbon monoxide (CO)-releasing molecule (CORM-A1) on the different sources of TNF-α/CHX-induced ROS production in MODE-K cells was assessed. This was compared with H2O2-, rotenone- or antimycin-A-induced ROS-generating systems. Intracellular total ROS, mitochondrial-derived ROS and mitochondrial superoxide anion (O2(-)) production levels were assessed. Additionally, the influence on TNF-α/CHX-induced changes in mitochondrial membrane potential (Ψm) and mitochondrial function was studied. In basal conditions, CORM-A1 did not affect intracellular total or mitochondrial ROS levels, while resveratrol increased intracellular total ROS but reduced mitochondrial ROS production. TNF-α/CHX- and H2O2-mediated increase in intracellular total ROS production was reduced by both resveratrol and CORM-A1, whereas only resveratrol attenuated the increase in mitochondrial ROS triggered by TNF-α/CHX. CORM-A1 decreased antimycin-A-induced mitochondrial O2(-) production without any influence on TNF-α/CHX- and rotenone-induced mitochondrial O2(-) levels, while resveratrol abolished all three effects. Finally, resveratrol greatly reduced and abolished TNF-α/CHX-induced mitochondrial depolarization and mitochondrial dysfunction, while CORM-A1 only mildly affected these parameters. These data indicate that the cytoprotective effect of resveratrol is predominantly due to mitigation of mitochondrial ROS, while CORM-A1 acts solely on NOX-derived ROS to protect MODE-K cells from TNF-α/CHX-induced cell death. This might explain the more pronounced cytoprotective effect of resveratrol.

Polyphenol Stilbenes: Molecular Mechanisms of Defence against Oxidative Stress and Aging-Related Diseases

Numerous studies have highlighted the key roles of oxidative stress and inflammation in aging-related diseases such as obesity, type 2 diabetes, age-related macular degeneration (AMD), and Alzheimer's disease (AD). In aging cells, the natural antioxidant capacity decreases and the overall efficiency of reparative systems against cell damage becomes impaired. There is convincing data that stilbene compounds, a diverse group of natural defence phenolics, abundant in grapes, berries, and conifer bark waste, may confer a protective effect against aging-related diseases. This review highlights recent data helping to clarify the molecular mechanisms involved in the stilbene-mediated protection against oxidative stress. The impact of stilbenes on the nuclear factor-erythroid-2-related factor-2 (Nrf2) mediated cellular defence against oxidative stress as well as the potential roles of SQSTM1/p62 protein in Nrf2/Keap1 signaling and autophagy will be summarized. The therapeutic potential of stilbene compounds against the most common aging-related diseases is discussed.

Resveratrol Upregulates Cardiac SDF-1 in Mice with Acute Myocardial Infarction through the Deacetylation of Cardiac p53

AIMS

We previously demonstrated that resveratrol (RSV) administration causes cardiac stromal cell-derived factor (SDF)-1 upregulation and can enhance the mobilization of stem cells in mice with acute myocardial infarction (AMI). However, the upstream signal transduction involved in SDF-1 regulation in the setting of AMI and RSV administration remains unclear. Because RSV is a sirtuin 1 (SIRT1) activator and SIRT proteins act as deacetylases, we investigated the role of SIRT1 in SDF-1 upregulation and its subsequent effects.

METHODS AND RESULTS

In vitro experiments with H9C2 cardiomyocytes under hypoxia and serum-deprivation conditions showed that p53 acted upstream of SDF-1. RSV could not regulate SDF-1 effectively after SIRT1 silencing, indicating that it is dependent on SIRT1. Subsequently, male C57BL/6 mice were divided into four groups: 1) sham, 2) MI, 3) MI+RSV, and 4) MI+RSV plus nicotinamide, an inhibitor of the deacetylase activity of SIRT (MI+RSV+NAM). Compared with the sham mice, AMI caused a slight increase in the cardiac p53 level and resulted in significant SIRT1 downregulation and p53 acetylation or activation. Compared with the MI mice, MI+RSV administration improved the cardiac SDF-1 level and reversed the reduction of SIRT1 and the activation of p53. Furthermore, we observed less cardiac dysfunction in MI+RSV mice and determined that NAM abolished the effects of RSV.

CONCLUSIONS

RSV enhances cardiac SDF-1 excretion after AMI partially through a SIRT1 normalization/p53 inactivation pathway.

Resveratrol supplementation: Where are we now and where should we go?

Pre-clinical findings have provided mounting evidence that resveratrol, a dietary polyphenol, may confer health benefits and protect against a variety of medical conditions and age-related complications. However, there is no consistent evidence of an increased protection against metabolic disorders and other ailments when comparing studies in laboratory animals and humans. A number of extraneous and potential confounding variables can affect the outcome of clinical research. To date, most of the studies that have investigated the effect of resveratrol administration on patient outcomes have been limited by their sample sizes. In this review, we will survey the latest advances regarding the timing, dosage, formulation, bioavailability, toxicity of resveratrol, and resveratrol-drug interactions in human studies. Moreover, the present report focuses on the actions of resveratrol treatment in combating diseases, such as cancer, diabetes, neurodegeneration, cardiovascular disease, and other age-related ailments.

Is AMPK the savior of the failing heart?

Heart failure (HF) is one of the leading causes of death, affecting more than 20 million people worldwide. A vast array of pathophysiological and molecular events contributes to the development and eventual worsening of HF. Of these, defects in myocardial metabolic processes that normally result in proper ATP production necessary to maintain contractile function appear to be a major contributor to HF pathogenesis. A key player involved in regulating myocardial metabolism is AMP-activated protein kinase (AMPK), a major regulatory kinase controlling numerous metabolic pathways. Here, we review the metabolic changes that occur in HF, what role alterations in energy metabolism has in its progression, and the involvement of AMPK in this context.

Cytochrome P450 1B1 contributes to increased blood pressure and cardiovascular and renal dysfunction in spontaneously hypertensive rats

PURPOSE

We investigated the contribution of cytochrome P450 (CYP) 1B1 to hypertension and its pathogenesis by examining the effect of its selective inhibitor, 2,4,3',5'-tetramethoxystilbene (TMS), in spontaneously hypertensive rats (SHR).

METHODS

Blood pressure (BP) was measured bi-weekly. Starting at 8 weeks, TMS (600 μg/kg, i.p.) or its vehicle was injected daily. At 14 weeks, samples were collected for measurement.

RESULTS

TMS reversed increased BP in SHR (207 ± 7 vs. 129 ± 2 mmHg) without altering BP in Wistar-Kyoto rats. Increased CYP1B1 activity in SHR was inhibited by TMS (RLU: aorta, 5.4 ± 0.7 vs. 3.7 ± 0.7; heart, 6.0 ± 0.8 vs. 3.4 ± 0.4; kidney, 411 ± 45 vs. 246 ± 10). Increased vascular reactivity, cardiovascular hypertrophy, endothelial and renal dysfunction, cardiac and renal fibrosis in SHR were minimized by TMS. Increased production of reactive oxygen species and NADPH oxidase activity in SHR, were diminished by TMS. In SHR, TMS reduced increased plasma levels of nitrite/nitrate (46.4 ± 5.0 vs. 28.1 ± 4.1 μM), hydrogen-peroxide (36.0 ± 3.7 vs. 14.1 ± 3.8 μM), and thiobarbituric acid reactive substances (6.9 ± 1.0 vs. 3.4 ± 1.5 μM). Increased plasma levels of pro-inflammatory cytokines and catecholamines, and cardiac activity of extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, c-Src tyrosine kinase, and protein kinase B in SHR were also inhibited by TMS.

CONCLUSIONS

These data suggests that increased oxidative stress generated by CYP1B1 contributes to hypertension, increased cytokine production and sympathetic activity, and associated pathophysiological changes in SHR. CYP1B1 could be a novel target for developing drugs to treat hypertension and its pathogenesis.

Alcohol consumption and risk of death in male physicians with heart failure

The 5-year risk of death after onset of heart failure (HF) is about 50%. Although previous studies have shown beneficial effects of light-to-moderate alcohol consumption and risk of cardiovascular diseases and mortality, it is unclear whether moderate alcohol consumption is associated with a lower risk of death in subjects with HF. We investigated whether alcohol consumption and type of alcohol preference are associated with the risk of total mortality in 449 US male physicians with prevalent HF. Alcohol consumption was assessed through food frequency questionnaire, and mortality was ascertained through annual follow-up questionnaires and adjudicated by an Endpoint Committee. The mean age of subjects was 75.7±8.2 years with an average follow-up of 7 years. We found evidence of a J-shaped relation between alcohol consumption and mortality (hazard ratio [95% confidence interval] 1.00 [reference], 0.85 [0.61 to 1.20], 0.60 [0.40 to 0.88], and 0.71 [0.42 to 1.21] for alcohol intake of none, <1 drink/day, 1 to 2 drinks/day, and 3+ drinks/day, respectively [p for quadratic trend=0.058]). There was no relation between beverage preference (beer, wine, or liquor) and mortality. In conclusion, our data showed a J-shaped association between alcohol intake and mortality in patients with HF.

Neuroprotective effects of resveratrol in Alzheimer disease pathology

Alzheimer's disease is a chronic neurodegenerative disorder characterized by a progressive loss of cognitive and behavioral abilities. Extracellular senile plaques and intracellular neurofibrillary tangles are hallmarks of AD. Researchers aim to analyze the molecular mechanisms underlying AD pathogenesis; however, the therapeutic options available to treat this disease are inadequate. In the past few years, several studies have reported interesting insights about the neuroprotective properties of the polyphenolic compound resveratrol (3, 5, 4'-trihydroxy-trans-stilbene) when used with in vitro and in vivo models of AD. The aim of this review is to focus on the neuroprotective and antioxidant effects of resveratrol on AD and its multiple potential mechanisms of action. In addition, because the naturally occurring forms of resveratrol have a very limited half-life in plasma, a description of potential analogs aimed at increasing the bioavailability in plasma is also discussed.

Does grape seed extract potentiate the inhibition of platelet reactivity in the presence of endothelial cells?

PURPOSE

Numerous studies have suggested that grape seed extract (GSE) confers vascular protection due to the direct effect of its polyphenol content on endothelial cells. The aim of the study was to determine whether GSE confers vascular protection through the direct effect of its polyphenol content on endothelial cells.

MATERIAL/METHODS

After incubation with GSE-treated human umbilical vein endothelial cells (HUVECs), blood platelet reactivity was evaluated with regard to the expression of CD62P and the activated form of GPIIbIIIa in ADP-stimulated platelets.

RESULTS

Lower concentrations of GSE were found to enhance the antiplatelet action of HUVECs: 1 μg/ml GSE reduced platelet reactivity by about 10%. While platelet reactivity was not altered by HUVECs incubated with higher concentrations of GSE, HUVEC proliferation was significantly reduced by GSE of up to 10 μg gallic acid equivalent/ml.

CONCLUSIONS

The results of the study show that low doses of GSE potentiate the inhibitory action of HUVECs on platelet reactivity, which may account, at least partially, for the protective effects of grape products against cardiovascular diseases. In contrast, high concentrations of GSE significantly impair endothelial cell proliferation in vitro.

Resveratrol: a supplementation for men or for mice?

Resveratrol is a polyphenolic compound found in several plants. In the last decades, the interest in this compound has enormously increased after benefits on metabolism and increased lifespan of various organisms have been reported with its supplementation. Several in-vitro and animal studies have observed that resveratrol can act on multiple molecular targets, including sirtuins, a class of NAD + -dependent deacetylases. Despite the enthusiastic results reported in many animal- and in-vitro studies, few trials have been performed in humans with contrasting results. These conflicting data may be due at least in part to differences in the characteristics of the patients enrolled, the dosages and the duration of supplementation. Furthermore, many questions remain still unsolved, such as the dose or the duration of treatment to maximize its effects, the bioavailability of resveratrol and the role of food matrix to improve its bioactivity.

In conclusion, at present the use of resveratrol as a supplement is not yet justified by the existing evidence.

Resveratrol and clinical trials: the crossroad from in vitro studies to human evidence

Resveratrol (3,5,4’-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of food-stuffs such as grapes and red wine. Resveratrol has been reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol-based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of ‘potential’ benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called ‘Resveratrol Paradox’, i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently available evidence regarding resveratrol’s effects on humans obtained from randomized clinical trials. In addition, we will provide a critical outlook for further research on this molecule that is evolving from a minor dietary compound to a possible multi-target therapeutic drug.

Resveratrol attenuates left ventricular remodeling in old rats with COPD induced by cigarette smoke exposure and LPS instillation

The objective of this study was to investigate left cardiac damage and the cardioprotective effects of resveratrol in old rats with COPD. Rats 22 months old were divided into three groups: control (CTL), smoking and lipopolysaccharides (SM/LPS), and SM/LPS plus resveratrol (SM/LPS-Res). Cardiac function, pathology, oxidative stress, and apoptosis index were measured. Expression of myocardial SIRT1 was studied by real-time quantitative polymerase chain reaction (PCR) and Western blot detection. The heart weight-body weight ratio (LVW/BW) increased in the SM/LPS group compared with the CTL group. Both the LVW/BW and the area of fibrosis in the SM/LPS-Res group decreased compared with those in the SM/LPS group. 8-OHdG expression increased in cardiac tissue of rats in the SM/LPS group, which could be inhibited by resveratrol. Resveratrol significantly increased the activity of superoxide dismutase (SOD) and reduced the cardiac malonyldialdehyde (MDA) level in the SM/LPS-Res group. There was a significant decrease in the extent of cardiomyocyte apoptosis in the SM/LPS-Res group compared with the SM/LPS group. SIRT1 mRNA increased in the SM/LPS-Res group compared with the SM/LPS group. In conclusion, resveratrol attenuated cardiac oxidative damage and left ventricular remodeling and enhanced the decreased expression of SIRT1 in hearts of old rats with emphysema and thus might be a therapeutic modality for cardiac injury complicated in chronic obstructive pulmonary disease (COPD).