Pharmacological preconditioning with resveratrol: role of nitric oxide

The Role of Resveratrol in Aging and Senescence: A Focus on Molecular Mechanisms

Resveratrol (Res), a polyphenol found in red wine, has been shown to decelerate aging, the progressive loss of physiological integrity and cellular senescence, characterized by the inability to progress through the cell cycle. No successful clinical trials have yet to be completed in humans on dose limitations. Yet, the potent anti-aging and anti-senescence efficacy of Res has been documented in several in vivo animal models. In this review, we highlight the molecular mechanisms of Res efficacy in antiaging disorders, such as diabetes, neurodegenerative disorders, eye diseases, and cardiovascular diseases.

Protective or Inhibitory Effect of Pharmacological Therapy on Cardiac Ischemic Preconditioning: A Literature Review

Ischemic preconditioning (IP) is an innate phenomenon, triggered by brief, non-lethal cycles of ischemia/reperfusion applied to a tissue or organ that confers tolerance to a subsequent more prolonged ischemic event. Once started, it can reduce the severity of myocardial ischemia associated with some clinical situations, such as percutaneous coronary intervention (PCI) and intermittent aortic clamping during coronary artery bypass graft surgery (CABG). Although the mechanisms underlying IP have not been completely elucidated, several studies have shown that this phenomenon involves the participation of cell triggers, intracellular signaling pathways, and end-effectors. Understanding this mechanism enables the development of preconditioning mimetic agents. It is known that a range of medications that activate the signaling cascades at different cellular levels can interfere with both the stimulation and the blockade of IP. Investigations of signaling pathways underlying ischemic conditioning have identified a number of therapeutic targets for pharmacological manipulation. This review aims to present and discuss the effects of several medications on myocardial IP.

Protective Effects of Polyphenols against Ischemia/Reperfusion Injury

Myocardial infarction (MI) is a leading cause of morbidity and mortality across the world. It manifests as an imbalance between blood demand and blood delivery in the myocardium, which leads to cardiac ischemia and myocardial necrosis. While it is not easy to identify the first pathogenic cause of MI, the consequences are characterized by ischemia, chronic inflammation, and tissue degeneration. A poor MI prognosis is associated with extensive cardiac remodeling. A loss of viable cardiomyocytes is replaced with fibrosis, which reduces heart contractility and heart function. Recent advances have given rise to the concept of natural polyphenols. These bioactive compounds have been studied for their pharmacological properties and have proven successful in the treatment of cardiovascular diseases. Studies have focused on their various bioactivities, such as their antioxidant and anti-inflammatory effects and free radical scavenging. In this review, we summarized the effects and benefits of polyphenols on the cardiovascular injury, particularly on the treatment of myocardial infarction in animal and human studies.

Biological Activities of Stilbenoids

Stilbenoids are a group of naturally occurring phenolic compounds found in various plant species. They share a common backbone structure known as stilbene, but differ in the nature and position of substituents. Stilbenoids are classified as phytoalexins, which are antimicrobial compounds produced de novo in plants to protect against fungal infection and toxins. In this review, the biological effects of stilbenoids such as resveratrol, pterostilbene, gnetol and piceatannol are discussed. Stilbenoids exert various biological activities ranging from cardioprotection, neuroprotection, anti-diabetic properties, depigmentation, anti-inflammation, cancer prevention and treatment. The results presented cover a myriad of models, from cell culture to animal studies as well as clinical human trials. Although positive results were obtained in most cell culture and animal studies, further human studies are needed to substantiate beneficial effects of stilbenoids. Resveratrol remains the most widely studied stilbenoid. However, there is limited information regarding the potential of less common stilbenoids. Therefore, further research is warranted to evaluate the salutary effects of various stilbenoids.

Effect of resveratrol and environmental enrichment on biomarkers of oxidative stress in young healthy mice

Resveratrol (RESV) and Environmental Enrichment (EE) have been separately reported to protect organisms against various diseases. This study investigated the potential benefit of the combination of RESV and EE on biomarkers of oxidative stress in young healthy mice. Fifty mice of both sexes were randomly divided into five groups of 10 animals each: group I served as control, group II were maintained on alternate day feeding, group III received RESV 50 mg/kg, suspended in caboxymethylcellulose orally per kg/day. Group IV received CMC and kept in an Enriched Environment, group V received RESV + EE. The treatment lasted for 28 days. The animals were sacrificed 24 h after the last treatment and brain samples were collected for biochemical evaluation. The results obtained showed a significant decrease (P < 0.05) in malondialdehyde concentration in EE group and RESV treated group kept EE when compared to the control. A significant decrease was also observed in glutathione peroxidase activity in all the treatment groups when compared to the control. A significant decrease in GPx activities in RESV, EE and RESV + EE treated groups in male and female mice when compared to the control groups respectively. However, a significant increase in GPx activities was observed in EE group in male mice and EODF, RESV groups in female mice when compared to RESV + EE groups respectively. In conclusion, the result of our study indicates that EE possesses antioxidant properties by decreasing MDA concentration and attenuating lipid peroxidation in the brain of young Swiss albino mice.

Protective effect of resveratrol against inflammation, oxidative stress and apoptosis in pancreas of aged SAMP8 mice

Aging is a physiological state in which a progressive decline in organ functions is accompanied by the development of age-related diseases. Resveratrol supplementation has been shown to exert anti-inflammatory and antioxidant effects in various mammalian models of aging. Senescence-accelerated mice (SAM) are commonly used as animal models to investigate the aging process. In the present study, the effects of inflammation, oxidative stress and apoptosis in pancreas of two different types of SAM (SAMR1 or resistant to aging, and SAMP8 or prone to aging) have been analysed, as well as the effect of resveratrol administration (5mg/kg/day) on these parameters in the SAMP8 strain. mRNA expressions of sirtuin 1 and FoxO factors were found to be decreased with aging in SAMP8 mice. An increase in inflammatory status and nuclear-factor kappa B (NFκB) protein expression was also observed in old mice, together with a decrease of anti-apoptotic markers and antioxidant-enzyme activity. Resveratrol administration was able to increase sirtuin 1 mRNA expression, as well as decreasing NFκB expression and reducing the proinflammatory and prooxidant status associated with age. In conclusion, resveratrol was able to modulate the inflammatory, oxidative and apoptotic status related to aging, thereby exerting a protective effect on pancreas age-induced damage.

The paradoxical pro- and antiangiogenic actions of resveratrol: therapeutic applications in cancer and diabetes

Resveratrol, a polyphenol found in grapes, peanuts, and red wine, plays different roles in diseases such as cancer and diabetes. Existing information indicates that resveratrol provides cardioprotection, as evidenced by superior postischemic ventricular recovery, reduced myocardial infarct size, and decreased number of apoptotic cardiomyocytes associated with resveratrol treatment in animal models. Cardiovascular benefits are experienced in humans with routine but not acute consumption of red wine. In this concise review, the paradoxical pro- and antiangiogenic effects of resveratrol are described, and different roles for resveratrol in the formation of new blood vessels are explained through different mechanisms. It is hypothesized that the effects of resveratrol on different cell types are not only dependent on its concentration but also on the physical and chemical conditions surrounding cells. The findings discussed herein shed light on potential therapeutic proapoptotic and antiangiogenic applications of low-dose resveratrol treatment in the prevention and treatment of different diseases.

Targeting Nitric Oxide with Natural Derived Compounds as a Therapeutic Strategy in Vascular Diseases

Within the family of endogenous gasotransmitters, nitric oxide (NO) is the smallest gaseous intercellular messenger involved in the modulation of several processes, such as blood flow and platelet aggregation control, essential to maintain vascular homeostasis. NO is produced by nitric oxide synthases (NOS) and its effects are mediated by cGMP-dependent or cGMP-independent mechanisms. Growing evidence suggests a crosstalk between the NO signaling and the occurrence of oxidative stress in the onset and progression of vascular diseases, such as hypertension, heart failure, ischemia, and stroke. For these reasons, NO is considered as an emerging molecular target for developing therapeutic strategies for cardio- and cerebrovascular pathologies. Several natural derived compounds, such as polyphenols, are now proposed as modulators of NO-mediated pathways. The aim of this review is to highlight the experimental evidence on the involvement of nitric oxide in vascular homeostasis focusing on the therapeutic potential of targeting NO with some natural compounds in patients with vascular diseases.

Resveratrol and anti-atherogenic effects

The role of inflammation and oxidative stress in atherosclerosis development has been increasingly well recognized over the past decade. Inflammation has a significant role at all stages of atherosclerosis, including initiation, progression and plaque formation. Resveratrol is a naturally occurring polyphenolic compound found in grape products, berry fruits and red wine. Its ability to behave therapeutically as a component of red wine has attracted wide attention. Accumulating evidence suggests that it is a highly pleiotropic molecule that modulates numerous targets and molecular functions. Epidemiological studies indicate that the Mediterranean diet, rich in resveratrol, is associated with a reduced risk of atherosclerosis. Resveratrol is believed to decrease circulating low-density lipoprotein cholesterol levels, reduce cardiovascular disease risk; it reduces lipid peroxidation, platelet aggregation and oxidative stress. Resveratrol is considered a safe compound, since no significant toxic effects have been demonstrated after administration of a broad range of concentrations, and an effective anti-atherogenic agent.

Natural polyphenols and spinal cord injury

Polyphenols have been shown to have some of the neuroprotective effects against neurodegenerative diseases. These effects are attributed to a variety of biological activities, including free radical scavenging/antioxidant and anti-inflammatory and anti-apoptotic activities. In this regard, many efforts have been made to study the effects of various well-known dietary polyphenols on spinal cord injury (SCI) and to explore the mechanisms behind the neuroprotective effects. The aim of this paper is to present the mechanisms of neuroprotection of natural polyphenols used in animal models of SCI.

Effect of aminoguanidine on sciatic functional index, oxidative stress, and rate of apoptosis in an experimental rat model of ischemia-reperfusion injury

This study was conducted to investigate the potential protective effects of aminoguanidine (AG) on sciatic functional index (SFI), oxidative stress status, and apoptosis index using a rat model of experimental sciatic nerve ischemia-reperfusion injury (I/R). Treatment groups received 150 mg AG/kg body mass, 24 h after the induction of ischemia. After reperfusion for 2, 4, 7, 14, and 28 days, we evaluated measured SFI, plasma antioxidant enzymes, total antioxidant capacity (TAC), malondialdehyde (MDA), and index of apoptosis. SFI was significantly improved on the 7th and 14th day of reperfusion in the AG-treated groups. AG treatment resulted in the significant reduction of MDA levels on the 7th and 14th day of reperfusion. TAC was only increased after 7 days of reperfusion compared with the untreated group. SOD activity was decreased in both the untreated and AG-treated groups by comparison with the control, but did not show a significant change. GPx activity decreased only after 7 days of reperfusion. The maximal rate of apoptosis occurred on the 7th day of reperfusion. Treatment with AG significantly reduced this enhancement. AG exhibits positive effects against sciatic nerve I/R injury, possibly in part because of the protective effects of AG against apoptosis and I/R-induced oxidative stress.

In vitro effects of resveratrol on oxidative stress in diabetic platelets

To evaluate the in vitro effects of resveratrol (RSV) incubation on platelets from compensated and decompensated diabetic patients in order to use it as an adjuvant therapy. The study was performed on 77 diabetic patients and divided into two phases: 29 compensated and 48 decompensated diabetic platelets were analyzed at recruitment (T₀) and after in vitro RSV incubation (20 μg/ml) for 3 h at 37 °C (T₁). Lipoperoxide and nitric oxide (NO) levels, superoxide dismutase (SOD) and Na(+)/K(+) ATPase activities, total antioxidant capacity (TAC), and membrane fluidity tested by anisotropy of fluorescent probes TMA-DPH and DPH were determined. In vitro RSV incubation counteracts oxidative damage associated with diabetes and its complications; it is able to improve platelet function through augmented membrane fluidity and Na(+)/K(+) ATPase activity; it enhances antioxidant systems' functionality by increasing NO levels, SOD activity, and TAC and by decreasing lipoperoxide levels in both compensated and decompensated patients. Such platelet functionality enhancement suggests a new method of secondary prevention of complications associated with platelet dysfunction. Being free from one of the major risks associated with many antidiabetic agents, it can be assumed that RSV utilization in the diabetic diet may have a preventive and protective role in the progression of diabetic oxidative damage.

Genetics and genomics of ischemic tolerance: focus on cardiac and cerebral ischemic preconditioning

A subthreshold ischemic insult applied to an organ such as the heart and/or brain may help to reduce damage caused by subsequent ischemic episodes. This phenomenon is known as ischemic tolerance mediated by ischemic preconditioning (IPC) and represents the most powerful endogenous mechanism against ischemic injury. Various molecular pathways have been implicated in IPC, and several compounds have been proposed as activators or mediators of IPC. Recently, it has been established that the protective phenotype in response to ischemia depends on a coordinated response at the genomic, molecular, cellular and tissue levels by introducing the concept of 'genomic reprogramming' following IPC. In this article, we sought to review the genetic expression profiles found in cardiac and cerebral IPC studies, describe the differences between young and aged organs in IPC-mediated protection, and discuss the potential therapeutic application of IPC and pharmacological preconditioning based on the genomic response.

Antioxidant effects of resveratrol in cardiovascular, cerebral and metabolic diseases

Resveratrol-a natural polyphenolic compound-was first discovered in the 1940s. Although initially used for cancer therapy, it has shown beneficial effects against most cardiovascular and cerebrovascular diseases. A large part of these effects are related to its antioxidant properties. Here we review: (a) the sources, the metabolism, and the bioavailability of resveratrol; (b) the ability of resveratrol to modulate redox signalling and to interact with multiple molecular targets of diverse intracellular pathways; (c) its protective effects against oxidative damage in cardio-cerebro-vascular districts and metabolic disorders such as diabetes; and (d) the evidence for its efficacy and toxicity in humans. The overall aim of this review is to discuss the frontiers in the field of resveratrol's mechanisms, bioactivity, biology, and health-related use.

Resveratrol protects C6 astrocyte cell line against hydrogen peroxide-induced oxidative stress through heme oxygenase 1

Resveratrol, a polyphenol presents in grapes and wine, displays antioxidant and anti-inflammatory properties and cytoprotective effect in brain pathologies associated to oxidative stress and neurodegeneration. In previous work, we demonstrated that resveratrol exerts neuroglial modulation, improving glial functions, mainly related to glutamate metabolism. Astrocytes are a major class of glial cells and regulate neurotransmitter systems, synaptic processing, energy metabolism and defense against oxidative stress. This study sought to determine the protective effect of resveratrol against hydrogen peroxide (H₂O₂)-induced cytotoxicity in C6 astrocyte cell line, an astrocytic lineage, on neurochemical parameters and their cellular and biochemical mechanisms. H₂O₂ exposure increased oxidative-nitrosative stress, iNOS expression, cytokine proinflammatory release (TNFα levels) and mitochondrial membrane potential dysfunction and decreased antioxidant defenses, such as SOD, CAT and creatine kinase activity. Resveratrol strongly prevented C6 cells from H₂O₂-induced toxicity by modulating glial, oxidative and inflammatory responses. Resveratrol per se increased heme oxygenase 1 (HO1) expression and extracellular GSH content. In addition, HO1 signaling pathway is involved in the protective effect of resveratrol against H₂O₂-induced oxidative damage in astroglial cells. Taken together, these results show that resveratrol represents an important mechanism for protection of glial cells against oxidative stress.

Modulation of microRNA 20b with resveratrol and longevinex is linked with their potent anti-angiogenic action in the ischaemic myocardium and synergestic effects of resveratrol and γ-tocotrienol

Resveratrol, a constituent of red wine, and γ-tocotrienol, a constituent of palm oil are important for cardioprotection. Although microRNAs are known regulators for genes involved in cardiac remodelling, the regulatory pathway involving microRNA has not been studied so far. We explored the cardioprotection by resveratrol, longevinex and γ−tocotrienol in ischaemia/reperfusion(I/R) model of rat and determined miRNA profile from isolated RNA. Systemic analyses of miRNA array and theirs targets were determined using a number of computational approaches. Resveratrol and γ-tocotrienol, either alone or in combination, modulated the expression pattern of miRNAs close to the control level based on PCA analyses. Differential expression was observed in over 75 miRNAs, some of them, such as miR-21 and miR-20b (anti-angiogenic) were previously implicated in cardiac remodelling. The target genes for the highest differentially expressed miRNA include genes of various molecular functions such as TGFβ1–Smad3 signalling pathway, inflammation and their transcription factors, which may play key role in reducing I/R injury. Administration of antagomiR-20 attenuated I/R induced vascular endothelial growth factor and HIF1α level. All the interventions treated for 3 weeks lead to significant cardioprotection against ischaemia/reperfusion injury. A unique signature of miRNA profile is observed in control heart pretreated with resveratrol or γ-tocotrienol. We have determined specific group of miRNA in heart that have altered during IR injuries. Most of those altered microRNA expressions modulated close to their basal level in resveratrol or longevinex treated I/R rat. Interestingly, resveratrol and γ-tocotrienol resulted in synergestic action.

Inhibition of Na⁺-H⁺ exchange as a mechanism of rapid cardioprotection by resveratrol

BACKGROUND AND PURPOSE Resveratrol is a polyphenol abundantly found in grape skin and red wine. In the present study, we investigated whether resveratrol exerts protective effects against cardiac ischaemia/reperfusion and also explored its mechanisms. EXPERIMENTAL APPROACH Infarct size and functional recovery in rat isolated perfused hearts subjected to no-flow global ischaemia followed by reperfusion were measured. Cultured neonatal rat cardiomyocytes were exposed to H(2)O(2) (100 µmol·L(-1)) to induce cell injury. Intracellular ion concentrations were measured using specific dyes. Western blotting was used to quantify protein expression levels. KEY RESULTS In rat isolated perfused hearts, treatment with resveratrol (20 and 100 µmol·L(-1)) 15 min before ischaemia considerably improved left ventricular functional recovery and infarct size. In cultured neonatal rat cardiomyocytes, resveratrol significantly attenuated the increase in reactive oxygen species (ROS) and loss of mitochondrial inner membrane potential. Resveratrol also suppressed the increase in intracellular concentrations of Na(+) ([Na(+)](i)) and Ca(2+) ([Ca(2+)](i)) after H(2)O(2) application; however, it did not suppress the ouabain-induced [Ca(2+) ](i) increase. By measuring changes in intracellular pH recovery after acidification, we also confirmed that acid-induced activation of the Na(+)-H(+) exchanger (NHE) was prevented by pretreatment with resveratrol. Furthermore, resveratrol inhibited the H(2)O(2)-induced translocation of PKC-α from the cytosol to the cell membrane; this translocation is believed to activate NHE. CONCLUSION AND IMPLICATIONS Resveratrol exerts cardioprotection by reducing ROS and preserving mitochondrial function. The PKC-α-dependent inhibition of NHE and subsequent attenuation of [Ca(2+)](i) overload may be a cardioprotective mechanism.

Resveratrol promotes cellular glucose utilization in primary cultured cortical neurons via calcium-dependent signaling pathway

BACKGROUND AND PURPOSE

Impairment of glucose utilization contributes to neuronal degeneration of Alzheimer's disease patients. Cellular glucose utilization can be regulated by calcium-dependent signaling pathways. Resveratrol (RSV) is a plant-derived polyphenol with multiple beneficial effects, including neuroprotection and metabolic improvement. Here, we investigated the effect of RSV on neuronal calcium signal and glucose utilization.

EXPERIMENTAL METHODS

Primary culture of cortical neurons, calcium imaging, 2-NBDG assay and western blotting were employed to investigate RSV-mediated effects on neuronal calcium signal and glucose utilization.

RESULTS

RSV elevated intracellular calcium in cortical neurons via modulation of secondary messenger system including nitrous oxide, cGMP and cAMP. Secondarily, a calcium-dependent enhancement of neuronal glucose utilization after RSV treatment was observed. The effects on neuronal glucose utilization are largely dependent on RSV-induced calcium-dependent AMP-activated protein kinase activation.

CONCLUSION

Our findings show that activation of calcium-dependent signaling pathways by RSV may convey improvements of neuronal glucose utilization.

A possible subcellular mechanism underlying the "French paradox": the opening of mitochondrial K(ATP) channels

A reduction in the risk of coronary heart disease has been associated to moderate red wine consumption. We tested whether a nonalcoholic red wine extract would open mitochondrial K(ATP) channels in guinea pig myocytes. The opening of mitochondrial K(ATP) channels was assessed by endogenous flavoprotein fluorescence. Red wine extract (100 μg·mL(-1)) increased flavoprotein oxidation (10.9% ± 1.2%, n = 20). This effect was prevented by the mitochondrial K(ATP) channel blocker, 5-hydroxydecanoate (500 µmol·L(-1); 0.3% ± 1.1%, n = 13), confirming the hypothesis that red wine extract opens mitochondrial K(ATP) channels.

Sepiapterin enhances angiogenesis and functional recovery in mice after myocardial infarction

Uncoupling of nitric oxide synthase (NOS) has been implicated in left ventricular (LV) remodeling and dysfunction after myocardial infarction (MI). We hypothesized that inducible NOS (iNOS) plays a crucial role in LV remodeling after MI, depending on its coupling status. MI was created in wild-type, iNOS-knockout (iNOS(-/-)), endothelial NOS-knockout (eNOS(-/-)), and neuronal NOS-knockout (nNOS(-/-)) mice. iNOS and nNOS expressions were increased after MI associated with an increase in nitrotyrosine formation. The area of myocardial fibrosis and LV end-diastolic volume and ejection fraction were more deteriorated in eNOS(-/-) mice compared with other genotypes of mice 4 wk after MI. The expression of GTP cyclohydrolase was reduced, and tetrahydrobiopterin (BH(4)) was depleted in the heart after MI. Oral administration of sepiapterin after MI increased dihydrobiopterin (BH(2)), BH(4), and BH(4)-to-BH(2) ratio in the infarcted but not sham-operated heart. The increase in BH(4)-to-BH(2) ratio was associated with inhibition of nitrotyrosine formation and an increase in nitrite plus nitrate. However, this inhibition of NOS uncoupling was blunted in iNOS(-/-) mice. Sepiapterin increased capillary density and prevented LV remodeling and dysfunction after MI in wild-type, eNOS(-/-), and nNOS(-/-) but not iNOS(-/-) mice. N(ω)-nitro-L-arginine methyl ester abrogated sepiapterin-induced increase in nitrite plus nitrate and angiogenesis and blocked the beneficial effects of sepiapterin on LV remodeling and function. These results suggest that sepiapterin enhances angiogenesis and functional recovery after MI by activating the salvage pathway for BH(4) synthesis and increasing bioavailable nitric oxide predominantly derived from iNOS.

Resveratrol inhibition of inducible nitric oxide synthase in skeletal muscle involves AMPK but not SIRT1

The plant-derived polyphenol resveratrol (RSV) modulates life span and metabolism, and it is thought that these effects are largely mediated by activating the deacetylase enzyme SIRT1. However, RSV also activates the cell energy sensor AMP-activated protein kinase (AMPK). We have previously reported that AMPK activators inhibit inducible nitric oxide synthase (iNOS), a key proinflammatory mediator of insulin resistance in endotoxemia and obesity. The aim of this study was to evaluate whether RSV inhibits iNOS induction in insulin target tissues and to determine the role of SIRT1 and AMPK activation in this effect. We found that RSV (40 mg/kg ip) treatment decreased iNOS induction and NO production in skeletal muscle and white adipose tissue, but not in liver, of endotoxin (LPS)-challenged mice. This effect of the polyphenol was recapitulated in vitro, where RSV (10-80 μM) robustly inhibited iNOS protein induction and NO production in cytokine/LPS-treated L6 myocytes and 3T3-L1 adipocytes. However, no effect of RSV was observed on iNOS induction in FAO hepatocytes. Further studies using inhibitors of SIRT1 revealed that the deacetylase enzyme is not involved in RSV action on iNOS. In marked contrast, RSV activates AMPK in L6 myocytes, and blunting its activation using Compound C or RNA interference partly blocked the inhibitory effect of RSV on NO production. These results show that RSV specifically inhibits iNOS induction in muscle through a mechanism involving AMPK but not SIRT1 activation. This anti-inflammatory action of RSV likely contributes to the therapeutic effect of this plant polyphenol.

Ascorbic acid and N-acetyl cysteine prevent uncoupling of nitric oxide synthase and increase tolerance to ischemia/reperfusion injury in diabetic rat heart

Oxidative stress may cause a loss of tetrahydrobiopterin (BH4), a co-factor of nitric oxide synthase (NOS), decrease the bioavailability of NO and aggravate ischemia/reperfusion (I/R) injury in diabetic heart. We hypothesized that ascorbic acid (AA) and N-acetyl cysteine (NAC) protect the diabetic heart from I/R injury by increasing BH4/dihydrobiopterin (BH2) ratio and inhibiting uncoupling of NOS. Diabetes mellitus was induced in rats by streptozotocin treatment, and the hearts were isolated and perfused. BH4 and BH4/BH2 ratio decreased in the diabetic heart associated with increased production of superoxide and nitrotyrosine (NT). Treatment with AA or NAC significantly increased BH4/BH2 ratio in the diabetic heart associated with decreased production of superoxide and NT and increased generation of nitrate plus nitrite (NOx). Pre-treatment with AA or NAC before 30 min ischemia followed by 120 min reperfusion improved left ventricular (LV) function and reduced infarct size in the diabetic but not non-diabetic hearts. The NOS inhibitor, L-NAME, inhibited the increase in the generation of superoxide, NT and NOx, but aggravated LV function and increased infarct size in the diabetic heart. L-NAME also abrogated the increase in NOx and improvement of LV function and the infarct size-limiting effect induced by AA or NAC in the diabetic heart. These results suggest that AA and NAC increase BH4/BH2 ratio and prevent NOS uncoupling in the diabetic heart. Resultant increase in the bioavailability of NO renders the diabetic heart toleratant to I/R injury.

Oxidative stress as pathogenesis of cardiovascular risk associated with metabolic syndrome

Metabolic syndrome (MetS) is characterized by accumulation of visceral fat associated with the clustering of metabolic and pathophysiological cardiovascular risk factors: impaired glucose tolerance, dyslipidemia, and hypertension. Although the definition of MetS is different among countries, visceral obesity is an indispensable component of MetS. A growing body of evidence suggests that increased oxidative stress to adipocytes is central to the pathogenesis of cardiovascular disease in MetS. Increased oxidative stress to adipocytes causes dysregulated expression of inflammation-related adipocytokines in MetS, which contributes to obesity-associated vasculopathy and cardiovascular risk primarily through endothelial dysfunction. The purpose of present review is to unravel the mechanistic link between oxidative stress and cardiovascular risk in MetS, focusing on insulin resistance, hypertension, and atherosclerosis. Then, therapeutic opportunities translated from the bench to bedside will be provided to develop novel strategies to cardiovascular risk factors in MetS.

Red wine: A drink to your heart

Mortality and morbidity are still high in cardiovascular disease (CVD). Myocardial ischemia reperfusion injury leading to myocardial infarction is one of the most frequent causes of the death in humans. Atherosclerosis and generation of reactive oxygen species through oxidative stress is the major risk factor for CVD. From the literature collection, it has been identified that moderate consumption of red wine helps in preventing CVD through several mechanisms, including increasing the high-density lipoprotein cholesterol plasma levels, decreasing platelet aggregation, by antioxidant effects, and by restoration of endothelial function. The aim of this review is to discuss the accumulating evidence that suggests that red wine possesses a diverse range of biological actions and may be beneficial in the prevention of CVD.

Calorie restriction and resveratrol in cardiovascular health and disease

Calorie restriction is one of the most effective nutritional interventions that reproducibly protects against obesity, diabetes and cardiovascular disease. Recent evidence suggests that even when implemented over a short period, calorie restriction is a safe and effective treatment for cardiovascular disease. Herein, we review the effects of calorie restriction on the cardiovascular system as well as the biological effects of resveratrol, the most widely studied molecule that appears to mimic calorie restriction. An overview of microarray data reveals that the myocardial transcriptional effects of calorie restriction overlap with the transcriptional responses to resveratrol treatment. In addition, calorie restriction and resveratrol modulate similar pathways to improve mitochondrial function, reduce oxidative stress and increase nitric oxide production that are involved in atherosclerosis prevention, blood pressure reduction, attenuation of left-ventricular hypertrophy, resistance to myocardial ischemic injury and heart failure prevention. We also review the data that suggest that the effects of calorie restriction and resveratrol on the cardiovascular system may involve signaling through the silent information regulator of transcription (SIRT), Akt and the AMP-activated protein kinase (AMPK) pathways. While accumulating data demonstrate the health benefits of calorie restriction and resveratrol in experimental animal models, whether these interventions translate to patients with cardiovascular disease remains to be determined.

Effects of some common food constituents on cardiovascular disease

Cardiovascular diseases are the major cause of morbidity and mortality worldwide, and there is considerable interest in the role of dietary constituents and supplements in the prevention and treatment of these disorders. We reviewed the major publications related to potential effects on cardiovascular risk factors and outcomes of some common dietary constituents: carotenoids, flavonoid-rich cocoa, tea, red wine and grapes, coffee, omega-3 fatty acids, and garlic. Increased intake of some of these has been associated with reduced all-cause mortality or reduced incidence of myocardial infraction, stroke, and hypertension. However, although the evidence from observational studies is supportive of beneficial effects for most of these foodstuffs taken as part of the diet, potential benefits from the use of supplements derived from these natural products remain largely inconclusive.

Polyphenolic profiles detected in the ripe berries of Vitis vinifera germplasm

Polyphenolic profiles in the berry samples of 344 European grape (Vitis vinifera) cultivars were evaluated for two consecutive years. These cultivars represent a diverse collection of V. vinifera germplasm maintained at the USDA-Agricultural Research Service Vitis Clonal Repository in Davis of California, USA. A total of 36 polyphenolic compounds, including 16 anthocyanins, 6 flavonols, 6 flavanols, 6 hydroxycinnamic acids and 2 hydroxybenzoic acids, were identified via HPLC-MS and quantified by HPLC-DAD. The mean contents for anthocyanins, flavanols, flavonols, hydroxycinnamic acids and hydroxybenzoic acids were 0.946 (coloured cultivars), 0.147, 0.043, 0.195 and 0.016mgg(-1) FW, respectively. On average, wine grapes had higher concentrations than had table grapes for all of these compounds except hydroxycinnamic acids. Berry colours affected the total contents of anthocyanins, but not others. Positive correlations (0.151-0.535) were found among these groups of compounds. As expected, these groups of compounds were all negatively correlated with berry weight.

Is red wine a SAFE sip away from cardioprotection? Mechanisms involved in resveratrol- and melatonin-induced cardioprotection

Epidemiological studies suggest that regular moderate consumption of red wine confers cardioprotection but the mechanisms involved in this effect remain unclear. Recent studies demonstrate the presence of melatonin in wine. We propose that melatonin, at a concentration found in red wine, confers cardioprotection against ischemia-reperfusion injury. Furthermore, we investigated whether both melatonin and resveratrol protect via the activation of the newly discovered survivor activating factor enhancement (SAFE) prosurvival signaling pathway that involves the activation of tumor necrosis factor alpha (TNFα) and the signal transducer and activator of transcription 3 (STAT3). Isolated perfused male mouse (wild type, TNFα receptor 2 knockout mice, and cardiomyocyte-specific STAT3-deficient mice) or rat hearts (Wistars) were subjected to ischemia-reperfusion. Resveratrol (2.3 mg/L) or melatonin (75 ng/L) was perfused for 15 min with a 10-min washout period prior to an ischemia-reperfusion insult. Infarct size was measured at the end of the protocol, and Western blot analysis was performed to evaluate STAT3 activation prior to the ischemic insult. Both resveratrol and melatonin, at concentrations found in red wine, significantly reduced infarct size compared with control hearts in wild-type mouse hearts (25 ± 3% and 25 ± 3% respectively versus control 69 ± 3%, P < 0.001) but failed to protect in TNF receptor 2 knockout or STAT3-deficient mice. Furthermore, perfusion with either melatonin or resveratrol increased STAT3 phosphorylation prior to ischemia by 79% and 50%, respectively (P < 0.001 versus control). Our data demonstrate that both melatonin and resveratrol, as found in red wine, protect the heart in an experimental model of myocardial infarction via the SAFE pathway.

Drugs, nutrients, and phytoactive principles improving the health span of rodent models of human age-related diseases

Rodents are often the species of choice to examine the effect of drugs on survival and on the progression of specific diseased tissues. This statement is also true for research laboratories working in the field of nutrition and aging. In addition to diets that can reduce the life expectancy of rodents, such as diabetogenic or high-fat diets, genetically modified rodents exhibiting different accelerated age-associated diseases also provide important biologic tools to decipher the impact of drugs, nutrients, or phytoactive compounds on their health and life span. This review covers some of the chemicals believed to decelerate the appearance of age-related diseases in different rodent models. Such chemicals include antioxidants, anti-inflammatory molecules, modulators of metabolic sensors, calorie restriction mimetics, and vegetal polyphenolic compounds that affect mitochondrial functions, cellular proliferation or differentiation as well as cell functionality.

Anti-inflammatory effects of resveratrol: possible role in prevention of age-related cardiovascular disease

Cardiovascular diseases are the most common cause of death among the elderly in the Western world. Resveratrol (3,5,4'-trihydroxystilbene) is a plant-derived polyphenol that was shown to exert diverse anti-aging activity mimicking some of the molecular and functional effects of caloric restriction. This mini-review focuses on the molecular and cellular mechanisms activated by resveratrol in the vascular system, and explores the links between its anti-oxidative and anti-inflammatory effects, which could be exploited for the prevention or amelioration of vascular aging in the elderly.

Reversal of inducible nitric oxide synthase uncoupling unmasks tolerance to ischemia/reperfusion injury in the diabetic rat heart

The diabetic heart is known to be susceptible to ischemia/reperfusion (I/R) injury by increased oxidative stress. Although oxidative stress upregulates inducible nitric oxide (iNOS), the role of iNOS in I/R injury in the diabetic heart has been poorly understood. Because iNOS-derived nitric oxide (NO) plays a crucial role in cardioprotection against I/R injury, we hypothesized that inhibition of iNOS uncoupling would restore tolerance to I/R injury in the diabetic heart. The present study demonstrated that iNOS-derived superoxide generation was reduced, and that the NO bioavailability was increased, by treatment with the NOS-cofactor, tetrahydrobiopterin (BH4), before I/R in the hearts isolated from diabetic rats. This was associated with a reduction of infarct size and improvement of left ventricular (LV) function after I/R. The cardioprotective effect of BH4 was abrogated by treatment with a thiol reducing agent dithiothreitol (DTT), but not a NO-sensitive guanylyl cyclase inhibitor ODQ, suggesting that iNOS-derived NO-mediated cardioprotection occurs through protein S-nitrosylation but not cGMP-dependent signaling in the diabetic heart. Indeed, protein S-nitrosylation was increased by treatment with BH4 in the diabetic heart and was inhibited by DTT. These results suggest that the inhibition of iNOS uncoupling unmasks tolerance to I/R injury through enhanced protein S-nitrosylation in the diabetic rat heart.

Restoration of altered microRNA expression in the ischemic heart with resveratrol

BACKGROUND

Resveratrol, a constituent of red wine, is important for cardioprotection. MicroRNAs are known regulators for genes involved in resveratrol-mediated cardiac remodeling and the regulatory pathway involving microRNA has not been studied so far.

METHODS

We explored the cardioprotection by resveratrol in ischemia/reperfusion model of rat and determined cardiac functions. miRNA profile was determined from isolated RNA using quantitative Real-time PCR based array. Systemic analyses of miRNA array and theirs targets were determined using a number of computational approaches.

RESULTS

Cardioprotection by resveratrol and its derivative in ischemia/reperfusion [I/R] rat model was examined with miRNA expression profile. Unique expression pattern were found for each sample, particularly with resveratrol [pure compound] and longevinex [commercial resveratrol formulation] pretreated hearts. Longevinex and resveratrol pretreatment modulates the expression pattern of miRNAs close to the control level based on PCA analyses. Differential expression was observed in over 25 miRNAs, some of them, such as miR-21 were previously implicated in cardiac remodeling. The target genes for the differentially expressed miRNA include genes of various molecular function such as metal ion binding, sodium-potassium ion, transcription factors, which may play key role in reducing I/R injury.

CONCLUSION

Rats pretreated with resveratrol for 3 weeks leads to significant cardioprotection against ischemia/reperfusion injury. A unique signature of miRNA profile is observed in control heart pretreated with resveratrol or longevinex. We have determined specific group of miRNA in heart that have altered during IR injuries. Most of those altered microRNA expressions modulated close to their basal level in resveratrol or longevinex treated I/R mice.

Cellular and mitochondrial effects of alcohol consumption

Alcohol dependence is correlated with a wide spectrum of medical, psychological, behavioral, and social problems. Acute alcohol abuse causes damage to and functional impairment of several organs affecting protein, carbohydrate, and fat metabolism. Mitochondria participate with the conversion of acetaldehyde into acetate and the generation of increased amounts of NADH. Prenatal exposure to ethanol during fetal development induces a wide spectrum of adverse effects in offspring, such as neurologic abnormalities and pre- and post-natal growth retardation. Antioxidant effects have been described due to that alcoholic beverages contain different compounds, such as polyphenols as well as resveratrol. This review analyzes diverse topics on the alcohol consumption effects in several human organs and demonstrates the direct participation of mitochondria as potential target of compounds that can be used to prevent therapies for alcohol abusers.