Resveratrol attenuates thromboxane A2 receptor agonist-induced platelet activation by reducing phospholipase C activity

Multidimensional biological activities of resveratrol and its prospects and challenges in the health field

Resveratrol (RES) is a naturally occurring polyphenolic compound. Recent studies have identified multiple potential health benefits of RES, including antioxidant, anti-inflammatory, anti-obesity, anticancer, anti-diabetic, cardiovascular, and neuroprotective properties. The objective of this review is to summarize and analyze the studies on the biological activities of RES in disease prevention and treatment, as well as its metabolism and bioavailability. It also discusses the challenges in its clinical application and future research directions. RES exhibits significant potential in the prevention and treatment of many diseases. The future direction of RES research should focus on improving its bioavailability, conducting more clinical trials to determine its effectiveness in humans, and investigating its mechanism of action. Once these challenges have been overcome, RES is expected to become an effective health intervention.

Insights into the Therapeutic and Pharmacological Properties of Resveratrol as a Nutraceutical Antioxidant Polyphenol in Health Promotion and Disease Prevention

Resveratrol (3, 5, 4'-trihydroxystilbene) is a polyphenolic derivative with herbal origin. It has attracted considerable attention in recent decades. Many studies have revealed the benefits of Resveratrol over several human disease models, including heart and neurological diseases, nephroprotective, immune regulation, antidiabetic, anti-obesity, age-related diseases, antiviral, and anticancer in experimental and clinical conditions. Recently, the antioxidant and anti-inflammatory activities of Resveratrol have been observed, and it has been shown that Resveratrol reduces inflammatory biomarkers, such as tissue degradation factor, cyclooxygenase 2, nitric oxide synthase, and interleukins. All of these activities appear to be dependent on its structural properties, such as the number and position of the hydroxyl group, which regulates oxidative stress, cell death, and inflammation. Resveratrol is well tolerated and safe even at higher pharmacological doses and desirably affects cardiovascular, neurological, and diabetic diseases. Consequently, it is plausible that Resveratrol can be regarded as a beneficial nutritional additive and a complementary drug, particularly for therapeutic applications. The present review provides an overview of currently available investigations on preventive and therapeutic characteristics and the main molecular mechanisms of Resveratrol and its potent derivatives in various diseases. Thus, this review would enhance knowledge and information about Resveratrol and encourage researchers worldwide to consider it as a pharmaceutical drug to struggle with future health crises against different human disorders.

Monitoring diacylglycerols in biofluids by non-isotopically paired charge derivatization combined with LC-MS/MS

Diacylglycerols (DAGs) are important lipid mediators in cellular signaling transduction and metabolism. Imbalanced production or consumption of DAGs has a negative impact on the physiological functions of the body. However, comprehensive monitoring of structurally diverse DAGs remains a daunting task due to the rapid metabolism and ion suppression characteristics in biofluids. These bottlenecks call for developing a method that enables sensitive quantification of DAGs in biological sample. In this work, a straightforward charge derivatization strategy was developed to insert a series of structure analogs charge label, i.e., N, N-dimethylglycine (DMG) and N, N-dimethylalanine (DMA), on the free hydroxyl group of the DAGs. Owing to the existence of tertiary amino groups in charge label, the mass spectrometry ionization response of the derivatized DAGs was significantly increased in comparison with traditional metal ion adducts. After charge derivatization, the specific neutral loss diagnostic ions (DMG, 103 Da and DMA, 117 Da) were captured by mass spectrometry. Then, the DMG/DMA-oriented paired multiple reaction monitoring methods based on the characteristic diagnostic ions of the derivatized DAGs have been developed as sensitive methods for the detection (detection limit = 16 aM) and quantification (quantification limit = 62.5 aM) of DAGs in serum. Moreover, the tagged 1,2-DAGs and 1,3-DAGs sn-isomers have been well separated on the reversed-phase column in combination with ultra-performance liquid chromatography. Finally, metabolic characterizations of the tagged DAGs were further explored in L-Arginine-induced acute pancreatitis mice and resveratrol treated model mice. The results indicated that 1,2-DAGs were increased in the serum of model mice relative to normal controls and resveratrol significantly altered this metabolic abnormality. The currently established DMG/DMA-oriented paired charge derivatization strategy is promising for depicting DAGs changes more accurately in metabolic studies of lipid-related diseases and accurately evaluating drug treatment strategies.

Resveratrol Inhibits Metabolism and Affects Blood Platelet Function in Type 2 Diabetes

Chronic hyperglycemia contributes to vascular complications in diabetes. Resveratrol exerts anti-diabetic and anti-platelet action. This study aimed to evaluate the effects of resveratrol on metabolism and the function of blood platelets under static and in in vitro flow conditions in patients with type 2 diabetes. Blood obtained from 8 healthy volunteers and 10 patients with type 2 diabetes was incubated with resveratrol and perfused over collagen-coated capillaries. Isolated blood platelets were incubated with resveratrol and activated by collagen to assess platelet function, metabolism, ATP release, TXA₂ production, lipid peroxidation, and gluthatione content. In the type 2 diabetes group, plasma glucose and fructosamine concentrations were significantly higher than in the healthy group. In in vitro studies, collagen-induced thrombi formation in the blood of diabetic patients was 33% higher than in the healthy group. Resveratrol reduced thrombi by over 50% in the blood of healthy and diabetic patients. TXA₂ production was 47% higher in diabetic platelets than in the healthy group. Resveratrol reduced TXA₂ release by 38% in healthy platelets and by 79% in diabetic platelets. Resveratrol also reduced the activities of enzymes responsible for glycolysis and oxidative metabolism in the platelets of both groups. These data indicate that the resveratrol-induced inhibition of platelet metabolism and TXA₂ release may lead to a reduction of platelet function and thrombus formation in patients with type 2 diabetes. Therefore, resveratrol may be beneficial to prevent vascular complications as a future complementary treatment in aspirin-resistant diabetic patients.

Resveratrol inhibits Ca2+ signals and aggregation of platelets

Background

Resveratrol has been shown to inhibit platelet aggregation. However, the mechanism for this action of resveratrol remains to be clarified. The purpose of this study was to elucidate the Ca²⁺-related mechanism for the inhibitory action of resveratrol on platelet aggregation.

Methods

Ca²⁺ entry and subsequent aggregation of human platelets induced by different stimulants including thrombin, thapsigargin, and 1-oleoyl-2-acetylglycerol (OAG) were measured by the fluorescence method and light transmittance method, respectively. Each stimulant was added to a nominally Ca²⁺-free medium containing platelets, and then CaCl₂ was added to the medium to induce Ca²⁺ influx into platelets.

Results

Thapsigargin-induced Ca²⁺ entry into platelets and subsequent platelet aggregation were significantly inhibited in the presence of resveratrol at 6.25 μM or higher concentrations, while OAG-induced Ca²⁺ entry and subsequent platelet aggregation were not affected by resveratrol at concentrations up to 50 μM. In the nominally Ca²⁺-free medium, thrombin induced a small transient increase in intracellular Ca²⁺ concentrations, which was attenuated in the presence of resveratrol at 12.5 μM or higher concentrations. Thrombin-induced Ca²⁺ entry into platelets and subsequent platelet aggregation were significantly inhibited in the presence of resveratrol at 12.5 μM or higher concentrations.

Conclusions

The results suggest that resveratrol inhibits thrombin-induced platelet aggregation through decreasing Ca²⁺ release from its stores and inhibiting store-operated Ca²⁺ influx into platelets.

Arvaniti O, Kallinikou E, Sakantani E, Tsolou A, Nomikos T, Samaras Y. Evaluation of Anti-Inflammatory, Anti-Platelet and Anti-Oxidant Activity of Wine Extracts Prepared from Ten Different Grape Varieties

Inflammation, thrombosis and oxidative stress are rarely studied together when wine's biological activity is concerned; hence the existing literature lacks a holistic point of view in the biological outcome. The scope of the present study is to parallel evaluate the effect of wine extracts on those mechanisms. Ten wine varieties and two different extraction methods were used leading to five extracts for each wine: total lipids (TL) and fractions with different phenolic compound classes (FI, FII, FIII and FIV). Their effect on oxidative stress, platelet aggregation and the secretion of cytokines from mononuclear cells was measured and a biological score was calculated. FII of white wines is the most potent extract and the extracts FIII and TL are following. Specifically, FII had higher anti-oxidant and anti-inflammatory score while all three fractions had a similar anti-platelet score. Furthermore, FII and FIII extracts were the most potent red wine extracts and revealed the highest anti-oxidant and anti-inflammatory scores. White wine FII extracts were more potent than the red wine ones while FI and FIV extracts of red wine were more potent than the white wine ones. In conclusion, the protective effect of a wine is independent of its color but is strongly associated with its microconstituents profile. FII extract revealed the highest biological score and further examination is needed in order to identify the compounds that are responsible for the aforementioned actions.

The French paradox three decades later: Role of inflammation and thrombosis

Although, three decades have pasted from the introduction of "French Paradox", is still an issue for debate. Epidemiology supports the J-shaped relationship between wine consumption and vascular events as well as cardiovascular mortality with a maximum protection at 21 g of alcohol consumption in the form of wine per day. Nevertheless, the aforementioned studies have used an observational design that raises concerns about potential confounding. Randomized clinical studies may provide data to end the controversy and in parallel with in vitro experiments to elucidate the mechanisms by which wine affects cardiovascular disease. In this concept, this review aims to address the presence of bioactive wine micro constituents, their potential mechanisms of action and also to summarize the cardio-protective effects of wine intake based on clinical trials. The role of wine micro-constituents in inflammation and haemostasis is discussed in detail.

Resveratrol: Isolation, and Its Nanostructured Lipid Carriers, Inhibits Cell Proliferation, Induces Cell Apoptosis in Certain Human Cell Lines Carcinoma and Exerts Protective Effect Against Paraquat-Induced Hepatotoxicity

Resveratrol (RES) (trans-3, 5,-4'-trihydroxystilebene) is a multi-biofunctional compound found in a variety of plants such as grapes and mulberries. Studies of nanoencapsulated resveratrol have indicated that this compound can inhibit the growth of cancer cells and free radicals. The aim of this study was to isolate resveratrol from Vitis vinifera, develop and evaluate resveratrol nanostructured lipid carriers (NLCs) and/or resveratrol encapsulated chitosan-coated nanostructured lipid carriers (CSNLCs) using low-viscous chitosan for anticancer therapy. In addition, our study was carried out to examine the prophylactic potential of RES, NLC, and CSNLC on paraquat-induced injury in rat hepatocytes. In this study we isolated resveratrol and encapsulated NLCs in phosphate-buffered saline solution using a phase inversion method. In addition, CSNLCs were prepared by ionic gelation method of NLCs using chitosan. NLCs and CSNLCs were then characterized for their particle size, zeta potential, morphology, and entrapment efficiency. Furthermore, NLCs and CSNLCs were evaluated for their cytotoxic effect on Hep-G2, human HCT-116 (colorectal cancer cell line), lymphoblastic leukemia (1301), and human MCF-7 (Michigan Cancer Foundation-7) cells as well as their effect on caspase-3 and death receptor (DR-4). In addition, incubation of hepatocytes with paraquat resulted in increased formation of TBARS (thiobarbituric acid reactive substances) with a parallel increase in lactate dehydrogenase (LDH) leakage at 1 h after incubation. Time-dependent depletion of cellular glutathione (GSH) was observed starting 2 h after incubation with paraquat. The mean particle size of NLC and CSNLC were 67.0 and 98.41 nm, zeta potential were (-) 24.8 and (+) 31.6 mV, entrapment efficiency were 74.15% and 85.46%, respectively, with the observed shapes of nanoparticle being spherical. The treatment of Hep-G2, human HCT-116, lymphoblastic leukemia (1301), and human MCF-7 cells with NLC led to high inhibition in the cell proliferation as concluded by the low IC₅₀ values 27.7, 17.43, 35.39, and 47.66 μg/mL, respectively, whereas CSNLC had high cytotoxic effect on Hep-G2, human HCT-116, lymphoblastic leukemia (1301), and human MCF-7 cells with low IC₅₀ values 13.29, 10.56, 16.79 and 22.60 μg/mL, respectively. Both NLC and CSNLC possess apoptotic properties through activation of the caspase-3 and death receptor (DR-4). In addition, incubation of hepatocytes with RES, NLC, and CSNLC markedly protected against paraquat-induced formation of TBARS, increase in LDH leakage, and prevented GSH depletion. The most effective doses for ethyl acetate, ethanolic, and aqueous extracts were 7.5, 10, and 12.5 μg, respectively. The results presented here may suggest that nanoencapsulated resveratrol isolated from the stems of V. vinifera to obtain NLC and CSNLC possess anticancer and apoptotic effects on cell proliferation, and therefore, can be used as new approach of pharmaceutical drugs. In addition, the results clearly suggest that the RES, NLC, and CSNLC exerted protective effect against cytotoxicity induced by paraquat. On the contrary, the effect decreased in order of CSNLC, NLC, and RES.

Resveratrol Nanoparticles: A Promising Therapeutic Advancement over Native Resveratrol

The importance of fruit-derived resveratrol (RES) in the treatment of various diseases has been discussed in various research publications. Those research findings have indicated the ability of the molecule as therapeutic in the context of in vitro and in vivo conditions. Mostly, the application of RES in in vivo conditions, encapsulation processes have been carried out using various nanoparticles that are made of biocompatible biomaterials, which are easily digested or metabolized, and RES is absorbed effectively. These biomaterials are non-toxic and are safe to be used as components in the biotherapeutics. They are made from naturally available by-products of food materials like zein or corn or components of the physiological system as with lipids. The versatility of the RES nanoparticles in their different materials, working range sizes, specificity in their targeting in various human diseases, and the mechanisms associated with them are discussed in this review.

Resveratrol-loaded biopolymer core–shell nanoparticles: bioavailability and anti-inflammatory effects

The cellular uptake and simulated intestinal wall transportation of resveratrol-loaded zein/pectin nanoparticles were assessed using Caco-2 cells and monolayers, respectively.

Increased Oral Bioavailability of Resveratrol by Its Encapsulation in Casein Nanoparticles

Resveratrol is a naturally occurring polyphenol that provides several health benefits including cardioprotection and cancer prevention. However, its biological activity is limited by a poor bioavailability when taken orally. The aim of this work was to evaluate the capability of casein nanoparticles as oral carriers for resveratrol. Nanoparticles were prepared by a coacervation process, purified and dried by spray-drying. The mean size of nanoparticles was around 200 nm with a resveratrol payload close to 30 μg/mg nanoparticle. In vitro studies demonstrated that the resveratrol release from casein nanoparticles was not affected by the pH conditions and followed a zero-order kinetic. When nanoparticles were administered orally to rats, they remained within the gut, displaying an important capability to reach the intestinal epithelium. No evidence of nanoparticle “translocation” were observed. The resveratrol plasma levels were high and sustained for at least 8 h with a similar profile to that observed for the presence of the major metabolite in plasma. The oral bioavailability of resveratrol when loaded in casein nanoparticles was calculated to be 26.5%, 10 times higher than when the polyphenol was administered as oral solution. Finally, a good correlation between in vitro and in vivo data was observed.

Resveratrol Functionalized Carboxymethyl-β-Cyclodextrin: Synthesis, Characterization, and Photostability

The resveratrol functionalized carboxymethyl-β-cyclodextrin conjugate was synthesized by two simple steps. The conjugate was successfully demonstrated by 1H NMR, 13C NMR, UV, and FTIR. The photostability of the conjugate was studied by ultraviolet absorption spectrum. After 360 min of UV light irradiation, the conjugate showed a total loss in absorbance of only 12.54%, while the resveratrol and its CM-β-CD inclusion complex showed a total loss in absorbance of 32.15% and 24.05%, respectively. The results indicate that the conjugate was more stable than resveratrol and its CM-β-CD inclusion complex.

Treatment of cardiovascular pathology with epigenetically active agents: Focus on natural and synthetic inhibitors of DNA methylation and histone deacetylation

Cardiovascular disease (CVD) retains a leadership as a major cause of human death worldwide. Although a substantial progress was attained in the development of cardioprotective and vasculoprotective drugs, a search for new efficient therapeutic strategies and promising targets is under way. Modulation of epigenetic CVD mechanisms through administration epigenetically active agents is one of such new approaches. Epigenetic mechanisms involve heritable changes in gene expression that are not linked to the alteration of DNA sequence. Pathogenesis of CVDs is associated with global genome-wide changes in DNA methylation and histone modifications. Epigenetically active compounds that influence activity of epigenetic modulators such as DNA methyltransferases (DNMTs), histone acetyltransferases, histone deacetylases (HDACs), etc. may correct these pathogenic changes in the epigenome and therefore be used for CVD therapy. To date, many epigenetically active natural substances (such as polyphenols and flavonoids) and synthetic compounds such as DNMT inhibitors or HDAC inhibitors are known. Both native and chemical DNMT and HDAC inhibitors possess a wide range of cytoprotective activities such as anti-inflammatory, antioxidant, anti-apoptotic, anti-anfibrotic, and anti-hypertrophic properties, which are beneficial of treatment of a variety of CVDs. However, so far, only synthetic DNMT inhibitors enter clinical trials while synthetic HDAC inhibitors are still under evaluation in preclinical studies. In this review, we consider epigenetic mechanisms such as DNA methylation and histone modifications in cardiovascular pathology and the epigenetics-based therapeutic approaches focused on the implementation of DNMT and HDAC inhibitors.

Resveratrol and Ophthalmic Diseases

Resveratrol, a naturally occurring plant polyphenol found in grapes, is the principal biologically active component in red wine. Clinical studies have shown that resveratrol due to its potent anti-oxidant and anti-inflammatory properties are cardio-protective, chemotherapeutic, neuroprotective, and display anti-aging effects. Oxidative stress and inflammation play a critical role in the initiation and progression of age-related ocular diseases (glaucoma, cataract, diabetic retinopathy and macular degeneration) that lead to progressive loss of vision and blindness. In vitro and in vivo (animal model) experimental studies performed so far have provided evidence for the biological effects of resveratrol on numerous pathways including oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, pro-survival or angiogenesis that are implicated in the pathogenesis of these age-related ocular disorders. In this review, we provide a brief overview of current scientific literature on resveratrol, its plausible mechanism(s) of action, its potential use and current limitations as a nutritional therapeutic intervention in the eye and its related disorders.

Chronic in vivo or acute in vitro resveratrol attenuates endothelium-dependent cyclooxygenase-mediated contractile signaling in hypertensive rat carotid artery

Exaggerated cyclooxygenase (COX) and thromboxane-prostanoid (TP) receptor-mediated endothelium-dependent contraction can contribute to endothelial dysfunction. This study examined the effect of resveratrol (RSV) on endothelium-dependent contraction and cell signaling in the common carotid artery (CCA) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Acetylcholine (Ach)-stimulated endothelium-dependent nitric oxide synthase (NOS)-mediated relaxation in precontracted SHR CCA was impaired (maximum 73 ± 6% vs. 87 ± 5% in WKY) (P < 0.05) by competitive COX-mediated contraction. Chronic (28-day) treatment in vivo (drinking water) with a ∼0.075 mg·kg(-1)·day(-1) RSV dose affected neither endothelium-dependent relaxation nor endothelium-dependent contraction and associated prostaglandin (PG) production evaluated in non-precontracted NOS-blocked CCA. In contrast, a chronic ∼7.5 mg·kg(-1)·day(-1) RSV dose improved endothelium-dependent relaxation (94 ± 6%) and attenuated endothelium-dependent contraction (58 ± 4% vs. 73 ± 5% in No-RSV) and PG production (183 ± 43 vs. 519 ± 93 pg/ml) in SHR CCA, while U46619-stimulated TP receptor-mediated contraction was unaffected. In separate acute in vitro experiments, 20-μM RSV preincubation attenuated endothelium-dependent contraction (6 ± 4% vs. 62 ± 2% in No Drug) and PG production (121 ± 15 vs. 491 ± 93 pg/ml) and attenuated U46619-stimulated contraction (134 ± 5% vs. 171 ± 4%) in non-precontracted NOS-blocked SHR CCA. Compound C, a known AMP-activated protein kinase (AMPK) inhibitor, did not prevent the RSV attenuating effect on Ach- and U46619-stimulated contraction but did prevent the RSV attenuating effect on PG production (414 ± 58 pg/ml). These data demonstrate that RSV can attenuate endothelium-dependent contraction both by suppressing arterial wall PG production, which may be partially mediated by AMPK, and by TP receptor hyporesponsiveness, which does not appear to be mediated by AMPK.

Bioavailability of Alfrutamide and Caffedymine and Their P-Selectin Suppression and Platelet-Leukocyte Aggregation Mechanisms in Mice

BACKGROUND

Alfrutamide and caffedymine are phenolic amides found in plants, including garlic and cocoa. However, the bioavailability of alfrutamide and caffedymine and their effects on cardiovascular diseases (CVDs), particularly via effects on P-selectin expression(PSE) and platelet-leukocyte aggregation (PLA), are unknown.

OBJECTIVE

The objective of this study was to investigate the bioavailability of alfrutamide and caffedymine and their effects on PSE and PLA, which are frequently involved in the progression of CVDs.

METHODS

Cyclooxygenase (COX) I and COX-II activities and cAMP were determined by using COX and cAMP kits. Bioavailability was determined by HPLC analysis of plasma samples from Swiss Webster mice orally administered alfrutamide and caffedymine (10 μg each). PSE and PLA were also measured by flow cytometry using blood samples from the same mice.

RESULTS

At 0.05 μmol/L, alfrutamide and caffedymine inhibited COX-I and COX-II by 20-40% (P < 0.05) and 16-33% (P < 0.05), respectively, compared with the control. At 0.1 μmol/L, the 2 compounds also inhibited platelet PSE by 28% (P < 0.05) and 35% (P < 0.05), respectively, compared with the control. The β2-adrenoceptor antagonists ICI118551 and butoxamine partially suppressed the inhibition of PSE by caffedymine, suggesting that β2 receptors are involved in inhibition by caffedymine but not by alfrutamide. At the same concentration (0.1 μmol/L), however, these 2 compounds inhibited PLA by 24-32% (P < 0.05) compared with the control. In addition, mice administered caffedymine and alfrutamide orally (10 μg/35 g body weight) exhibited maximum concentrations >0.6 μmol/L and significant inhibition of PSE by 23-34% (P < 0.05) and PLA by 20-27% (P < 0.05) compared with control mice.

CONCLUSIONS

These data show the adequate bioavailability of alfrutamide and caffedymine and their different mechanisms of suppressing PSE and PLA: alfrutamide exerts its effects only via COX inhibition, whereas caffedymine works through both COX inhibition and cAMP amplification.

An Organ System Approach to Explore the Antioxidative, Anti-Inflammatory, and Cytoprotective Actions of Resveratrol

Resveratrol is a phenolic phytochemical, with a stilbene backbone, derived from edible plants such as grape and peanut. It is a bioactive molecule with physiological effects on multiple organ systems. Its effects range from the neuroprotective to the nephroprotective, including cardiovascular, neuronal, and antineoplastic responses as a part of its broad spectrum of action. In this review, we examine the effects of resveratrol on the following organ systems: the central nervous system, including neurological pathology such as Parkinson's and Alzheimer's disease; the cardiovascular system, including disorders such as atherosclerosis, ischemia-reperfusion injury, and cardiomyocyte hypertrophy; the kidneys, including primary and secondary nephropathies and nephrolithiasis; multiple forms of cancer; and metabolic syndromes including diabetes. We emphasize commonalities in extracellular matrix protein alterations and intracellular signal transduction system induction following resveratrol treatment. We summarize the known anti-inflammatory, antioxidative, and cytoprotective effects of resveratrol across disparate organ systems. Additionally, we analyze the available literature regarding the pharmacokinetics of resveratrol formulations used in these studies. Finally, we critically examine select clinical trials documenting a lack of effect following resveratrol treatment.

Resveratrol and cardiovascular health--promising therapeutic or hopeless illusion?

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural polyphenolic compound that exists in Polygonum cuspidatum, grapes, peanuts and berries, as well as their manufactured products, especially red wine. Resveratrol is a pharmacologically active compound that interacts with multiple targets in a variety of cardiovascular disease models to exert protective effects or induce a reduction in cardiovascular risks parameters. This review attempts to primarily serve to summarize the current research findings regarding the putative cardioprotective effects of resveratrol and the molecular pathways underlying these effects. One intent is to hopefully provide a relatively comprehensive resource for clues that may prompt ideas for additional mechanistic studies which might further elucidate and strengthen the role of the stilbene family of compounds in cardiovascular disease and cardioprotection. Model systems that incorporate a significant functional association with tissues outside of the cardiovascular system proper, such as adipose (cell culture, obesity models) and pancreatic (diabetes) tissues, were reviewed, and the molecular pathways and/or targets related to these models and influenced by resveratrol are discussed. Because the body of work encompassing the stilbenes and other phytochemicals in the context of longevity and the ability to presumably mitigate a plethora of afflictions is replete with conflicting information and controversy, especially so with respect to the human response, we tried to remain as neutral as possible in compiling and presenting the more current data with minimal commentary, permitting the reader free reign to extract the knowledge most helpful to their own investigations.

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.

Antiplatelet properties of natural products

Cardiovascular diseases (CVD) and its main underlying cause, atherothrombosis, are the major culprits of morbidity and mortality worldwide. Apart from the treatment of cardiovascular risk factors and the use of antithrombotic agents there is considerable interest in the role of natural food products and their bioactive components in the prevention and treatment of cardiovascular disorders. The consumption of healthy diets rich in functional foods, such as the Mediterranean diet, has shown to exert profound cardioprotective effects in the primary and secondary prevention of CVD. Moreover, accumulating data have attributed these beneficial effects, at least in part, to the modulation of key players in the pathogenesis of atherosclerosis, including amelioration in the lipid profile and vascular function and a decrease in oxidative stress and inflammation. Although with a much less clear picture, natural dietary compounds have also demonstrated to exert antiplatelet activities, further contributing to reduce the thrombotic risk. This article provides a brief overview of the atherothrombotic process to further provide an up-to-date review of the antiplatelet properties exerted by natural products and/or food-derived bioactive constituents - including ω-3 PUFA, olive oil, garlic and onions, tomatoes, mushrooms, polyphenol-rich beverages, and flavonol-rich cocoa - as well as to describe the mechanisms underlying these antiplatelet activities.

Effects of resveratrol on blood homocysteine level, on homocysteine induced oxidative stress, apoptosis and cognitive dysfunctions in rats

We aimed to examine the protective effects of resveratrol against homocysteine induced oxidative stress, apoptosis and cognitive impairment. Rats were randomly divided into three groups. Control group received standard rat food; homocysteine group (Hcy group) received daily methionine at a dose of 1g/kg-body weight dissolved in drinking water for thirty days; third group (Hcy+Res group) received same amount of methionine plus 20mg/kg/day resveratrol intraperitoneally for thirty days. Cognitive performances of the animals were tested by Morris water maze test. Then all animals were sacrificed to study lipid peroxidation (LPO), DNA fragmentation and p53 mRNA expression in the rat brain. The aortas of the sacrificed rats were processed for histopathological examination. Apoptosis in the aortas was assessed by TUNEL staining. Resveratrol significantly decreased serum levels of homocysteine, reversed Hcy induced LPO increase, decreased DNA fragmentation and p53 mRNA expression in the rat brains, and improved homocysteine induced impairment of long term spatial memory. Resveratrol could inhibit homocysteine induced apoptosis and histopathological deterioration in the rat aortic sections. In conclusion, resveratrol is effective in preventing homocysteine induced vascular and neural defects. In hyperhomocysteinemic rat model, our findings consequently warrant in future studies to reveal the true improvement mechanism of resveratrol.

Cellular and molecular effects of resveratrol in health and disease

Resveratrol, a natural polyphenol abundantly found in grape skins and red wine, possesses diverse biochemical and physiological actions, including anti-inflammatory, anti-oxidation, anti-proliferation and promotion of differentiation, and chemopreventive effects. Recently, it is attracting increased attention due to its health benefits, especially in common age-related diseases such as cardiovascular disease, cancer, type 2 diabetes, and neurological conditions. In this review, we discuss the latest cellular and molecular findings that account for the beneficial actions of resveratrol.

Effect of resveratrol on platelet activation in hypercholesterolemic rats: CD40-CD40L system as a potential target

Our aim was to investigate whether trans-resveratrol (t-resveratrol), a red wine constituent known for its cardioprotective effects, was able to influence CD40 ligand (CD40L) and its receptor CD40 in platelets of hypercholesterolemic rats. Sixty Wistar rats were divided into 5 groups: control (C), ethanol (E), t-resveratrol (R), hypercholesterolemia (HC), and hypercholesterolemia plus t-resveratrol (HCR). Rats in the C, E, and R groups were fed a normal diet for 80 days. For 20 days before sacrifice, we intraperitoneally (i.p.) administered 0.1 mL ethanol (50% v/v) to the E group, and 0.1 mL t-resveratrol (20 mg·kg(-1)·day(-1)) to the R group. Rats in the HC and HCR groups were fed a 5% cholesterol diet for 80 days. Rats in the HCR group were administered i.p. 0.1 mL t-resveratrol (20 mg·kg(-1)·day(-1)) for 20 days before sacrifice. Serum levels of total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), very low-density lipoprotein (VLDL-C), and total triglycerides (TG) were assayed with a commercial colorimetric kit. Platelet P-selectin, CD40, and CD40L expression was determined by flow cytometry. sCD40L and IL6 levels were measured by ELISA. In the HC group, we observed a significant increase in serum TC, LDL-C, VLDL-C, TG, sCD40, and IL-6 levels and platelet activation markers compared with levels in the control group. However, t-resveratrol administration to the HC group (HCR group) attenuated the increase in lipids, sCD40, and IL-6 and down-regulated platelet P-selectin, CD40, and CD40L expressions. A positive correlation was found for serum lipids and all the platelet activation markers. Our study showed that the CD40-CD40L dyad is up-regulated in the presence of hypercholesterolemia and that t-resveratrol administration down-regulated the increase.

Resveratrol ameliorates lung injury via inhibition of apoptosis in rats with severe acute pancreatitis

The objective of this study was to evaluate the protective effects of resveratrol on lung injury in rats with severe acute pancreatitis. Ninety-six male Sprague-Dawley rats were randomly classified into 4 equal groups (n = 24): control, model, resveratrol-treated, and dexamethasone-treated. The rats were evaluated at 3, 6, and 12 hours after induction of pancreatitis. The following were assessed: P(a)O(2)by arterial blood gas analysis; pancreatic and lung injury by histology; and ultrastructure of lung tissue by transmission electron microscopy. The authors investigated mitochondrial cytochrome c release and evaluated the Bax, Bcl-2, and caspase-3 expression levels in lung tissue over the time course of apoptosis. Changes in lung cell mitochondrial membrane potential were evaluated by confocal laser scanning microscopy. In the model group, lung congestion, edema, inflammatory-cell infiltration, mitochondrial swelling, and cell apoptosis were apparent. In the resveratrol and dexamethasone groups, the morphological changes of the lungs were alleviated. The expression level of Bcl-2 was significantly higher and those of Bax, caspase-3, and cytochrome c were significantly lesser in the resveratrol group than in the model group. Apoptosis is involved in lung injury associated with severe acute pancreatitis, and resveratrol can ameliorate this injury, thus protecting lung function in rats with severe acute pancreatitis.

Resveratrol ameliorates hepatic injury via the mitochondrial pathway in rats with severe acute pancreatitis

To gain insight into the processes by which severe acute pancreatitis induced apoptosis takes place in the liver, and to observe the protective effect of resveratrol on hepatic injury, a rat model of severe acute pancreatitis was induced by administering 4% sodium taurocholate through the common biliopancreatic duct. Pancreatic and hepatic injury was assessed by histology. Serum ALT (alanine aminotransferase), AST (aspartate aminotransferase) and total bilirubin were determined by reaction rate assay, and the serum levels of TNF-alpha (tumor necrosis factor-alpha) and IL-6 (interleukin-6) were detected by ELISA (enzyme linked immunosorbent assay). We investigated cytochrome c released from mitochondria and used the RT-PCR (reverse transcription PCR), Western blot technique to evaluate Bax, Bcl-2, and caspase-3 expression levels in hepatic tissue over the time course of apoptosis. Changes in hepatic cell mitochondrial membrane potential were observed by confocal laser scanning microscopy. The majority of cytochrome c release occurred early in apoptosis from mitochondria, which undergo gradual hepatic impairment. The released cytochrome c can be reduced by resveratrol through both up-regulation of Bcl-2 and down-regulation of Bax and caspase-3. These data provide substantial evidence that apoptosis is involved in hepatic injury during the severe acute pancreatitis process and that resveratrol can ameliorate the situation, thus protecting liver function in rats with severe acute pancreatitis.

Strategies for antiplatelet targets and agents

Platelets play a key role in thrombosis and haemostasis, which can be either beneficial or deleterious depending on the circumstance. Antiplatelet therapy is the 'cornerstone' in the prevention and treatment of thrombotic diseases. Platelet activation is a complex process known as transmembrane signaling which then serves to activate the platelet via a cascade of biochemical interactions. Currently available strategies of antiplatelet therapy are generally based on the signaling pathway of platelet activation, which possess the characters that mono-agent, mono-target, and mainly irreversible inhibition. Therefore, both established and novel antiplatelet agents have their own pros and cons and such problems as resistance, drug-drug interaction, discontinuation and monitoring, etc. have been appeared. Due to the problems existing in current antiplatelet agents, future new strategies for antiplatelet targets, agent-developing and treatment might probably include three aspects: targeting the factors associated with platelet hyperactivity, developing novel antiplatelet agents with multiple targets, mild and reversible properties from natural products, and keeping healthy lifestyle and emphasizing prevention.