Resveratrol Ameliorates Arterial Stiffness Assessed by Cardio-Ankle Vascular Index in Patients With Type 2 Diabetes Mellitus

Beneficial effects of resveratrol on diabetes mellitus and its complications: focus on mechanisms of action

Diabetes mellitus (DM) is a significant global health issue, associated with various microvascular and macrovascular complications that significantly impair patients' quality of life as well as healthspan and lifespan. Despite the availability of several anti-diabetic medications with different mechanisms of action, there remains no definite curative treatment. Hence, discovering new efficient complementary therapies is essential. Natural products have received significant attention due to their advantages in various pathological conditions. Resveratrol is a natural polyphenol that possesses antioxidant and anti-inflammatory properties, and its efficacy has been previously investigated in several diseases, including DM. Herein, we aimed to provide a holistic view of the signaling pathways and mechanisms of action through which resveratrol exerts its effects against DM and its complications.

Anti-oxidants as therapeutic agents for oxidative stress associated pathologies: future challenges and opportunities

Free radicals have been implicated in the pathogenesis of cancer along with cardiovascular, neurodegenerative, pulmonary and inflammatory disorders. Further, the relationship between oxidative stress and disease is distinctively established. Clinical trials using anti-oxidants for the prevention of disease progression have indicated some beneficial effects. However, these trials failed to establish anti-oxidants as therapeutic agents due to lack of efficacy. This is attributed to the fact that living systems are under dynamic redox control wherein their redox behavior is compartmentalized and simple aggregation of redox couples, distributed throughout the system, is of miniscule importance while determining their overall redox state. Further, free radical metabolism is intriguingly complex as they play plural roles segregated in a spatio-temporal manner. Depending on quality, quantity and site of generation, free radicals exhibit beneficial or harmful effects. Use of nonspecific, non-targeted, general ROS scavengers lead to systemic elimination of all types of ROS and interferes in cellular signaling. Failure of anti-oxidants to act as therapeutic agents lies in this oversimplification of extremely dynamic cellular redox environment as a static and non-compartmentalized redox state. Rather than generalizing the term "oxidative stress" if we can identify the "type of oxidative stress" in different types of diseases, a targeted and more specific anti-oxidant therapy may be developed. In this review, we discuss the concept of redox dynamics, role and type of oxidative stress in disease conditions, and current status of anti-oxidants as therapeutic agents. Further, we probe the possibility of developing novel, targeted and efficacious anti-oxidants with drug-like properties.

Analysis of the Effects of Short-Term Pterostilbene Intake on Healthy Participants: A Pilot Study

Pterostilbene, a polyphenolic compound and an analog of resveratrol, exerts various biological activities and has higher bioavailability and metabolic stability than resveratrol. However, the effectiveness of pterostilbene intake in humans, particularly its effect on blood microRNA (miRNA) expression levels, has not been evaluated. Accordingly, this pilot study aimed to investigate the effects of pterostilbene on blood biochemistry and blood miRNA expression levels and the safety of continuous intake at doses of 10 or 100 mg/d over 12 wk. A double-blind, placebo-controlled parallel-arm comparison trial was conducted with 30 healthy men. In the analysis of blood miRNA expression levels, miR-34a and miR-193b showed very high increases at week 4 and after week 4 of intake, respectively, suggesting that the responders might be present among participants in the pterostilbene intake group. No adverse events were reported during the trial in any participant, and no abnormalities were observed upon examination by the responsible physician. Thus, pterostilbene intake would regulate blood miRNA expression levels, and the results can be utilized in human studies investigating miRNA expression levels with functional food ingredients.

PAI-1 Regulates the Cytoskeleton and Intrinsic Stiffness of Vascular Smooth Muscle Cells

BACKGROUND

Plasma concentration of PAI-1 (plasminogen activator inhibitor-1) correlates with arterial stiffness. Vascular smooth muscle cells (SMCs) express PAI-1, and the intrinsic stiffness of SMCs is a major determinant of total arterial stiffness. We hypothesized that PAI-1 promotes SMC stiffness by regulating the cytoskeleton and that pharmacological inhibition of PAI-1 decreases SMC and aortic stiffness.

METHODS

PAI-039, a specific inhibitor of PAI-1, and small interfering RNA were used to inhibit PAI-1 expression in cultured human SMCs. Effects of PAI-1 inhibition on SMC stiffness, F-actin (filamentous actin) content, and cytoskeleton-modulating enzymes were assessed. WT (wild-type) and PAI-1-deficient murine SMCs were used to determine PAI-039 specificity. RNA sequencing was performed to determine the effects of PAI-039 on SMC gene expression. In vivo effects of PAI-039 were assessed by aortic pulse wave velocity.

RESULTS

PAI-039 significantly reduced intrinsic stiffness of human SMCs, which was accompanied by a significant decrease in cytoplasmic F-actin content. PAI-1 gene knockdown also decreased cytoplasmic F-actin. PAI-1 inhibition significantly increased the activity of cofilin, an F-actin depolymerase, in WT murine SMCs, but not in PAI-1-deficient SMCs. RNA-sequencing analysis suggested that PAI-039 upregulates AMPK (AMP-activated protein kinase) signaling in SMCs, which was confirmed by Western blotting. Inhibition of AMPK prevented activation of cofilin by PAI-039. In mice, PAI-039 significantly decreased aortic stiffness and tunica media F-actin content without altering the elastin or collagen content.

CONCLUSIONS

PAI-039 decreases intrinsic SMC stiffness and cytoplasmic stress fiber content. These effects are mediated by AMPK-dependent activation of cofilin. PAI-039 also decreases aortic stiffness in vivo. These findings suggest that PAI-1 is an important regulator of the SMC cytoskeleton and that pharmacological inhibition of PAI-1 has the potential to prevent and treat cardiovascular diseases involving arterial stiffening.

Potential use of antioxidants for the treatment of chronic inflammatory diseases

The excessive production of various reactive oxidant species over endogenous antioxidant defense mechanisms leads to the development of a state of oxidative stress, with serious biological consequences. The consequences of oxidative stress depend on the balance between the generation of reactive oxidant species and the antioxidant defense and include oxidative damage of biomolecules, disruption of signal transduction, mutation, and cell apoptosis. Accumulating evidence suggests that oxidative stress is involved in the physiopathology of various debilitating illnesses associated with chronic inflammation, including cardiovascular diseases, diabetes, cancer, or neurodegenerative processes, that need continuous pharmacological treatment. Oxidative stress and chronic inflammation are tightly linked pathophysiological processes, one of which can be simply promoted by another. Although, many antioxidant trials have been unsuccessful (some of the trials showed either no effect or even harmful effects) in human patients as a preventive or curative measure, targeting oxidative stress remains an interesting therapeutic approach for the development of new agents to design novel anti-inflammatory drugs with a reliable safety profile. In this regard, several natural antioxidant compounds were explored as potential therapeutic options for the treatment of chronic inflammatory diseases. Several metalloenzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, are among the essential enzymes that maintain the low nanomolar physiological concentrations of superoxide (O2•-) and hydrogen peroxide (H2O2), the major redox signaling molecules, and thus play important roles in the alteration of the redox homeostasis. These enzymes have become a striking source of motivation to design catalytic drugs to enhance the action of these enzymes under pathological conditions related to chronic inflammation. This review is focused on several major representatives of natural and synthetic antioxidants as potential drug candidates for the treatment of chronic inflammatory diseases.

Resveratrol and vascular health: evidence from clinical studies and mechanisms of actions related to its metabolites produced by gut microbiota

Cardiovascular diseases are among the leading causes of mortality worldwide, with dietary factors being the main risk contributors. Diets rich in bioactive compounds, such as (poly)phenols, have been shown to potentially exert positive effects on vascular health. Among them, resveratrol has gained particular attention due to its potential antioxidant and anti-inflammatory action. Nevertheless, the results in humans are conflicting possibly due to interindividual different responses. The gut microbiota, a complex microbial community that inhabits the gastrointestinal tract, has been called out as potentially responsible for modulating the biological activities of phenolic metabolites in humans. The present review aims to summarize the main findings from clinical trials on the effects of resveratrol interventions on endothelial and vascular outcomes and review potential mechanisms interesting the role of gut microbiota on the metabolism of this molecule and its cardioprotective metabolites. The findings from randomized controlled trials show contrasting results on the effects of resveratrol supplementation and vascular biomarkers without dose-dependent effect. In particular, studies in which resveratrol was integrated using food sources, i.e., red wine, reported significant effects although the resveratrol content was, on average, much lower compared to tablet supplementation, while other studies with often extreme resveratrol supplementation resulted in null findings. The results from experimental studies suggest that resveratrol exerts cardioprotective effects through the modulation of various antioxidant, anti-inflammatory, and anti-hypertensive pathways, and microbiota composition. Recent studies on resveratrol-derived metabolites, such as piceatannol, have demonstrated its effects on biomarkers of vascular health. Moreover, resveratrol itself has been shown to improve the gut microbiota composition toward an anti-inflammatory profile. Considering the contrasting findings from clinical studies, future research exploring the bidirectional link between resveratrol metabolism and gut microbiota as well as the mediating effect of gut microbiota in resveratrol effect on cardiovascular health is warranted.

Resveratrol attenuates high glucose-induced inflammation and improves glucose metabolism in HepG2 cells

Diabetes mellitus (DM) is characterized by impaired glucose and insulin metabolism, resulting in chronic hyperglycemia. Hyperglycemia-induced inflammation is linked to the onset and progression of diabetes. Resveratrol (RES), a polyphenol phytoalexin, is studied in diabetes therapeutics research. This study evaluates the effect of RES on inflammation and glucose metabolism in HepG2 cells exposed to high glucose. Inflammation and glucose metabolism-related genes were investigated using qPCR. Further, inflammatory genes were analyzed by applying ELISA and Bioplex assays. High glucose significantly increases IKK-α, IKB-α, and NF-kB expression compared to controls. Increased NF-kB expression was followed by increased expression of pro-inflammatory cytokines, such as TNF-α, IL-6, IL-β, and COX2. RES treatment significantly reduced the expression of NF-kB, IKK-α, and IKB-α, as well as pro-inflammatory cytokines. High glucose levels reduced the expression of TGFβ1, while treatment with RES increased the expression of TGFβ1. As glucose levels increased, PEPCK expression was reduced, and GCK expression was increased in HepG2 cells treated with RES. Further, HepG2 cells cultured with high glucose showed significant increases in KLF7 and HIF1A but decreased SIRT1. Moreover, RES significantly increased SIRT1 expression and reduced KLF7 and HIF1A expression levels. Our results indicated that RES could attenuate high glucose-induced inflammation and enhance glucose metabolism in HepG2 cells.

Resveratrol and beyond: The Effect of Natural Polyphenols on the Cardiovascular System: A Narrative Review

Cardiovascular diseases (CVDs) are among the leading causes of morbidity and mortality worldwide. Unhealthy dietary habits have clearly been shown to contribute to the development of CVDs. Beyond the primary nutrients, a healthy diet is also rich in plant-derived compounds. Natural polyphenols, found in fruits, vegetables, and red wine, have a clear role in improving cardiovascular health. In this review, we strive to summarize the results of the relevant pre-clinical and clinical trials that focused on some of the most important natural polyphenols, such as resveratrol and relevant flavonoids. In addition, we aim to identify their common sources, biosynthesis, and describe their mechanism of action including their regulatory effect on signal transduction pathways. Finally, we provide scientific evidence regarding the cardiovascular benefits of moderate, long-term red wine consumption.

Vascular Ageing: Mechanisms, Risk Factors, and Treatment Strategies

Ageing constitutes the biggest risk factor for poor health and adversely affects the integrity and function of all the cells, tissues, and organs in the human body. Vascular ageing, characterised by vascular stiffness, endothelial dysfunction, increased oxidative stress, chronic low-grade inflammation, and early-stage atherosclerosis, may trigger or exacerbate the development of age-related vascular diseases, which each year contribute to more than 3.8 million deaths in Europe alone and necessitate a better understanding of the mechanisms involved. To this end, a large number of recent preclinical and clinical studies have focused on the exponential accumulation of senescent cells in the vascular system and paid particular attention to the specific roles of senescence-associated secretory phenotype, proteostasis dysfunction, age-mediated modulation of certain microRNA (miRNAs), and the contribution of other major vascular risk factors, notably diabetes, hypertension, or smoking, to vascular ageing in the elderly. The data generated paved the way for the development of various senotherapeutic interventions, ranging from the application of synthetic or natural senolytics and senomorphics to attempt to modify lifestyle, control diet, and restrict calorie intake. However, specific guidelines, considering the severity and characteristics of vascular ageing, need to be established before widespread use of these agents. This review briefly discusses the molecular and cellular mechanisms of vascular ageing and summarises the efficacy of widely studied senotherapeutics in the context of vascular ageing.

Insights on antioxidant therapeutic strategies in type 2 diabetes mellitus: A narrative review of randomized control trials

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disease of impaired glucose utilization. Imbalance in generation and elimination of free radicals generate oxidative stress which modulates glucose metabolism and insulin regulation, resulting in the occurrence and progression of diabetes and associated complications. Antioxidant supplements in T2DM can be seen as a potential preventive and effective therapeutic strategy.

AIM

To compare randomized controlled trials (RCTs) in which antioxidants have been shown to have a therapeutic effect in T2DM patients.

METHODS

We systematically searched the electronic database PubMed by keywords. RCTs evaluating the effect of antioxidant therapy on glycaemic control as well as oxidant and antioxidant status as primary outcomes were included. The outcomes considered were: A reduction in blood glucose; changes in oxidative stress and antioxidant markers. Full-length papers of the shortlisted articles were assessed for the eligibility criteria and 17 RCTs were included.

RESULTS

The administration of fixed-dose antioxidants significantly reduces fasting blood sugar and glycated hemoglobin and is associated with decreased malondialdehyde, advanced oxidation protein products, and increased total antioxidant capacity.

CONCLUSION

Antioxidant supplements can be a beneficial approach for the treatment of T2DM.

Nutraceuticals in the Prevention and Therapeutic Treatment of Cardiovascular and Cerebrovascular Disease

PURPOSE

This review overviews and highlights arterial stiffening as a key physiological process and target for the prevention and/or lowering of cardio- and cerebrovascular disease (collectively CVD) risk.

METHODS

We identified nutraceutical approaches from randomized controlled trials and discussed the associated mechanisms by which these compounds lower age-related arterial stiffness. Age-related CVD are the leading cause of mortality in modernized societies. Arterial dysfunction, specifically stiffening of the large elastic arteries during midlife, is a key physiological process resulting in increased CVD risk. Current pharmaceutical approaches for lowering age-related arterial stiffness have limited efficacy, thus highlighting the need to identify novel approaches for lowering arterial stiffness and thereby CVD risk. Lifestyle interventions are a historical first-line approach to prevent and/or lower the adverse arterial stiffening effects observed with aging. Nutraceutical interventions, defined as a food or part of a food providing health benefits, are a nonpharmacological, novel lifestyle approach to lower age-associated arterial stiffness. Therefore, identifying nutraceutical approaches to lower CVD risk is clinically significant.

SUMMARY

This review provides a basic, yet essential, understanding for emerging nutraceutical strategies for the prevention and therapeutic treatment of CVD.

Efficacy of Dietary Polyphenols from Whole Foods and Purified Food Polyphenol Extracts in Optimizing Cardiometabolic Health: A Meta-Analysis of Randomized Controlled Trials

The evidence from clinical trials concerning the efficacy of dietary polyphenols on cardiometabolic health is divergent. Therefore, this review aimed to determine the pooled effect of dietary polyphenols on cardiometabolic risk markers and compare the difference in efficacy between whole polyphenol-rich foods and purified food polyphenol extracts. We conducted a random-effect model meta-analysis of randomized controlled trials (RCTs) on the effect of polyphenols on blood pressure, lipid profile, flow-mediated dilation (FMD), fasting blood glucose (FBG), waist circumference, and markers of inflammation. Effect size was expressed as weighted mean difference and 95% CI. RCTs published in English between 2000 and 2021 involving adult participants with cardiometabolic risks were searched in electronic databases. Forty-six RCTs involving 2494 participants with a mean age of 53.3 ±10 y were included in this review. Whole polyphenol-rich food but not purified food polyphenol extracts significantly reduced systolic blood pressure (SBP, -3.69 mmHg; 95% CI: -4.24, -3.15 mmHg; P = 0.00001) and diastolic blood pressure (DBP, -1.44 mmHg; 95% CI: -2.56, -0.31 mmHg; P = 0.0002). Concerning waist circumference, purified food polyphenol extracts led to a larger effect (-3.04 cm; 95% CI: -7.06, -0.98 cm; P = 0.14). Significant effects on total cholesterol (-9.03 mg/dL; 95% CI: -16.46, -1.06 mg/dL; P = 0.02) and TGs (-13.43 mg/dL; 95% CI: -23.63, -3.23; P = 0.01) were observed when purified food polyphenol extracts were considered separately. None of the intervention materials significantly affected LDL-cholesterol, HDL-cholesterol, FBG, IL-6, and CRP. When both whole food and extracts were pooled together, there was a significant reduction in SBP, DBP, FMD, TGs, and total cholesterol. These findings suggest that polyphenols both as whole food and purified extracts can be efficacious in reducing cardiometabolic risks. However, these results must be interpreted with caution because of high heterogeneity and risk of bias among RCTs. This study was registered on PROSPERO as CRD42021241807.

Effects of resveratrol supplementation on cardiac remodeling in hypertensive patients: a randomized controlled clinical trial

Resveratrol (RES) has been demonstrated to be protective in the cardiovascular system in animal studies, but the evidence is limited in humans. The purpose of the study was to evaluate the effect of RES supplementation on cardiac remodeling in patients with hypertension. Eighty Subjects were randomly divided into RES group (plus RES 400 mg/d in addition to conventional therapy, n = 43) and control group (conventional therapy, n = 37). The main outcomes of the study were changes within cardiac-remodeling parameters. Secondary outcomes were changes in anthropometric parameters, arterial stiffness parameters and mechanism indices. There was no statistically significant difference between the RES group and control group in terms of baseline characteristics. After 6 months, the RES group had smaller left atrial, lower E/e', higher left ventricular global longitudinal strain and lower biomarkers indicating cardiac fibrosis (expressed by decreases in procollagen type I C-peptide and galectin-3) compared to the control group. However, there was no significant difference in left ventricular structure between the two groups. Although the RES group showed a significant decrease in brachial-ankle pulse wave velocity compared to the pre-intervention value, the difference between the RES and the control groups was not obvious. What's more, compared with the control group, the serum levels of sirtuin3, superoxide dismutase and klotho were significantly increased in the RES group. In conclusion, RES supplementation can alleviate left atrial remodeling, improve left ventricular diastolic function and may alleviate cardiac fibrosis in hypertensive patients, and could be used as an adjunct to conventional therapies of hypertensive heart disease.

The Journey of Resveratrol from Vineyards to Clinics

With rising technological advancements, several factors influence the lifestyle of people and stimulate chronic inflammation that severely affects the human body. Chronic inflammation leads to a broad range of physical and pathophysiological distress. For many years, non-steroidal drugs and corticosteroids were most frequently used in treating inflammation and related ailments. However, long-term usage of these drugs aggravates the conditions of chronic diseases and is presented with morbid side effects, especially in old age. Hence, the quest for safe and less toxic anti-inflammatory compounds of high therapeutic potential with least adverse side effects has shifted researchers' attention to ancient medicinal system. Resveratrol (RSV) - 3,4,5^' trihydroxystilbene is one such naturally available polyphenolic stilbene derivative obtained from various plant sources. For over 2000 years, these plants have been used in Asian medicinal system for curing inflammation-associated disorders. There is a wealth of in vitro, in vivo and clinical evidence that shows RSV could induce anti-aging health benefits including, anti-cancer, anti-inflammatory, anti-oxidant, phytoesterogenic, and cardio protective properties. However, the issue of rapid elimination of RSV through the metabolic system and its low bio-availability is of paramount importance which is being studied extensively. Therefore, in this article, we scientifically reviewed the molecular targets, biological activities, beneficial and contradicting effects of RSV as evinced by clinical studies for the prevention and treatment of inflammation-mediated chronic disorders.

Genome-Wide Transcriptional Profiling Reveals PHACTR1 as a Novel Molecular Target of Resveratrol in Endothelial Homeostasis

Atherosclerosis is a chronic inflammatory vascular disease in which endothelial cells play an important role in maintaining vascular homeostasis. Endotheliitis caused by endothelial dysfunction (ED) is the key cause for the development of cardiovascular and cerebrovascular diseases as well as other vascular system diseases. Resveratrol (RES), a multi-functional polyphenol present in edible plants and fruits, prevents cardiovascular disease by regulating a variety of athero-relevant signaling pathways. By transcriptome profiling of RES-treated human umbilical vein endothelial cells (HUVECs) and in-depth bioinformatic analysis, we observed that differentially expressed genes (DEGs) were enriched in KEGG pathways of fluid shear stress and atherosclerosis, suggesting that the RES may serve as a good template for a shear stress mimetic drug that hold promise in combating atherosclerosis. A heat map and multiple datasets superimposed screening revealed that RES significantly down-regulated phosphatase and actin modulator 1 (PHACTR1), a pivotal coronary artery disease risk gene associated with endothelial inflammation and polyvascular diseases. We further demonstrate that RES down-regulated the gene and protein expression of PHACTR1 and inhibited TNF-α-induced adhesion of THP-1 monocytes to activated endothelial cells via suppressing the expression of PHACTR1. Taken together, our study reveals that PHACTR1 represents a new molecular target for RES to maintain endothelial cell homeostasis and prevent atherosclerotic cardiovascular disease.

Selected Plant-Derived Polyphenols as Potential Therapeutic Agents for Peripheral Artery Disease: Molecular Mechanisms, Efficacy and Safety

Vascular diseases, such as peripheral artery disease (PAD), are associated with diabetes mellitus and a higher risk of cardiovascular disease and even death. Surgical revascularization and pharmacological treatments (mainly antiplatelet, lipid-lowering drugs, and antidiabetic agents) have some effectiveness, but the response and efficacy of therapy are overly dependent on the patient’s conditions. Thus, the demand for new cures exists. In this regard, new studies on natural polyphenols that act on key points involved in the pathogenesis of vascular diseases and, thus, on PAD are of great urgency. The purpose of this review is to take into account the mechanisms that lead to endothelium dysfunction, such as the glycoxidation process and the production of advanced glycation end-products (AGEs) that result in protein misfolding, and to suggest plant-derived polyphenols that could be useful in PAD. Thus, five polyphenols are considered, baicalein, curcumin, mangiferin, quercetin and resveratrol, reviewing the literature in PubMed. The key molecular mechanisms and preclinical and clinical studies of each selected compound are examined. Furthermore, the safety profiles of the polyphenols are outlined, together with the unwanted effects reported in humans, also by searching the WHO database (VigiBase).

The Effect of Resveratrol on Blood Lipid Profile: A Dose-Response Meta-Analysis of Randomized Controlled Trials

(1) Background: The effects of resveratrol on blood lipids are controversial. Whether there is a dose-response of the lipid profile upon resveratrol supplementation is unknown. (2) Methods: This dose-response meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of resveratrol supplementation on lipid profile. A systematical and comprehensive search of several databases was conducted by 30 June 2022. (3) Results: The results indicated that the intake of resveratrol could significantly decrease the total cholesterol (TC) (mean difference = −10.28; 95%CI: −13.79, −6.76, p < 0.001), triglyceride (TG) (Mean difference = −856; 95%CI: −12.37, −4.75, p < 0.001) and low-density lipoprotein cholesterol (LDL-C) (mean difference = −5.69; 95%CI: −11.07, −0.31, p = 0.038) level, but did not alter the level of high-density lipoprotein cholesterol (HDL-C). In the non-linear dose−response analysis, we observed a significant effect of the supplementation dosage on the level of LDL-C (p-nonlinearity = 0.002). Results from the sub-group analysis showed that the reduction of LDL-C was more significant in the trials with a duration of ≥12 weeks and in subjects with type 2 diabetes mellitus. (4) Conclusion: Findings from this study suggest that resveratrol may be beneficial to reduce TC, TG, and LDL-C levels in the blood. The dosage of the resveratrol intervention is an essential factor that affects the level of LDL-C.

Influence of Age and Dose on the Effect of Resveratrol for Glycemic Control in Type 2 Diabetes Mellitus: Systematic Review and Meta-Analysis

Background: Several clinical trials have suggested that resveratrol has hypoglycemic properties; however, there are other studies in which such an effect has not been observed. Methods: We carried out a systematic search in several databases; seventeen studies were selected for the systematic review and fifteen were included in the meta-analysis. Results: Resveratrol decreases glucose levels in subjects aged 45−59 years at doses <250 mg/day (−8.64 mg/dL, p < 0.00001), 250−500 mg/day (−22.24 mg/dL, p = 0.0003), and 500−1000 mg/day (−28.40 mg/dL, p = 0.0008), while in subjects older than 60 years, it only decreases with doses of 250−500 mg/day. Likewise, HbA1c improved in subjects aged 45−59 years with doses of 250−500 mg (−0.60%, p < 0.00001), but not in subjects older than 60 years. Insulin levels improved in subjects aged 45−59 years with doses < 250 mg/day (−0.80 mIU/L, p = 0.0003) and doses of 250−500 mg/day (−5.0 mIU/L, p = 0.0003), although in subjects older than 60 years, they only improved with doses of 250−500 mg/day (−1.79 mIU/L, p = 0.01). On the other hand, HOMA-IR only improved in subjects older than 60 years with doses of 250−500 mg/day (−0.40, p = 0.01). Conclusions: Resveratrol has a statistically significant dose−response effect on glucose concentrations, HbA1c, and insulin levels; however, there is not enough scientific evidence to propose a therapeutic dose.

Effects of resveratrol therapy on glucose metabolism, insulin resistance, inflammation, and renal function in the elderly patients with type 2 diabetes mellitus: A randomized controlled clinical trial protocol

BACKGROUND

Diabetes mellitus is a spectrum of metabolic disorders characterized by hyperglycemia and shows a growing global public health problem in the elderly. Resveratrol presents antiaging, anti-inflammatory, antitumor antioxidant, and cardioprotective activities. The purpose of this study was to investigate the ameliorative effects of resveratrol on blood glucose, insulin metabolism, lipid profile, renal function, inflammation, and nutrient sensing systems in the elderly patients with type 2 diabetes mellitus.

METHODS

The study is a single-blind, parallel-group, randomized controlled clinical trial consisting of a 6-month treatment period. A total of 472 elderly patients with type 2 diabetes mellitus were enrolled, and included participants will be randomized into 2 groups: resveratrol (n = 242) and placebo (n = 230). The clinical efficacy and changes in clinical parameters in each group will be measured at the indicated time. Clinical parameters included blood glucose, insulin resistance index, blood lipid index, proinflammatory cytokines, renal function, and nutrient sensing systems.

RESULTS

Resveratrol treatment greatly improved glucose metabolism, insulin tolerance, and insulin metabolism compared to placebo. Resveratrol relieved symptoms through enhancing nutrient sensing systems, which in turn reduced production and activity of glucose-6-phosphatase. Compared with placebo, resveratrol treatment significantly decreased proinflammatory cytokines glycated hemoglobin/hemoglobin A1c, interleukin-6, tumor necrosis factor-alpha, and interleukin-1beta in the elderly diabetes. Resveratrol treatment decreased blood glucose parameters, improved the lipid profile (total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides), and renal function compared to placebo.

CONCLUSION

In conclusion, resveratrol treatment improves inflammation, renal function, blood glucose parameters, inflammation, insulin resistance, and nutrient sensing systems in the elderly patients with type 2 diabetes mellitus, indicating resveratrol may be a potential therapeutic drug for the treatment of the elderly patients with type 2 diabetes mellitus.

Role of Oxidative Stress in the Pathogenesis of Atherothrombotic Diseases

Oxidative stress is generated by the imbalance between reactive oxygen species (ROS) formation and antioxidant scavenger system’s activity. Increased ROS, such as superoxide anion, hydrogen peroxide, hydroxyl radical and peroxynitrite, likely contribute to the development and complications of atherosclerotic cardiovascular diseases (ASCVD). In genetically modified mouse models of atherosclerosis, the overexpression of ROS-generating enzymes and uncontrolled ROS formation appear to be associated with accelerated atherosclerosis. Conversely, the overexpression of ROS scavenger systems reduces or stabilizes atherosclerotic lesions, depending on the genetic background of the mouse model. In humans, higher levels of circulating biomarkers derived from the oxidation of lipids (8-epi-prostaglandin F_2α, and malondialdehyde), as well as proteins (oxidized low-density lipoprotein, nitrotyrosine, protein carbonyls, advanced glycation end-products), are increased in conditions of high cardiovascular risk or overt ASCVD, and some oxidation biomarkers have been reported as independent predictors of ASCVD in large observational cohorts. In animal models, antioxidant supplementation with melatonin, resveratrol, Vitamin E, stevioside, acacetin and n-polyunsaturated fatty acids reduced ROS and attenuated atherosclerotic lesions. However, in humans, evidence from large, placebo-controlled, randomized trials or prospective studies failed to show any athero-protective effect of antioxidant supplementation with different compounds in different CV settings. However, the chronic consumption of diets known to be rich in antioxidant compounds (e.g., Mediterranean and high-fish diet), has shown to reduce ASCVD over decades. Future studies are needed to fill the gap between the data and targets derived from studies in animals and their pathogenetic and therapeutic significance in human ASCVD.

The Role of Polyphenol in Modulating Associated Genes in Diabetes-Induced Vascular Disorders

Diabetes-induced vascular disorder is considered one of the deadly risk factors among diabetic patients that are caused by persistent hyperglycemia that eventually leads to cardiovascular diseases. Elevated reactive oxygen species (ROS) due to high blood glucose levels activate signaling pathways such as AGE/RAGE, PKC, polyol, and hexosamine pathways. The activated signaling pathway triggers oxidative stress, inflammation, and apoptosis which later lead to vascular dysfunction induced by diabetes. Polyphenol is a bioactive compound that can be found abundantly in plants such as vegetables, fruits, whole grains, and nuts. This compound exerts therapeutic effects in alleviating diabetes-induced vascular disorder, mainly due to its potential as an anti-oxidative, anti-inflammatory, and anti-apoptotic agent. In this review, we sought to summarize the recent discovery of polyphenol treatments in modulating associated genes involved in the progression of diabetes-induced vascular disorder.

Efficacy of Resveratrol Supplementation on Glucose and Lipid Metabolism: A Meta-Analysis and Systematic Review

Background

Lipids are ubiquitous metabolites with diverse functions. Excessive lipid accumulation can trigger lipid redistribution among metabolic organs such as adipose, liver and muscle, thus altering the lipid metabolism. It has been revealed that disturbed lipid metabolism would cause multiple disease complications and is highly correlated with human morbidity. Resveratrol (RSV), a phytoestrogen with antioxidant, can modulate insulin resistance and lipid profile. Recently, research on RSV supplementation to improve glucose and lipid metabolism has been controversial. A meta-analysis may provide a scientific reference for the relationship between lipid metabolism and RSV supplementation.

Methods and Analysis

We searched the PubMed, Cochrane Library, Web of Science, and Embase databases from inception to October 2021 using relevant keywords. A comprehensive search for randomized controlled trials (RCTs) was performed. For calculating pooled effects, continuous data were pooled by mean difference (MD) and 95% confidence interval (CI). Adopting the method of inverse-variance with a random-effect, all related statistical analyses were performed using the Rev Man V.5.3 and STATA V.15 software.

Results

A total of 25 articles were incorporated into the final meta-analysis after removal of duplicates by checking titles and abstracts and excluding non-relevant articles. The selected articles had a total of 1,171 participants, including 578 in the placebo group and 593 in the intervention group. According to the current meta-analysis, which demonstrated that there was a significant decrease in waist circumference (SMD = –0.36; 95% CI: –0.59, –0.14; P = 0.002; I² = 88%), hemoglobin A1c (–0.48; –0.69, –0.27; P ≤ 0.001; I² = 94%), total cholesterol (–0.15; –0.3, –0.01; P = 0.003; I² = 94%), low density lipoprotein cholesterol (–0.42; –0.57, –0.27; P ≤ 0.001; I² = 92%), high density lipoprotein cholesterol (0.16; –0.31, –0.02; P = 0.03; I² = 81%) following resveratrol administration.

Conclusion

These results suggest that RSV has a dramatic impact on regulating lipid and glucose metabolism, and the major clinical value of resveratrol intake is for obese and diabetic patients. We hope that this study could provide more options for clinicians using RSV. Furthermore, in the future, large-scale and well-designed trials will be warranted to confirm these results.

Systematic Review Registration

Website [https://www.crd.york.ac.uk/prospero/#recordDetails], identifier [CRD42021244904].

Effects of Resveratrol on Metabolic Indicators in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Previous studies on the effects of resveratrol on metabolic indicators reported contradictory findings, and these indicators have not been frequently studied in patients with type 2 diabetes. In this study, we aimed to examine the effects of resveratrol on metabolic indicators in a specific group of people with type 2 diabetes using the most recent literature.

METHODS

We used RevMan 5.4 and Stata 14.0 software to identify randomized controlled studies on the impact of resveratrol on metabolic indicators in patients with type 2 diabetes using relevant search terms and keywords such as "resveratrol" and "type 2 diabetes" in the China National Knowledge Infrastructure, PubMed, Cochrane, and Embase. Data were expressed as the weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

This meta-analysis included 19 studies involving 1151 patients with type 2 diabetes, including 584 patients treated with resveratrol and 567 patients who received placebo. Compared with the control data, large doses of resveratrol (≥1000 mg) reduced fasting blood glucose levels (WMD: -18.76 mg/dL, 95% CI: -23.43, -14.09; P < 0.00001). Additionally, resveratrol reduced systolic blood pressure (WMD: -7.97 mmHg, 95% CI: -10.63, -5.31; P < 0.00001) and diastolic blood pressure (WMD: -3.55 mmHg, 95% CI: -5.18, -1.93; P < 0.00001) in patients with type 2 diabetes but did not improve waist circumference (WMD: 0.05 cm, 95% CI: -1.77, 1.88; P=0.95), triglyceride levels (WMD: -4.49 mg/dL, 95% CI: -24.23, 15.25; P=0.66), or high-density lipoprotein cholesterol levels (WMD: -1.05 mg/dL, 95% CI: -2.44, 0.33; P=0.14) in patients with type 2 diabetes.

CONCLUSION

This systematic review and meta-analysis updated the most recent literature and provided new evidence, proving that resveratrol treatment can reduce systolic blood pressure and diastolic blood pressure. High-dose resveratrol can reduce fasting blood glucose in patients with type 2 diabetes, although it has no effect on waist circumference, triglyceride, and high-density lipoprotein cholesterol.

Therapeutic potential of resveratrol in diabetic nephropathy according to molecular signaling

BACKGROUND

Diabetic nephropathy (DN) as a severe complication of diabetes mellitus (DM), is a crucial menace for human health and survival and remarkably elevates the healthcare systems' costs. Therefore, it is worth noting to identify novel preventive and therapeutic strategies to alleviate the disease conditions. Resveratrol, as a well-defined anti-diabetic/ antioxidant agent has capabilities to counteract diabetic complications. It has been predicted that resveratrol will be a fantastic natural polyphenol for diabetes therapy in the next few years.

OBJECTIVE

Accordingly, the current review aims to depict the role of resveratrol in the regulation of different signaling pathways that are involved in the reactive oxygen species (ROS) production, inflammatory processes, autophagy, and mitochondrial dysfunction, as critical contributors to DN pathophysiology.

RESULTS

The pathogenesis of DN can be multifactorial; hyperglycemia is one of the prominent risk factors of DN development that is closely related to oxidative stress. Resveratrol, as a well-defined polyphenol, has various biological and medicinal properties, including anti-diabetic, anti-inflammatory, and anti-oxidative effects.

CONCLUSION

Resveratrol prevents kidney damages that are caused by oxidative stress, enhances antioxidant capacity, and attenuates the inflammatory and fibrotic responses. For this reason, resveratrol is considered an interesting target in DN research due to its therapeutic possibilities during diabetic disorders and renal protection.

The effects of resveratrol on glycemic control and cardiometabolic parameters in patients with T2DM: A systematic review and meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a progressive meta-inflammatory disorder, which induce micro and macrovascular complications. Resveratrol is a nutraceutical known to have antioxidant and anti-inflammatory properties. It improves insulin resistance; however, no clear evidence regarding its effects in patients with T2DM.

OBJECTIVES

We aimed to evaluate the efficacy and the safety of oral resveratrol supplementation in type 2 diabetic patients concerning dose and duration.

METHODS

We searched PubMed, Cochrane Library, Scopus, WOS, Wiley, and Google Scholar for RCTs evaluating the efficacy and safety of resveratrol on patients with T2DM. We screened the studies for the eligibility criteria, performed the quality assessment, extracted the studies' characteristics, baseline, and outcome data of interest, and finally conducted the meta-analysis using RevManV5.3.

RESULTS

This systematic review and meta-analysis, including 17 RCTs with total 871 patients with T2DM, showed that resveratrol was superior to placebo on fasting blood glucose (FBG) and total cholesterol (TC) with doses ≥500mg {MD=-13.34, 95%CI [-22.73, -3.95], P=0.005}, {MD=-5.64, 95%CI [-6.95, -4.33], P<0.00001} respectively. Moreover, it improved HbA1c at three months {MD=-0.41, 95%CI [-0.65, -0.16], P=0.001 and systolic blood pressure {MD: -7.91, 95%CI [-10.44, -5.37], P<0.00001}.

CONCLUSION

We concluded that resveratrol beneficially modulates glycemic control as well as cardiometabolic parameters in patients with T2DM.

Effect of resveratrol supplementation on biomarkers associated with atherosclerosis in humans

Previous studies have suggested the beneficial effects of resveratrol against cardiovascular disease (CVD). However, there are inconsistent results on cardiovascular-related biomarkers mainly because of variable dosage, intervention time and baseline characteristics of the population. Thus, the exact effect of resveratrol remains unclear. We conducted a review to classify the studies that applied resveratrol to supplement humans according to the major biomarkers and identify which protocol characteristics would be associated with each result profile. Randomized clinical trials that assessed resveratrol effect on biomarkers related to atherosclerosis were searched in databases. Biochemical data were collected from 27 studies on the baseline and post-intervention time. We selected 12 biomarkers to compose the matrix, based on their clinical relevance and higher variation level. A total of 32 assays were obtained from these 27 studies. The net change (%) was calculated for each biomarker. Applying multivariate analysis, the assays were grouped into 3 clusters. Studies that composed Cluster II were characterized by a mean dose of 454.14 mg/day for 74.21 days and showed higher reduction of triglyceride concentration and blood pressure, while those composing Cluster III applied doses around 273.75 mg/day for about 175.33 days and showed the highest HDL increase. Thus, interventions with resveratrol could be customized according to the patient condition, in terms of "dose/time of intervention". This information can be applied to combine resveratrol with drugs to reduce blood pressure or improve lipid profile in further clinical studies.

The Effect of Resveratrol on the Cardiovascular System from Molecular Mechanisms to Clinical Results

Cardiovascular diseases are the leading causes of death worldwide. The cardioprotective effects of natural polyphenols such as resveratrol (3,5,4-trihydroxystilbene) have been extensively investigated throughout recent decades. Many studies of RES have focused on its favorable effects on pathological conditions related to cardiovascular diseases and their risk factors. The aim of this review was to summarize the wide beneficial effects of resveratrol on the cardiovascular system, including signal transduction pathways of cell longevity, energy metabolism of cardiomyocytes or cardiac remodeling, and its anti-inflammatory and antioxidant properties. In addition, this paper discusses the significant preclinical and human clinical trials of recent years with resveratrol on cardiovascular system. Finally, we present a short overview of antiviral and anti-inflammatory properties and possible future perspectives on RES against COVID-19 in cardiovascular diseases.

Efficacy and Safety of Resveratrol Supplements on Blood Lipid and Blood Glucose Control in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Diabetes is a major public health concern. Resveratrol has shown great beneficial effects on hyperglycemia and insulin resistance and as an antioxidant.

Methods

We searched the Chinese and English databases (such as CNKI, PubMed, and Embase) and extracted data from randomized controlled trials (RCTs). Then, RevMan 5.3 was used for bias risk assessment and meta-analysis. The primary outcome indicators include insulin-resistance-related indicators and blood-lipid-related indicators. This systematic review and meta-analysis was registered in PROSPERO (CRD42018089521).

Results

Fifteen RCTs involving 896 patients were included. For insulin-resistance-related indicators, the summary results showed that, compared with the control group, homeostasis model assessment for insulin resistance (HOMA-IR) in the resveratrol group is lower (WMD: −0.99; 95% CI −1.61, −0.38; P=0.002). For blood-lipid-related indicators, the total cholesterol (TC) and triglyceride (TG) in the resveratrol group is of no statistical significance (for TC, WMD: −7.11; 95% CI −16.28, 2.06; P=0.13; for TG, WMD: −2.15; 95% CI −5.52, 1.22; P=0.21). For adverse events, the summary results showed that there was no statistical difference in the incidence of adverse events between the resveratrol and control groups (WMD: 2; 95% CI 0.44, 9.03; P=0.37).

Conclusion

Based on the current evidence, resveratrol may improve insulin resistance, lower fasting blood glucose and insulin levels, and improve oxidative stress in patients with type 2 diabetes mellitus.

Assessment of Arterial Stiffness Using the Cardio-Ankle Vascular Index – What We Know and What We Strive for

Currently, the importance of assessing arterial stiffness as an integral indicator of cardiovascular risk, an indicator of arteriosclerosis, and a predictor of cardiovascular events has been demonstrated. The traditional indicator of arterial stiffness-pulse wave velocity-depends on the level of blood pressure, which makes it difficult to use it for dynamic assessment. The proposed new arterial stiffness index-the cardio-ankle vascular index (CAVI), does not depend on the level of blood pressure and is more convenient in practical use. CAVI has been widely used in clinical medicine for the past 15 years as an index for assessing cardiovascular diseases and risk factors, which has allowed for the expansion and deepening of research on this topic. This review focuses primarily on recent publications and new opportunities for evaluating vascular function using CAVI. The review provides information on solving methodological problems in evaluating CAVI, highlights the relationship between CAVI and future cardiovascular events, and provides cross-sectional data on the Association of CAVI with the presence of cardiovascular diseases and their risk factors. The results of studies on the effect of drug therapy and measures to control risk factors for cardiovascular diseases on CAVI are presented. While it remains unclear how much changes in CAVI over time can affect the forecast, research is currently being conducted in this direction. The use of CAVI also opens up new perspectives in the assessment of cardiovascular interactions, the study of vascular function in vasculitis and vascular injuries, as well as in geriatric medicine (concepts of premature vascular aging and excess vascular aging).

Healthberry 865® and Its Related, Specific, Single Anthocyanins Exert a Direct Vascular Action, Modulating Both Endothelial Function and Oxidative Stress

In recent years, epidemiological studies have identified a relationship between diet and cerebro-cardiovascular disease (CVD). In this regard, there is a promising dietary group for cardiovascular protection are polyphenols, especially anthocyanins. Vascular reactivity studies were performed using Healthberry 865^® and constituent single anthocyanins to characterize vasomotor responses; immunofluorescence analysis with dichlorofluorescein diacetate and dihydroethidium were used to evaluate nitric oxide and oxidative stress; lucigenin assay was used to measure NADPH oxidase activity; and gel electrophoresis and immunoblotting were used to dissect the molecular mechanisms involved. We demonstrated that Healthberry 865^® exerts an important vasorelaxant effect of resistance artery functions in mice. Its action is mediated by nitric oxide release through the intracellular signaling PI3K/Akt. Moreover, behind its capability of modulating vascular tone, it also exerts an important antioxidant effect though the modulation of the NADPH oxidase enzyme. Interestingly, its cardiovascular properties are mediated by the selective action of different anthocyanins. Finally, the exposure of human dysfunctional vessels to Healthberry 865^® significantly reduces oxidative stress and improves NO bioavailability. Although further investigations are needed, our data demonstrate the direct role of Healthberry 865^® on the modulation of vasculature, both on the vasorelaxation and on oxidative stress; thus, supporting the concept that a pure mixture of anthocyanins could be helpful in preventing the onset of vascular dysfunction associated with the development of CVD.

Natural and synthetic antioxidants targeting cardiac oxidative stress and redox signaling in cardiometabolic diseases

Cardiometabolic diseases (CMDs) are metabolic diseases (e.g., obesity, diabetes, atherosclerosis, rare genetic metabolic diseases, etc.) associated with cardiac pathologies. Pathophysiology of most CMDs involves increased production of reactive oxygen species and impaired antioxidant defense systems, resulting in cardiac oxidative stress (OxS). To alleviate OxS, various antioxidants have been investigated in several diseases with conflicting results. Here we review the effect of CMDs on cardiac redox homeostasis, the role of OxS in cardiac pathologies, as well as experimental and clinical data on the therapeutic potential of natural antioxidants (including resveratrol, quercetin, curcumin, vitamins A, C, and E, coenzyme Q10, etc.), synthetic antioxidants (including N-acetylcysteine, SOD mimetics, mitoTEMPO, SkQ1, etc.), and promoters of antioxidant enzymes in CMDs. As no antioxidant indicated for the prevention and/or treatment of CMDs has reached the market despite the large number of preclinical and clinical studies, a sizeable translational gap is evident in this field. Thus, we also highlight potential underlying factors that may contribute to the failure of translation of antioxidant therapies in CMDs.

Chinese Herbal Medicines and Active Metabolites: Potential Antioxidant Treatments for Atherosclerosis

Atherosclerosis is a complex chronic disease that occurs in the arterial wall. Oxidative stress plays a crucial role in the occurrence and progression of atherosclerotic plaques. The dominance of oxidative stress over antioxidative capacity generates excess reactive oxygen species, leading to dysfunctions of the endothelium and accelerating atherosclerotic plaque progression. Studies showed that Chinese herbal medicines and traditional Chinese medicine (TCM) might regulate oxidative stress; they have already been used to treat diseases related to atherosclerosis, including stroke and myocardial infarction. This review will summarize the mechanisms of oxidative stress in atherosclerosis and discuss studies of Chinese herbal medicines and TCM preparations treating atherosclerosis, aiming to increase understanding of TCM and stimulate research for new drugs to treat diseases associated with oxidative stress.

Role of Resveratrol in Prevention and Control of Cardiovascular Disorders and Cardiovascular Complications Related to COVID-19 Disease: Mode of Action and Approaches Explored to Increase Its Bioavailability

Resveratrol is a phytoalexin produced by many plants as a defense mechanism against stress-inducing conditions. The richest dietary sources of resveratrol are berries and grapes, their juices and wines. Good bioavailability of resveratrol is not reflected in its high biological activity in vivo because of resveratrol isomerization and its poor solubility in aqueous solutions. Proteins, cyclodextrins and nanomaterials have been explored as innovative delivery vehicles for resveratrol to overcome this limitation. Numerous in vitro and in vivo studies demonstrated beneficial effects of resveratrol in cardiovascular diseases (CVD). Main beneficial effects of resveratrol intake are cardioprotective, anti-hypertensive, vasodilatory, anti-diabetic, and improvement of lipid status. As resveratrol can alleviate the numerous factors associated with CVD, it has potential as a functional supplement to reduce COVID-19 illness severity in patients displaying poor prognosis due to cardio-vascular complications. Resveratrol was shown to mitigate the major pathways involved in the pathogenesis of SARS-CoV-2 including regulation of the renin-angiotensin system and expression of angiotensin-converting enzyme 2, stimulation of immune system and downregulation of pro-inflammatory cytokine release. Therefore, several studies already have anticipated potential implementation of resveratrol in COVID-19 treatment. Regular intake of a resveratrol rich diet, or resveratrol-based complementary medicaments, may contribute to a healthier cardio-vascular system, prevention and control of CVD, including COVID-19 disease related complications of CVD.

Fine wine or sour grapes? A systematic review and meta-analysis of the impact of red wine polyphenols on vascular health

PURPOSE

Red wine polyphenols (RWP) are plant-based molecules that have been extensively studied in relation to their protective effects on vascular health in both animals and humans. The aim of this review was to quantify and compare the efficacy of RWP and pure resveratrol on outcomes measures of vascular health and function in both animals and humans.

METHODS

Comprehensive database searches were carried out through PubMed, Web of Science and OVID for randomised, placebo-controlled studies in both animals and humans. Meta-analyses were carried out on acute and chronic studies of RWP in humans, alongside sub-group analysis where possible. Risk-of-bias assessment was carried out for all included studies based on randomisation, allocation, blinding, outcome data reporting, and other biases.

RESULTS

48 animal and 37 human studies were included in data extraction following screening. Significant improvements in measures of blood pressure and vascular function following RWP were seen in 84% and 100% of animal studies, respectively. Human studies indicated significant improvements in systolic blood pressure overall (- 2.6 mmHg, 95% CI: [- 4.8, - 0.4]), with a greater improvement in pure-resveratrol studies alone (- 3.7 mmHg, 95% CI: [- 7.3, - 0.0]). No significant effects of RWP were seen in diastolic blood pressure or flow-mediated dilation (FMD) of the brachial artery.

CONCLUSION

RWP have the potential to improve vascular health in at risk human populations, particularly in regard to lowering systolic blood pressure; however, such benefits are not as prevalent as those observed in animal models.

Flavonoids as natural phenolic compounds and their role in therapeutics: an overview

BACKGROUND

Natural plants and plant-derived formulations have been used by mankind from the ancient period of time. For the past few years, many investigations elaborated the therapeutic potential of various secondary chemicals present in the plants. Literature revealed that the various secondary metabolites, viz. phenolics and flavonoids, are responsible for a variety of therapeutic action in humans.

MAIN BODY

In the present review, an attempt has been made to compile the exploration of natural phenolic compounds with major emphasis on flavonoids and their therapeutic potential too. Interestingly, long-term intake of many dietary foods (rich in phenolics) proved to be protective against the development and management of diabetes, cancer, osteoporosis, cardiovascular diseases and neurodegenerative diseases, etc.

CONCLUSION

This review presents an overview of flavonoid compounds to use them as a potential therapeutic alternative in various diseases and disorders. In addition, the present understanding of phenolics and flavonoids will serve as the basis for the next scientific studies.

The Role of Antioxidants Supplementation in Clinical Practice: Focus on Cardiovascular Risk Factors

Oxidative stress may be defined as an imbalance between reactive oxygen species (ROS) and the antioxidant system to counteract or detoxify these potentially damaging molecules. This phenomenon is a common feature of many human disorders, such as cardiovascular disease. Many of the risk factors, including smoking, hypertension, hypercholesterolemia, diabetes, and obesity, are associated with an increased risk of developing cardiovascular disease, involving an elevated oxidative stress burden (either due to enhanced ROS production or decreased antioxidant protection). There are many therapeutic options to treat oxidative stress-associated cardiovascular diseases. Numerous studies have focused on the utility of antioxidant supplementation. However, whether antioxidant supplementation has any preventive and/or therapeutic value in cardiovascular pathology is still a matter of debate. In this review, we provide a detailed description of oxidative stress biomarkers in several cardiovascular risk factors. We also discuss the clinical implications of the supplementation with several classes of antioxidants, and their potential role for protecting against cardiovascular risk factors.

Histone Deacetylase SIRT1, Smooth Muscle Cell Function, and Vascular Diseases

Vascular smooth muscle cells (VSMCs), located in the media of artery, play key roles in maintaining the normal vascular physiological functions. Abnormality in VSMCs is implicated in vascular diseases (VDs), including atherosclerosis, abdominal aortic aneurysm (AAA), aortic dissection, and hypertension by regulating the process of inflammation, phenotypic switching, and extracellular matrix degradation. Sirtuins (SIRTs), a family of proteins containing seven members (from SIRT1 to SIRT7) in mammals, function as NAD⁺-dependent histone deacetylases and ADP-ribosyltransferases. In recent decades, great attention has been paid to the cardiovascular protective effects of SIRTs, especially SIRT1, suggesting a new therapeutic target for the treatment of VDs. In this review, we introduce the basic functions of SIRT1 against VSMC senescence, and summarize the contribution of SIRT1 derived from VSMCs in VDs. Finally, the potential new strategies based on SIRT1 activation have also been discussed with an emphasis on SIRT1 activators and calorie restriction to improve the prognosis of VDs.

Oxidative Stress in Cardiovascular Diseases

Reactive oxygen species (ROS) are subcellular messengers in signal transductions pathways with both beneficial and deleterious roles. ROS are generated as a by-product of mitochondrial respiration or metabolism or by specific enzymes such as superoxide dismutases, glutathione peroxidase, catalase, peroxiredoxins, and myeloperoxidases. Under physiological conditions, the low levels of ROS production are equivalent to their detoxification, playing a major role in cellular signaling and function. In pathological situations, particularly atherosclerosis or hypertension, the release of ROS exceeds endogenous antioxidant capacity, leading to cell death. At cardiovascular levels, oxidative stress is highly implicated in myocardial infarction, ischemia/reperfusion, or heart failure. Here, we will first detail the physiological role of low ROS production in the heart and the vessels. Indeed, ROS are able to regulate multiple cardiovascular functions, such as cell proliferation, migration, and death. Second, we will investigate the implication of oxidative stress in cardiovascular diseases. Then, we will focus on ROS produced by NAPDH oxidase or during endothelial or mitochondrial dysfunction. Given the importance of oxidative stress at the cardiovascular level, antioxidant therapies could be a real benefit. In the last part of this review, we will detail the new therapeutic strategies potentially involved in cardiovascular protection and currently under study.

Resveratrol and insulin association reduced alveolar bone loss and produced an antioxidant effect in diabetic rats

BACKGROUND

The present investigation studied the effects of systemic administration of resveratrol (RSV) on the development of experimental periodontitis (EP) and on the release of markers of inflammation, bone metabolism, and oxidative stress in diabetic rats.

METHODS

Seventy-five male rats were divided into five groups: DM+PLAC: Diabetes Mellitus + placebo solution; DM+INS: DM + insulin therapy; DM+RSV: DM + RSV; DM+RSV+INS: DM + RSV and insulin; NDM: non-diabetic. Streptozotocin was used to induce DM and EP was induced by the placement of a ligature at the fist mandibular and the second maxillary molars. Euthanasia occurred 30 days after the initiation of the study and mandible specimens were subjected for morphometric analysis of bone level. Gingival tissues from mandibular molars were collected for quantification of inflammatory and oxidative stress markers by multiplex assay system and ELISA assay, respectively. Maxillary gingival tissues were processed for real-time polymerase chain reaction (real-time PCR) assessment of markers of bone metabolism and oxidative stress.

RESULTS

Morphometric analysis revealed greater bone loss in DM+PLAC and DM+INS in comparison to the other treatments (P < 0.05). RSV used in conjunction with INS reduced the levels of interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN-γ) and superoxide dismutase 1 (SOD) (P < 0.05). RSV alone reduced nicotinamide adenine dinucleotide phosphatase oxidase (NADPH oxidase) levels, in comparison to DM+INS and DM+RSV+INS (P < 0.05). All treatments upregulated mRNA levels for osteoprotegerin (OPG) in comparison to PLAC (P < 0.05). Sirtuin 1 (SIRT) mRNA levels were lower in PLAC when compared to DM+RSV, DM+RSV+INS and NDM (P < 0.05).

CONCLUSION

RSV reduced the progression of EP and the levels of NADPH oxidase. Co-treatment with RSV and insulin reduced the levels of pro-inflammatory factors (either proteins or mRNA) and increased the levels of SOD. The data also demonstrated that treatment with RSV and INS alone or in combination had beneficial effects on bone loss.

New Horizons of Arterial Stiffness Developed Using Cardio-Ankle Vascular Index (CAVI)

Arterial stiffness is recognized mainly as an indicator of arteriosclerosis and a predictor of cardiovascular events. Cardio-ankle vascular index (CAVI), which reflects arterial stiffness from the origin of the aorta to the ankle, was developed in 2004. An important feature of this index is the independency from blood pressure at the time of measurement. A large volume of clinical evidence obtained using CAVI has been reported. CAVI is high in patients with various atherosclerotic diseases including coronary artery disease and chronic kidney disease. Most coronary risk factors increase CAVI and their improvement reduces CAVI. Many prospective studies have investigated the association between CAVI and future cardiovascular disease (CVD), and proposed CAVI of 9 as the optimal cut-off value for predicting CVD. Research also shows that CAVI reflects afterload and left ventricular diastolic dysfunction in patients with heart failure. Furthermore, relatively acute changes in CAVI are observed under various pathophysiological conditions including mental stress, septic shock and congestive heart failure, and in pharmacological studies. CAVI seems to reflect not only structural stiffness but also functional stiffness involved in acute vascular functions. In 2016, Spronck and colleagues proposed a variant index CAVI₀, and claimed that CAVI₀ was truly independent of blood pressure while CAVI was not. This argument was settled, and the independence of CAVI from blood pressure was reaffirmed. In this review, we summarize the recently accumulated evidence of CAVI, focusing on the proposed cut-off values for CVD events, and suggest the development of new horizons of vascular function index using CAVI.

The effects of resveratrol on lipid profiles and liver enzymes in patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

There are current trials investigating the effect of resveratrol supplementation on lipid profiles and liver enzymes among patients with metabolic syndrome (MetS) and related disorders; however, their findings are controversial. This systematic review and meta-analysis were aimed to determine the effects of resveratrol supplementation on lipid profiles and liver enzymes among patients with MetS and related disorders.

METHODS

We performed a comprehensive search of the following online databases up to November 2018: Cochrane Library, PubMed, Embase, and Web of Science. The relevant articles were assessed for quality of studies using the Cochrane risk of bias tool.

RESULTS

Out of 2459 citations, 31 articles were appropriate for including to the current meta-analysis. The pooled results indicated that resveratrol use significantly decreased total cholesterol [weighted mean difference (WMD) = - 7.65 mg/dL; 95% CI, - 12.93, - 2.37; P < 0.01; I2: 83.4%] and increased gamma-glutamyl transferase (GGT) concentrations (WMD = 1.76 U/l; 95% CI, 0.58, 2.94; P < 0.01; I2: 20.1%). We found no significant effect of resveratrol supplementation on triglycerides (WMD = - 5.84 mg/dL; 95% CI, - 12.68, 1.00; P = 0.09; I2: 66.8%), LDL- (WMD = -2.90 mg/dL; 95% CI, - 10.88, 5.09; P = 0.47; I2: 96.0%), HDL-cholesterol (WMD = 0.49 mg/dL; 95% CI, - 0.80, 1.78; P = 0.45; I2: 74.0%), alanine aminotransferase (ALT) (WMD = -0.14 U/l; 95% CI, - 3.69, 3.41; P = 0.93; I2: 79.6%), and aspartate aminotransferase (AST) (WMD = -0.34 U/l; 95% CI, - 2.94, 2.27; P = 0.80; I2: 88.0%) concentrations.

CONCLUSIONS

This meta-analysis demonstrated that resveratrol supplementation among patients with MetS and related disorders significantly reduced total cholesterol and increased GGT concentrations, but did not affect triglycerides, LDL-, HDL-cholesterol, ALT, and AST concentrations. This data suggests that resveratrol may have a potential cardio-protective effect in patients with MetS and related disorders.

Resveratrol for adults with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic disorder that is characterised by insulin resistance and hyperglycaemia, which over time may give rise to vascular complications. Resveratrol is a plant-derived nutritional supplement shown to have anti-diabetic properties in many animal models. Less evidence is available on its safety and efficacy in the management of T2DM in humans.

OBJECTIVES

To assess the efficacy and safety of resveratrol formulations for adults with type 2 diabetes mellitus.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and International Pharmaceutical Abstracts, as well as the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. The date of the last search was December 2018 for all databases. No language restrictions were applied.

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing effects of oral resveratrol (any dose or formulation, duration, or frequency of administration) with placebo, no treatment, other anti-diabetic medications, or diet or exercise, in adults with a diagnosis of T2DM.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified and included RCTs, assessed risk of bias, and extracted study-level data. Study authors were contacted for any missing information or for clarification of reported data. We assessed studies for certainty of the evidence using the GRADE instrument.

MAIN RESULTS

We identified three RCTs with a total of 50 participants. Oral resveratrol not combined with other plant polyphenols was administered at 10 mg, 150 mg, or 1000 mg daily for a period ranging from four weeks to five weeks. The comparator intervention was placebo. Overall, all three included studies had low risk of bias. None of the three included studies reported long-term, patient-relevant outcomes such as all-cause mortality, diabetes-related complications, diabetes-related mortality, health-related quality of life, or socioeconomic effects. All three included studies reported that no adverse events were observed, indicating that no deaths occurred (very low-quality evidence for adverse events, all-cause mortality, and diabetes-related mortality). Resveratrol versus placebo showed neutral effects for glycosylated haemoglobin A1c (HbA1c) levels (mean difference (MD) 0.1%, 95% confidence interval (CI) -0.02 to 0.2; P = 0.09; 2 studies; 31 participants; very low-certainty evidence). Due to the short follow-up period, HbA1c results have to be interpreted cautiously. Similarly, resveratrol versus placebo showed neutral effects for fasting blood glucose levels (MD 2 mg/dL, 95% CI -2 to 7; P = 0.29; 2 studies; 31 participants), and resveratrol versus placebo showed neutral effects for insulin resistance (MD -0.35, 95% CI -0.99 to 0.28; P = 0.27; 2 studies; 36 participants). We found eight ongoing RCTs with approximately 800 participants and two studies awaiting assessment, which, when published, could contribute to the findings of this review.

AUTHORS' CONCLUSIONS

Currently, research is insufficient for review authors to evaluate the safety and efficacy of resveratrol supplementation for treatment of adults with T2DM. The limited available research does not provide sufficient evidence to support any effect, beneficial or adverse, of four to five weeks of 10 mg to 1000 mg of resveratrol in adults with T2DM. Adequately powered RCTs reporting patient-relevant outcomes with long-term follow-up periods are needed to further evaluate the efficacy and safety of resveratrol supplementation in the treatment of T2DM.

Resveratrol and the Interaction between Gut Microbiota and Arterial Remodelling

Arterial remodelling refers to the alteration in the structure of blood vessel that contributes to the progression of hypertension and other cardiovascular complications. Arterial remodelling is orchestrated by the crosstalk between the endothelium and vascular smooth muscle cells (VSMC). Vascular inflammation participates in arterial remodelling. Resveratrol is a natural polyphenol that possesses anti-oxidant and anti-inflammatory properties and has beneficial effects in both the endothelium and VSMC. Resveratrol has been studied for the protective effects in arterial remodelling and gut microbiota, respectively. Gut microbiota plays a critical role in the immune system and inflammatory processes. Gut microbiota may also regulate vascular remodelling in cardiovascular complications via affecting endothelium function and VSMC proliferation. Currently, there is new evidence showing that gut microbiota regulate the proliferation of VSMC and the formation of neointimal hyperplasia in response to injury. The change in population of the gut microbiota, as well as their metabolites (e.g., short-chain fatty acids) could critically contribute to VSMC proliferation, cell cycle progression, and migration. Recent studies have provided strong evidence that correlate the effects of resveratrol in arterial remodelling and gut microbiota. This review aims to summarize recent findings on the resveratrol effects on cardiovascular complications focusing on arterial remodelling and discuss the possible interactions of resveratrol and the gut microbiota that modulate arterial remodelling.

Relation of Fruits and Vegetables with Major Cardiometabolic Risk Factors, Markers of Oxidation, and Inflammation

Noncommunicable diseases (NCDs) are considered to be the leading cause of death worldwide. Inadequate fruit and vegetable intake have been recognized as a risk factor for almost all NCDs (type 2 diabetes mellitus, cancer, and cardiovascular and neurodegenerative diseases). The main aim of this review is to examine the possible protective effect that fruit and vegetable consumption or their bioactive compounds may have on the development of NCDs such as atherosclerosis. The accumulated evidence on the protective effects of adequate consumption of fruits and vegetables in some cases, or the lack of evidence in others, are summarized in the present review. The main conclusion of this review is that well-designed, large-scale, long-term studies are needed to truly understand the role fruit and vegetable consumption or their bioactive compounds have in atherosclerosis.

The effects of resveratrol on metabolic status in patients with type 2 diabetes mellitus and coronary heart disease

This study was performed to investigate the effects of resveratrol on metabolic status in patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). This randomized, double-blind, placebo-controlled trial was performed with 56 patients having T2DM and CHD. The patients were randomly divided into two groups to receive either 500 mg resveratrol per day (n = 28) or placebo (n = 28) for 4 weeks. Resveratrol reduced fasting glucose (β-10.04 mg dL^-1; 95% CI, -18.23, -1.86; P = 0.01), insulin (β-1.09 μIU mL^-1; 95% CI, -1.93, -0.24; P = 0.01) and insulin resistance (β-0.48; 95% CI, -0.76, -0.21; P = 0.001) and significantly increased insulin sensitivity (β 0.006; 95% CI, 0.001, 0.01; P = 0.02) when compared with the placebo. Resveratrol also significantly increased HDL-cholesterol levels (β 3.38 mg dL^-1; 95% CI, 1.72, 5.05; P < 0.001) and significantly decreased the total-/HDL-cholesterol ratio (β-0.36; 95% CI, -0.59, -0.13; P = 0.002) when compared with the placebo. Additionally, resveratrol caused a significant increase in total antioxidant capacity (TAC) (β 58.88 mmol L^-1; 95% CI, 17.33, 100.44; P = 0.006) and a significant reduction in malondialdehyde (MDA) levels (β-0.21 μmol L^-1; 95% CI, -0.41, -0.005; P = 0.04) when compared with the placebo. Resveratrol upregulated PPAR-γ (P = 0.01) and sirtuin 1 (SIRT1) (P = 0.01) in the peripheral blood mononuclear cells (PBMCs) of T2DM patients with CHD. Resveratrol supplementation did not have any effect on inflammatory markers. Four-week supplementation of resveratrol in patients with T2DM and CHD had beneficial effects on glycemic control, HDL-cholesterol levels, the total-/HDL-cholesterol ratio, TAC and MDA levels. Resveratrol also upregulated PPAR-γ and SIRT1 in the PBMCs of T2DM patients with CHD.

SIRT1-Dependent Upregulation of Antiglycative Defense in HUVECs Is Essential for Resveratrol Protection against High Glucose Stress

Uncontrolled accumulation of methylglyoxal (MG) and reactive oxygen species (ROS) occurs in hyperglycemia-induced endothelial dysfunction associated with diabetes. Resveratrol (RSV) protects the endothelium upon high glucose (HG); however, the mechanisms underlying such protective effects are still debated. Here we identified key molecular players involved in the glycative/oxidative perturbations occurring in endothelial cells exposed to HG. In addition, we determined whether RSV essentially required SIRT1 to trigger adaptive responses in HG-challenged endothelial cells. We used primary human umbilical vein endothelial cells (HUVECs) undergoing a 24-h treatment with HG, with or without RSV and EX527 (i.e., SIRT1 inhibitor). We found that HG-induced glycative stress (GS) and oxidative stress (OS), by reducing SIRT1 activity, as well as by diminishing the efficiency of MG- and ROS-targeting protection. RSV totally abolished the HG-dependent cytotoxicity, and this was associated with SIRT1 upregulation, together with increased expression of GLO1, improved ROS-scavenging efficiency, and total suppression of HG-related GS and OS. Interestingly, RSV failed to induce effective response to HG cytotoxicity when EX527 was present, thus suggesting that the upregulation of SIRT1 is essential for RSV to activate the major antiglycative and antioxidative defense and avoid MG- and ROS-dependent molecular damages in HG environment.

The Effect of Resveratrol Supplementation on Cardio-Metabolic Risk Factors in Patients with Type 2 Diabetes: A Randomized, Double-Blind Controlled Trial

The aim of the present randomized controlled trial was to evaluate the effect of a micronized resveratrol supplement on glycemic status, lipid profile, and body composition in patients with type 2 diabetes mellitus (T2DM). A total of 71 overweight patients with T2DM (body mass index ranged 25-30) were randomly assigned to receive 1000 mg/day trans-resveratrol or placebo (methyl cellulose) for 8 weeks. Anthropometric indices and biochemical indices including lipid and glycemic profile were measured before and after the intervention. In adjusted model (age, sex, and baseline body mass index), resveratrol decreased fasting blood sugar (-7.97±13.6 mg/dL, p=0.05) and increased high density lipoprotein (3.62±8.75 mg/dL, p=0.01) levels compared with placebo. Moreover, the mean difference in insulin levels reached significance (-0.97±1.91, μIU/mL, p= 0.02). However, no significant differences were observed for anthropometric measures. It was found that 8-week resveratrol supplementation produced useful effects on some cardio-metabolic parameters in patients with T2DM. More studies are needed to confirm these findings.

Resveratrol and 1,25-dihydroxyvitamin D co-administration protects the heart against D-galactose-induced aging in rats: evaluation of serum and cardiac levels of klotho

The current study investigates the cooperative cardioprotective effect of calcitriol (active form of vitamin D) combined with resveratrol in a rat model of D-galactose (D.gal)-induced aging. Male Wistar rats received resveratrol (D.gal + Res), calcitriol (D.gal + Cal), or a combination of them (D.gal + Res + Cal). Intact animals served as control (Ctl). Blood pressure (BP) was recorded by cannulation of the left carotid artery. Fibrosis and cell size were assessed by Masson's trichrome and hematoxylin-eosin staining, respectively. Cardiac and serum level of antiaging protein, klotho, was measured by ELISA assay method. Gene expression was evaluated by real-time RT-PCR. Biochemical tests were performed according to the standardized method. In D.gal + Res + Cal group, BP, heart weight-to-body weight ratio, and cardiomyocytes size decreased significantly compared with D-gal group. The cardiac transcription levels of catalase and superoxide dismutase 1 and 2 were upregulated in D.gal + Res + Cal compared to the D.gal group (P < 0.001, P < 0.05, P < 0.05, respectively). Increased level of malondialdehyde was observed in D.gal group (P < 0.01 vs. Ctl) which was normalized partially in D.gal + Res + Cal group (P < 0.05). Catalase and superoxide dismutase activity also increased in D.gal + Res + Cal group (P < 0.01 vs. D.gal). Cardiac Klotho, as the antiaging protein, remained unchanged at mRNA and protein levels among the experimental groups. The serum level of Klotho did not change significantly in D.gal group; however, in D.gal + Res + Cal group, serum klotho concentration was increased (P < 0.05 vs. D.gal). It could be concluded that co-administration of resveratrol and vitamin D protects the heart against aging-induced damage by the modulation of hemodynamic parameters and antioxidant status of the heart. Furthermore, increased serum level of klotho could be a novel mechanism for antiaging effects of resveratrol and vitamin D.

The Effects of Resveratrol Supplementation on Endothelial Function and Blood Pressures Among Patients with Metabolic Syndrome and Related Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

There are current trials investigating the effect of resveratrol supplementation on endothelial function and blood pressures among patients with metabolic syndrome (MetS); however, the findings are controversial.

AIM

This systematic review and meta-analysis of randomized controlled trials (RCTs) were carried out to summarize the effects of resveratrol supplementation on endothelial activation and blood pressures among patients with MetS and related disorders.

METHODS

We searched systematically online databases including: PubMed-Medline, Embase, ISI Web of Science and Cochrane Central Register of Controlled Trials until October, 2018. Two independent authors extracted data and assessed the quality of included articles. Data were pooled using the fixed- or random-effects model and considered as standardized mean difference (SMD) with 95% confidence intervals (95% CI).

RESULTS

Out of 831 electronic citations, 28 RCTs (with 33 findings reported) were included in the meta-analyses. The findings showed that resveratrol intervention significantly increased flow-mediated dilatation (FMD) levels (SMD 1.77; 95% CI 0.25, 3.29; P = 0.02; I2: 96.5). However, resveratrol supplements did not affect systolic blood pressure (SBP) (SMD - 0.27; 95% CI - 0.57, 0.03; P = 0.07; I2: 88.9) and diastolic blood pressure (DBP) (SMD - 0.21; 95% CI - 0.52, 0.11; P = 0.19; I2: 89.8).

CONCLUSIONS

Resveratrol supplementation significantly increased FMD among patients with MetS and related disorders, but did not affect SBP and DBP. Additional prospective studies are needed to investigate the effect of resveratrol supplementation on endothelial function and blood pressures, using higher-dose of resveratrol with longer durations.