Resveratrol supplementation decreases blood glucose without changing the circulating CD14 + CD16 + monocytes and inflammatory cytokines in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled study

Resveratrol as an Anti-inflammatory Agent in Coronary Artery Disease: A Systematic Review, Meta-Analysis and Meta-Regression

BACKGROUND

Resveratrol is a non-flavonoid polyphenol that shows promise in reducing pro-inflammatory factors and maintaining endothelial function, which hints at its potential role in slowing atherosclerosis and preventing acute coronary events.

OBJECTIVE

To study the cardioprotective effects of resveratrol on inflammatory mediators and endothelial function in patients with coronary artery disease (CAD).

METHODS

A thorough search was conducted in databases (Cochrane Library, ProQuest, PubMed, LILACS, ScienceDirect, Springer, Taylor&Francis, CNKI, Wanfang, and Weipu) until September 24, 2023. The vasopro-inflammatory mediators, endothelial function and outcomes related to cardiovascular events were observed. Titles and abstracts were assessed, and bias was evaluated with Cochrane RoB 2.0. Heterogeneity of results was explored by meta-regression, certainty of evidence was assessed by the GRADE system, and conclusive evidence was enhanced by trial sequence analysis.

RESULTS

Ten randomized controlled trials and 3 animal studies investigated resveratrol's impact on inflammatory mediators and endothelial function. In primary prevention studies, meta-analysis showed a significant reduction (95% CI: -0.73 to -0.20; P=0.0005) in tumor necrosis factor-α (TNF-α) expression with resveratrol, demonstrating a dose-dependent relationship. No significant difference was observed in interleukin-6 (IL-6) expression with P=0.58 for primary prevention and P=0.57 for secondary prevention. Vascular endothelial nitric oxide synthase (eNOS) expression was significantly increased after resveratrol pre-treatment following CAD events. Secondary prevention studies yielded no significant results; however, meta-regression identified associations between age, hypertension, and lower doses with the extent of TNF-α alterations. High certainty of evidence supported TNF-α reduction, while evidence for IL-6 reduction and eNOS elevation was deemed low.

CONCLUSION

Resveratrol reduces TNF-α in individuals at risk for CAD, specifically 15 mg per day. However, its usefulness in patients with confirmed CAD is limited due to factors such as age, high blood pressure, and insufficient dosage. Due to the small sample size, the reduction of IL-6 is inconclusive. Animal studies suggest that resveratrol enhances endothelial function by increasing eNOS. (PROSPERO registration No. CRD42023465234).

Porous corn starch granules as effective host matrices for encapsulation and sustained release of curcumin and resveratrol

Type 2 Diabetes Mellitus (T2DM) is a carbohydrate-rich diet-regulated ailment with carbohydrates digested and absorbed rapidly. Hence, modulating carbohydrate digestion is warranted; to this end, polyphenols from plant sources are handy. However, polyphenols' instability and low bioavailability limit their wholesome use, and thus, encapsulating them into an inexpensive and suitable wall material would be the best strategy. Herein, the potential of porous starch granules is demonstrated. Curcumin and resveratrol were chosen as the test polyphenols due to their proven health benefits, and porous corn starch granules were chosen as the wall material. Porous corn starch granules were prepared through enzymatic modification with 11, 22, and 33 units of amyloglucosidase at three reaction times of 2, 4, and 6 h. The polyphenols were loaded at 100, 200, and 500 mg concentrations in 1 g of starch for 21 days and were characterized through Scanning Electron Microscope (SEM) and Fourier Transform Infrared spectroscopy (FTIR) analyses. The encapsulation efficiency was determined, the rate of starch digestion was calculated through the Englyst test, and polyphenols' in vitro release behavior in gastric and intestinal fluids was measured. Results suggest that 33 enzyme units for a 2 h reaction time were optimal for forming spherical-oval pores on corn starch granules with the maximum encapsulation efficiency of 80.16 % and 88.33 % for curcumin and resveratrol, respectively. The FTIR results suggest the entrapment of polyphenols inside the starch matrix. The inclusion significantly reduced starch digestion and increased the percentage of resistant starch up to 41.11 % and 66.36 % with curcumin and resveratrol, respectively. The in vitro release behavior demonstrated good stability in the simulated gastric fluids and sustained release in simulated intestinal fluids. The encapsulated polyphenols showed a complex Fickian type of diffusion mechanism. Overall, the results suggest that porous corn starch granules could be a potential delivery system for curcumin and resveratrol and will aid in developing novel functional foods to address the T2DM concerns.

The Impact of Curcumin, Resveratrol, and Cinnamon on Modulating Oxidative Stress and Antioxidant Activity in Type 2 Diabetes: Moving beyond an Anti-Hyperglycaemic Evaluation

Research indicates that up to half of the population resorts to dietary supplements for managing diseases such as type 2 diabetes rather than changing their nutritional habits. These supplements not only aim to have an anti-hyperglycaemic effect but also seek to reduce oxidative stress to prevent diabetes complications. This systematic literature systematic review aims to evaluate the efficacy of curcumin, resveratrol, and cinnamon in modulating oxidative stress and antioxidant activity in individuals with type 2 diabetes. Data were collected from PubMed, Web of Sciences, and Scopus databases regarding the impact of curcumin, resveratrol, and cinnamon on total antioxidant capacity (TAC), malondialdehyde (MDA), tumour necrosis factor α (TNF-α), interleukin 6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP) levels for this review. Effect sizes for each study were calculated using Cohen's or Hedges's d coefficient. Parameters of oxidative stress and inflammatory status, such as TAC, MDA, TNF-α, IL-6, and hs-CRP, improved following phytochemicals. Additionally, curcumin, resveratrol, and cinnamon exhibited regulatory effects on carbohydrate metabolism by reducing glucose, insulin, and glycated haemoglobin concentrations and lipid metabolism by lowering total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG) and increasing high-density lipoprotein (HDL). Incorporating curcumin, resveratrol, and cinnamon into diets may be beneficial for maintaining organism homeostasis and improving metabolic control in individuals with type 2 diabetes. However, the conflicting results reported in the literature highlight the need for further detailed investigations into the effectiveness of phytochemical use for type 2 diabetes.

Regulation of immunomodulatory networks by Nrf2-activation in immune cells: Redox control and therapeutic potential in inflammatory diseases

Inflammatory diseases present a serious health challenge due to their widespread prevalence and the severe impact on patients' lives. In the quest to alleviate the burden of these diseases, nuclear factor erythroid 2-related factor 2 (Nrf2) has emerged as a pivotal player. As a transcription factor intimately involved in cellular defense against metabolic and oxidative stress, Nrf2's role in modulating the inflammatory responses of immune cells has garnered significant attention. Recent findings suggest that Nrf2's ability to alter the redox status of cells underlies its regulatory effects on immune responses. Our review delves into preclinical and clinical evidence that underscores the complex influence of Nrf2 activators on immune cell phenotypes, particularly in the inflammatory milieu. By offering a detailed analysis of Nrf2's role in different immune cell populations, we cast light on the potential of Nrf2 activators in shaping the immune response towards a more regulated state, mitigating the adverse effects of inflammation through modeling redox status of immune cells. Furthermore, we explore the innovative use of nanoencapsulation techniques that enhance the delivery and efficacy of Nrf2 activators, potentially advancing the treatment strategies for inflammatory ailments. We hope this review will stimulate the development and expansion of Nrf2-targeted treatments that could substantially improve outcomes for patients suffering from a broad range of 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 for the Management of Human Health: How Far Have We Come? A Systematic Review of Resveratrol Clinical Trials to Highlight Gaps and Opportunities

Resveratrol has long been proposed as being beneficial to human health across multiple morbidities, yet there is currently no conclusive clinical evidence to advocate its recommendation in any healthcare setting. A large cohort with high-quality clinical data and clearly defined biomarkers or endpoints are required to draw meaningful conclusions. This systematic review compiles every clinical trial conducted using a defined dose of resveratrol in a purified form across multiple morbidities to highlight the current 'state-of-play' and knowledge gaps, informing future trial designs to facilitate the realisation of resveratrol's potential benefits to human health. Over the last 20 years, there have been almost 200 studies evaluating resveratrol across at least 24 indications, including cancer, menopause symptoms, diabetes, metabolic syndrome, and cardiovascular disease. There are currently no consensus treatment regimens for any given condition or endpoint, beyond the fact that resveratrol is generally well-tolerated at a dose of up to 1 g/day. Additionally, resveratrol consistently reduces inflammatory markers and improves aspects of a dysregulated metabolism. In conclusion, over the last 20 years, the increasing weight of clinical evidence suggests resveratrol can benefit human health, but more large, high-quality clinical trials are required to transition this intriguing compound from health food shops to the clinic.

Phytochemicals for the treatment of metabolic diseases: Evidence from clinical studies

With the continuous improvement of people's living standard, the incidence of metabolic diseases is gradually increasing in recent years. There is growing interest in finding drugs to treat metabolic diseases from natural compounds due to their good efficacy and limited side effects. Over the past few decades, many phytochemicals derived from natural plants, such as berberine, curcumin, quercetin, resveratrol, rutin, and hesperidin, have been shown to have good pharmacological activity against metabolic diseases in preclinical studies. More importantly, clinical trials using these phytochemicals to treat metabolic diseases have been increasing. This review comprehensively summarizes the clinical progress of phytochemicals derived from natural plants in the treatment of several metabolic diseases, including type 2 diabetes mellitus (T2DM), obesity and non-alcoholic fatty liver disease (NAFLD). Accumulating clinical evidence shows that a total of 18 phytochemicals have good therapeutic effects on the three metabolic diseases by lowering blood glucose and lipid levels, reducing insulin resistance, enhancing insulin sensitivity, increasing energy expenditure, improving liver function, and relieving inflammation and oxidative stress. The information will help us better understand the medicinal value of these phytochemicals and promote their clinical application in the treatment of metabolic diseases.

Resveratrol may mildly improve renal function in the general adult population: A systematic review and meta-analysis of randomized controlled clinical trials

Whether renal health biomarkers can benefit from resveratrol supplements is unknown. Thus, we conducted a systematic review and meta-analysis to summarize evidence from randomized controlled trials investigating the effect of resveratrol supplementation on renal health biomarkers. We hypothesized that resveratrol supplementation is associated with improved renal health biomarkers. Four electronic databases, including PubMed, Scopus, and Institute for Scientific Information Web of Science, and Cochrane Central, were searched for relevant articles up to February 2023. The pooled effect sizes were estimated using a random effects model and expressed as weighted mean difference (WMD) and 95% CI. In total, 32 articles were eligible for inclusion in the current meta-analysis. The pooled results indicated that resveratrol significantly decreased blood urea nitrogen (weighted mean difference [WMD]= -0.84 mg/dL; 95% CI, -1.48 to -0.20; P = .01; I² = 64.4%) and creatinine levels (WMD = -1.90 µmol/L; 95% CI, -3.59 to -0.21; P = .03; I²= 52.1%), and increased glomerular filtration rate (WMD = 7.58 mL/min/1.73 m²; 95% CI, 5.25-9.91; P < .001; I² = 0%). The favorable change of blood urea nitrogen was significant in studies with short follow-up duration (12 weeks or less), with lower doses of resveratrol (less than 500 mg/d), and those conducted in patients with diabetes. However, higher doses of resveratrol are needed to observe significant reductions in creatinine. No significant change was observed in albumin, total protein, and uric acid concentrations. This meta-analysis provides a low certainty of evidence indicating a mild renal protective effect of resveratrol in adults. Further high-quality evidence in patients with impaired renal function and estimates of mortality risk in these patients is required before resveratrol can be advocated as an adjuvant therapy.

Effect of Resveratrol on Markers of Oxidative Stress and Sirtuin 1 in Elderly Adults with Type 2 Diabetes

Type 2 diabetes (T2D) affects a large part of the adult population and impairs its quality of life. Because of this, natural compounds with antioxidant, anti-inflammatory and hypoglycemic properties have been used as adjuvants. Among these compounds, resveratrol (RV) stands out, a polyphenol that has been studied in several clinical trials, the results of which are controversial. We conducted a randomized clinical trial on 97 older adults with T2D to evaluate the effect of RV on oxidative stress markers and sirtuin 1, using doses of 1000 mg/day (EG1000, n = 37) and 500 mg/day (EG500, n = 32) compared with a placebo (PG, n = 28). Biochemical markers, oxidative stress and sirtuin 1 levels were measured at baseline and after six months. We observed a statistically significant increase (p < 0.05) in total antioxidant capacity, antioxidant gap, the percentage of subjects without oxidant stress and sirtuin 1 levels in EG1000. In the PG, we observed a significant increase (p < 0.05) in lipoperoxides, isoprostanes and C-reactive protein levels. An increase in the oxidative stress score and in the percentage of subjects with mild and moderate oxidative stress was observed too. Our findings suggest that 1000 mg/day of RV exerts a more efficient antioxidant effect than 500 mg/day.

The effect of resveratrol supplementation on biomarkers of liver health: A systematic review and meta-analysis of randomized controlled trials

This study aimed to evaluate the effect of resveratrol on liver biomarkers in adult participants, using systematic review and meta-analysis of randomized controlled trials. PubMed, Scopus, Web of Science and Cochran Library was searched, up to October 2021. The pooled effects were calculated using a random-effects model and expressed as weighted mean difference and 95% confidence interval. The methodological quality of studies as well as certainty of evidence were assessed by standard tools. Thirty-seven relevant trials were found. Although overall analysis found no significant change, subgroup analysis showed a significant improvement in alanine aminotransferase (ALT; -7.79 U/L) and glutamyl transferase (-6.0 U/L) in patients with liver disorders, and ALT (-2.22 U/L) in younger adults; however, high-dose supplementation (>1,000 mg/day) appeared to increase alkaline phosphatase concentration (+5.07 U/L). ALT also increased in older adults (+2.33 U/L) following resveratrol supplementation. We found resveratrol did not have a significant effect on liver health in the general population. However, resveratrol could be effective in patients with liver disorders. Our findings also suggest that high-dose resveratrol administration and supplementation in older adults should be performed with caution. Further high-quality clinical trials are also needed to firmly establish the clinical efficacy of resveratrol.

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.

The Role of Nutrition on Meta-inflammation: Insights and Potential Targets in Communicable and Chronic Disease Management

PURPOSE OF REVIEW

Chronic low-grade inflammation may contribute to the onset and progression of communicable and chronic diseases. This review examined the effects and eventual mediation roles of different nutritional factors on inflammation.

RECENT FINDINGS

Potential nutritional compounds influencing inflammation processes include macro and micronutrients, bioactive molecules (polyphenols), specific food components, and culinary ingredients as well as standardized dietary patterns, eating habits, and chrononutrition features. Therefore, research in this field is still required, taking into account critical aspects of heterogeneity including type of population, minimum and maximum intakes and adverse effects, cooking methods, physiopathological status, and times of intervention. Moreover, the integrative analysis of traditional variables (age, sex, metabolic profile, clinical history, body phenotype, habitual dietary intake, physical activity levels, and lifestyle) together with individualized issues (genetic background, epigenetic signatures, microbiota composition, gene expression profiles, and metabolomic fingerprints) may contribute to the knowledge and prescription of more personalized treatments aimed to improving the precision medical management of inflammation as well as the design of anti-inflammatory diets in chronic and communicable diseases.

Effects of Fruit and Vegetable Polyphenols on the Glycemic Control and Metabolic Parameters in Type 2 Diabetes Mellitus: A Review

The high prevalence of diabetes in recent decades has been associated with lifestyle changes and dietary habits correlated with economic development. Fruits and vegetables are a vital source of nutraceuticals and components of the healthy diet recommended in the medical nutrition therapy for type 2 diabetes mellitus (T2DM) to prevent hyperglycemia and related complications. They are low in calories and rich in dietary fiber, consist of many polyphenols, and are an essential component of a healthy lifestyle. Recently, researchers have developed a significant interest in understanding the effects of polyphenols (flavonoids and non-flavonoids) on blood glucose levels. In this review, the authors summarize the effects of polyphenols commonly found in the fruits and vegetables, such as resveratrol and anthocyanins, on the glycemic control and metabolic parameters, based on human clinical trials. Significant reductions in fasting blood glucose, glycated hemoglobin, and low-density lipoprotein cholesterol levels were reported after resveratrol, anthocyanin, and naringin were administered to patients with prediabetes and diabetes. Decreased insulin levels were observed after resveratrol intervention but not with the other types of polyphenols. These effects of polyphenolic compounds on the glycemic and metabolic parameters might be mediated by multiple pathophysiological mechanisms, such as activating regulator proteins to increase insulin signaling and eventually suppress insulin resistance. The benefits of certain polyphenols on T2DM remain ambiguous; therefore, further studies, especially clinical trials, are required to substantiate the available evidence.

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.

Role of resveratrol supplementation in regulation of glucose hemostasis, inflammation and oxidative stress in patients with diabetes mellitus type 2: A randomized, placebo-controlled trial

OBJECTIVE

The objective was to determine the effects of resveratrol supplementation on glucose homeostasis, oxidative stress, inflammation and microRNAs expression in patients with diabetes mellitus type 2 on oral hypoglycemic drugs.

METHOD

This was a randomized, double blinded placebo-controlled parallel group trial. The diabetic patients (n=110) were randomly assigned either to resveratrol (n=55) and placebo (55) groups after informed consent and given once daily resveratrol 200mg and cellulose capsules respectively for 24 weeks. Fasting glucose, insulin, HbA1c, lipid profile, TNF- α, IL-6, hs-CRP, MDA & circulatory microRNAs were measured at start and end of 24- week intervention.

RESULTS

Out of 110 patients recruited, 94 patients completed the study comprising of 45 in resveratrol and 46 in placebo group. The resveratrol supplementation after 24 weeks was resulted in significant reduction [mean difference (95%CI)] of plasma glucose[-0.50(-0.94 to -0.06)], insulin[-1.31(-2.24 to -0.38)], homeostatic model assessment of insulin resistance[-0.83(-1.37 to -0.29)], malondialdehyde[-0.36(-0.61 to -0.11)], high sensitive-C-reactive protein[-0.35(-0.70 to -0.01)], tumor necrosis factor-alpha[-1.25(-1.90 to -0.61)] and interleukin-6[-1.99(-3.29 to -0.69)]. More than two-fold down regulation in miRNA-34a, miRNA-375, miRNA-21, miRNA-192 and up regulation in miRNA-126 and miRNA-132 expression was noted in patients receiving resveratrol as compared to placebo. No side effects were reported during the trial.

CONCLUSION

Resveratrol supplementation contributes in improvement of glycemic control by reducing insulin resistance. It has significant beneficial impact on chronic inflammation, oxidative stress and associated microRNA expression in diabetic patients. Thus, supplementation of resveratrol along with oral hypoglycemic agents may be useful in the reduction of diabetic associated complications.

Evidence for the effect of soluble uric acid in augmenting endoplasmic reticulum stress markers in human peripheral blood mononuclear cells

There is evidence regarding the association of hyperuricemia with inflammatory disorders. Hence, it has been of particular interest to dissect the exact role of alteration in uric acid (UA) levels in the context of inflammation. Recently, the endoplasmic reticulum (ER) stress pathway has come into the forefront as a possible mechanism linking hyperuricemia to inflammation. Here, we intended to examine the role of UA in the presence or absence of a second stimulus, LPS, in human peripheral blood mononuclear cells (PBMCs), and analyzed ROS production as well as expression of ER stress markers: GRP78 and CHOP, and inflammatory cytokines.PBMCs were isolated using Ficoll gradient centrifugation from healthy volunteers. Cell viability was measured by MTT assay. PBMCs were treated with an increasing concentration of soluble UA (0, 5, 12, and 20 mg/dl) for 20 h, followed by the addition of 100 ng/mL of LPS or vehicle for another 4 h. Real time-PCR was performed to investigate the mRNA expression of GRP78, CHOP, TNF-α, IL-1β, and IL-6, and western blot was used to investigate the protein levels of GRP78 and CHOP. Moreover, ELISA was used to evaluate the protein levels of TNF-α, IL-1β, and IL-6. Finally, intracellular ROS production was determined using fluorescent probes (DCFH-DA).High concentrations of UA either alone or combined with LPS increased the protein levels of GRP78 and CHOP. On the other hand, LPS alone increased the protein levels of GRP78 and CHOP. However, there was no significant difference between the mRNA expression of GRP78, CHOP, TNF-α, IL-1β, and IL-6 when PBMCs were treated with UA. High concentrations of UA augmented LPS-stimulated IL-1β transcript and protein levels as well as TNF-α protein levels in PBMC culture. Moreover, high concentrations of UA along with LPS significantly increased intracellular ROS production.It seems that a high concentration of UA not only induces the protein levels of ER stress markers in PBMCs but also augments the impact of LPS on the levels of pro-inflammatory markers and ROS production.

Association of Neutrophil-to-Lymphocyte Ratio with the Risk of Fatal Stroke Occurrence in Older Chinese

BACKGROUND

Associations of neutrophil-to-lymphocyte ratio (NLR) and its longitudinal change with risk of fatal strokes are unclear in older populations.

METHODS

In this retrospective analysis, a total of 27,799 participants were included and followed up for a mean of 14.3 years (standard deviation = 3.2). 838 stroke deaths were recorded. Cox proportional hazards regression was used to assess associations of NLR with fatal strokes.

RESULTS

Compared to those in the first quartile and after adjustment for a series of factors, the participants in the highest neutrophil quartile had an increased risk of fatal all stroke (adjusted hazard ratio (aHR) = 1.45, 95% confidence interval (CI), 1.18-1.79) and fatal ischaemic stroke (aHR = 1.58, 95% CI, 1.17-2.12). Restricted cubic splines showed an increased trend of relationship between the NLR and fatal all stroke. The participants with the highest NLR quartile had an increased risk of fatal all stroke (aHR = 1.52, 95% CI, 1.23-1.88) and fatal ischaemic stroke (aHR = 1.59, 95% CI, 1.13-2.26), respectively; Similar associations repeated after further C-reactive protein adjustment; a 21% and a 32% increased risk of fatal all stroke and fatal ischaemic stroke showed in a continuous variable model. Those in NLR change with 5% increase had a 70% increased risk of fatal all stroke (aHR = 1.70, 95%CI, 1.13-2.57), compared to those in stable (-5%∼5%).

CONCLUSIONS

Higher NLR was associated with an increased risk of fatal all stroke and fatal ischaemic stroke, and its longitudinal change increase of ≥ 5% was associated with an increased risk of fatal all stroke in a relatively healthy older population.

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.

Dietary natural products as a potential inhibitor towards advanced glycation end products and hyperglycemic complications: A phytotherapy approaches

Natural products exist in various natural foods such as plants, herbs, fruits, and vegetables. Furthermore, marine life offers potential natural products with significant biological activity. The biochemical reaction is known as advanced glycation end products (AGEs) occurs in the human body. On the other hand, foods are capable of a wide range of processing conditions resulting in the generation of exogenous AGEs adducts. Protein glycation and the formation of advanced glycation end products both contribute to the pathogenesis of hyperglycemic complications. AGEs also play a pivotal role in microvascular and macrovascular complications progression by receptors for advanced glycation end products (RAGE). RAGE activate by AGEs leads to up-regulation of transcriptional factor NF-kB and inflammatory genes. Around the globe, researchers are working in various approaches for therapeutical implications on controlling AGEs mediated disease complications. In this regard, one of the potential promising agents observed with a wide range of AGEs inhibition by food-derived natural products. Current biotechnological tools have been turned to natural products or phytochemicals to manufacture the molecules without compromising their functionality. Metabolic engineering and bioinformatics perspectives have recently enabled the generation of a few potent metabolites with anti-diabetic activity. As the primary focus, this review article will also discuss multidisciplinary approaches that emphasize current advances in anti-diabetic therapeutic action and future perspectives of natural products.

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.

Effect of resveratrol on inflammatory cytokines: A meta-analysis of randomized controlled trials

The aim of the current study was to perform a meta-analysis of randomized clinical trials regarding the effect of resveratrol in decreasing the levels of inflammatory cytokines, including interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α in a combination of inflammatory diseases. Literature search was carried out in Scopus, ISI web of science, Medline, and Cochrane Library databases by up to September 2020. The pooled effect size was determined through measuring the weighted mean differences (WMD) and their corresponding 95% confidence intervals (CI) for the difference between the resveratrol-receiving and control groups. Finally, 33 publications, including 3 studies on IL-1, 26 studies on IL-6, 4 studies on IL-8, and 21 studies on TNF-α met our final inclusion criteria and included in the quantitative analysis. Analysis in the overall population showed a significant effect of resveratrol consumption in reducing serum TNF-α levels (WMD = -0.66 pg/ml, 95% CI = -1.05 to -0.27, P = 0.001). A significant reduction of IL-6 concentration was observed only in the patients receiving ≥500 mg/day dose of resveratrol (WMD = -1.89 pg/ml, 95% CI = -3.73 to -0.05, P = 0.04) with inter-study heterogeneity (I2 = 94.4%, P < 0.001). Nonetheless, no significant alteration was observed in IL-1 (WMD = -0.14 pg/ml, 95% CI = -0.31 to 0.03, P = 0.10) and IL-8 (WMD = 0.18 pg/ml, 95% CI = -1.04 to 1.40, P = 0.73) levels following resveratrol consumption. Based on the present findings, resveratrol is able to decrease TNF-α and IL-6 (in ≥500 mg/day dose) levels but not IL-1 and IL-8 levels.

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.

Effect of resveratrol on C-reactive protein: An updated meta-analysis of randomized controlled trials

We conducted a meta-analysis on the available randomized clinical trials (RCTs) to assess the role of resveratrol in lowering C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP) levels, as markers of inflammation, in various inflammatory disorders. Literature search through Medline/PubMed, Scopus, ISI Web of Science, and Cochrane Library yielded 35 RCTs (24 studies for hs-CRP and 11 studies for CRP). Pooled results revealed that resveratrol supplementation significantly reduced the hs-CRP (MWD = -0.40 mg/L; 95% CI: -0.70 to -0.09 mg/L; p = .01) and CRP (MWD = -0.31 mg/L; 95% CI: -0.47 to -0.15 mg/L; p < .001) levels in serum. Subgroup analysis revealed that resveratrol in group with ≥10 weeks significantly reduces hs-CRP levels (MWD = -0.48 mg/L; 95% CI: -0.92 to -0.04 mg/L; p = .03) and CRP (WMD = -0.47 mg/L, 95% CI = -0.69 to -0.25, p < .001). A dose of ≥500 mg/day supplementation improves the levels of CRP, but not hs-CRP. This meta-analysis demonstrates that resveratrol consumption is effective in lowering the levels of CRP and hs-CRP in inflammatory conditions, especially if supplementation takes place for ≥10 weeks with ≥500 mg/day.

Towards resolving the enigma of the dichotomy of resveratrol: cis- and trans-resveratrol have opposite effects on TyrRS-regulated PARP1 activation

Unlike widely perceived, resveratrol (RSV) decreased the average lifespan and extended only the replicative lifespan in yeast. Similarly, although not widely discussed, RSV is also known to evoke neurite degeneration, kidney toxicity, atherosclerosis, premature senescence, and genotoxicity through yet unknown mechanisms. Nevertheless, in vivo animal models of diseases and human clinical trials demonstrate inconsistent protective and beneficial effects. Therefore, the mechanism of action of RSV that elicits beneficial effects remains an enigma. In a previously published work, we demonstrated structural similarities between RSV and tyrosine amino acid. RSV acts as a tyrosine antagonist and competes with it to bind to human tyrosyl-tRNA synthetase (TyrRS). Interestingly, although both isomers of RSV bind to TyrRS, only the cis-isomer evokes a unique structural change at the active site to promote its interaction with poly-ADP-ribose polymerase 1 (PARP1), a major determinant of cellular NAD+-dependent stress response. However, retention of trans-RSV in the active site of TyrRS mimics its tyrosine-bound conformation that inhibits the auto-poly-ADP-ribos(PAR)ylation of PARP1. Therefore, we proposed that cis-RSV-induced TyrRS-regulated auto-PARylation of PARP1 would contribute, at least in part, to the reported health benefits of RSV through the induction of protective stress response. This observation suggested that trans-RSV would inhibit TyrRS/PARP1-mediated protective stress response and would instead elicit an opposite effect compared to cis-RSV. Interestingly, most recent studies also confirmed the conversion of trans-RSV and its metabolites to cis-RSV in the physiological context. Therefore, the finding that cis-RSV and trans-RSV induce two distinct conformations of TyrRS with opposite effects on the auto-PARylation of PARP1 provides a potential molecular basis for the observed dichotomic effects of RSV under different experimental paradigms. However, the fact that natural RSV exists as a diastereomeric mixture of its cis and trans isomers and cis-RSV is also a physiologically relevant isoform has not yet gained much scientific attention.

An updated pharmacological insight of resveratrol in the treatment of diabetic nephropathy

As one of the most common complications of diabetes, nephropathy develops in approximately 40% of diabetic individuals. Although end stage kidney disease is known as one of the most consequences of diabetic nephropathy, the majority of diabetic individuals might die from cardiovascular diseases and infections before renal replacement treatment. Moreover, the routine medical treatments for diabetes hold undesirable side effects. The explosive prevalence of diabetes urges clinicians and scientists to investigate the complementary or alternative therapies. Phytochemicals are emerging as alternatives with a wide range of therapeutic effects on various pathologies, including diabetic kidney disease. Of those phytochemicals, resveratrol, a natural polyphenolic stilbene, has been found to exert a broad spectrum of health benefits via various signaling molecules. In particular, resveratrol has gained a great deal of attention because of its anti-oxidative, anti-inflammatory, anti-diabetic, anti-obesity, cardiovascular-protective, and anti-tumor properties. In the renal system, emerging evidence shows that resveratrol has already been used to ameliorate chronic or acute kidney injury. This review critically summarizes the current findings and molecular mechanisms of resveratrol in diabetic renal damage. In addition, we will discuss the adverse and inconsistent effects of resveratrol in diabetic nephropathy. Although there is increasing evidence that resveratrol affords great potential in diabetic nephropathy therapy, these results should be treated with caution before its clinical translation. In addition, the unfavorable pharmacokinetics and/or pharmacodynamics profiles, such as poor bioavailability, may limit its extensive clinical applications. It is clear that further research is needed to unravel these limitations and improve its efficacy against diabetic nephropathy. Increasing investigation of resveratrol in diabetic kidney disease will not only help us better understand its pharmacological actions, but also provide novel potential targets for therapeutic intervention.

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.

Resveratrol supplementation and type 2 diabetes: a systematic review and meta-analysis

This study aimed to review the literature on studies that evaluated resveratrol's effects supplementation on parameters of diabetes in humans. We conducted an online search in the following databases: Pubmed, Lilacs, Scielo, Scopus, Web of Science, Embase, and Cochrane. It included experimental studies that investigated the effects of resveratrol supplementation for diabetes treatment or prevention and its relationship with fasting blood glucose, insulin resistance, and glycated hemoglobin. Observational, non-human studies and non-randomized clinical trials were excluded. We conducted a meta-analysis to evaluate the effects of resveratrol supplementation on fasting blood glucose, insulin resistance, and glycated hemoglobin. Thirty studies were included in the review. Almost 60% demonstrated at least one significant effect of the resveratrol supplementation related to diabetes. In the meta-analysis, there was a significant effect on the reduction of insulin resistance [SMD: -0.34; CI 95%: -0.64, -0.04; p = 0.01; I² = 70%] and glycated hemoglobin [SMD: -0.64; CI 95%: -1.22, -0.07; p = 0.01; I² = 90%]. For fasting blood glucose, the results were significant only for individuals with diabetes [SMD: -0.85; CI 95%: -1.49, -0.21; p = 0.01; I² = 90%]. This systematic review with meta-analysis demonstrated that resveratrol supplementation has protective effects on diabetes parameters.

Hypoglycemic Effect of Resveratrol: A Systematic Review and Meta-Analysis

Resveratrol (RV) is a polyphenolic compound with antioxidant, anti-inflammatory, and hypoglycemic properties. Several in vitro and animal model studies have demonstrated the beneficial effects of RV; however, the results in humans are not conclusive. After a search of different databases, 32 studies were selected for this systematic review and 30 were included in the meta-analysis. Studies that evaluated the effect of RV on glucose, insulin, HbA1c, and insulin resistance (HOMA-IR) levels were included. A significant decrease of glucose (-5.24 mg/dL, p = 0.002) and insulin levels (-1.23 mIU/L, p = 0.0003) was observed. HbA1c and HOMA-IR did not show significant changes. Due to heterogeneity, sub-analyzes were performed. Sub-analysis by dose revealed that glucose levels improve significantly after the administration of 500-1000 mg/day of RV (-7.54 mg/dL, p = 0.002), while insulin improves with doses lower than 500 mg/day (-1.43 mIU/L, p = 0.01) and greater than 1000 mg/day (-2.12 mIU/L, p = 0.03). HbA1c and HOMA-IR remained unchanged after sub-analysis by dose. Our findings suggest that RV improves glucose and insulin levels in subjects with type 2 diabetes mellitus (T2DM) and aged 45-59 years, regardless of the duration of the intervention. HbA1c improves with interventions ≥3 months. HOMA-IR does not exhibit significant changes after RV administration.

Preventive Role of Resveratrol Against Inflammatory Cytokines and Related Diseases

BACKGROUND

Immunity is the ultimate barrier between foreign stimuli and a host cell. Unwanted immune responses can threaten the host cells and may eventually damage a vital organ. Overproduction of inflammatory cytokines may also lead to autoimmune diseases. Inflammatory cells and pro-inflammatory cytokines can eventually progress to renal, cardiac, brain, hepatic, pancreatic and ocular inflammation that can result in severe damage in the long run. Evidence also suggests that inflammation may lead to atherosclerosis, Alzheimer's, hypertension, stroke, cysts and cancers.

METHODS

This study was designed to correlate the possible molecular mechanisms for inflammatory diseases and prevent biochemical changes owing to inflammatory cytokines by using Resveratrol. Therefore, we searched and accumulated very recent literature on inflammatory disorders and Resveratrol. We scoured PubMed, Scopus, Science Direct, PLoS One and Google Scholar to gather papers and related information.

RESULTS

Reports show that inflammatory diseases are very complex, as multiple cascade systems are involved; therefore, they are quite difficult to cure. However, our literature search also correlates some possible molecular interactions by which inflammation can be prevented. We noticed that Resveratrol is a potent lead component and has multiple activities against harmful inflammatory cytokines and related microRNA. Our study also suggests that the anti-inflammatory properties of Resveratrol have been highly studied on animal models, cell lines and human subjects and proven to be very effective in reducing inflammatory cell production and pro-inflammatory cytokine accumulation. Our tables and figures also demonstrate recent findings and possible preventive activities to minimize inflammatory diseases.

CONCLUSION

This study would outline the role of harmful inflammatory cytokines as well as how they accelerate pathophysiology and progress to an inflammatory disorder. Therefore, this study might show a potential therapeutic value of using Resveratrol by health professionals in preventing inflammatory disorders.

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.

The effect of resveratrol supplementation on C-reactive protein (CRP) in type 2 diabetic patients: Results from a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

C-reactive protein (CRP) is considered to be an inflammatory marker in type 2 diabetes (T2D) and it is produced by liver cells. The evidence has suggested that resveratrol has anti-inflammatory effect. This study aimed to evaluate the effect of resveratrol supplementation on CRP level in patients with T2D using a systematic review and meta-analysis of randomized controlled trials.

METHODS

Electronic databases were completely searched using Medline, ISI Web of Science, EMBASE and Cochrane Library and Scopus until October 2019. Meta-analysis was performed using random-effects model and inverse variance method. Heterogeneity and publication bias were evaluated in selected studies. Sensitivity analyses and prespecified subgroup were conducted to evaluate potential heterogeneity. Meta-regression was performed to assess the effect of potential confounders on the estimated effect sizes.

RESULTS

Six trials comprising a total of 491 subjects were included in this meta-analysis. The results showed significant reduction in the level of CRP [SMD (-0.34 mg/l) (95 % CI, -0.52, to -0.16) p < 0.05] in participants with T2D following supplementation with resveratrol. No significant publication bias was observed in the meta-analysis. Subgroup and sensitivity analyses indicated that the pooled effects of resveratrol supplementation on CRP level in T2D patients were affected by resveratrol dose and duration of resveratrol. Random-effects meta-regression did not indicate any significant association of CRP level with potential confounders including resveratrol dose, duration of treatment, age and gender of type 2 diabetic patients.

CONCLUSION

We found a significant reduction in CRP level in patients with type 2 diabetes, who received resveratrol supplementation.

Multicomponent self nano emulsifying delivery systems of resveratrol with enhanced pharmacokinetics profile

Resveratrol is a drug with high potential for clinical application based on experimental models. Though, resveratrol translation to clinical use has not been successful yet due to its poor pharmacokinetics, related to poor solubility and fast metabolism. The use of drug delivery systems, namely self-emulsifying drug delivery systems (SEDDS), may be a viable strategy to overcome the poor in vivo performance of resveratrol. In this work, a rational development of two different ternary SEDDS was conducted. Experimental data showed that quantitative variations on SEDDS composition impacted dispersion and robustness to dilution of SEDDS, as well as loading capacity and droplet size. Formulations composed of Lauroglycol® 90/Labrasol®/Capryol® PGMC (12.5/75.0/12.5) (Lau/Lab/Cap) and Tween® 80/Transcutol®/Imwitor® 742 (33.3/33.3/33.3) (T80/Trans/Imw) featured improved performance and were selected for further studies. T80/Trans/Imw formulation yield faster emulsification and originated smaller droplet size, with lower cumulative percentile of 90% of particles (D₉₀) (below 200 nm), as compared to the than Lau/Lab/Cap formulation. Higher resveratrol permeation rate was observed in Caco-2 cell monolayer permeability studies for both formulations as compared to the free drug. Reduction of the metabolization and/or efflux of resveratrol was also noticed in the case of SEDDs, as suggested by the increased recovery of total drug. Plasmatic drug concentrations in rats observed after oral gavage indicate that both formulations provided faster resveratrol absorption than free drug, resulting in shorter T_max values (30 min vs. 2 h). No statistically significant differences were observed for AUC_0-t values of both formulations and the free drug. Still, C_max for the Lau/Lab/Cap SEDDs formulation was 2-fold higher than for the free drug. These findings suggest that SEDDS can increase resveratrol solubility and reduce its metabolization, resulting in an overall improvement of its oral pharmacokinetics profile.

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.

The effects of resveratrol intake on weight loss: a systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize the effect of resveratrol intake on weight loss. We searched the following databases until July 2018: MEDLINE, EMBASE, Web of Science and Cochrane Central Register of Controlled Trials. Data were pooled using the inverse variance method and expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Out of 831 reports, 36 RCTs were eligible for including to our meta-analysis. The pooled results, using random-effects model showed that resveratrol supplementation significantly decreased body weight (SMD = -0.17; 95% CI, -0.33, -0.01; P = 0.03; I²: 62.6), body mass index (BMI) (SMD = -0.20; 95% CI, -0.35, -0.05; P = 0.01; I²: 60.6), fat mass (SMD = -0.32; 95% CI, -0.62, -0.03; P = 0.03; I²: 77.9) and waist circumference (WC) (SMD = -0.42; 95% CI, -0.68, -0.16; P = 0.001; I²: 75.2), and significantly increased lean mass (SMD = 1.21; 95% CI, 0.75, 1.67; P < 0.001; I²: 87.6). We found no significant effect of resveratrol administration on leptin (SMD = -0.20; 95% CI, -0.68, 0.27; P = 0.40; I²: 85.3) and adiponectin levels (SMD = 0.08; 95% CI, -0.39, 0.55; P = 0.74; I²: 91.0). Resveratrol supplementation significantly decreased body weight in obese patients (SMD -0.43; 95% CI, -0.60, -0.26) compared with other diseases (SMD 0.02; 95% CI, -0.29, 0.33), and type 2 diabetes mellitus (SMD -0.17; 95% CI, -0.37, 0.02). Overall, the current meta-analysis demonstrated that resveratrol intake significantly reduced weight, BMI, WC and fat mass, and significantly increased lean mass, but did not affect leptin and adiponectin levels.

Resveratrol, Metabolic Syndrome, and Gut Microbiota

Resveratrol is a polyphenol which has been shown to have beneficial effects on metabolic syndrome-related alterations in experimental animals, including glucose and lipid homeostasis improvement and a reduction in fat mass, blood pressure, low-grade inflammation, and oxidative stress. Clinical trials have been carried out to address its potential; however, results are still inconclusive. Even though resveratrol is partly metabolized by gut microbiota, the relevance of this “forgotten organ” had not been widely considered. However, in the past few years, data has emerged suggesting that the therapeutic potential of this compound may be due to its interaction with gut microbiota, reporting changes in bacterial composition associated with beneficial metabolic outcomes. Even though data is still scarce and for the most part observational, it is promising nevertheless, suggesting that resveratrol supplementation could be a useful tool for the treatment of metabolic syndrome and its associated conditions.

Effect of Resveratrol Supplementation on Inflammatory Markers: A Systematic Review and Meta-analysis of Randomized Controlled Trials

PURPOSE

The evidence has suggested that resveratrol has anti-inflammatory effect; however, the results are inconsistent and inconclusive. The aim of this study was to assess the effect of resveratrol supplementation on the levels of inflammatory markers through a systematic review and meta-analysis of available randomized controlled trials (RCTs).

METHODS

A search strategy was completed using Medline, ISI Web of Science, Directory of Open Access Journal, SID, ProQuest, Cochrane Library, Scopus, and EMBASE up to May 2017, to identify placebo-controlled RCTs that assessed resveratrol effects on circulating (serum and plasma) inflammatory markers (interleukin [IL]-6, tumor necrosis factor-α [TNF-α], and high-sensitivity C-reactive protein [hs-CRP]) among adult participants aged 17 years and older in 17 RCTs with a total of 736 subjects. The evaluation of study quality was performed using the Jadad scale. Weighted mean difference (WMD) was calculated for evaluating the changes in the inflammatory markers using fixed-effects or random-effects models. We performed subgroup and sensitivity analyses to evaluate the heterogeneity of the studies.

FINDINGS

Seventeen RCTs, including 736 subjects, fulfilled the eligibility criteria and were selected for analyses. The results of meta-analysis found significant reductions in the level of TNF-α (WMD, -0.44; 95% CI, -0.71 to -0.164; P = 0.002; Q statistic = 21.60; I² = 49.1%; P = 0.02) and hs-CRP (WMD, -0.27; 95% CI, -0.5 to -0.02; P = 0.033; Q statistic = 26.95; I² = 51.8%; P = 0.013) after supplementation with resveratrol. Resveratrol supplementation had no significant effect on the level of IL-6 (WMD, -0.16; 95% CI, -0.53 to 0.20; P = 0.38; Q statistic = 36.0; I² = 72.3%; P = 0.001). Statistically significant heterogeneity was observed for the type of sample in IL-6 and study duration in inflammatory markers IL-6, TNF-α, and hs-CRP.

IMPLICATIONS

Available evidence from RCTs suggests that resveratrol supplementation significantly reduced TNF-α and hs-CRP levels. Significant improvement in inflammatory markers support resveratrol as an adjunct to pharmacologic management of metabolic diseases.

The effects of resveratrol supplementation on biomarkers of inflammation and oxidative stress among patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials

The effect of resveratrol supplementation on biomarkers of inflammation and oxidative stress among patients with metabolic syndrome are controversial.