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

The efficacy of resveratrol supplementation on inflammation and oxidative stress in type-2 diabetes mellitus patients: randomized double-blind placebo meta-analysis

Background

The effects of resveratrol supplementation on inflammation and oxidative stress in patients with type 2 diabetes mellitus (T2DM) were controversial. A meta-analysis was performed to assess the changes in levels of inflammation and oxidative stress in patients with T2DM.

Methods

Relevant literatures before November 6, 2024 were screened through Web of Science,Embase,the Cochrane Library and other sources (ClinicalTrials, ProQuest Dissertations and Theses). The quality of the literature was evaluated according to the Cochrane Handbook of Systematic Reviews. The study quality was assessed using the risk-of-bias 2 tool and the Grading of Recommendations Assessment,Development and Evaluation (GRADE) system. Review Manager 5.3 conducted meta-analysis of the data included in the literature.

Results

This meta-analysis was conducted in six randomized controlled trials involving 533 participants. Our results showed that supplementation with resveratrol significantly reduced C-reactive protein levels(SMD = -1.40, 95%CI(-2.60, -0.21), P = 0.02; Level of evidence: low), lipid peroxide levels (SMD = -0.99, 95%CI(-1.36, -0.61), P < 0.00001; Level of evidence: low), 8-isoprostanes(SMD = -0.79, 95%CI(-1.16, -0.42), P < 0.0001; Level of evidence: low) and oxidative stress score (SMD = -1.62, 95%CI(-2.49, -0.75), P = 0.0003; Level of evidence: very low). In addition, compared to placebo, Supplementation with resveratrol significantly increased glutathione peroxidase levels (SMD = 0.38, 95%CI(0.03, 0.74), P = 0.04; Level of evidence:low) and catalase levels (SMD = 0.33, 95%CI(0.03, 0.63), P = 0.03; Level of evidence: low). However, no significant difference was observed in improving interleukin-6 levels (SMD = -1.35, 95%CI(-2.75, -0.05), P = 0.06; Level of evidence: very low), tumor necrosis factor α levels (SMD = -3.30, 95%CI(-7.47, 0.87), P = 0.12; Level of evidence: very low), superoxide dismutase levels (SMD = 0.39, 95%CI(-0.26, 1.04), P = 0.24; Level of evidence: very low), total antioxidant capacity levels (SMD = 0.39, 95%CI(-0.23, 1.00), P = 0.21; Level of evidence: very low) and malondialdehyde levels (SMD = -3.36, 95%CI(-10.30, 3.09), P = 0.29; Level of evidence: very low).

Conclusion

Resveratrol improved inflammation and oxidative stress in T2DM patients to some extent. This provides a new idea and method for clinical treatment. However, due to the limitations of the study, more large-sample, multi-center clinical studies are needed to verify this conclusion.

Preclinical evidence and possible mechanisms of cardioprotective effects of resveratrol in diabetic cardiomyopathy: a systematic review and meta-analysis

INTRODUCTION

Diabetic cardiomyopathy (DCM) is a significant complication of diabetes, characterized primarily by the development of heart failure in individuals with diabetes. Numerous animal studies have indicated that resveratrol enhances cardiac function in diabetic cardiomyopathy; however, its reliability and underlying mechanism remain unclear. This study aims to assess the cardioprotective effects of resveratrol on DCM and explore its potential mechanism.

METHODS

We searched PubMed, EMBASE, WOS, Cochrane Library, CNKI, CBM, Chinese VIP, and Wan Fang Database until March 31st, 2024, without language restrictions. Continuous outcome measures were analyzed using weighted mean difference or standardized mean difference, and heterogeneity was assessed with I2. The risk of bias in animal experiments was evaluated using the SYRCLE tool, and evidence reliability was determined with the GRADE tool. All data were analyzed using Review Manager 5.4.1 and Stata 17. This study has been registered on the PROSPERO (CRD42024523944).

RESULTS

A total of 18 studies meeting the criteria were identified. The analysis revealed that the resveratrol intervention group exhibited significant improvements in LVEF (WMD = 17.88), LVFS (WMD = 8.77), HW/BW (SMD=-2.92), SOD (SMD = 4.53), and MDA (SMD=-5.07) compared to the control group. The GRADE grading assessment indicated moderate certainty for LVEF, HW/BW, and MDA, while certainty for other factors was considered low.

CONCLUSION

Our research suggests that resveratrol may protect cardiac function in DCM through anti-inflammatory and anti-oxidative stress effects. However, these findings are based on preclinical data, and further extensive trials are needed to confirm their effectiveness and safety before clinical application.

Cellular Senescence: A Bridge Between Diabetes and Microangiopathy

Cellular senescence is a state of permanent cell cycle arrest and plays an important role in many vascular lesions. This study found that the cells of diabetic patients have more characteristics of senescence, which may cause microvascular complications. Cell senescence, as one of the common fates of cells, links microangiopathy and diabetes. Cell senescence in a high-glucose environment can partially elucidate the mechanism of diabetic microangiopathy, and various types of cellular senescence induced by it can promote the progression of diabetic microangiopathy. Still, the molecular mechanism of microangiopathy-related cellular senescence has not yet been clearly studied. Building on recent research evidence, we herein summarize the fundamental mechanisms underlying the development of cellular senescence in various microangiopathies associated with diabetes. We gradually explain how cellular senescence serves as a key driver of diabetic microangiopathy. At the same time, the treatment of basic senescence mechanisms such as cellular senescence may have a great impact on the pathogenesis of the disease, may be more effective in preventing the development of diabetic microangiopathy, and may provide new ideas for the clinical treatment and prognosis of diabetic microangiopathy.

Composing functional food from agro-forest wastes: Selectively extracting bioactive compounds using supercritical fluid extraction

Supercritical fluid extraction (SFE) employing carbon dioxide (SC-CO2) is an efficient method to extract bioactive compounds from agro-forest wastes. These compounds maintain and/or improve food nutrition, safety, freshness, taste, and health and are employed as natural functional food components. To highlight the potential of this technology, we focus on the following current advances: (I) parameters affecting solubility in SFE (pressure, temperature, SC-CO2 flow rate, extraction time, and co-solvents); (II) extraction spectra and yield obtained according to proportion and composition of co-solvents; (III) extract bioactivity for functional food production. Fatty acids, monoterpenes, sesquiterpenes, diterpenoids, and low-polarity phenolic acids and triterpenoids were extracted using SFE without a co-solvent. High-polarity phenolic acids and flavonoids, tannins, carotenoids, and alkaloids were only extracted with the help of co-solvents. Using a co-solvent significantly improved the triterpenoid, flavonoid, and phenolic acid yield with a medium polarity.

Bioactive alkaloidal and phenolic phytochemicals as promising epidrugs for diabetes mellitus 2: A review of recent development

Type 2 diabetes (T2D) remains a major chronic metabolic disorder affecting hundreds of millions of the global population, mostly among adults, engendering high rates of morbidity and mortality. It is characterized by complex aetiologies including insulin deficiency and resistance, and hyperglycemia, and these significantly constitute therapeutic challenges. Several pathways have been implicated in its pathophysiology and treatment including the epigenetic regulatory mechanism, notably, deoxyribonucleic acid (DNA) methylation/demethylation, histone modification, non-coding ribonucleic acid (ncRNA) modulation and other relevant pathways. Many studies have recently documented the implications of phytochemicals on the aforementioned biomarkers in the pathogenesis and treatment of T2D. In this review, the cellular and molecular mechanisms of the epigenetic effects of some bioactive alkaloidal and phenolic phytochemicals as potential therapeutic alternatives for T2D have been overviewed from the recent literature (2019-2024). From the survey, the natural product-based compounds, C1-C32 were curated as potent epigenetic modulators for T2D. Their cellular and molecular mechanisms of anti-T2D activities with relevant epigenetic biomarkers were revealed. Although, more comprehensive experimental analyses are observably required for validating their activity and toxicological indices. Thus, perspectives and challenges were enumerated for such demanding future translational studies. The review reveals advances in scientific efforts towards reversing the global trend of T2D through epigenetic phytotherapeutics.

The impact of systemic administration of polyphenols on periodontitis associated with diabetes mellitus: a systematic review

OBJECTIVE

The aim of this work was to explore the potential of polyphenol supplement consumption in enhancing the treatment of periodontitis and diabetes mellitus in both diabetic animals and humans.

MATERIALS AND METHODS

A comprehensive search across eight databases (MEDLINE, EBSCO, Taylor & Francis, PRIMO, Web of Science, Wiley Online Library, ScienceDirect, and SAGE Journals) and two registers (ClinicalTrials.gov and Cochrane Library Trials) was conducted. Methodological quality assessment employed the Cochrane Collaboration Risk of Bias Assessment Tool for randomised controlled trials and the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool for experimental animal studies.

RESULTS

Ten articles meeting inclusion criteria were identified. Three clinical studies demonstrated significant reductions in probing depth (PD) and clinical attachment loss (CAL). Ginger supplementation showed a decrease in CAL (-0.57 ± 0.50 vs. -0.14 ± 0.35, p = 0.003) and PD (-0.52 ± 0.51 vs. -0.19 ± 0.51, p = 0.04), while resveratrol supplementation exhibited a reduction in PD (-1.1 ± 0.58 vs. -0.6 ± 0.47, p < 0.001). Additionally, cranberry juice supplementation led to a decrease in PD (-0.56 ± 0.03, p < 0.001). However, there was no significant improvement in inflammation status. Although polyphenol supplementation did not impact fasting blood glucose levels, it did result in improved insulin resistance (3.66 ± 0.97 vs. 4.49 ± 1.56, p = 0.045). In diabetic animals, six studies reported a significant reduction (p < 0.05) in bone loss along with marked improvements in inflammation status.

CONCLUSIONS

Despite the promising results observed in the included studies, the overall evidence supporting the positive effects of polyphenols on periodontal and diabetes mellitus status, along with their anti-inflammatory properties, remains inadequate.

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage T2DM is widely documented. These dietary compounds exert their beneficial effects through several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorate diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

Mitochondrial Dysfunction, Oxidative Stress, and Inter-Organ Miscommunications in T2D Progression

Type 2 diabetes (T2D) is a heterogenous disease, and conventionally, peripheral insulin resistance (IR) was thought to precede islet β-cell dysfunction, promoting progression from prediabetes to T2D. New evidence suggests that T2D-lean individuals experience early β-cell dysfunction without significant IR. Regardless of the primary event (i.e., IR vs. β-cell dysfunction) that contributes to dysglycemia, significant early-onset oxidative damage and mitochondrial dysfunction in multiple metabolic tissues may be a driver of T2D onset and progression. Oxidative stress, defined as the generation of reactive oxygen species (ROS), is mediated by hyperglycemia alone or in combination with lipids. Physiological oxidative stress promotes inter-tissue communication, while pathological oxidative stress promotes inter-tissue mis-communication, and new evidence suggests that this is mediated via extracellular vesicles (EVs), including mitochondria containing EVs. Under metabolic-related stress conditions, EV-mediated cross-talk between β-cells and skeletal muscle likely trigger mitochondrial anomalies leading to prediabetes and T2D. This article reviews the underlying molecular mechanisms in ROS-related pathogenesis of prediabetes, including mitophagy and mitochondrial dynamics due to oxidative stress. Further, this review will describe the potential of various therapeutic avenues for attenuating oxidative damage, reversing prediabetes and preventing progression to T2D.

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.

Quality of systematic reviews with meta-analyses of resveratrol: A methodological systematic review

Recently, several meta-analyses (MAs) have focused on the health effects of resveratrol. However, the methodological and reporting quality of these MAs has not yet been fully evaluated so far. Therefore, the present study evaluated the quality of these MAs through a methodological systematic review. Systematic searches were conducted in PubMed, Embase, Web of Science, and Cochrane Library from inception until May 20, 2022, and PubMed was used to update the search until September 6, 2023. The methodological and reporting quality of the selected MAs was evaluated using AMSTAR-2 and PRISMA 2009. Fifty-one MAs published during 2013-2023 were included. In each review, the number of primary studies ranged from 3 to 37, and the number of participants ranged from 50 to 2114. Among the first-listed primary outcomes, only 23 (45.10%) were "positive." As for the methodological quality, most MAs (44, 86.27%) on resveratrol were rated critically low. Inadequate reporting of the included MAs mainly involved items 2 ("Structured summary"), 5 ("Protocol and registration"), 8 ("Search"), 9 ("Study selection"), 10 ("Data collection process"), 12 ("Risk of bias in individual studies"), and 24 ("Summary of evidence") based on the PRISMA 2009. Additionally, journal's impact factor, number of authors, and funding support were positively associated with the overall methodological quality but were not statistically significant (p > 0.05). Future MAs on resveratrol require better design, implementation, and reporting by following the Cochrane Handbook, AMSTAR-2, and PRISMA.

Resveratrol and Gut Microbiota Synergy: Preventive and Therapeutic Effects

The role of an imbalanced high-fat diet in the pathophysiology of common chronic noncommunicable diseases has been known for years. More recently, the concept of 'gut microbiota' and the interaction between their composition and gut metabolites produced from the intake of dietary products have gained the focus of researchers, mostly from the perspective of the prevention of cardiovascular and metabolic disorders, which are still the leading cause of death globally. The aim of this work is to highlight the health benefits of the interaction between resveratrol (RSV), red grape polyphenol, and gut microbiota, through aspects of their therapeutic and preventive potentials. Since changed microbiota (mostly as a consequence of antibiotic overuse) contribute to the persistence of post ('long')-COVID-19 symptoms, these aspects will be covered too. Data were obtained from the electronic databases (MedLine/PubMed), according to specific keywords regarding the protective role of resveratrol, the gut microbiota, and their synergy. RSV exerts beneficial properties in the modulation of cardiovascular, metabolic, and post-COVID-19-related disorders. In healthy individuals, it maintains an ergogenic capacity, prevents oxidative stress, and modulates the inflammatory response. Overall, it improves quality of life. The RSV-gut-microbiota interaction is beneficial in terms of maintaining human health. Along with physical activity, it is key for the prevention of chronic noncommunicable diseases.

Natural Polyphenols-Resveratrol, Quercetin, Magnolol, and β-Catechin-Block Certain Aspects of Heroin Addiction and Modulate Striatal IL-6 and TNF-α

We have examined the effects of four different polyphenols in attenuating heroin addiction using a conditioned place preference (CPP) paradigm. Adult male Sprague Dawley rats received heroin (alternating with saline) in escalating doses starting from 10 mg/kg, i.p. up to 80 mg/kg/d for 14 consecutive days. The rats were treated with distilled water (1 mL), quercetin (50 mg/kg/d), β-catechin (100 mg/kg/d), resveratrol (30 mg/kg/d), or magnolol (50 mg/kg/d) through oral gavage for 7 consecutive days, 30 min before heroin administration, starting on day 8. Heroin withdrawal manifestations were assessed 24 h post last heroin administration following the administration of naloxone (1 mg/kg i.p). Heroin CPP reinstatement was tested following a single dose of heroin (10 mg/kg i.p.) administration. Striatal interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) were quantified (ELISA) after naloxone-precipitated heroin withdrawal. Compared to the vehicle, the heroin-administered rats spent significantly more time in the heroin-paired chamber (p < 0.0001). Concomitant administration of resveratrol and quercetin prevented the acquisition of heroin CPP, while resveratrol, quercetin, and magnolol blocked heroin-triggered reinstatement. Magnolol, quercetin, and β-catechin blocked naloxone-precipitated heroin withdrawal and increased striatal IL-6 concentration (p < 0.01). Resveratrol administration was associated with significantly higher withdrawal scores compared to those of the control animals (p < 0.0001). The results of this study show that different polyphenols target specific behavioral domains of heroin addiction in a CPP model and modulate the increase in striatal inflammatory cytokines TNF-α and IL-6 observed during naloxone-precipitated heroin withdrawal. Further research is needed to study the clinical utility of polyphenols and to investigate the intriguing finding that resveratrol enhances, rather than attenuates naloxone-precipitated heroin withdrawal.

δ-Tocotrienol in Combination with Resveratrol Improves the Cardiometabolic Risk Factors and Biomarkers in Patients with Metabolic Syndrome: A Randomized Controlled Trial

Background: Metabolic syndrome (MetS) is a cluster of central obesity, hypertension, hyperglycemia, and dyslipidemia. It is a global health issue with an increased risk of cardiovascular disease. Recently, a few natural products have been reported with promising anti-inflammatory and antioxidative effects. We aimed to evaluate the impact of δ-tocotrienol and resveratrol mixture (TRM) supplementation on cardiometabolic risk factors and biomarkers in patients with MetS. Methods: A randomized controlled trial was conducted at the hospitals of National University of Medical Sciences Rawalpindi, Pakistan. A total of 82 patients with MetS aged 18-60 years were enrolled based on International Diabetes Federation-2005 diagnostic criteria and randomly grouped into TRM (n = 41) and placebo (n = 41). Patients in the TRM group were given a 400 mg capsule (δ-tocotrienol 250 mg; resveratrol 150 mg), and a placebo (cellulose 400 mg) twice daily for 24 weeks. The biochemical tests were analyzed on ADVIA 1800 Chemistry^® analyzer and inflammatory biomarkers by ELISA methods. Results: In the TRM group, a significant reduction in waist circumference, blood pressure, mean (95% confidence interval) of fasting plasma glucose -0.15 mmol/L (-0.22 to -0.08), serum triglyceride -0.32 mmol/L (-0.47 to -0.17), and increment in high-density lipoprotein cholesterol were observed as compared with placebo. TRM supplementation also improved biomarkers: high-sensitive C-reactive protein -0.61 mg/L (-0.89 to -0.33), interleukin-6-1.99 pg/mL (-2.50 to -1.48), tumor necrosis factor-α -2.19 pg/mL (-2.55 to -1.83), malondialdehyde -0.48 μmol/L (-0.65 to -0.30), and total antioxidant capacity 1.71 U/mL (1.29 to 2.13). Conclusion: TRM supplementations improved cardiometabolic risk factors and biomarkers of inflammation and oxidative stress without any significant side effects in the patients with MetS. Clinical Trials Registry: The clinical trial was registered in Sri Lanka Clinical Trials Registry (https://slctr.lk/trials/slctr-2019-021).

Vitamin C supplementation for diabetes management: A comprehensive narrative review

Growing evidence suggests that vitamin C supplementation may be an effective adjunct therapy in the management of people with diabetes. This paper critically reviews the current evidence on effects of vitamin C supplementation and its potential mechanisms in diabetes management. Evidence from meta-analyses of randomized controlled trials (RCTs) show favourable effects of vitamin C on glycaemic control and blood pressure that may be clinically meaningful, and mixed effects on blood lipids and endothelial function. However, evidence is mostly of low evidence certainty. Emerging evidence is promising for effects of vitamin C supplementation on some diabetes complications, particularly diabetic foot ulcers. However, there is a notable lack of robust and well-designed studies exploring effects of vitamin C as a single compound supplement on diabetes prevention and patient-important outcomes (i.e. prevention and amelioration of diabetes complications). RCTs are also required to investigate potential preventative or ameliorative effects of vitamin C on gestational diabetes outcomes. Oral vitamin C doses of 500-1000 mg per day are potentially effective, safe, and affordable for many individuals with diabetes. However, personalisation of supplementation regimens that consider factors such as vitamin C status, disease status, current glycaemic control, vitamin C intake, redox status, and genotype is important to optimize vitamin C's therapeutic effects safely. Finally, given a high prevalence of vitamin C deficiency in patients with complications, it is recommended that plasma vitamin C concentration be measured and monitored in the clinic setting.

Profiling of insulin and resveratrol interaction using multi-spectroscopy and molecular docking study

Background

Resveratrol, a phenolic compound, has various medicinal properties, including anticancer, anti-diabetic, antioxidant, anti-inflammatory, etc. Diabetes is a killing disease, especially for people who cannot maintain a healthy lifestyle. People with diabetes need additional information about a supplement that can prevent and treat diabetes. The present study aims to investigate the interaction of insulin with resveratrol using fluorescence spectroscopy, UV–Vis spectroscopy, CD spectropolarimeter, and molecular docking methods. As an outcome of this study, we expect to understand the contribution of resveratrol in insulin resistance.

Result

The fluorescence spectroscopy results showed that the peak intensity of insulin emission decreased with resveratrol. The interaction of insulin with resveratrol involved a combination of static and dynamic quenching effects. Temperature changes caused the binding constant (K) and the binding site (n) unstable. The interaction occurred through hydrogen bonding, van der Waal, and was hydrophobic. The results of UV–Vis spectroscopy showed that the addition of resveratrol caused a peak in a blueshift, and the absorbance was hyperchromic. Also, there was a reduction in electron transition and the extinction coefficient. The CD spectropolarimeter results showed that the addition of resveratrol affected the secondary structure of insulin. The amount of α-helix and β-sheet slightly change and increase in the secondary structure’s length. The molecular docking study showed that resveratrol interacts via hydrogen bonding with glycine and asparagine. van der Waal interactions occurred in asparagine, phenylalanine, and cysteine. The interaction of electrons occurred through the π orbitals of resveratrol with tyrosine A and B. The binding energy of molecules interaction happened spontaneously on a hydrophobic surface.

Conclusion

Profiling the interaction of insulin and resveratrol shows that resveratrol can stabilize insulin structure and prevent insulin resistance in diabetes.

Updated Information of the Effects of (Poly)phenols against Type-2 Diabetes Mellitus in Humans: Reinforcing the Recommendations for Future Research

(Poly)phenols have anti-diabetic properties that are mediated through the regulation of the main biomarkers associated with type 2 diabetes mellitus (T2DM) (fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), insulin resistance (IR)), as well as the modulation of other metabolic, inflammatory and oxidative stress pathways. A wide range of human and pre-clinical studies supports these effects for different plant products containing mixed (poly)phenols (e.g., berries, cocoa, tea) and for some single compounds (e.g., resveratrol). We went through some of the latest human intervention trials and pre-clinical studies looking at (poly)phenols against T2DM to update the current evidence and to examine the progress in this field to achieve consistent proof of the anti-diabetic benefits of these compounds. Overall, the reported effects remain small and highly variable, and the accumulated data are still limited and contradictory, as shown by recent meta-analyses. We found newly published studies with better experimental strategies, but there were also examples of studies that still need to be improved. Herein, we highlight some of the main aspects that still need to be considered in future studies and reinforce the messages that need to be taken on board to achieve consistent evidence of the anti-diabetic effects of (poly)phenols.