Effect of resveratrol on lipid profile: An updated systematic review and meta-analysis on randomized clinical trials

Natural products in atherosclerosis therapy by targeting PPARs: a review focusing on lipid metabolism and inflammation

Inflammation and dyslipidemia are critical inducing factors of atherosclerosis. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors and control the expression of multiple genes that are involved in lipid metabolism and inflammatory responses. However, synthesized PPAR agonists exhibit contrary therapeutic effects and various side effects in atherosclerosis therapy. Natural products are structural diversity and have a good safety. Recent studies find that natural herbs and compounds exhibit attractive therapeutic effects on atherosclerosis by alleviating hyperlipidemia and inflammation through modulation of PPARs. Importantly, the preparation of natural products generally causes significantly lower environmental pollution compared to that of synthesized chemical compounds. Therefore, it is interesting to discover novel PPAR modulator and develop alternative strategies for atherosclerosis therapy based on natural herbs and compounds. This article reviews recent findings, mainly from the year of 2020 to present, about the roles of natural herbs and compounds in regulation of PPARs and their therapeutic effects on atherosclerosis. This article provides alternative strategies and theoretical basis for atherosclerosis therapy using natural herbs and compounds by targeting PPARs, and offers valuable information for researchers that are interested in developing novel PPAR modulators.

Lipid profile and reproductive performance of female offspring of SWISS mouse females supplemented with resveratrol or canjiqueira (Byrsonima cydoniifolia A Juss) during gestation

This study aimed to resveratrol supplementation (at 5 or 10 mg/kg) and a hydroethanolic extract of canjiqueira fruits (150 mg/kg) on female SWISS mice. Total cholesterol, high-density lipoprotein (HDL), triglyceride levels, gestation rates, and embryonic implantation rates in their female Offspring was evaluated. In conclusion, the consumption of canjiqueira fruit extract altered the lipid profile of their female offspring, and did not impact their reproductive performance. Supplementing female SWISS mice with 10 mg/kg of resveratrol increased total cholesterol, triglycerides, and HDL levels, thereby enhancing the reproductive efficiency of their offspring.

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.

A Randomized Trial on Resveratrol Supplement Affecting Lipid Profile and Other Metabolic Markers in Subjects with Dyslipidemia

Resveratrol is a polyphenol with a well-established beneficial effect on dyslipidemia and hyperuricemia in preclinical experiments. Nonetheless, its efficacy and dose-response relationship in clinical trials remains unclear. This study examined whether resveratrol supplement improves the serum lipid profile and other metabolic markers in a dose-response manner in individuals with dyslipidemia. A total of 168 subjects were randomly assigned to placebo (n = 43) and resveratrol treatment groups of 100 mg/d (n = 41), 300 mg/d (n = 43), and 600 mg/d (n = 41). Anthropometric and biochemical parameters were analyzed at baseline and 4 and 8 weeks. Resveratrol supplementation for 8 weeks did not significantly change the lipid profile compared with the placebo. However, a significant decrease of serum uric acid was observed at 8 weeks in 300 mg/d (-23.60 ± 61.53 μmol/L, p < 0.05) and 600 mg/d resveratrol groups (-24.37 ± 64.24 μmol/L, p < 0.01) compared to placebo (8.19 ± 44.60 μmol/L). Furthermore, xanthine oxidase (XO) activity decreased significantly in the 600 mg/d resveratrol group (-0.09 ± 0.29 U/mL, p < 0.05) compared with placebo (0.03 ± 0.20 U/mL) after 8 weeks. The reduction of uric acid and XO activity exhibited a dose-response relationship (p for trend, <0.05). Furthermore, a marked correlation was found between the changes in uric acid and XO activity in the resveratrol groups (r = 0.254, p < 0.01). Resveratrol (10 μmol/L) treatment to HepG2 cells significantly reduced the uric acid levels and intracellular XO activity. Nevertheless, we failed to detect significant differences in glucose, insulin, or oxidative stress biomarkers between the resveratrol groups and placebo. In conclusion, resveratrol supplementation for 8 weeks had no significant effect on lipid profile but decreased uric acid in a dose-response manner, possibly due to XO inhibition in subjects with dyslipidemia. The trial was registered on ClinicalTrials.gov (NCT04886297).

Resveratrol reverses TGF-β1-mediated invasion and metastasis of breast cancer cells via the SIRT3/AMPK/autophagy signal axis

Resveratrol (Resv) has antitumorigenic and antimetastatic activities; however, the molecular mechanisms underlying the inhibitory effects of Resv on the invasion and metastasis of breast cancer cells are still a subject of debate. In our study, we demonstrated that Resv inhibited tumor cell proliferation and tumor growth. It also suppressed invasion and pulmonary metastasis of breast cancer by reversing the transforming growth factor beta 1 (TGF-β1)-mediated EMT process. Meanwhile, the anticarcinogenic effects of Resv were abolished by the autophagy blocker 3-methyladenine (3-MA) or Beclin 1 small interfering RNA. Moreover, Resv upregulated autophagy-related genes and protein levels and induced the formation of autophagosomes in 4T1 breast cancer cells and xenograft mice, suggesting that autophagy was involved in the anticarcinogenic activities of Resv in both models. In addition, Resv-induced autophagy by increasing the expression of SIRT3 and phosphorylated AMPK. SIRT3 knockdown reduced AMPK phosphorylation and autophagy-related proteins levels, and suppressed the anticancer effects of Resv, demonstrating that the inhibitory effects of Resv on tumor progression were mediated via the SIRT3/AMPK/autophagy pathway. Taken together, our study provided novel insight into the anticancer effects of Resv and revealed that targeting the SIRT3/AMPK/autophagy pathway can serve as a new therapeutic target against breast cancer.

Resveratrol as antioxidant in cardiac surgery: is there potential for clinical application?

Cardiopulmonary bypass (CPB) is an essential technique in cardiac surgery but is also associated with adverse effects, including the systemic inflammatory response syndrome that manifests itself as ischaemia-reperfusion injury and multi-organ dysfunction. The aim of this mini review is to take a look at the current knowledge of resveratrol, a stilbenoid and natural antioxidant believed to have many cardioprotective effects including vasodilation, lowering of blood pressure and reactive oxygen species levels, suppression of low-density lipoprotein peroxidation, and mitigation of ischaemia/-reperfusion injury. We mostly focus on its cardioprotective potential in patients undergoing cardiac surgery supported by CPB. Current findings, however, are still inconclusive and call for further research, including clinical trials.

Nutraceutical Approaches to Dyslipidaemia: The Main Formulative Issues Preventing Efficacy

Currently, the nutraceutical approach to treat dyslipidaemia is increasing in use, and in many cases is used by physicians as the first choice in the treatment of patients with borderline values. Nutraceuticals represent an excellent opportunity to treat the preliminary conditions not yet showing the pathological signs of dyslipidaemia. Their general safety, the patient's confidence, the convincing proof of efficacy and the reasonable costs prompted the market of new preparations. Despite this premise, many nutraceutical products are poorly formulated and do not meet the minimum requirements to ensure efficacy in normalizing blood lipid profiles, promoting cardiovascular protection, and normalizing disorders of glycemic metabolism. In this context, bioaccessibility and bioavailability of the active compounds is a crucial issue. Little attention is paid to the proper formulations needed to improve the overall bioavailability of the active molecules. According to these data, many products prove to be insufficient to ensure full enteric absorption. The present review analysed the literature in the field of nutraceuticals for the treatment of dyslipidemia, focusing on resveratrol, red yeast rice, berberine, and plant sterols, which are among the nutraceuticals with the greatest formulation problems, highlighting bioavailability and the most suitable formulations.

Progress in the Preclinical and Clinical Study of Resveratrol for Vascular Metabolic Disease

Vascular metabolic dysfunction presents in various diseases, such as atherosclerosis, hypertension, and diabetes mellitus. Due to the high prevalence of these diseases, it is important to explore treatment strategies to protect vascular function. Resveratrol (RSV), a natural polyphenolic phytochemical, is regarded as an agent to regulate metabolic pathways. Many studies have proven that RSV has beneficial effects on improving metabolism in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), which provide new directions to treat vascular metabolic diseases. Herein, we overviewed that RSV could regulate cell metabolism activity by inhibiting glucose uptake, suppressing glycolysis, preventing cells from fatty acid-related damages, reducing lipogenesis, increasing fatty acid oxidation, enhancing lipolysis, elevating uptake and synthesis of glutamine, and increasing NO release. Furthermore, in clinical trials, although the results from different studies remain controversial, we proposed that RSV had better therapeutic effects at high concentrations and for patients with metabolic disorders.

Natural Radiosensitizers in Radiotherapy: Cancer Treatment by Combining Ionizing Radiation with Resveratrol

Conventional cancer treatment is mainly based on the surgical removal of the tumor followed by radiotherapy and/or chemotherapy. When surgical removal is not possible, radiotherapy and, less often, chemotherapy is the only way to treat patients. However, despite significant progress in understanding the molecular mechanisms of carcinogenesis and developments in modern radiotherapy techniques, radiotherapy (alone or in combination) does not always guarantee treatment success. One of the main causes is the radioresistance of cancer cells. Increasing the radiosensitivity of cancer cells improves the processes leading to their elimination during radiotherapy and prolonging the survival of cancer patients. In order to enhance the effect of radiotherapy in the treatment of radioresistant neoplasms, radiosensitizers are used. In clinical practice, synthetic radiosensitizers are commonly applied, but scientists have recently focused on using natural products (phytocompounds) as adjuvants in radiotherapy. In this review article, we only discuss naturally occurring radiosensitizers currently in clinical trials (paclitaxel, curcumin, genistein, and papaverine) and those whose radiation sensitizing effects, such as resveratrol, have been repeatedly confirmed by many independent studies.

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.

Neuroprotective Effects of Resveratrol by Modifying Cholesterol Metabolism and Aβ Processing in SAMP8 Mice

Cholesterol metabolism seems dysregulated and linked to amyloid-β (Aβ) formation in neurodegeneration, but the underlying mechanisms are poorly known. Resveratrol (RSV) is a polyphenol with antioxidant activity and neuroprotective properties. Here, we analyzed the effect of age and RSV supplementation on cholesterol metabolism in the brain and blood serum, and its potential link to Aβ processing, in SAMP8 mice—an animal model of aging and Alzheimer’s disease. In the brain, our results revealed an age-related increase in ApoE and unesterified cholesterol in the plasma membrane whereas LDL receptor, HMG-CoA reductase, HMG-CoA-C1 synthase, and ABCA1 transporter remained unaltered. Furthermore, BACE-1 and APP gene expression was decreased. This dysregulation could be involved in the amyloidogenic processing pathway of APP towards Aβ formation. In turn, RSV exhibited an age-dependent effect. While levels of unesterified cholesterol in the plasma membrane were not affected by RSV, several participants in cholesterol uptake, release, and de novo synthesis differed, depending on age. Thus, RSV supplementation exhibited a different neuroprotective effect acting on Aβ processing or cholesterol metabolism in the brain at earlier or later ages, respectively. In blood serum, HDL lipoprotein and free cholesterol were increased by age, whereas VLDL and LDL lipoproteins remained unaltered. Again, the protective effect of RSV by decreasing the LDL or increasing the HDL levels also seems to depend on the intervention’s moment. In conclusion, age is a prominent factor for cholesterol metabolism dysregulation in the brain of SAMP8 mice and influences the protective effects of RSV through cholesterol metabolism and Aβ processing.

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.

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.

The effects of resveratrol supplementation in patients with type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease: an umbrella review of meta-analyses of randomized controlled trials

BACKGROUND

Uncertainty remains about the estimates of the effects for resveratrol supplementation, including the certainty of the evidence for each estimate and the magnitude of the observed impact based on the minimal important difference.

OBJECTIVE

We aimed to provide an overview of the effects of resveratrol supplementation, in comparison to control groups, for the management of cardiometabolic risk factors in patients with type 2 diabetes (T2D), metabolic syndrome (MetS), and nonalcoholic fatty liver disease (NAFLD).

METHODS

PubMed, Scopus, and ISI Web of Science were searched from inception to May 2021. For each meta-analysis, the mean difference and its 95% CI were recalculated using a random-effects model. The certainty of evidence was rated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.

RESULTS

We identified 11 meta-analyses corresponding to 29 outcomes in 1476 individuals with T2D, 17 meta-analyses reporting 26 outcomes in 727 participants with the MetS, and 10 meta-analyses reporting 24 outcomes in 271 patients with NAFLD. Resveratrol supplementation had beneficial effects on some outcomes such as blood pressure, lipid profile, glycemic control, and insulin resistance in T2D, waist circumference in MetS, and body-weight and inflammation markers in NAFLD; however, for almost all outcomes, the magnitude of the effect was trivial, the certainty of evidence was very low to low, or the number of trials was too few. In the case of glycated hemoglobin (HbA1c), there was evidence that resveratrol can exert favorable and clinically important effects in the short term (<12 wk; mean difference: -1.05%, 95% CI: -2.09%, -0.02%; n = 6; GRADE = moderate).

CONCLUSIONS

Current evidence does not support supplementation with resveratrol for the management of cardiometabolic risk factors in patients with T2D, MetS, and NAFLD. In the case of HbA1c, subject to the limitations such as short-term follow-up and small sample size, there was a clinically important effect. The protocol of the present systematic review was registered in Open Science Framework (https://osf.io/ake85; registration doi: 10.17605/OSF.IO/AKE85).

Resveratrol promotes lysosomal function via ER calcium-dependent TFEB activation to ameliorate lipid accumulation

Abnormal lipid accumulation is associated to the development of metabolic diseases such as hepatic steatosis and lipid storage diseases. Pharmacological agents that can attenuate lipid accumulation therefore have therapeutic potentials for these diseases. Resveratrol (RSV), a natural active substance found in fruits and nuts, has been reported to effectively reduce the intracellular lipid accumulation, but the underlying mechanisms of RSV remain elusive. Here, we show that RSV triggers an endoplasmic reticulum (ER)- Ca2+ signaling that activates transcriptional factor EB (TFEB), a master transcriptional regulator of autophagic and lysosomal biogenesis. Moreover, RSV activates protein phosphatase 2A (PP2A), which binds and dephosphorylates TFEB, promoting its nuclear translocation and the expression of TFEB target genes required for autophagosome and lysosomal biogenesis. Notably, genetic inhibition of TFEB significantly ameliorates RSV-mediated lipid clearance. Taken together, these data link RSV-induced ER calcium signaling, PP2A and TFEB activation to promote autophagy and lysosomal function, by which RSV may trigger a cellular self-defense mechanism that effectively mitigate lipid accumulation commonly associated with many metabolic diseases.

Caloric Restriction Mimetics in Nutrition and Clinical Trials

The human diet and dietary patterns are closely linked to the health status. High-calorie Western-style diets have increasingly come under scrutiny as their caloric load and composition contribute to the development of non-communicable diseases, such as diabetes, cancer, obesity, and cardiovascular disorders. On the other hand, calorie-reduced and health-promoting diets have shown promising results in maintaining health and reducing disease burden throughout aging. More recently, pharmacological Caloric Restriction Mimetics (CRMs) have gained interest of the public and scientific community as promising candidates that mimic some of the myriad of effects induced by caloric restriction. Importantly, many of the CRM candidates activate autophagy, prolong life- and healthspan in model organisms and ameliorate diverse disease symptoms without the need to cut calories. Among others, glycolytic inhibitors (e.g., D-allulose, D-glucosamine), hydroxycitric acid, NAD+ precursors, polyamines (e.g., spermidine), polyphenols (e.g., resveratrol, dimethoxychalcones, curcumin, EGCG, quercetin) and salicylic acid qualify as CRM candidates, which are naturally available via foods and beverages. However, it is yet unclear how these bioactive substances contribute to the benefits of healthy diets. In this review, we thus discuss dietary sources, availability and intake levels of dietary CRMs. Finally, since translational research on CRMs has entered the clinical stage, we provide a summary of their effects in clinical trials.

Resveratrol and Markers of Polycystic Ovary Syndrome: a Systematic Review of Animal and Clinical Studies

Polycystic ovary syndrome (PCOS) is a common disorder affecting childbearing-age women, and is associated with reproductive and metabolic disturbances. The present study aimed to systematically review current animal studies and randomized placebo-controlled clinical trials (RCT) regarding the effects of resveratrol, a natural polyphenolic compound, on PCOS features. PubMed, Scopus, Web of Knowledge, and Google Scholar were comprehensively searched until December 2020. All original animal articles and RCTs evaluating the effects of resveratrol on PCOS were eligible for the review. Out of 289 initial records, eight animal studies and three RCTs met our inclusion criteria. Most of the included animal studies reported beneficial effects of resveratrol on the histomorphological features, sex hormones and gonadotropins, glycemic control, inflammation, and oxidative stress. Resveratrol also ameliorated ovarian volume, high-quality oocyte rate, high-quality embryo rate, androgens and gonadotropins concentrations, angiogenic factors levels, and endoplasmic reticulum stress in PCOS patients. Upregulation of sirtuin-1 was an examined mechanism proposed for some observed effects of resveratrol. The current literature is limited to conclude the beneficial effects of resveratrol on the management of PCOS. Although, according to the promising results of the animal studies and limited RCTs, resveratrol might be an effective phytochemical in PCOS control, especially regarding hormonal and reproductive abnormalities. More mechanistic studies and RCTs are warranted to obvious whether resveratrol can be prescribed in the clinical situation.

Reactive Oxygen Species as a Link between Antioxidant Pathways and Autophagy

Reactive oxygen species (ROS) are highly reactive molecules that can oxidize proteins, lipids, and DNA. Under physiological conditions, ROS are mainly generated in the mitochondria during aerobic metabolism. Under pathological conditions, excessive ROS disrupt cellular homeostasis. High levels of ROS result in severe oxidative damage to the cellular machinery. However, a low/mild level of ROS could serve as a signal to trigger cell survival mechanisms. To prevent and cope with oxidative damage to biomolecules, cells have developed various antioxidant and detoxifying mechanisms. Meanwhile, ROS can initiate autophagy, a process of self-clearance, which helps to reduce oxidative damage by engulfing and degrading oxidized substance. This review summarizes the interactions among ROS, autophagy, and antioxidant pathways. The effects of natural phytochemicals on autophagy induction, antioxidation, and dual-function are also discussed.

Can resveratrol modulate sirtuins in obesity and related diseases? A systematic review of randomized controlled trials

PURPOSE

Human sirtuins can be a powerful therapeutic target in preventing and treating obesity and age-related diseases. Some dietary components can modulate sirtuins' activity, such as resveratrol. This systematic review aimed to assess whether resveratrol (RSV), without other interventions, can stimulate sirtuins in the treatment of excess weight and its comorbidities.

METHODS

MEDLINE/Pubmed, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) were used for search eligible articles. Randomized clinical trials assessing RSV supplementation on changes in the sirtuins' gene expression/protein levels was the primary outcome. Other possible changes in cardiometabolic markers were considered the second outcome. Following PRISMA guidelines and using predefined inclusion and exclusion criteria, two reviewers independently and in parallel screened, assessed the studies' quality, and compiled data. Disagreements were resolved by consensus or consulting a third author.

RESULTS

This review included seven randomized control trials. Four articles demonstrated a significant increase in SIRT-1 with different RSV dosages and interventions time. The secondary outcomes showed improvements in insulin sensitivity, lipid profile, metabolic flexibility, total antioxidant capacity, energy expenditure changes, and reduction of ectopic accumulation of fat.

CONCLUSION

Data from RCTs studies showed that RSV supplementation could stimulate SIRT-1 in humans, and therefore contribute to the treatment of excess weight and its comorbidities. However, more research is needed because it was not possible to confirm this effect truly. [PROSPERO registration number: CRD42020205571].

Comparison of Resveratrol Supplementation and Energy Restriction Effects on Sympathetic Nervous System Activity and Vascular Reactivity: A Randomized Clinical Trial

Background: Chronic sympathetic nervous system activation is associated with endothelial dysfunction and cardiometabolic disease, which may be modulated by resveratrol (RSV) and energy restriction (ER). This study aimed to examine the effects of RSV and ER on plasma noradrenaline (NA), flow-mediated vasodilation (ed-FMD), and endothelium-independent nitrate-mediated vasodilation (ei-NMD). Methods: The study included 48 healthy adults randomized to 30-days intervention of RSV or ER. Results: Waist circumference, total cholesterol, HDL-c, LDL-c, apoA-I, and plasma NA decreased in the ER group, whilst RSV increased apoB and total cholesterol, without changing plasma NA. No effects on vascular reactivity were observed in both groups. Plasma NA change was positively correlated with total cholesterol (r = 0.443; p = 0.002), triglycerides (r = 0.438; p = 0.002), apoA-I (r = 0.467; p = 0.001), apoB (r = 0.318; p = 0.032) changes, and ei-NMD (OR = 1.294; 95%CI: 1.021–1.640). Conclusions: RSV does not improve cardiometabolic risk factors, sympathetic activity, and endothelial function. ER decreases plasma NA and waist circumference as well as improves blood lipids, but does not modify endothelial function. Finally, plasma NA was associated with ei-NMD, which could be attributed to a higher response to nitrate in patients with greater resting sympathetic vasoconstriction.

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

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

The impact of resveratrol on skin wound healing, scarring, and aging

Resveratrol is a well‐known antioxidant that harbours many health beneficial properties. Multiple studies associated the antioxidant, anti‐inflammatory, and cell protective effects of resveratrol. These diverse effects of resveratrol are also potentially involved in cutaneous wound healing, scarring, and (photo‐)aging of the skin. Hence, this review highlighted the most relevant studies involving resveratrol in wound healing, scarring, and photo‐aging of the skin. A systematic review was performed and the database PubMed was searched for suitable publications. Only original articles in English that investigated the effects of resveratrol in wound healing, scarring, and (photo‐)aging of the skin were analysed. The literature search yielded a total of 826 studies, but only 41 studies met the inclusion criteria. The included studies showed promising results that resveratrol might be a feasible treatment approach to support wound healing, counteract excessive scarring, and even prevent photo‐aging of the skin. Resveratrol represents an interesting and promising novel therapy regime but to confirm resveratrol‐associated effects, more evidence based in vitro and in vivo studies are needed.

[The role of resveratrol on heavy metal-induced oxidative stress]

Introduction

Introduction and objetives: oxidative stress is considered one of the main mechanisms of genotoxicity and carcinogenicity of heavy metals. In contrast, resveratrol has antioxidant properties and is one of the most studied polyphenols due to its wide variety of beneficial health effects. However, there are no systematic reviews of the scientific literature in which the effects of resveratrol on oxidative stress induced by heavy metals are analyzed. Methods: in this review, articles were searched using the PubMed and ScienceDirect databases (1996-2018). After applying various filters, eleven in vivo and in vitro researches were considered, in which the effects of resveratrol on oxidative stress induced by arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr) and iron (Fe) were studied. Results: this review presents an analysis of the chemical effects of resveratrol on oxidative stress associated with the exposure of metal compounds. The interaction of resveratrol with the production of reactive oxygen species (ERO's), the endogenous antioxidant system and its effects on DNA damage is discussed. From these studies, a diagram that shows the proposed interactions for resveratrol; heavy metals As, Cd, Cu, Cr and Fe; and oxidative stress is generated. Conclusions: the studies analyzed show that resveratrol is able to modulate the oxidative stress generated by different heavy metal compounds such as As, Cd, Cu, Cr and Fe.

Sulforaphane ameliorates lipid profile in rodents: an updated systematic review and meta-analysis

Sulforaphane (SFN), a naturally-occurring isothiocyanate enriched in cabbage and broccoli, has been provided as food supplements to improve weight management and reduce lipid levels. However, its effects on serum lipid profiles are contradictory. In this review, a meta-analysis and systematic review of SFN on lipid reduction and weight control is assessed with mice and rats fed on high-fat diet. The effects of SFN supplementation were evaluated by weighted mean difference (WMD) in body weight (BW), liver weight (LW) and also by its effect on serum lipids. A random-effects model was applied to estimate the overall summary effect. SFN reduced BW (WMD: − 2.76 g, 95% CI: − 4.19, − 1.34) and LW (WMD: − 0.93 g, 95% CI: − 1.63, − 0.23) significantly in our ten trials. Its effects on serum total cholesterol (TC) (WMD: − 15.62 mg/dL, 95% CI: − 24.07, − 7.18), low-density lipoprotein cholesterol (LDL-C) (WMD: − 8.35 mg/dL, 95% CI: − 15.47, − 1.24) and triglyceride (TG) (WMD: − 40.85 mg/dL, 95% CI: − 67.46, − 14.24) were significant except for high-density lipoprotein cholesterol (HDL-C) component (WMD: 1.05 mg/dL, 95% CI: − 3.44, 5.54). However, species, disease model, duration, SFN dosage as well as route of administration did not explain the heterogeneity among studies. In summary, these findings provide new insights concerning preclinical strategies for treating diseases including obesity, diabetes, hypertension, non-alcoholic fatty liver disease as well as cardiovascular disease with SFN supplements.

The interplay between lipid and Aβ amyloid homeostasis in Alzheimer's Disease: risk factors and therapeutic opportunities

Alzheimer's Diseases (AD) is characterized by the accumulation of amyloid deposits of Aβ peptide in the brain. Besides genetic background, the presence of other diseases and an unhealthy lifestyle are known risk factors for AD development. Albeit accumulating clinical evidence suggests that an impaired lipid metabolism is related to Aβ deposition, mechanistic insights on the link between amyloid fibril formation/clearance and aberrant lipid interactions are still unavailable. Recently, many studies have described the key role played by membrane bound Aβ assemblies in neurotoxicity. Moreover, it has been suggested that a derangement of the ubiquitin proteasome pathway and autophagy is significantly correlated with toxic Aβ aggregation and dysregulation of lipid levels. Thus, studies focusing on the role played by lipids in Aβ aggregation and proteostasis could represent a promising area of investigation for the design of valuable treatments. In this review we examine current knowledge concerning the effects of lipids in Aβ aggregation and degradation processes, focusing on the therapeutic opportunities that a comprehensive understanding of all biophysical, biochemical, and biological processes involved may disclose.

C-Glucosylation as a tool for the prevention of PAINS-induced membrane dipole potential alterations

The concept of Pan-Assay Interference Compounds (PAINS) is regarded as a threat to the recognition of the broad bioactivity of natural products. Based on the established relationship between altered membrane dipole potential and transmembrane protein conformation and function, we investigate here polyphenols' ability to induce changes in cell membrane dipole potential. Ultimately, we are interested in finding a tool to prevent polyphenol PAINS-type behavior and produce compounds less prone to untargeted and promiscuous interactions with the cell membrane. Di-8-ANEPPS fluorescence ratiometric measurements suggest that planar lipophilic polyphenols-phloretin, genistein and resveratrol-act by decreasing membrane dipole potential, especially in cholesterol-rich domains such as lipid rafts, which play a role in important cellular processes. These results provide a mechanism for their labelling as PAINS through their ability to disrupt cell membrane homeostasis. Aiming to explore the role of C-glucosylation in PAINS membrane-interfering behavior, we disclose herein the first synthesis of 4-glucosylresveratrol, starting from 5-hydroxymethylbenzene-1,3-diol, via C-glucosylation, oxidation and Horner-Wadsworth-Emmons olefination, and resynthesize phloretin and genistein C-glucosides. We show that C-glucosylation generates compounds which are no longer able to modify membrane dipole potential. Therefore, it can be devised as a strategy to generate bioactive natural product derivatives that no longer act as membrane dipole potential modifiers. Our results offer a new technology towards rescuing bioactive polyphenols from their PAINS danger label through C-C ligation of sugars.

Resveratrol enhances trans-intestinal cholesterol excretion through selective activation of intestinal liver X receptor alpha

Resveratrol (RSV) is a dietary polyphenol with well-documented cardio-protective activity, but its effects on blood cholesterol levels remain to be established. Due to its poor bioavailability, tissue accumulation of RSV is extremely low except for that in the small intestine. In the present study, we aimed to investigate the dose-dependent effects of RSV on blood cholesterol levels and the involvement of small intestine in the cholesterol-lowering impacts of RSV. Mice were administrated with RSV at various doses with high-fat diet (HFD) or high-fat and high-cholesterol diet (HCD) for 12 weeks. The fecal neutral sterol contents were analyzed, and intestinal perfusion test was performed. An enteric barrier model using Caco-2 cells was established. We observed that RSV reduced blood cholesterol levels in a dose-dependent manner in mice fed with HFD or HCD. Further investigation revealed that RSV administration increased the bile acid pool size but did not affect cholesterol consumption or de novo cholesterol synthesis. Interestingly, RSV promoted trans-intestinal cholesterol excretion (TICE) by 2-fold in the intestinal perfusion test. In addition, RSV upregulated the expressions of ATP-binding cassette sub-family G member 5 or 8 (Abcg5/8) and ATP-binding cassette sub-family B member 1a or 1b (Abcb1a/b) by up to 8 times in the duodenum mucosa but not in the liver. RSV also significantly downregulated the expression of intestinal Niemann-Pick C1-Like 1 (Npc1l1). Knock-down of liver X receptor alpha (LXRα) but not Sirt1 by siRNA significantly blocked RSV-induced cholesterol excretion in Caco-2 cells. In conclusion, RSV could decrease circulating cholesterol levels through enhancing TICE and limiting cholesterol absorption via selective activation of intestinal LXRα.

Polyphenol-Rich and Alcoholic Beverages and Metabolic Status in Adults Living in Sicily, Southern Italy

Polyphenol-rich beverage consumption is not univocally accepted as a risk modulator for cardio-metabolic risk factors, despite mechanistic and epidemiological evidence suggesting otherwise. The aim of this study was to assess whether an association between polyphenol-rich beverage consumption and metabolic status could be observed in a Mediterranean cohort with relatively low intake of tea, coffee, red and white wine, beer, and fresh citrus juice. Demographic and dietary characteristics of 2044 adults living in southern Italy were analyzed. Multivariate logistic regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between polyphenol-rich and alcoholic beverage consumption and metabolic status adjusted for potential confounding factors. Specific polyphenol-rich beverages were associated, to a various extent, with metabolic outcomes. Individuals with a higher total polyphenol-rich beverages had higher polyphenols intake and were less likely to have hypertension, type-2 diabetes, and dyslipidemia (OR = 0.57, 95% CI: 0.44–0.73; OR = 0.41, 95% CI: 0.26–0.66; and OR = 0.41, 95% CI: 0.29–0.57, respectively). However, when adjusted for potential confounding factors, only the association with hypertension remained significant (OR = 0.69, 95% CI: 0.50–0.94). Current scientific evidence suggests that such beverages may play a role on cardio-metabolic risk factors, especially when consumed within the context of a dietary pattern characterized by an intake of a plurality of them. However, these associations might be mediated by an overall healthier lifestyle.

Clinical trials of resveratrol efficacy and safety

Trans-resveratrol is a phytoalexin from the stilbene class, polyphenolic compound from non-flavonoid group. In vitro and animal studies have shown that trans-resveratrol may exert a wide range of potential beneficial effects to human health, which involves antioxidant, anti-inflammatory, cardioprotective, neuroprotective, anti-diabetic and anti-cancer activity. The objective of this paper was to summarize available data concerning the most important clinical trials focused on resveratrol biological effects. The results of clinical trials indicate that resveratrol has potential cardioprotective activity in patients with increased risk of cardiovascular disease. It can also have positive effect on the circulatory function and exert anti-diabetic activity in humans, while the anti-cancer activity is still insufficiently tested. Some issues remain unsolved, such as the dose and length of treatment that would maximize the potential of resveratrol. It is expected that future, better designed and more extensive clinical trials will provide additional information related to this topic.

The Potential of Resveratrol to Act as a Caloric Restriction Mimetic Appears to Be Limited: Insights from Studies in Mice

Caloric restriction (CR) has been shown repeatedly to prolong the lifespan in laboratory animals, with its benefits dependent on molecular targets forming part of the nutrient signaling network, including the NAD-dependent deacetylase silent mating type information regulation 2 homologue 1 (SIRT1). It has been hypothesized that the stilbene resveratrol (RSV) may counteract age- and obesity-related diseases similarly to CR. In yeast and worms, RSV-promoted longevity also depended on SIRT1. While it remains unclear whether RSV can prolong lifespans in mammals, some studies in rodents supplemented with RSV have reported lowered body weight (BW) and fat mass, improved insulin sensitivity, lowered cholesterol levels, increased fitness, and mitochondrial biogenesis. Molecular mechanisms possibly leading to such changes include altered gene transcription and activation of SIRT1, AMP-activated kinase (AMPK), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A). However, some mouse models did not benefit from RSV treatment to the same extent as others. We conducted a literature search on PubMed (15 April, 2020) for trials directly comparing RSV application to CR feeding in mice. In most studies retrieved by this systematic PubMed search, mice supplemented with RSV did not show significant reductions of BW, glucose, or insulin. Moreover, in some of these studies, RSV and CR treatments affected molecular targets differently and/or findings on RSV and CR impacts varied between trials. We discuss those RSV-induced changes in gene transcription hypothesized to partly counteract age-related alterations. Although there may be a moderate effect of RSV supplementation on parameters such as insulin sensitivity toward a more CR-like profile in mice, data are inconsistent. Likewise, RSV supplementation trials in humans report controversial findings. While we consider that RSV may, under certain circumstances, moderately mimic some aspects of CR, current evidence does not fully support its use to prevent or treat age- or obesity-related diseases.

Efficacy of resveratrol supplementation on liver enzymes in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis

OBJECTIVE

Randomized clinical trials (RCTs) examining the effects of resveratrol supplementation on liver enzymes in non-alcoholic fatty liver disease (NAFLD) have reported conflicting results. The aim of this systematic review was to summarize evidence of the effects of resveratrol supplementation on alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in patients with NAFLD by performing a meta-analysis of RCTs.

METHODS

PubMed, Cochrane Library, Scopus, and Web of Science databases were electronically explored from inception to August 2020 for all relevant studies. Random effect models were used to estimate liver enzymes changes between resveratrol supplementation and control groups by evaluating the weighted mean differences (WMD) with 95 % confidence intervals (CIs).

RESULTS

Five trials with a total of 216 patients were included in the meta-analysis. The pooled results showed that resveratrol supplementation did not result in significant changes in serum ALT (WMD= -2.48 IU/L; 95 % CI: -12.30, 7.34; P = 0.62), and AST (WMD = -2.90 IU/L; 95 % CI: -9.77, 3.98; P = 0.40) concentrations. Subgroup analysis revealed a significant reduction in serum ALT and AST concentrations in the participants with mean age <45 years, and studies with intervention dosage <1000 mg/day. In addition, ALT and AST levels were decreased significantly in studies with duration >12 weeks and participants with BMI < 30 kg/m², respectively.

CONCLUSIONS

The overall results indicated that resveratrol supplementation did not affect liver enzymes in patients with NAFLD. More studies examining the effect of resveratrol supplementation on liver enzymes are needed in the future.

Resveratrol and cardiovascular system-the unfulfilled hopes

INTRODUCTION

Resveratrol is a natural polyphenolic compound with a stilbene structure endowed with multiple health-promoting effects. Among phenolic compounds, resveratrol is assigned a leading role in the health-promoting effects of red wine.

METHODS

The aim of the study was to assess the effect of resveratrol on the cardiovascular system in the experimental and clinical studies conducted so far. Moreover, the paper discusses the results of the most recent meta-analyses assessing resveratrol's therapeutic effect on the cardiovascular system in humans.

RESULTS

In animal and preclinical studies, resveratrol has demonstrated a wide physiological and biochemical spectrum of activity, including antioxidant, anti-inflammatory, antiplatelet, and anticoagulant activities, which translated into its health-promoting effects on the cardiovascular system. The performed meta-analyses allow to confirm such an impact, however, after the assessment with the use of the SYRCLE's tool, these studies are burdened with a high risk of bias, and the results are not clearly presented.

CONCLUSION

Despite numerous articles and clinical studies, the convincing beneficial mechanisms of resveratrol as well as its health-promoting effects in cardiovascular diseases have not been clearly confirmed in humans. Therefore, there is a need for further clinical studies, especially randomized, double-blind, placebo-controlled trials to objectively confirm the possible health-promoting effects of this substance and to determine both the efficacy and safety, and possible therapeutic potential.

Influence of Resveratrol on the Cardiovascular Health Effects of Chronic Kidney Disease

Cardiovascular disease (CVD) is closely related to chronic kidney disease (CKD), and patients with CKD have a high risk of CVD-related mortality. Traditional CVD risk factors cannot account for the higher cardiovascular risk of patients with CKD, and standard CVD interventions cannot reduce the mortality rates among patients with CKD. Nontraditional factors related to mineral and vitamin-D metabolic disorders provide some explanation for the increased CVD risk. Non-dialyzable toxins, indoxyl sulfate (IS) and p-cresol sulfate (PCS)-produced in the liver by colonic microorganisms-cause kidney and vascular dysfunction. Plasma trimethylamine-N-oxide (TMAO)-a gut microbe-dependent metabolite of dietary L-carnitine and choline-is elevated in CKD and related to vascular disease, resulting in poorer long-term survival. Therefore, the modulation of colonic flora can improve prospects for patients with CKD. Managing metabolic syndrome, anemia, and abnormal mineral metabolism is recommended for the prevention of CVD in patients with CKD. Considering nontraditional risk factors, the use of resveratrol (RSV), a nutraceutical, can be helpful for patients with CVD and CKD. This paper discusses the beneficial effects of RSV on biologic, pathophysiological and clinical responses, including improvements in intestinal epithelial integrity, modulation of the intestinal microbiota and reduction in hepatic synthesis of IS, PCS and TMAO in patients with CVD and CKD.

Pleiotropic effects of polyphenols on glucose and lipid metabolism: Focus on clinical trials

Epidemiological evidence from observational studies suggests that dietary polyphenols (PPs) - phytochemicals found in a variety of plant-based foods - can reduce the risk of developing type 2 diabetes mellitus (T2DM). Clinical trials have also indicated that PPs may help manage the two key features of T2DM, hyperglycemia and dyslipidemia. Since the incidence of T2DM is dramatically increasing worldwide, identifying food-based approaches that can reduce the risk of developing it and help manage its main risk factors in early-stage disease has clinical and socioeconomic relevance. After a brief overview of current epidemiological data on the incidence of T2DM in individuals consuming PP-rich diets, we review the evidence from clinical trials investigating PP-enriched foods and/or PP-based nutraceutical compounds, report their main results, and highlight the knowledge gaps that should be bridged to enhance our understanding of the role of PPs in T2DM development and management.

No effect of resveratrol supplementation after 6 months on insulin sensitivity in overweight adults: a randomized trial

BACKGROUND

Effects of resveratrol on metabolic health have been studied in several short-term human clinical trials, with conflicting results. Next to dose, the duration of the clinical trials may explain the lack of effect in some studies, but long-term studies are still limited.

OBJECTIVES

The objective of this study was to investigate the effects of 6-mo resveratrol supplementation on metabolic health outcome parameters.

METHODS

Forty-one overweight men and women (BMI: 27-35 kg/m2; aged 40-70 y) completed the study. In this parallel-group, double-blind clinical trial, participants were randomized to receive either 150 mg/d of resveratrol (n = 20) or placebo (n = 21) for 6 mo. The primary outcome of the study was insulin sensitivity, using the Matsuda index. Secondary outcome measures were intrahepatic lipid (IHL) content, body composition, resting energy metabolism, blood pressure, plasma markers, physical performance, quality of life, and quality of sleep. Postintervention differences between the resveratrol and placebo arms were evaluated by ANCOVA adjusting for corresponding preintervention variables.

RESULTS

Preintervention, no differences were observed between the 2 treatment arms. Insulin sensitivity was not affected after 6 mo of resveratrol treatment (adjusted mean Matsuda index: 5.18 ± 0.35 in the resveratrol arm compared with 5.50 ± 0.34 in the placebo arm), although there was a significant difference in postintervention glycated hemoglobin (HbA1c) between the arms (P = 0.007). The adjusted means showed that postintervention HbA1c was lower on resveratrol (35.8 ± 0.43 mmol/mol) compared with placebo (37.6 ± 0.44 mmol/mol). No postintervention differences were found in IHL, body composition, blood pressure, energy metabolism, physical performance, or quality of life and sleep between treatment arms.

CONCLUSIONS

After 6 mo of resveratrol supplementation, insulin sensitivity was unaffected in the resveratrol arm compared with the placebo arm. Nonetheless, HbA1c was lower in overweight men and women in the resveratrol arm. This trial was registered at Clinicaltrials.gov as NCT02565979.

Naturally Occurring PCSK9 Inhibitors

Genetic, epidemiological and pharmacological data have led to the conclusion that antagonizing or inhibiting Proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces cardiovascular events. This clinical outcome is mainly related to the pivotal role of PCSK9 in controlling low-density lipoprotein (LDL) cholesterol levels. The absence of oral and affordable anti-PCSK9 medications has limited the beneficial effects of this new therapeutic option. A possible breakthrough in this field may come from the discovery of new naturally occurring PCSK9 inhibitors as a starting point for the development of oral, small molecules, to be used in combination with statins in order to increase the percentage of patients reaching their LDL-cholesterol target levels. In the present review, we have summarized the current knowledge on natural compounds or extracts that have shown an inhibitory effect on PCSK9, either in experimental or clinical settings. When available, the pharmacodynamic and pharmacokinetic profiles of the listed compounds are described.

SIRT1 Regulation in Ageing and Obesity

Ageing and obesity have common hallmarks: altered glucose and lipid metabolism, chronic inflammation and oxidative stress are some examples. The downstream effects of SIRT1 activity have been thoroughly explored, and their research is still in expanse. SIRT1 activation has been shown to regulate pathways with beneficiary effects on 1) ageing and obesity-associated metabolic disorders such as metabolic syndrome, insulin resistance and type-II diabetes with, 2) chronic inflammatory processes such as arthritis, atherosclerosis and emphysema, 3) DNA damage and oxidative stress with impact on neurodegenerative diseases, cardiovascular health and some cancers. This knowledge intensified the interest in uncovering the mechanisms regulating the expression and activity of SIRT1. This review focuses on the upstream regulatory mechanisms controlling SIRT1, and how this knowledge could potentially contribute to the development of therapeutic interventions.

Effect of grape polyphenols on selected inflammatory mediators: A systematic review and meta-analysis randomized clinical trials

Grapes contain different polyphenols and might prevent inflammation by reducing Nitric Oxide (NO) inactivation through antioxidative enzymes. The aim of this article was to demonstrate the effects of grape polyphenols on the selected inflammatory mediators, such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-a), and high-sensitivity C-reactive protein (hs-CRP). To find papers assessing the effects of grape polyphenols on inflammatory mediators, electronic data bases, including ISI web of science, PubMed/Medline, SCOPUS, and Google scholar, were searched up to March 2019. Delphi checklist was used for evaluating the qualities of the included articles. The protocol was registered in PROSPERO (No. CRD42019116695). The mean changes in the intervention and control groups were calculated by subtracting the end values from the baselines. Then, the difference between the two changes was measured and utilized as the effect size in meta-analysis. 9 and 8 articles were included in the systematic review and meta-analysis, respectively. Our results indicated that grape polyphenols did not reduce hs-CRP levels, but omission of one article could lead to a significant reduction in hs-CRP (Weight Mean Difference (WMD): −0.54 mg/L, 95 % CI: −1.02, -0.06; P=0.026, I²=0.0 %). Regarding IL-6 and TNF-α, no significant changes were observed in the intervention compared to the control group (WMD: 0.04 pg/mL, 95 % CI: −0.02, 0.28; P=0.744, I²=0.0 %, WMD: -0.10 pg/mL, 95 % CI: −0.25, 0.05; P=0.183, I²=0.0 %, respectively). We found no beneficial effects of grape polyphenols on the selected inflammatory mediators. Still, more studies with higher doses of polyphenols, longer treatment durations, different sources of grape polyphenols, and larger numbers of participants are required.

Pharmacological basis and new insights of resveratrol action in the cardiovascular system

Resveratrol (trans-3,4',5-trihydroxystilbene) belongs to the family of natural phytoalexins. Resveratrol first came to our attention in 1992, following reports of the cardioprotective effects of red wine. Thereafter, resveratrol was shown to exert antioxidant, anti-inflammatory, anti-proliferative, and angio-regulatory effects against atherosclerosis, ischaemia, and cardiomyopathy. This article critically reviews the current findings on the molecular basis of resveratrol-mediated cardiovascular benefits, summarizing the broad effects of resveratrol on longevity regulation, energy metabolism, stress resistance, exercise mimetics, circadian clock, and microbiota composition. In addition, this article also provides an update, both preclinically and clinically, on resveratrol-induced cardiovascular protection and discusses the adverse and inconsistent effects of resveratrol reported in both preclinical and clinical studies. Although resveratrol has been claimed as a master anti-aging agent against several age-associated diseases, further detailed mechanistic investigation is still required to thoroughly unravel the therapeutic value of resveratrol against cardiovascular diseases at different stages of disease development. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Etiology of atherosclerosis informs choice of animal models and tissues for initial functional genomic studies of resveratrol

Resveratrol, a phytoalexin, is a natural polyphenol synthesized exclusively by plants in response to environmental stresses. However, the molecule has also many exogenous bioactivities in animal cells. These bioactivities may lead to anti-cancer and cardio-protective health benefits. Because cellular responses to the treatment with resveratrol include the changes of expression patterns, functional genomics is an attractive tool to study them. In recent and today's experimental practice, this mostly means microarray profiling of gene expression (using RNAs isolated from bulk tissues). Herein, we review such published studies undertaken in the context of cardiovascular diseases (CVDs). CVDs are a number one public health problem in developed countries, outweighing in magnitude even cancer. In particular, we review the studies of resveratrol in several animal models relevant to CVDs. These models included: normal and pre-mature aging in mice, as well as atherogenic diet in mice / pigs / non-human primates. Additionally, there were few clinical studies published in the context of the comorbidities of atherosclerosis in humans (e.g. obesity, diabetes, hypertension). For the purposes of these studies, three types of samples were most commonly profiled with microarrays: the liver, the skeletal muscle, and peripheral blood mononuclear cells. Resveratrol-induced changes of gene expression typically mimicked those associated with calorie restriction and lifespan extension. They also opposed changes induced by the atherogenic diet. We conclude by discussing few experimental factors that were relatively neglected thus far, but which could be interesting to investigate in the future. These factors include sex and the exact formulation of resveratrol (plant extract, or synthetic chemical).

Association between genetically determined leptin and blood lipids considering alcohol consumption: a Mendelian randomisation study

OBJECTIVES

The objective of this study was to evaluate the association of genetically determined leptin with lipids.

DESIGN

We conducted a Mendelian randomisation study to assess a potential causal relationship between serum leptin and lipid levels. We also evaluated whether alcohol drinking modified the associations of genetically determined leptin with blood lipids.

SETTING AND PARTICIPANTS

3860 participants of the Framingham Heart Study third generation cohort.

RESULTS

Both genetic risk scores (GRSs), the GRS generated using leptin loci independent of body mass index (BMI) and GRS generated using leptin loci dependent of BMI, were positively associated with log-transformed leptin (log-leptin). The BMI-independent leptin GRS was associated with log-transformed triglycerides (log-TG, β=-0.66, p=0.01), but not low-density lipoprotein cholesterol (LDL-C, p=0.99), high-density lipoprotein cholesterol (HDL-C, p=0.44) or total cholesterol (TC, p=0.49). Instrumental variable estimation showed that per unit increase in genetically determined log-leptin was associated with 0.55 (95% CI: 0.05 to 1.00) units decrease in log-TG. Besides significant association with log-TG (β=-0.59, p=0.009), the BMI-dependent GRS was nominally associated with HDL-C (β=-10.67, p=0.09) and TC (β=-28.05, p=0.08). When stratified by drinking status, the BMI-dependent GRS was associated with reduced levels of LDL-C (p=0.03), log-TG (p=0.004) and TC (p=0.003) among non-current drinkers only. Significant interactions between the BMI-dependent GRS and alcohol drinking were identified for LDL-C (p=0.03), log-TG (p=0.03) and TC (p=0.02).

CONCLUSION

These findings together indicated that genetically determined leptin was negatively associated with lipid levels and the association may be modified by alcohol consumption.

Urine Metabolites and Antioxidant Effect after Oral Intake of Date (Phoenix dactylifera L.) Seeds-Based Products (Powder, Bread and Extract) by Human

A cross-over study was conducted in 16 healthy adult volunteers to describe the urinary excretion of polyphenols from date seeds and investigate the antioxidant effect after consumption of different doses of date seeds powder (DSP), bread (DSB) and extract (DSE). After 12 h of fasting, one of the six treatments (0.25 g and 0.5 g/kg bodyweight DSP, 360 g of 10% and 15% DSB, 30 mg and 60 mg/kg bodyweight DSE) was provided along with breakfast, with a two weeks wash-out period between 2 consecutive treatments. Blood was drawn at baseline, 1, 2, 8 and 24 h post intake. Urine was collected at baseline, 3, 8, and 24 h post intake. An abundant release of polyphenols was detected in urine within the 0-3 h post intake, reached a peak at 8 h, then decreased with polyphenols still being detected up to 24 h post intake. The antioxidant defence system, as measured by reduced glutathione (GSH), was strengthened as soon as 1 h and up to 8 h post intake. Markers of protein and lipid oxidative damages were reduced from 1 h and up to 8 and 24 h post intake, respectively. This supports an antioxidant effect of date seeds products in humans, most probably due to their polyphenols.

Natural Products from Mediterranean Diet: From Anti-hyperlipidemic Agents to Dietary Epigenetic Modulators

Background:

Cardiovascular Diseases (CVD) are, currently, the major contributor to global mortality and will continue to dominate mortality rates in the future. Hyperlipidemia refers to the elevated levels of lipids and cholesterol in the blood, and is also identified as dyslipidemia, manifesting in the form of different disorders of lipoprotein metabolism. These abnormalities may lead to the development of atherosclerosis, which can lead to coronary artery disease and stroke. In recent years, there is a growing interest in the quest for alternative therapeutic treatments based on natural products, offering better recovery and the avoidance of side effects. Recent technological advances have further improved our understanding of the role of epigenetic mechanisms in hyperlipidemic disorders and dietary prevention strategies.

Objective:

This is a comprehensive overview of the anti-hyperlipidemic effects of plant extracts, vegetables, fruits and isolated compounds thereof, with a focus on natural products from the Mediterranean region as well as the possible epigenetic changes in gene expression or cardiometabolic signaling pathways.

Methods:

For the purpose of this study, we searched the PubMed, Scopus and Google Scholar databases for eligible articles and publications over the last five years. The keywords included: “hyperlipidemia”, “plant extract”, “herbs”, “natural products”, “vegetables”, “cholesterol” and others. We initially included all relevant articles referring to in vitro studies, animal studies, Randomized Controlled Trials (RCTs) and previous reviews.

Conclusion:

Many natural products found in the Mediterranean diet have been studied for the treatment of hyperlipidemia. The antihyperlipidemic effect seems to be dose and/or consumption frequency related, which highlights the fact that a healthy diet can only be effective in reversing disease markers if it is consistent and within the framework of a healthy lifestyle. Finally, epigenetic biomarkers are increasingly recognized as new lifestyle management tools to monitor a healthy dietary lifestyle for the prevention of hyperlipidaemic disorders and comorbidities to promote a healthy life.

ATP-citrate lyase (ACLY) in lipid metabolism and atherosclerosis: An updated review

ATP citrate lyase (ACLY) is an important enzyme linking carbohydrate to lipid metabolism by generating acetyl-CoA from citrate for fatty acid and cholesterol biosynthesis. Mendelian randomization of large human cohorts has validated ACLY as a promising target for low-density-lipoprotein-cholesterol (LDL-C) lowering and cardiovascular protection. Among current ACLY inhibitors, Bempedoic acid (ETC-1002) is a first-in-class, prodrug-based direct competitive inhibitor of ACLY which regulates lipid metabolism by upregulating hepatic LDL receptor (LDLr) expression and activity. ACLY deficiency in hepatocytes protects from hepatic steatosis and dyslipidemia. In addition, pharmacological inhibition of ACLY by bempedoic acid, prevents dyslipidemia and attenuates atherosclerosis in hypercholesterolemic ApoE^-/- mice, LDLr^-/- mice, and LDLr^-/- miniature pigs. Convincing data from clinical trials have revealed that bempedoic acid significantly lowers LDL-C as monotherapy, combination therapy, and add-on with statin therapy in statin-intolerant patients. More recently, a phase 3 CLEAR Harmony clinical trial ("Safety and Efficacy of Bempedoic Acid to Reduce LDL Cholesterol") has shown that bempedoic acid reduces the level of LDL-C in hypercholesterolemic patients receiving guideline-recommended statin therapy with a good safety profile. Hereby, we provide a updated review of the expression, regulation, genetics, functions of ACLY in lipid metabolism and atherosclerosis, and highlight the therapeutic potential of ACLY inhibitors (such as bempedoic acid, SB-204990, and other naturally-occuring inhibitors) to treat atherosclerotic cardiovascular diseases. It must be pointed out that long-term large-scale clinical trials in high-risk patients, are warranted to validate whether ACLY represent a promising therapeutic target for pharmaceutic intervention of dyslipidemia and atherosclerosis; and assess the safety and efficacy profile of ACLY inhibitors in improving cardiovascular outcome of patients.

Resveratrol Action on Lipid Metabolism in Cancer

Cancer diseases have the leading position in human mortality nowadays. The age of oncologic patients is still decreasing, and the entire scientific society is eager for new ways to fight against cancer. One of the most discussed issues is prevention by means of natural substances. Resveratrol is a naturally occurring plant polyphenol with proven antioxidant, anti-inflammatory, and anticancer effects. Tumor cells display specific changes in the metabolism of various lipids. Resveratrol alters lipid metabolism in cancer, thereby affecting storage of energy, cell signaling, proliferation, progression, and invasiveness of cancer cells. At the whole organism level, it contributes to the optimal metabolism extent with respect to the demands of the organism. Thus, resveratrol could be used as a preventive and anticancer agent. In this review, we focus on some of the plethora of lipid pathways and signal molecules which are affected by resveratrol during carcinogenesis.

Aging, lifestyle and dementia

Aging is the greatest risk factor for most diseases including cancer, cardiovascular disorders, and neurodegenerative disease. There is emerging evidence that interventions that improve metabolic health with aging may also be effective for brain health. The most robust interventions are non-pharmacological and include limiting calorie or protein intake, increasing aerobic exercise, or environmental enrichment. In humans, dietary patterns including the Mediterranean, Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) and Okinawan diets are associated with improved age-related health and may reduce neurodegenerative disease including dementia. Rapamycin, metformin and resveratrol act on nutrient sensing pathways that improve cardiometabolic health and decrease the risk for age-associated disease. There is some evidence that they may reduce the risk for dementia in rodents. There is a growing recognition that improving metabolic function may be an effective way to optimize brain health during aging.

Resveratrol reduces liver endoplasmic reticulum stress and improves insulin sensitivity in vivo and in vitro

Purpose: The aim of the study was to examine the effects of resveratrol upon hepatic endoplasmic reticulum stress (ERS) and insulin sensitivity in vivo and in vitro. Material and methods: C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, and insulin resistance was evaluated by the intraperitoneal glucose tolerance test (IPGTT). Mice were then treated with resveratrol for 12 weeks and blood and liver samples collected. Blood biochemical indicators were determined by kits, liver protein expression was determined by western blot, and morphological changes were observed by histological staining. Palmitic acid (PA)-induced insulin-resistant HepG2 cells were established. Cells were exposed to 100, 50 or 20 μM resveratrol for 24 hrs, and proliferation/cytotoxicity was determined. Cells were divided into five groups: control, PA, PA + Rev (100 μM), PA + Rev (50 μM) and PA + Rev (20 μM) groups. After 24 hrs of treatment, cellular proteins were analyzed the same way as animal tissues. Results: The IPGTT confirmed that the insulin resistance model was established successfully. After resveratrol treatment, fasting blood glucose and cholesterol levels declined and the quantitative insulin sensitivity check index increased. Western-blot results showed that resveratrol-treated HFD mice had reduced hepatic levels of p-PERK, ATF-4 and TRIB3, and increased the levels of ATF-6, p-AKT and p-GSK3β. In the cell model, resveratrol with 100 and 50 μM enhanced ERS and insulin resistance, whereas 20 μM had beneficial effects, similar to the animal model. Conclusion: Resveratrol reduced hepatic ERS, thereby improving insulin sensitivity and glucose levels. However, high doses of resveratrol had harmful effects on cells, elevating ERS and insulin resistance. The safe dose of resveratrol needs further investigation.

Clinical Advances in Immunonutrition and Atherosclerosis: A Review

Atherosclerosis is a chronic low-grade inflammatory disease that affects large and medium-sized arteries and is considered to be a major underlying cause of cardiovascular disease (CVD). The high risk of mortality by atherosclerosis has led to the development of new strategies for disease prevention and management, including immunonutrition. Plant-based dietary patterns, functional foods, dietary supplements, and bioactive compounds such as the Mediterranean Diet, berries, polyunsaturated fatty acids, ω-3 and ω-6, vitamins E, A, C, and D, coenzyme Q10, as well as phytochemicals including isoflavones, stilbenes, and sterols have been associated with improvement in atheroma plaque at an inflammatory level. However, many of these correlations have been obtained in vitro and in experimental animals' models. On one hand, the present review focuses on the evidence obtained from epidemiological, dietary intervention and supplementation studies in humans supporting the role of immunonutrient supplementation and its effect on anti-inflammatory response in atherosclerotic disease. On the other hand, this review also analyzes the possible molecular mechanisms underlying the protective action of these supplements, which may lead a novel therapeutic approach to prevent or attenuate diet-related disease, such as atherosclerosis.