Resveratrol, obesity and diabetes

Attenuation of diabetic retinopathy and neuropathy by resveratrol: Review on its molecular mechanisms of action

Resveratrol is an important phenolic phytochemical from the therapeutic perspective. It has therapeutic impacts over wide range of diseases, especially the ones related to oxidative stress. Resveratrol, being primarily a potent anti-oxidant phytochemical, has significant impact against major diseases as inflammatory disorders, diabetes, and cancer. In the current review article, we intend to highlight the molecular aspects of the mechanism of action of resveratrol against major diabetic implications, namely, retinopathy and neuropathy. Both these diabetic implications are among the first fallouts of chronic hyperglycaemia. Resveratrol, via multiple molecular pathways, tend to attenuate and reverse these deformity and other disease-causing implications.

Efficacy and Safety of Resveratrol in Type 1 Diabetes Patients: A Two-Month Preliminary Exploratory Trial

Resveratrol has been reported to be beneficial against diabetes complications. The objective of this study was to evaluate the efficacy of resveratrol in decreasing hyperglycemia in patients with type 1 diabetes (T1D) by a preliminary investigation designed as an exploratory clinical trial. Thirteen patients with T1D from both the sexes participated in this trial. All patients received resveratrol in 500 mg capsules, twice daily for 60 days. Bodyweight, fasting blood sugar (FBS), hemoglobin A1c (HbA1c), insulin, homeostasis model of assessment for insulin resistance (HOMA-IR), homeostasis model of assessment for β-cell function (HOMA-β), and markers of liver and kidney damage, inflammation, and oxidative stress were measured before the intervention, at 30 days and at 60 days. Resveratrol supplementation for 60 days significantly decreased FBS and HbA1c in comparison with the baseline values. Resveratrol treatment also resulted in a decrease in the level of a marker for oxidative stress, malondialdehyde, and an increase in total antioxidant capacity in T1D patients. Insulin, HOMA-IR, HOMA-β, and markers of liver and kidney function and inflammation were not significantly affected by resveratrol treatment. Overall, the results showed that 60 days of resveratrol supplementation exerted strong antidiabetic and antioxidant effects in patients with T1D.

Natural stilbenes effects in animal models of Alzheimer's disease

Alzheimer’s disease is one of the most frequent neurodegenerative diseases. This pathology is characterized by protein aggregates, mainly constituted by amyloid peptide and tau, leading to neuronal death and cognitive impairments. Drugs currently proposed to treat this pathology do not prevent neurodegenerative processes and are mainly symptomatic therapies. However, stilbenes presenting multiple pharmacological effects could be good potential therapeutic candidates. The aim of this review is to gather the more significant papers among the broad literature on this topic, concerning the beneficial effects of stilbenes (resveratrol derivatives) in animal models of Alzheimer’s disease. Indeed, numerous studies focus on cellular models, but an in vivo approach remains of primary importance since in animals (mice or rats, generally), bioavailability and metabolism are taken into account, which is not the case in in vitro studies. Furthermore, examination of memory ability is feasible in animal models, which strengthens the relevance of a compound with a view to future therapy in humans. This paper is addressed to any researcher who needs to study untested natural stilbenes or who wants to experiment the most effective natural stilbenes in largest animals or in humans. This review shows that resveratrol, the reference polyphenol, is largely studied and seems to have interesting properties on amyloid plaques, and cognitive impairment. However, some resveratrol derivatives such as gnetin C, trans-piceid, or astringin have never been tested on animals. Furthermore, pterostilbene is of particular interest, by its improvement of cognitive disorders and its neuroprotective role. It could be relevant to evaluate this molecule in clinical trials.

Resveratrol alleviates non-alcoholic fatty liver disease through epigenetic modification of the Nrf2 signaling pathway

Recent findings have demonstrated the aberrant DNA methylation of the Nrf2-Keap1 genes in human cancers; however, the epigenetic control of this pathway in non-alcoholic fatty liver disease (NAFLD) is unknown. Resveratrol can modify epigenetic mechanisms. Our objectives in this study were to explore the correlation between promoter methylation of the Nrf2-Keap1 genes and NAFLD, and that investigate the effect of resveratrol on the epigenetic regulation Nrf2-Keap1 in vitro and in vivo models of NAFLD. Resveratrol attenuated high fat-diet (HFD)-induced methylation of the Nrf2 promoter in the liver of mice, and this effect was correlated with reduction in triglyceride level and decrease in the expression of lipogenesis-related genes such as FAS and SREBP-1c. In addition, treatment of HepG2 cells with high glucose (HG) enhanced methylation level of the Nrf2 promoter, whereas resveratrol reversed this effect. Treatment of the cells with resveratrol or 5-aza, a demethylating agent, could prevent HG-induced reactive oxygen species production and expression of Nrf2-controlled antioxidant genes. Moreover, resveratrol or 5-aza could significantly attenuate HG-induced triglyceride accumulation in HepG2 cells. These findings indicate that resveratrol attenuates NAFLD through the epigenetic modification the Nrf2 signaling.

Bioactive Compounds from Norway Spruce Bark: Comparison Among Sustainable Extraction Techniques for Potential Food Applications

Picea abies (L.) Karst, (Norway spruce) bark, generally considered as wood industry waste, could potentially be used as a valuable source of antioxidants for food applications. In this study, supercritical fluid extraction (SFE), pressurized liquid extraction (PLE), and ultrasound-assisted extraction (UAE) were carried out in order to recover bioactive compounds from bark of Norway spruce. Obtained results show that PLE with ethanol as solvent was the most effective method for extracting total flavonoid compounds (21.14 ± 1.42 mg quercetin g⁻¹ sample) and consequently exerted the highest antioxidant activity measured by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (257.11 ± 13.31 mg Trolox g⁻¹ sample). On the other hand, UAE extract contained the maximum phenolic concentration (54.97 ± 2.00 mg gallic acid g⁻¹ sample) and the most interesting antioxidant activity measured by the ferric-reducing antioxidant power (580.25 ± 25.18 µmol FeSO₄ g⁻¹ sample). Additionally, PLE and UAE have demonstrated great efficiency in the extraction of trans-resveratrol, quantified by HPLC (0.19 and 0.29 mg trans-RSV g⁻¹ sample, respectively).

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

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

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

Strategies to Improve Resveratrol Systemic and Topical Bioavailability: An Update

In recent years, a great deal of attention has been paid to natural compounds due to their many biological effects. Polyphenols are a class of plant derivatives that have been widely investigated for preventing and treating many oxidative stress-related pathological conditions, such as neurodegenerative and cardiovascular diseases, cancer, diabetes mellitus and inflammation. Among these polyphenols, resveratrol (RSV) has attracted considerable interest owing to its high antioxidant and free radical scavenging activities. However, the poor water solubility and rapid metabolism of RSV lead to low bioavailability, thus limiting its clinical efficacy. After discussing the main biochemical mechanisms involved in RSV biological activities, this review will focus on the strategies attempted to improve RSV effectiveness, both for systemic and for topical administration. In particular, technological approaches involving RSV incorporation into different delivery systems such as liposomes, polymeric and lipid nanoparticles, microemulsions and cyclodextrins will be illustrated, highlighting their potential clinical applications. In addition, chemical modifications of this antioxidant aimed at improving its physicochemical properties will be described along with the results of in vitro and in vivo studies.

Resveratrol shifts energy metabolism to increase lipid oxidation in healthy old mice

OBJECTIVES

The objective of this work was to determine the specific mechanisms by which resveratrol inhibits lipogenesis and stimulates lipolysis.

METHODS

Twelve male mice were individually introduced into a metabolic cage for 24 h to measure basal metabolic rate, prior to intervention. They were randomly divided into two groups, resveratrol (RSV) and control (C), and administered resveratrol intraperitoneally or vehicle, respectively, for two consecutive days. After 24 h, the metabolic energy expenditure was again determined for 24 h, before mice were sacrificed. Protein and gene expression of different enzymes related to metabolism in the hepatic tissue, adipose tissue and gastrocnemius of mice were analyzed by RT-PCR, western blot or ELISA.

RESULTS

We report that resveratrol lowers the respiratory quotient in old mice and that this may be due to the activation of fatty acid mobilization from white adipose tissue (because hormone-activated lipase expression is increased) and fatty acid transport into mitochondria and eventual oxidation in muscle and liver (because transport enzymes and beta oxidation enzymes are also increased). Indeed, we have observed that resveratrol in vivo causes an increase in the expression and phosphorylation of AMPKα in liver, muscle and adipose tissue and an increase in the expression of acyl-CoA synthetase, of carnitine palmitoyl transferase 1 and of carnitine acylcarnitine translocase, all enzymes involved in lipid catabolism. On the other hand, the levels of acetyl-CoA carboxylase as well as those its product, i.e. malonyl CoA, are decreased.

CONCLUSIONS

We conclude that a controlled dose of resveratrol activates fatty acid mobilization and degradation and inhibits fatty acid synthesis in old mice. This is the first time that these effects of resveratrol in lipid metabolism in healthy old (non-obese) animals are reported.

Impact of resveratrol supplementation on inflammatory, antioxidant, and periodontal markers in type 2 diabetic patients with chronic periodontitis

BACKGROUND

Diabetes mellitus and periodontal disease are two common and chronic diseases with bidirectional relationship influence public health and quality of life. The aims of this study was to study the impact of resveratrol supplementation in adjunct with non-surgical periodontal therapy on inflammatory, antioxidant, and periodontal markers in patients with type 2 diabetes with periodontal disease.

MATERIALS AND METHODS

In this randomized clinical trial, 43 patients with diabetes and chronic periodontitis were randomly allocated into two intervention and control groups receiving either resveratrol supplements or placebo for 4 weeks. Serum levels of interleukin 6 (IL6), tumor necrosis factor α (TNFα), total antioxidant capacity (TAC) and clinical attachment loss (CAL) as the main index of periodontal marker were measured pre-intervention and post-intervention.

RESULTS

In the intervention group, the mean serum level of IL6 was reduced significantly (P = 0.039) post-intervention (2.19 ± 1.09 and 1.58 ± 1.06). No significant differences were seen in the mean levels of IL6, TNFα, TAC and CAL between two groups post-intervention.

CONCLUSIONS

It is suggested that daily consumption of resveratrol supplement may not change TNFα, TAC and CAL, but it would be beneficial in reducing serum levels of IL6. Therefore, further studies are suggested to investigate the effects of resveratrol supplementation along with NST on periodontal status.

Development of microparticles for controlled release of resveratrol to adipose tissue and the impact of drug loading on particle morphology and drug release

Resveratrol is a small molecule produced by various plants with a remarkable range of beneficial functions in animals. One of these is stimulating signaling pathways in adipose tissue that protect against obesity. Unfortunately, resveratrol suffers from poor bioavailability that inhibits its accumulation in target tissues, including fat, thus hindering the realization of its therapeutic potential. To address this, we are developing biodegradable microparticles as drug depots for controlled release of resveratrol within fat. In this study, resveratrol was encapsulated into poly(lactide-co-glycolide) microparticles using an oil-in-water emulsion/solvent evaporation technique. The oil phase consisted of resveratrol and poly(lactide-co-glycolide) dissolved in a mixture of dichloromethane and ethanol; meanwhile, the aqueous phase contained poly(vinyl alcohol) as the emulsifier. Increasing ethanol's volume ratio increased resveratrol's solubility in the oil phase and particle drug loading. The maximal loading achieved was 65 µg/mg (6.5%) and occurred when the ethanol to dichloromethane ratio was 1:3. Under these conditions, particles exhibited ruffled surfaces, which resulted in variable drug release over the first three days of a six-week release assay. By decreasing resveratrol and ethanol in the oil phase and increasing poly(vinyl alcohol) in the aqueous phase, smooth particles were achieved, but they suffered a 15-25-fold decrease in drug loading depending on size. Small particles exhibited higher drug loading and burst drug release compared to larger particles because of their higher specific surface area. Utilizing mild chemistry, we functionalized poly(vinyl alcohol) with fluorescein isothiocyanate and demonstrated that encapsulation of resveratrol in the particle decreases the amount of fluorescent polymer on the particle surface, suggesting resveratrol displaces the emulsifier during particle formation. Taken together, resveratrol can be encapsulated into poly(lactide-co-glycolide) microparticles, but it accumulates at the particle surface impacting drug loading, surface roughness, and drug release.

An Efficient Synthesis of Deoxyrhapontigenin-3-O-β-D-glucuronide, a Brain-targeted Derivative of Dietary Resveratrol, and its Precursor 4'-O-Me-Resveratrol

Bioactive dietary polyphenols have health benefits against a variety of disorders, but some benefits of polyphenols may be not directly related to them, but rather to their metabolites. Recently, we have identified the brain-available phenol glucuronide metabolite deoxyrhapontigenin-3-O-β-D-glucuronide (5) in perfused rat brains following sub-acute treatment with the stilbene resveratrol (1). However, the role of such a metabolite in the neuroprotective activity of resveratrol (1) is not understood, in part due to the non-commercial availability of 5 for performing biological evaluation in animal models of Alzheimer's disease or other neurological disorders. Here, we describe a concise chemical synthesis of deoxyrhapontigenin-3-O-β-D-glucuronide (5) and its precursor, 4-O-Me-resveratrol (2), accomplished in 4 and 6 steps with 74% and 21% overall yields, respectively, starting from commercially available 3,5-dihydroxybenzaldehyde. Pivotal reactions employed in the synthesis include the palladium-catalyzed C-C coupling between 3,5-di-tert-butyldiphenylsilyloxystyrene and p-iodoanisole in the presence of tributylamine and the acid-catalysed glucuronidation between the trichloroacetimidate-activated glucuronic acid and 4-O-Me-resveratrol.

Fabrication of resveratrol coated gold nanoparticles and investigation of their effect on diabetic retinopathy in streptozotocin induced diabetic rats

This study includes the fabrication of gold nanoparticles (AuNPs) with the help of a plant polyphenol called Resveratrol through an ecofriendly synthetic process without any use of harmful reductants. In the fabrication of AuNPs, Resveratrol acts as both stabilizing and reducing agent. The prepared AuNPs is tested on streptozotocin (STZ) induced diabetic rats for their amelioration consequence. The images of TEM displayed the development of spherical nanoparticles (NPs) with a median of 20 nm particle size. The STZ injected diabetic rats were administrated orally with calcium dobesilate (CD; 500 mg/kg/day) or AuNPs (200, 300 mg/kg/day) for a period of 3 months. The characteristics displayed by AuNPs were found to be similar with CD in decreasing permeability of blood-retinal barrier in STZ injected diabetic rats. The retinal vessels in the AuNPs administrated diabetic rats were observed to be decreased through the retinal histopathological examination. In the AuNPs administrated diabetic rats, the retinal expression of renal Pigment Epithelium-Derived Factor (PEDF) was observed to be increased and the Vascular Endothelial Growth Factor (VEGF-1), which was increased in diabetic rats was declined on treating with AuNPs. On treating the STZ injected diabetic rats with AuNPs, all the retinal mRNA expressions of VEGF-1, Tumor Necrosis Factor (TNFα), Monocyte Chemotactic Proteins-1 (MCP-1), Intercellular Adhesion Molecule-1 (ICAM-1), and Interleukin (IL)-6, IL-1β were observed to be reduced. Furthermore, AuNPs can reduce phosphorylation of Nuclear Factor Kappa B (NF-κB) p65 and Extracellular signal Regulated Kinase (ERK) 1/2 along with a growth in nuclear translocation of pNF-κB p65 produced by STZ. To conclude, the protective effect of AuNPs on STZ injected diabetic rats could help in redeveloping the balance among the inhibitors and stimulators of angiogenesis. Furthermore, on treating with AuNPs results in inhibiting the signaling pathway of ERK1/2 as well as with amelioration of retinal inflammation through trans repression of NF-κB.

Nanoencapsulation of functional food ingredients

Many functional food ingredients are poorly soluble in water, susceptible to chemical degradation, and incompatible with surrounding food matrix. Other issues are related to limited oral bioavailability, unpleasant sensory properties, and poor release profiles. Nanoencapsulation of functional food ingredients can help increase their water solubility/dispersibility in foods and beverages, improve their bioavailability by exhibiting good dose-dependent functionalities, mask undesired flavors/tastes to reduce the adverse effect on mouth-feel, enhance shelf-life and compatibility during production, storage, transportation and utilization of food products, and control release rate or specific delivery environment for better performance on their functionalities. This chapter provides an overview of different delivery systems for different functional food ingredients, the types of materials suitable for wall materials or building blocks of nanocapsules, the fabrication methods to assemble different delivery systems and release these active ingredients under different physiological conditions.

Resveratrol Anti-Obesity Effects: Rapid Inhibition of Adipocyte Glucose Utilization

Studies in animal models of diabetes and obesity have shown that resveratrol mitigates complications of metabolic diseases, beyond those resulting from oxidative stress. Furthermore, results obtained with cultured preadipocytes have also revealed that prolonged resveratrol treatment impairs adipogenesis. Considering the role of adipocytes in the hypertrophy of fat stores, and keeping in mind that insulin is the main trigger of excessive energy storage during post-prandial periods, the present study aimed to investigate how short-term effects of resveratrol can limit glucose disposal in a gut-adipose tissue axis. We found that resveratrol exhibits a more potent inhibitory capacity towards α-glucosidase than pancreatic lipase activity. Resveratrol also rapidly blunts glucose transport in mature fat cells by counteracting the effect of insulin and insulin-like lipogenic agents. Within two hours, resveratrol also inhibited the incorporation of glucose into lipids of adipocytes, which was unaffected by membrane cholesterol depletion. Moreover, the comparison between adipocytes with invalidated semicarbazide-sensitive amine oxidase activity and their control, or between resveratrol and several inhibitors, did not indicate that the recently described interaction of resveratrol with amine oxidases was involved in its antilipogenic effect. Caffeine and piceatannol, previously said to interact with glucose carriers, also inhibit lipogenesis in adipocytes, whereas other antioxidant phytochemicals do not reproduce such an antilipogenic effect. This study highlights the diverse first steps by which resveratrol impairs excessive fat accumulation, indicating that this natural molecule and its derivatives deserve further studies to develop their potential anti-obesity properties.

Resveratrol inhibits cancer cell proliferation by impairing oxidative phosphorylation and inducing oxidative stress

The resveratrol (RSV) efficacy to affect the proliferation of several cancer cell lines was initially examined. RSV showed higher potency to decrease growth of metastatic HeLa and MDA-MB-231 (IC₅₀ = 200-250 μM) cells than of low metastatic MCF-7, SiHa and A549 (IC₅₀ = 400-500 μM) and non-cancer HUVEC and 3T3 (IC₅₀≥600 μM) cells after 48 h exposure. In order to elucidate the biochemical mechanisms underlying RSV anti-cancer effects, the energy metabolic pathways and the oxidative stress metabolism were analyzed in HeLa cells as metastatic-type cell model. RSV (200 μM/48 h) significantly decreased both glycolysis and oxidative phosphorylation (OxPhos) protein contents (30-90%) and fluxes (40-70%) vs. non-treated cells. RSV (100 μM/1-5 min) also decreased at a greater extent OxPhos flux (net ADP-stimulated respiration) of isolated tumor mitochondria (> 50%) than of non-tumor mitochondria (< 50%), particularly with succinate as oxidizable substrate. In addition, RSV promoted an excessive cellular ROS (2-3 times) production corresponding with a significant decrement in the SOD activity (but not in its content) and GSH levels; whereas the catalase, glutahione reductase, glutathione peroxidase and glutathione-S-transferase activities (but not their contents) remained unchanged. RSV (200 μM/48 h) also induced cellular death although not by apoptosis but rather by promoting a strong mitophagy activation (65%). In conclusion, RSV impaired OxPhos by inducing mitophagy and ROS over-production, which in turn halted metastatic HeLa cancer cell growth.

Health benefits of resveratrol: Evidence from clinical studies

Resveratrol is a polyphenolic nutraceutical that exhibits pleiotropic activities in human subjects. The efficacy, safety, and pharmacokinetics of resveratrol have been documented in over 244 clinical trials, with an additional 27 clinical trials currently ongoing. Resveretrol is reported to potentially improve the therapeutic outcome in patients suffering from diabetes mellitus, obesity, colorectal cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The polyphenol is reported to be safe at doses up to 5 g/d, when used either alone or as a combination therapy. The molecular basis for the pleiotropic activities of resveratrol are based on its ability to modulate multiple cell signaling molecules such as cytokines, caspases, matrix metalloproteinases, Wnt, nuclear factor-κB, Notch, 5'-AMP-activated protein kinase, intercellular adhesion molecule, vascular cell adhesion molecule, sirtuin type 1, peroxisome proliferator-activated receptor-γ coactivator 1α, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, Ras association domain family 1α, pAkt, vascular endothelial growth factor, cyclooxygenase 2, nuclear factor erythroid 2 like 2, and Kelch-like ECH-associated protein 1. Although the clinical utility of resveratrol is well documented, the rapid metabolism and poor bioavailability have limited its therapeutic use. In this regard, the recently produced micronized resveratrol formulation called SRT501, shows promise. This review discusses the currently available clinical data on resveratrol in the prevention, management, and treatment of various diseases and disorders. Based on the current evidence, the potential utility of this molecule in the clinic is discussed.

Effects of dietary resveratrol supplementation during gestation and lactation of sows on milk composition of sows and fat metabolism of sucking piglets

The purpose of this article was to investigate the effects of dietary resveratrol supplementation during gestation and lactation of sows on the milk composition of sows and the fat metabolism of sucking piglets. Forty sows were allotted to two experimental treatment groups that included the following: (a) control sows (CON treatment, n = 20) fed with a corn-soybean meal control diet and (b) treatment sows (RES treatment, n = 20) fed with a control diet with addition of 300 mg/kg resveratrol. The results showed that the content of lactose in the colostrum was increased (p < 0.05) and the content of fat in 21-day milk was increased (p < 0.05) by dietary resveratrol supplementation. In the RES treatment group, the concentrations of high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), lipase activity and insulin (INS) in plasma of sucking piglets were increased (p < 0.05). In the adipose tissue, the enzyme activities of hormone-sensitive lipase (HSL), acetyl-CoA carboxylase (ACC) and lipoprotein lipase (LPL) increased significantly by RES treatment (p < 0.05), and the mRNA levels of acetyl coenzyme A-alpha (ACCα), LPL, fatty acid transport protein (FATP1) and CCAAT-enhancer-binding protein gene (C/EBPα) were higher in the RES treatment group (p < 0.05). In conclusion, resveratrol supplementation on gestational and lactating sows improved the content of lactose in the colostrum and the content of fat in milk at day 21 of lactation. In addition, resveratrol supplementation on sows increased HDL and LDL in the plasma of piglets. In piglet adipose tissue, the enzyme activity and mRNA level related to lipolysis, fatty acid uptake from circulating triacylglycerols and lipogenesis are partially improved by resveratrol supplementation on sows. These aspects affect fat metabolism in piglets.

Establishment of an adult zebrafish model of retinal neurodegeneration induced by NMDA

AIM

To establish a model of retinal neurodegeneration induced by N-Methyl-D-aspartic acid (NMDA) in adult zebrafish.

METHODS

We compared the effects of three different NMDA delivery methods on retinal neurodegeneration in adult zebrafish: immersion (I.M.), intravitreal injection (I.V.), and intraperitoneal injection (I.P.), and examined retinal pathology and degeneration by hematoxylin and eosin and TUNEL staining in the treated zebrafish. Effects of the NMDA receptor antagonist MK-801 and the natural product resveratrol on NMDA-induced retinal neurodegeneration were also assessed.

RESULTS

The thickened inner retina was seen in histology with 100 µmol/L NMDA by I.M. administration. Significant apoptosis in the retinal ganglion cell layer and retinal thickness reduction occurred in 0.5 mol/L NMDA I.P. administration group.Seizure-like behavioral changes, but no retinal histological alteration occurred in 16 mg/kg NMDA I.P. administration group. Resveratrol and MK-801 prevented NMDA-induced retinal neurodegeneration in the zebrafish.

CONCLUSION

Among the three drug administration methods, I.V. injection of NMDA is the most suitable for establishment of an acute retinal damage model in zebrafish. I.M. with NMDA is likely the best for use as a chronic retinal damage model. I.P. treatment with NMDA causes brain damage. Resveratrol and MK801 may be a clinically valuable treatment for retinal neurodegeneration.

Modulation of Renal Insulin Signaling Pathway and Antioxidant Enzymes with Streptozotocin-Induced Diabetes: Effects of Resveratrol

Background and objectives: Diabetes mellitus is a disease of insulin deficiency or its inability of usage by the target tissues leading to impairment of carbohydrate, lipid, and protein metabolisms. Resveratrol, having robust anti-inflammatory and anti-oxidant properties, has a high potential to treat or prevent the pathogenesis of diseases. This study was conducted to reveal the relationship between diabetes-induced oxidative stress and tissue inflammation with changes in main enzymatic antioxidants (cat, sod, gpx, and gst) and the components of the insulin signaling pathway (insulin Rβ, irs-1, pi3k, akt, mtor) in kidney tissues. Additionally, the effects of resveratrol on these parameters were evaluated. Materials and Methods: Male Wistar rats were randomly divided into four groups; (1) control/vehicle; (2) control/20 mg/kg resveratrol; (3) diabetic/vehicle; (4) diabetic/20 mg/kg resveratrol. Gene and protein expressions of antioxidant enzymes and insulin signaling elements were evaluated in renal tissues. Results: Downregulation of antioxidant enzymes’ gene expression in the kidney tissues of diabetic rats was demonstrated and this situation was devoted partially to the reduced gene expression of nfκb. Moreover, the components of renal insulin signaling elements were upregulated at both gene and protein expression levels in diabetic rats, and resveratrol treatment decreased this sensitization towards the control state. Conclusion: Resveratrol partially improved diabetes-induced renal oxidative stress and inflammation due to healing action on renal antioxidant enzymes and insulin signaling pathway components.

Influence of trans-resveratrol on macrophage and lymphocyte activity in rainbow trout (Oncorhynchus mykiss) - in vitro study

The objective of this study was to investigate the effect of trans-resveratrol, a potent antioxidant with anti-inflammatory and chemopreventive properties, naturally occurring in many fruits and plants on lymphocytes proliferation and also on macrophages metabolic and phagocytic activity. The aim of this study was to demonstrate the immunomodulatory effects of the compound on fish immunocompetent cells and determine the type of this interaction (immunosuppression or immunostimulation). Proliferative activity of lymphocytes was studied by MTT assay, and the respiratory burst was evaluated using the respiratory burst activity (RBA) test. Phagocytic killing was tested using the PKA test. The experiment have shown that trans-resveratrol suppressed blood B cells, while there was no significant influence on blood T lymphocytes. However, insignificant stimulatory effect occurred at the lowest concentration. In addition, the compound inhibited proliferation of T and B lymphocytes isolated from the organs. Importantly, trans-resveratrol caused stimulation of blood and organs macrophages phagocytic killing, and also increased the respiratory burst of macrophages isolated from organ. These results suggest a potential use of trans-resveratrol as an immunomodulator of innate immunity in fish. This is particularly important, as this kind of resistance plays leading role in protecting the body against infection. In comparison, adaptive immunity is slower and also much less precise.

Oxyresveratrol Increases Energy Expenditure through Foxo3a-Mediated Ucp1 Induction in High-Fat-Diet-Induced Obese Mice

The phytochemical oxyresveratrol has been shown to exert diverse biological activities including prevention of obesity. However, the exact reason underlying the anti-obese effects of oxyresveratrol is not fully understood. Here, we investigated the effects and mechanism of oxyresveratrol in adipocytes and high-fat diet (HFD)-fed obese mice. Oxyresveratrol suppressed lipid accumulation and expression of adipocyte markers during the adipocyte differentiation of 3T3-L1 and C3H10T1/2 cells. Administration of oxyresveratrol in HFD-fed obese mice prevented body-weight gains, lowered adipose tissue weights, improved lipid profiles, and increased glucose tolerance. The anti-obese effects were linked to increases in energy expenditure and higher rectal temperatures without affecting food intake, fecal lipid content, and physical activity. The increased energy expenditure by oxyresveratrol was concordant with the induction of thermogenic genes including Ucp1, and the reduction of white adipocyte selective genes in adipose tissue. Furthermore, Foxo3a was identified as an oxyresveratrol-induced gene and it mimicked the effects of oxyresveratrol for induction of thermogenic genes and suppression of white adipocyte selective genes, suggesting the role of Foxo3a in oxyresveratrol-mediated anti-obese effects. Taken together, these data show that oxyresveratrol increases energy expenditure through the induction of thermogenic genes in adipose tissue and further implicates oxyresveratrol as an ingredient and Foxo3a as a molecular target for the development of functional foods in obesity and metabolic diseases.

Reduced sirtuin 1/adenosine monophosphate-activated protein kinase in amyotrophic lateral sclerosis patient-derived mesenchymal stem cells can be restored by resveratrol

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neuron system. Our previous study has shown that bone marrow-mesenchymal stem cells (BM-MSCs) from ALS patients have functional limitations in releasing neurotrophic factors and exhibit the senescence phenotype. In this study, we examined sirtuin 1/adenosine monophosphate-activated protein kinase (SIRT1/AMPK) activities and identified significant decreases in the ALS-MSCs compared with normal healthy control originated BM-MSCs. This decline was restored by pretreatment with resveratrol (RSV), measured using quantitative polymerase chain reaction, NAD/NADH assay, and immunoblot analysis. Neuroprogenitor markers were increased in RSV-treated ALS-MSCs (RSV/ALS-MSCs). The differentiated ALS-MSCs (ALS-dMSCs) exhibited a cell body and dendritic shape similar to neurons. RSV/ALS-MSCs showed significantly increased differentiation rate as compared with the untreated ALS-dMSCs. The neurite numbers and lengths were also significantly increased. This was confirmed with immunoblot analysis using neuron specific markers such as nestin, NF-M, Tuj-1, and Map-2 in RSV/ALS-dMSCs. Thus, this study shows that ALS-MSCs showed down-regulation of AMPK/SIRT1 signalling, which was recovered by treatment with RSV. This data suggest that RSV can be one of the candidate agents for improving therapeutic efficacy of ALS patients' originated MSCs.

Resveratrol: from enhanced biosynthesis and bioavailability to multitargeting chronic diseases

Resveratrol, a phytoalexin with a wide range of pharmacological properties is synthesised by plants in response to stress, injury, infection or UV radiations. As it is a secondary metabolite with many health promoting properties, various methods employing microorganisms and genetic manipulation of different synthetic enzymes, have been comprehensively studied to increase its production. Its rapid metabolism and low bioavailability have been addressed by the use of bio enhancers and nano-formulations. This flavonoid is extensively researched due to its pharmacological properties such as anti-oxidative, anti-inflammatory and immuno-modulating effects. Knowledge of these properties of resveratrol has led to elaborate studies on its effect on diabetes, neurodegenerative diseases, cancer, ageing, obesity and cardiovascular diseases. At molecular level it targets sirtuin, adenosine monophosphate kinase, nuclear Factor-κB, inflammatory cytokines, anti-oxidant enzymes along with cellular processes such as angiogenesis, apoptosis, mitochondrial biogenesis, gluconeogenesis and lipid metabolism. This review discusses the properties of resveratrol and the different approaches of addressing the unfavourable synthesis and pharmacokinetics of this stilbene. Pre-clinical evaluations of resveratrol on diabetes mellitus, cardiovascular and neurological diseases are elaborately discussed and the underlying pathways involved in its therapeutic activity have been given paramount importance. Following the pre-clinical studies, clinical trials on the same reveal the efficacy of resveratrol in the effective management of these diseases. This review provides an intricate insight on resveratrol's significance from a dietary component to a therapeutic agent.

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

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

The Effects of Resveratrol, Metformin, Cold and Strength Training on the Level of Perilipin 5 in the Heart, Skeletal Muscle and Brown Adipose Tissues in Mouse

The high accumulation of lipid droplets in the cell is related to metabolic disorders, such as obesity. Perilipin 5 (Plin5), plays an important role in triglyceride hydrolysis in the lipid droplets. In this study, this protein has been evaluated in different tissues and conditions in mice. Fifty male mice were divided into 5 groups and treated for 45 days with Resveratrol, Metformin, strength training, and 4 °C cold. Brown adipose tissue (BAT), gastrocnemius skeletal muscle and heart were isolated for RNA extraction. The Plin5 gene expression was evaluated, using Real-Time PCR, and the plin5 was analyzed at the protein level, using western blot. In BAT, Resveratrol significantly reduced the plin5 protein level and gene expression (p < 0.05). In heart tissue, Resveratrol and strength training, decreased (p < 0.05) the plin5 expression, but Metformin increased the gene expression (p < 0.05). In skeletal muscle, resveratrol, strength training, cold and Metformin significantly increased the plin5 expression at the gene and protein level (p < 0.05). In BAT, Resveratrol has a greater effect in decreasing lipid deposits, compared with the strength training and cold; thus, it can play a better role in preventing lipid accumulation. In heart tissue, Resveratrol probably decreases insulin resistance, due to the increased expression of plin5 in skeletal muscle.

Relationship between Mediterranean Dietary Polyphenol Intake and Obesity

Obesity is a multifactorial and complex disease defined by excess of adipose mass and constitutes a serious health problem. Adipose tissue acts as an endocrine organ secreting a wide range of inflammatory adipocytokines, which leads to systemic inflammation, insulin resistance, and metabolic disorders. The traditional Mediterranean diet is characterized by a high phenolic-rich foods intake, including extra-virgin olive oil, nuts, red wine, vegetables, fruits, legumes, and whole-grain cereals. Evidence for polyphenols’ effect on obesity and weight control in humans is inconsistent and the health effects of polyphenols depend on the amount consumed and their bioavailability. The mechanisms involved in weight loss in which polyphenols may have a role are: activating β-oxidation; a prebiotic effect for gut microbiota; inducing satiety; stimulating energy expenditure by inducing thermogenesis in brown adipose tissue; modulating adipose tissue inhibiting adipocyte differentiation; promoting adipocyte apoptosis and increasing lipolysis. Even though the intake of some specific polyphenols has been associated with body weight changes, there is still no evidence for the effects of total polyphenols or some polyphenol subclasses in humans on adiposity.

Preventative effects of resveratrol and estradiol on streptozotocin-induced diabetes in ovariectomized mice and the related mechanisms

Resveratrol, a non-flavonoid polyphenolic compound, is structurally and functionally similar to estrogen and has drawn great attention for its potentially beneficial effects on diabetes. However, it is not known whether it shares the same protective effect against diabetes as estrogen and the underlying mechanisms. The aim of the present study was to investigate the protective effects of phytoestrogen resveratrol and exogenous 17β-estradiol against streptozotocin (STZ)-induced type 1 diabetes. Female mice were ovariectomized (OVX) and chronically injected with different concentrations of resveratrol (0.1, 1 or 10 mg/kg) and 17β-estradiol (0.01, 0.1 or 1 mg/kg) subcutaneously for 4 weeks, and the levels of blood glucose, plasma insulin, plasma antioxidant capacity, the changes of pancreatic islet cells and the expressions of glucose transporter 4 (GLUT4), insulin receptor substrate 1 (IRS-1) and phosphorylation of extracellular signal-regulated kinase (p-ERK) were detected. Resveratrol and 17β-estradiol significantly inhibited the increase of the blood glucose level and the rise of plasma malondialdehyde in STZ-induced diabetic mice, improved the levels of plasma antioxidant capacity and plasma insulin, protected the pancreatic islet cells, and increased the expressions of GLUT4 and IRS-1, but decreased p-ERK expression in skeletal muscle and myocardial tissue. The results suggest that resveratrol or 17β-estradiol shows obvious protection against STZ-induced diabetes in OVX mice, the mechanisms probably involve their ameliorating antioxidant activities and islet function, promoting muscle glucose uptake and inhibiting the expression of p-ERK.

Ultrasound-assisted extraction of resveratrol from grape leaves and its purification on mesoporous carbon

Resveratrol has been extracted from grape leaves by ultrasound-assisted extraction with aqueous ethanol and further concentrated on a column of mesoporous carbon. The ethanol concentration, extraction temperature, solid/liquid ratio, and extraction time have been investigated, and the extraction kinetics has been studied. After one treatment run with mesoporous carbon, the resveratrol purity was improved from 2.1 to 20.6%. The antioxidant activities of grape leaf extracts before and after concentration have been analyzed. Mesoporous carbon has been applied in the purification of resveratrol from grape leaves for the first time, and it is shown to offer a promising procedure in this field. Grape leaf is a promising material for the extraction of resveratrol, which shows antioxidant properties.

Resveratrol and Pterostilbene, Two Analogue Phenolic Compounds, Affect Aquaglyceroporin Expression in a Different Manner in Adipose Tissue

Aquaglyceroporins (AQPs) are transmembrane channels that mediate glycerol release and glycerol uptake. They are involved in fat metabolism, with implications in obesity. The aim was to determine whether the administration of resveratrol and pterostilbene during the six weeks of the experimental period would modify AQPs expression in white and brown adipose tissues from Wistar rats fed an obesogenic diet, and to establish a potential relationship with the delipidating properties of these compounds. Consequently, thirty-six rats were divided into four groups: (a) group fed a standard diet; and three more groups fed a high-fat high-sucrose diet: (b) high-fat high-sucrose group: (c) pterostilbene-treated group (30 mg/kg/d): (d) resveratrol-treated group (30 mg/kg/d). Epididymal, subcutaneous white adipose tissues and interscapular brown adipose tissue were dissected. AQPs gene expression (RT-PCR) and protein expression (western-blot) were measured. In white adipose tissue, pterostilbene reduced subcutaneous adipose tissue weight and prevented the decrease in AQP9 induced by obesogenic feeding, and thus glycerol uptake for triglyceride accumulation. Resveratrol reduced epididymal adipose tissue weight and avoided the decrease in AQPs related to glycerol release induced by high-fat high-sucrose feeding, suggesting the involvement of lipolysis in its body-fat lowering effect. Regarding brown adipose tissue, AQP7 seemed not to be involved in the previously reported thermogenic activity of both phenolic compounds.

Influence of the periprostatic adipose tissue in obesity-associated mouse urethral dysfunction and oxidative stress: Effect of resveratrol treatment

Obese mice display overactive bladder (OAB) associated with impaired urethra smooth muscle (USM) function. In this study, we evaluated the role of the adipose tissue surrounding the urethra and prostate in obese mice (here referred as periprostatic adipose tissue; PPAT) to the USM dysfunction. Male C57BL6/JUnib mice fed with either a standard-chow or high-fat diet to induce obesity were used. In PPAT, histological analysis, and qPCR analysis for gp91phox, tumor necrosis factor-α (TNF-α) and superoxide dismutase (SOD) were conducted. In USM, concentration-response curves to contractile and relaxing agents, as well as measurements of reactive-oxygen species and nitric oxide (NO) levels were performed. The higher PPAT area in obese mice was accompanied by augmented gp91phox (NOX2) and TNF-α expressions, together with decreased SOD1 expression. In USM of obese group, the contractile responses to phenylephrine and vasopressin were increased, whereas the relaxations induced with glyceryl trinitrate were reduced. The reactive-oxygen species and NO levels in USM of obese mice were increased and decreased, respectively. A higher SOD expression was also detected in obese group whilst no changes in the gp91phox levels were observed. We next evaluated the effects of the antioxidant resveratrol (100 mg/kg/day, two-weeks, PO) in the functional alterations and NO levels of obese mice. Resveratrol treatment in obese mice reversed both the functional USM dysfunction and the reduced NO production. Our data show that PPAT exerts a local inflammatory response and increases oxidative stress that lead to urethral dysfunction. Resveratrol could be an auxiliary option to prevent obesity-associated urethral dysfunction.

Detection of resveratrol by phosphorescence quantum dots without conjunction and mutual impact exploration

In this study, a convenient and sensitive method for the detection of resveratrol was established based on phosphorescence quenching of resveratrol for MPA-capped Mn:ZnS QDs. The quenching intensity was in proportion to the concentration of resveratrol within a certain range. Under optimal conditions, the present assay was valid for detecting resveratrol in the range from 0.03 μM to 14 μM with a detection limit of 0.01 μM. The mechanism of action was also explored, and its application in actual samples was also demonstrated with satisfactory results. This study aims to provide a convenient method for the detection of resveratrol.

Effect of resveratrol and metformin on ovarian reserve and ultrastructure in PCOS: an experimental study

Background

PCOS is a reproductive hormonal abnormality and a metabolic disorder. It is frequently associated with insulin resistance, hyperandrogenism, chronic inflammation, and oxidative stress. We aim to investigate the potential therapeutic effects of combined therapy of resveratrol and metformin on polycystic ovaries via SIRT1 and AMPK activation.

Methods

Wistar albino rats were divided into control and experimental (PCOS) groups. DHEA-induced PCOS rats were given resveratrol (20 mg/kg/day), metformin (300 mg/kg/day) and combined therapy. At the end of the experiment, the body and ovarian weight of rats were measured and blood samples were analyzed for FSH, LH, testosterone, AMH, TNF-α and MDA levels. Histopathological evaluation of ovaries were carried out by light and electron microscopy. SIRT1 and AMPK immunreactivity and TUNEL assay were scored. Data were statistically analyzed by SPSS programme.

Results

Metformin and combined treatment groups reduced the body and ovary weights compared to the PCOS group. Serum testosterone levels were significantly higher in the PCOS group than in the control group and this was reduced when PCOS was treated with all but especially resveratrol. All the treatment groups decreased LH, LH/FSH, TNF-α and tissue AMH levels which were induced in the PCOS group, whereas metformin was unable to improve the increased MDA and plasma AMH levels. Treatment with resveratrol and/or metformin ameliorated the elevated number of secondary and atretic follicles and the decreased number of Graafian follicles in the PCOS group, which indicates the effect of the treatments on the maintenance of folliculogenesis. Light and electron microscopic findings supported the analysis of follicular count. Increased number of TUNEL (+) granulosa cells in the PCOS group were reduced significantly in the treatment groups. Resveratrol and metformin increased SIRT1 and AMPK immunreactivity, respectively, compared to the PCOS group.

Conclusions

The results suggest that combined therapy of metformin and resveratrol may improve the weight gain, hormone profile and ovarian follicular cell architecture by inducing antioxidant and antiinflammatory systems via SIRT1 and AMPK activation in PCOS.

Supplementation with resveratrol as Polygonum cuspidatum Sieb. et Zucc. extract induces changes in the excretion of urinary markers associated to aging in rats

An UPLC-HR-MS metabolomics approach was used to study the effects of a 49-days oral supplementation with Polygonum cuspidatum extract in healthy rats. Multivariate analysis allowed to observe significant differences in the excretion of several markers between treated animals and control group. Among the others, the amounts of N-methyl-2-pyridone-5-carboxamide (2PY) and phenylacetylglycine (PAG) were reduced in the treated group compared to control. These compounds have been previously considered as markers of aging. Furthermore, the excretion of 3-hydroxysebacic acid and 4,6-dihydroxyquinoline was also changed following supplementation, although not significantly. Despite the relatively short time of treatment (7 weeks), the significant changes in the urinary levels of aging markers observed at day 49 suggests a potential role of this type of studies as a new approach in the evaluation of the anti-aging effects of plant extracts.

Switching from high-fat diet to foods containing resveratrol as a calorie restriction mimetic changes the architecture of arcuate nucleus to produce more newborn anorexigenic neurons

PURPOSE

These days, obesity threatens the health for which one of the main interventions is calorie restriction (CR). Due to the difficulty of compliance with this treatment, CR mimetics such as resveratrol (RSV) have been considered. The present study compared the effects of RSV and CR on hypothalamic remodeling in a diet-switching experiment.

METHODS

C57BL/6 male mice received high-fat diet (HFD) for 4 weeks, subsequently their diet switched to chow diet, HFD + RSV, chow diet + RSV or CR diet for a further 6 weeks. Body weight, fat accumulation, hypothalamic apoptosis and expression of trophic factors as well as generation and fate specification of newborn cells in arcuate nucleus (ARC) were evaluated.

RESULTS

Switching diet to RSV-containing foods leading to weight and fat loss after 6 weeks. In addition, not only a significant reduction in apoptosis but also a considerable increase in production of newborn cells in ARC occurred following consumption of RSV-enriched diets. These were in line with augmentation of hypothalamic ciliary neurotrophic factor and leukemia inhibitory factor expression. Interestingly, RSV-containing diets changed the fate of newborn neurons toward generation of more proopiomelanocortin than neuropeptide Y neurons. The CR had effects similar to those of RSV-containing diets in the all-evaluated aspects besides neurogenesis in ARC.

CONCLUSIONS

Although both RSV-containing and CR diets changed the fate of newborn neurons to create an anorexigenic architecture for ARC, newborn neurons were more available after switching to RSV-enriched diets. It can be consider as a promising mechanism for future investigations.

Resveratrol provides benefits in mice with type II diabetes-induced chronic renal failure through AMPK signaling pathway

Type II diabetes-induced ischemic injuries are known to lead to the rapid degeneration of the kidneys as a result of chronic renal failure. Chronic renal failure is a condition, which typically manifests with symptoms including cardiovascular system and left ventricular hypertrophy, atherosclerosis as well as arterial and aortic stiffness. Resveratrol is a multifunctional compound that has been reported to produce beneficial outcomes for patients with type-II diabetes due to prevention of oxidative stress and apoptosis. However, the beneficial effects of resveratrol in chronic renal failure and the underlying mechanisms have remained to be fully elucidated. The present study investigated the therapeutic effects of resveratrol in mice with chronic renal failure induced by type-II diabetes and assessed the mechanism of action. Oxidative stress, apoptosis and adenosine monophosphate-activated protein kinase (AMPK) in the renal cells of the model mice were assessed. Changes in inflammatory factors renal cells from experimental mice as well as insulin resistance were also analyzed. Morphological changes and immunocytes in renal cells were determined by immunostaining. The results demonstrated that resveratrol treatment decreased the apoptotic rate of renal cells from experimental mice. Oxidative stress also improved in renal cells, as indicated by inhibition of superoxide dismutase and reduced glutathione and 4-hydroxy-2-nonenal levels. In addition, insulin resistance was improved after an 8-week treatment with resveratrol. Inflammatory factors were decreased and factors promoting kidney function were increased after resveratrol treatment. Furthermore, morphological changes were observed to be ameliorated, indicating the therapeutic efficacy of resveratrol. In addition, immunocyte precipitation in renal cells was markedly decreased in resveratrol-treated mice. Importantly, the AMPK signaling pathway was found to be involved in the beneficial effect of resveratrol on the model mice. In conclusion, the present study suggested that resveratrol may be an ideal agent for the treatment of chronic renal failure induced by type-II diabetes through regulation of the AMPK signaling pathway, which should be further investigated in clinical trials.

Ion Channels Induced by Antimicrobial Agents in Model Lipid Membranes are Modulated by Plant Polyphenols Through Surrounding Lipid Media

The potential therapeutic applications of plant polyphenols in various neurological, cardiovascular, metabolic and malignant disorders determine the relevance of studying the molecular mechanisms of their action on the cell membranes. Here, the quantitative changes in the physical parameters of model bilayer lipid membranes upon the adsorption of plant polyphenols were evaluated. It was shown that butein and naringenin significantly decreased the intrinsic dipole potential of cholesterol-free and cholesterol-enriched membranes. Cardamonin, 4'-hydroxychalcone, licochalcone A and liquiritigenin demonstrated the average efficiency, while resveratrol did not characterized by the ability to modulate the bilayer electrostatics. At the same time, the tested polyphenols affected melting of phospholipids with saturated acyl chains. The effects were attributed to the lipid disordering and a promotion of the positive curvature stress. According to DSC data and results of measurements of the threshold voltages that cause bilayer breakdown licochalcone A is the most effective agent. Furthermore, the role of the polyphenol induced changes in the electric and elastic properties of lipid host in the regulation of reconstituted ion channels was examined. The ability of the tested polyphenols to decrease the conductance of single ion channels produced by the antifungal cyclic lipopeptide syringomycin E was in agreement with their effects on the dipole potential of the lipid bilayers. The greatest effect of licochalcone A on the steady-state membrane conductance induced by the antifungal polyene macrolide antibiotic nystatin correlated with its greatest efficacy to induce the positive curvature stress. We also found that butein and naringenin bind specifically to a single pore formed by α-hemolysin from Staphylococcus aureus.

Combination of nutritional polyphenols supplementation with exercise training counteracts insulin resistance and improves endurance in high-fat diet-induced obese rats

Separately, polyphenols and exercise are known to prevent insulin resistance (IR) but their combined curative effects on established obesity and IR require further investigation. Therefore, we compared the metabolic effects of a combination of exercise and grape polyphenols supplementation in obese IR rats with high-fat diet (EXOPP) to the effect of high-fat diet alone (HF) or with a nutritional supplementation of grape polyphenols (PP) or with endurance exercise (EXO) during 8 wks. We observed an improvement of systemic and skeletal muscle insulin sensitivity in EXO and EXOPP rats. EXOPP rats compared to HF rats presented a lower insulinemia and HOMA-IR with higher liver and muscle glycogen contents. Interestingly, EXOPP rats had a 68% enhanced endurance capacity compared to EXO rats with also a higher activation of AMPK compared to sedentary and EXO rats with increased lipid oxidation. Together, our results suggest that grape polyphenols supplementation combined with exercise has a synergistic effect by increasing muscle lipid oxidation and sparing glycogen utilization which thus enhances endurance capacity. Our data highlight that in cases of established obesity and IR, the combination of nutritional grape polyphenols supplementation and exercise heighten and intensify their individual metabolic effects.

Pharmacological Review on Asiatic Acid and Its Derivatives: A Potential Compound

Natural triterpenes represent a group of pharmacologically active and structurally diverse organic compounds. The focus on these phytochemicals has been enormous in the past few years, worldwide. Asiatic acid (AA), a naturally occurring pentacyclic triterpenoid, is found mainly in the traditional medicinal herb Centella asiatica. Triterpenoid saponins, which are the primary constituents of C. asiatica, are commonly believed to be responsible for their extensive therapeutic actions. Published research work has described the molecular mechanisms underlying the various biological activities of AA and its derivatives, which vary for each chronic disease. However, a compilation of the various pharmacological properties of AA has not yet been done. Herein, we describe in detail the pharmacological properties of AA and its derivatives that inhibit multiple pathways of intracellular signaling molecules and transcription factors that are involved in the various stages of chronic diseases. Furthermore, the pharmacological activities of AA were compared with two natural compounds: curcumin and resveratrol. This review summarizes the research on AA and its derivatives and helps to provide future directions in the area of drug development.

Effect of resveratrol and pterostilbene on aging and longevity

Over the past years, several studies have found that foods rich in polyphenols protect against age-related disease, such as atherosclerosis, cardiovascular disease, cancer, arthritis, cataracts, osteoporosis, type 2 diabetes (T2D), hypertension and Alzheimer's disease. Resveratrol and pterostilbene, the polyphenol found in grape and blueberries, have beneficial effects as anti-aging compounds through modulating the hallmarks of aging, including oxidative damage, inflammation, telomere attrition and cell senescence. In this review, we discuss the relationship between resveratrol and pterostilbene and possible aging biomarker, including oxidative stress, inflammation, and high-calorie diets. Moreover, we also discuss the positive effect of resveratrol and pterostilbene on lifespan, aged-related disease, and health maintenance. Furthermore, we summarize a variety of important mechanisms modulated by resveratrol and pterostilbene possibly involved in attenuating age-associated disorders. Overall, we describe resveratrol and pterostilbene potential for prevention or treatment of several age-related diseases by modulating age-related mechanisms. © 2017 BioFactors, 44(1):69-82, 2018.

Trans-resveratrol mitigates type 1 diabetes-induced oxidative DNA damage and accumulation of advanced glycation end products in glomeruli and tubules of rat kidneys

Hyperglycemia induces the formation of advanced glycation end products (AGEs) and their receptors (RAGEs), which alter several intracellular signaling mechanisms leading to the onset and progression of diabetic nephropathy. The present study focused on, i) modulatory effects of trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) on structural changes, AGE (N^Ɛ-carboxymethyl-lysine), RAGE, oxidative stress and DNA damage, and apoptosis, and ii) localization of fibrotic changes, AGE, RAGE, 8-oxo-dG and 4-hydroxynonenal (4-HNE) in diabetic rat kidneys. Resveratrol (5mg/kg; po, administered during last 45days of 90-day-long hyperglycemic period) administration to streptozotocin-induced type 1 diabetic male Wistar rats reduced renal hypertrophy and structural changes (tubular atrophy, mesangial expansion or shrinkage, diffuse glomerulonephritis, and fibrosis), AGE accumulation, oxidative stress and DNA damage (8-oxo-dG), 4-HNE, caspase-3, and cleaved-caspase-3, but not the RAGE expression. The AGE accumulated in the mesangium, vascular endothelium, and proximal convoluted tubules and less intensely in distal convoluted tubules of diabetic rat kidneys. The RAGE expression increased in the convoluted tubules and collecting ducts of diabetic rat kidneys, but not in the mesangium. Diabetes increased the expression of 8-oxo-dG in nuclei and cytoplasm of renal cells, and 4-HNE in glomeruli, convoluted tubules, the loops of Henle and collecting ducts. Hyperglycemia-induced AGE-RAGE axis and oxidative stress in turn induced apoptosis in diabetic kidneys. Resveratrol mitigated all diabetic effects except the RAGE expression. In conclusion, Resveratrol significantly alleviates diabetes-induced glycation, oxidative damage, and apoptosis to inhibit the progression of diabetic nephropathy. Resveratrol supplementation may be useful to hinder the onset and progression of diabetic kidney diseases.

Resveratrol attenuates reproductive alterations in type 1 diabetes-induced rats

The progression of diabetes mellitus leads to several complications including overproduction of reactive oxygen species and reproductive alterations. As resveratrol (RES) is a powerful anti-oxidant and an anti-apoptotic compound, we hypothesized that side effects of type-1 diabetes (DM1) on male reproduction could be reduced by the RES treatment. Eighty-four prepubertal male rats were distributed into seven groups: sham-control (SC), RES-treated (R), resveratrol-vehicle-treated (RV), diabetic (D), diabetic-insulin-treated (DI), diabetic-RES-treated (DR), diabetic-insulin and RES-treated (DIR). DM1 was induced by a single intraperitoneal streptozotocin (STZ) injection (65 mg/kg) on the 30th day postpartum (dpp). Animals of DR, DIR and R groups received 150 mg/day of RES by gavage for 43 consecutive days (from the 33 to 75 dpp). DI and DIR rats received subcutaneous injections of insulin (1 U/100 g b.w./day) from 5th day after the DM1 induction. The blood glucose level was monitored. At 75 dpp, the euthanasia was performed for morphometric and biometric testicular analyses, spermatic evaluation and hormonal doses. In the D group, the blood glucose level was higher than in the DR, DI and DIR groups. Besides morphometric testicular measurements, testosterone and estradiol doses were lower in D group than in DR and DIR groups; LH dose was also lower than in DR. The preputial separation age was delayed in diabetes-induced groups. The DR and DIR groups showed an improvement in sperm mitochondrial activity, epididymal sperm counts and the frequency of morphologically normal sperms. RES treatment improved glycaemic level, sperm quantitative and qualitative parameters and the hormonal profile in DM1-induced rats and seems to be a good reproductive protector.

Potential miRNA involvement in the anti-adipogenic effect of resveratrol and its metabolites

OBJECTIVE

Scientific research is constantly striving to find molecules which are effective against excessive body fat and its associated complications. Taking into account the beneficial effects that resveratrol exerts on other pathologies through miRNA, the aim of the present work was to analyze the possible involvement of miRNAs in the regulation of adipogenic transcription factors peroxisome proliferator-activated receptor γ (pparγ), CCAAT enhancer-binding proteins α and β (cebpβ and cebpα) induced by resveratrol and its metabolites.

METHODS

3T3-L1 maturing pre-adipocytes were treated during differentiation with 25 μM of trans-resveratrol (RSV), trans-resveratrol-3-O-sulfate (3S), trans-resveratrol-3'-O-glucuronide (3G) and trans-resveratrol-4'-O-glucuronide (4G). After computational prediction and bibliographic search of miRNAs targeting pparγ, cebpβ and cebpα, the expression of microRNA-130b-3p (miR-130b-3p), microRNA-155-5p (miR-155-5p), microRNA-27b-3p (miR-27b-3p), microRNA-31-5p (miR-31-5p), microRNA-326-3p (miR-326-3p), microRNA-27a-3p (miR-27a-3p), microRNA-144-3p (miR-144-3p), microRNA-205-5p (miR-205-5p) and microRNA-224-3p (miR-224-3p) was analyzed. Moreover, other adipogenic mediators such as sterol regulatory element binding transcription factor 1 (srebf1), krüppel-like factor 5 (klf5), liver x receptor α (lxrα) and cAMP responding element binding protein 1 (creb1), were measured by Real Time RT-PCR. As a confirmatory assay, cells treated with RSV were transfected with anti-miR-155 in order to measure cebpβ gene and protein expressions.

RESULTS

Of the miRNAs analyzed only miR-155 was modified after resveratrol and glucuronide metabolite treatment. In transfected cells with anti-miR-155, RSV did not reduce cebpβ gene and protein expression. 3S decreased gene expression of creb1, klf5, srebf1 and lxrα.

CONCLUSIONS

While RSV and glucuronide metabolites exert their inhibitory effect on adipogenesis through miR-155 up-regulation, the anti-adipogenic effect of 3S is not mediated via miRNAs.

Antiobesity effects of resveratrol: which tissues are involved?

The prevalence of obesity has been increasing in recent decades and is reaching epidemic proportions. The current options for overweight and obesity management are energy restriction and physical activity. However, compliance with these treatments is frequently poor and less successful than expected. Therefore, the scientific community is interested in active biomolecules, which may be useful in body weight management. Among them, resveratrol (3,5,4'-trihydroxy-trans-stilbene) has generated great interest as an antiobesity agent. The focus of this report is the mechanisms of action of resveratrol on several tissues (i.e., white and brown adipose tissues, liver, and skeletal muscle). Resveratrol blunts fat accumulation through decreasing adipogenesis and/or de novo lipogenesis in white adipose tissue. The effects on lipolysis are controversial. Regarding brown adipose tissue, resveratrol increases the capacity for adaptive thermogenesis. As far as liver and skeletal muscle is concerned, resveratrol increases lipid oxidation in both tissues. Therefore, in rodents, there is a general consensus concerning the effect of resveratrol on reducing body fat accumulation. By contrast, in humans, the studies are scarce, and no clear antiobesity action has been revealed so far.