stilbenes and Dyslipidemias

Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors which belong to the ligand-activated nuclear receptor superfamily. They are ubiquitously expressed throughout the body. So far, three major subtypes have been identified, PPARα, PPARβ/δ and PPARγ. They are crucial for lipid and glucose metabolism and are also involved in the regulation of several types of tumors, inflammation, cardiovascular diseases and infertility. The importance of these transcription factors in physiology and pathophysiology has been largely investigated. Synthetic PPAR ligands are widely used in the treatment of dyslipidemia (e.g. fibrates - PPARα activators) or in diabetes mellitus (e.g. thiazolidinediones - PPARγ agonists) while a new generation of dual agonists reveals hypolipemic, hypotensive, antiatherogenic, anti-inflammatory and anticoagulant action. Many natural ligands, including polyphenolic compounds, influence the expression of these receptors. They have several health-promoting properties, including antioxidant, anti-inflammatory, and antineoplastic activities. Resveratrol, a stilbene polyphenol, is a biological active modulator of several signaling proteins, including PPARs. Given the enormous pharmacological potential of resveratrol, stilbene-based medicinal chemistry had a rapid increase covering various areas of research. The present review discusses ligands of PPARs that contain stilbene scaffold and summarises the different types of compounds on the basis of chemical structure.

Topics: Diabetes Mellitus; Dyslipidemias; Humans; Ligands; PPAR alpha; PPAR gamma; Stilbenes; Thiazolidinediones

Overproduction of hepatic apoB100-containing VLDL particles has been well documented in animal models and in humans with insulin resistance such as the metabolic syndrome and type 2 diabetes, and contributes to the typical dyslipidemia of these conditions. In addition, postprandial hyperlipidemia and elevated plasma concentrations of intestinal apoB48-containing chylomicron and chylomicron remnant particles have been demonstrated in insulin resistant states. Intestinal lipoprotein production is primarily determined by the amount of fat ingested and absorbed. Until approximately 10 years ago, however, relatively little attention was paid to the role of the intestine itself in regulating the production of triglyceride-rich lipoproteins (TRL) and its dysregulation in pathological states such as insulin resistance. We and others have shown that insulin resistant animal models and humans are characterized by overproduction of intestinal apoB48-containing lipoproteins. Whereas various factors are known to regulate hepatic lipoprotein particle production, less is known about factors that regulate the production of intestinal lipoprotein particles. Monosacharides, plasma free fatty acids (FFA), resveratrol, intestinal peptides (e.g. GLP-1 and GLP-2), and pancreatic hormones (e.g. insulin) have recently been shown to be important regulators of intestinal lipoprotein secretion. Available evidence in humans and animal models strongly supports the concept that the small intestine is not merely an absorptive organ but rather plays an active role in regulating the rate of production of chylomicrons in fed and fasting states. Metabolic signals in insulin resistance and type 2 diabetes and in some cases an aberrant intestinal response to these factors contribute to the enhanced formation and secretion of TRL. Understanding the regulation of intestinal lipoprotein production is imperative for the development of new therapeutic strategies for the prevention and treatment of dyslipidemia. Here we review recent developments in this field and present evidence that intestinal lipoprotein production is a process with metabolic plasticity and that modulation of intestinal lipoprotein secretion may be a feasible therapeutic strategy in the treatment of dyslipidemia and possibly prevention of atherosclerosis.

Topics: Animals; Apolipoprotein B-100; Apolipoprotein B-48; Atherosclerosis; Bile Acids and Salts; Cholesterol; Chylomicrons; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Dyslipidemias; Exenatide; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Resistance; Intestine, Small; Lipoproteins; Microbiota; Peptides; Receptors, Glucagon; Resveratrol; Secretory Rate; Stilbenes; Triglycerides; Venoms

Peroxisome proliferator-activated receptors are promising therapeutic targets for metabolic diseases, including obesity, diabetes, and dyslipidemia. This study describes the design, synthesis and pharmacological evaluation of stilbene-based compounds as dual PPARα/γ partial agonists with potency in the nanomolar range. In vitro and in vivo assays revealed that the lead compound (E)-4-styrylphenoxy-propanamide (5b) removed

Topics: Adipogenesis; Animals; Cholesterol; Diabetes Mellitus; Diet, High-Fat; Dyslipidemias; Glucose; Lipoproteins, HDL; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; PPAR alpha; Stilbenes

Topics: Animals; Chemical and Drug Induced Liver Injury; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Dyslipidemias; Glycemic Load; Male; Protective Agents; Rats; Rats, Sprague-Dawley; Specific Pathogen-Free Organisms; Stilbenes

Previous research demonstrated that resveratrol possesses promising properties for preventing obesity. Endoplasmic reticulum (ER) stress was proposed to be involved in the pathophysiology of both obesity and hepatic steatosis. In the current study, we hypothesized that resveratrol could protect against high-fat diet (HFD)-induced hepatic steatosis and ER stress and regulate the expression of genes related to hepatic steatosis. Rats were fed either a control diet or a HFD for 12 weeks. After 4 weeks, HFD-fed rats were treated with either resveratrol or vehicle for 8 weeks. Body weight, serum metabolic parameters, hepatic histopathology, and hepatic ER stress markers were evaluated. Moreover, an RT2 Profiler Fatty Liver PCR Array was performed to investigate the mRNA expressions of 84 genes related to hepatic steatosis. Our work showed that resveratrol prevented dyslipidemia and hepatic steatosis induced by HFD. Resveratrol significantly decreased activating transcription factor 4, C/EBP-homologous protein and immunoglobulin binding protein levels, which were elevated by the HFD. Resveratrol also decreased PKR-like ER kinase phosphorylation, although it was not affected by the HFD. Furthermore, resveratrol increased the expression of peroxisome proliferator-activated receptor δ, while decreasing the expression of ATP citrate lyase, suppressor of cytokine signaling-3, and interleukin-1β. Our data suggest that resveratrol can prevent hepatic ER stress and regulate the expression of peroxisome proliferator-activated receptor δ, ATP citrate lyase, suppressor of cytokine signaling-3, tumor necrosis factor α, and interleukin-1β in diet-induced obese rats, and these effects likely contribute to resveratrol's protective function against excessive accumulation of fat in the liver.

Topics: Animals; Diet, High-Fat; Dyslipidemias; Endoplasmic Reticulum Stress; Gene Expression; Inflammation; Insulin Resistance; Lipid Metabolism; Liver; Male; Non-alcoholic Fatty Liver Disease; Phytotherapy; Plant Extracts; Rats, Sprague-Dawley; Resveratrol; Stilbenes

Elevated levels of plasma free fatty acids (FFA), which are commonly found in obesity, induce insulin resistance. FFA activate protein kinases including the proinflammatory IκBα kinase β (IKKβ), leading to serine phosphorylation of insulin receptor substrate 1 (IRS-1) and impaired insulin signaling. To test whether resveratrol, a polyphenol found in red wine, prevents FFA-induced insulin resistance, we used a hyperinsulinemic-euglycemic clamp with a tracer to assess hepatic and peripheral insulin sensitivity in overnight-fasted Wistar rats infused for 7 h with saline, Intralipid plus 20 U·mL(-1) heparin (IH; triglyceride emulsion that elevates FFA levels in vivo; 5.5 μL·min(-1)) with or without resveratrol (3 mg·kg(-1)·h(-1)), or resveratrol alone. Infusion of IH significantly decreased glucose infusion rate (GIR; P < 0.05) and peripheral glucose utilization (P < 0.05) and increased endogenous glucose production (EGP; P < 0.05) during the clamp compared with saline infusion. Resveratrol co-infusion, however, completely prevented the effects induced by IH infusion: it prevented the decreases in GIR (P < 0.05 vs. IH), peripheral glucose utilization (P < 0.05 vs. IH), and insulin-induced suppression of EGP (P < 0.05 vs. IH). Resveratrol alone had no effect. Furthermore, IH infusion increased serine (307) phosphorylation of IRS-1 in soleus muscle (∼30-fold, P < 0.001), decreased total IRS-1 levels, and decreased IκBα content, consistent with activation of IKKβ. Importantly, all of these effects were abolished by resveratrol (P < 0.05 vs. IH). These results suggest that resveratrol prevents FFA-induced hepatic and peripheral insulin resistance and, therefore, may help mitigate the health consequences of obesity.

Topics: Animals; Biomarkers; Blood Glucose; Disease Models, Animal; Dyslipidemias; Emulsions; Fatty Acids, Nonesterified; Female; Glucose Clamp Technique; I-kappa B Kinase; I-kappa B Proteins; Insulin; Insulin Receptor Substrate Proteins; Insulin Resistance; Liver; Muscle, Skeletal; NF-KappaB Inhibitor alpha; Phospholipids; Phosphorylation; Rats, Wistar; Resveratrol; Serine; Soybean Oil; Stilbenes; Time Factors; Up-Regulation

Epidemiological studies have demonstrated that the Mediterranean diet, which is rich in resveratrol, is associated with a significantly reduced risk of cardiovascular disease. However, the molecular mechanisms that underlie the beneficial effects of resveratrol on cardiovascular function remain incompletely understood. Therefore, we set out to identify the molecular target(s) mediating the protective action of resveratrol on vascular function. To this end, we performed vascular reactivity studies to evaluate the effects of resveratrol on superior thyroid artery obtained from 59 patients with hypertension and dyslipidemia. We found that resveratrol evoked vasorelaxation and reduced endothelial dysfunction through the modulation of NO metabolism via (1) an 5' adenosine monophosphate-activated protein kinase-mediated increase in endothelial NO synthase activity; (2) a rise in tetrahydrobiopterin levels, which also increases endothelial NO synthase activity; and (3) attenuation of vascular oxidative stress, brought about by overexpression of manganese superoxide dismutase via an nuclear factor erythroid-derived 2-like 2-dependent mechanism. The effects of resveratrol on acetylcholine vasorelaxation were also tested in vessels from patients with nonhypertensive nondyslipidemia undergoing thyroid surgery. In this setting, resveratrol failed to exert any effect. Thus, our finding that resveratrol reduces endothelial dysfunction, an early pathophysiological feature and independent predictor of poor prognosis in most forms of cardiovascular disease, supports the concept that the risk of vascular events could be further reduced by adherence to a set of dietary and behavioral guidelines.

Topics: Acetylcholine; Biopterins; Dyslipidemias; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; NF-E2-Related Factor 2; Nitric Oxide; Nitric Oxide Synthase Type III; Phosphorylation; Resveratrol; Stilbenes; Superoxide Dismutase; Vasodilation

We hypothesized that resveratrol, a natural phytoalexin found in grapes, can prevent oxidative stress, obesity and its related disturbances in obese rats programmed by early weaning. Lactating Wistar rats were separated into two groups: early weaning (EW) - dams who were wrapped with a bandage to interrupt the lactation in the last 3 days of lactation; control - dams whose pups had free access to milk during all lactation. At the 150th day, EW offspring were randomly subdivided into EW+resveratrol (EW+Res) - resveratrol (30 mg/kg/day); EW+vehicle (EW) - rats that received 0.5% (w/v) aqueous methylcellulose. The control group received vehicle. Rats were treated by gavage daily for 30 days. EW offspring developed hyperphagia, higher body weight, visceral obesity, higher systolic (SBP) and diastolic blood pressure (DBP) (+15% and +20%, respectively; P<.05) and higher serum triglycerides (TG) and low-density lipoprotein but lower high-density lipoprotein (+55%, +33% and -13%, respectively; P<.05). Resveratrol normalized food intake, SBP and DBP and prevented obesity and dyslipidemia in EW+Res. EW rats had higher plasma and liver thiobarbituric-acid-reactive substances (TBARS) and lower plasma superoxide dismutase (SOD) and liver glutathione peroxidase activities (+51%, +18%, -58%, -31%, respectively; P<.05), and resveratrol normalized both plasma and liver TBARS and increased the activity of SOD and catalase in plasma. EW rats presented liver steatosis and higher liver TG, and resveratrol prevented these hepatic alterations. In conclusion, this study demonstrated a potential therapeutic use of resveratrol in preventing obesity and oxidative stress and reducing the risk of hypertension, dyslipidemia and steatosis in adult rats programmed by early weaning.

Topics: Animals; Antioxidants; Blood Glucose; Dyslipidemias; Fatty Liver; Female; Glutathione Peroxidase; Hyperphagia; Hypertension; Insulin Resistance; Liver; Obesity; Oxidative Stress; Rats; Rats, Wistar; Resveratrol; Stilbenes; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Weaning

The combination of a lipid-lowering diet and scientifically proven nutraceutical supplements has the ability to significantly reduce low-density lipoprotein (LDL) cholesterol, increase LDL particle size, decrease LDL particle number, lower trigylcerides and very LDL levels, and increase total and high-density lipoprotein 2b cholesterol. In addition, inflammation, oxidative stress, and immune responses are decreased. In several prospective clinical trials, coronary heart disease and cardiovascular disease have been reduced with many nutraceutical supplements. This nutritional and nutraceutical supplement treatment is a valid alternative for patients who are intolerant to statins, cannot take other drugs for the treatment of dyslipidemia, or prefer alternative treatments. This new approach to lipid management to decrease vascular disease utilizes a functional medicine approach with a broader treatment program that will address the multitude of steps involved in lipid-induced vascular damage.

Topics: Atherosclerosis; Dietary Fats; Dietary Supplements; Dyslipidemias; Humans; Lipoproteins; Lipoproteins, VLDL; Oxidative Stress; Pantetheine; Resveratrol; Stilbenes; Tocotrienols; Triglycerides; Vascular Diseases; Vasodilator Agents

This study investigated the effects of resveratrol (RV) on diabetes-related metabolic changes in a spontaneous model of type 2 diabetes, as well as activation of AMP-activated protein kinase (AMPK) and downstream targets.. C57BL/KsJ-db/db mice were fed a normal diet with RV (0.005% and 0.02%, w/w) or rosiglitazone (RG, 0.001%, w/w) for 6 weeks. Both doses of RV significantly decreased blood glucose, plasma free fatty acid, triglyceride, apo B/apo AІ levels and increased plasma adiponectin levels. RV activated AMPK and downstream targets leading to decreased blood HbA1c levels, hepatic gluconeogenic enzyme activity, and hepatic glycogen, while plasma insulin levels, pancreatic insulin protein, and skeletal muscle GLUT4 protein were higher after RV supplementation. The high RV dose also significantly increased hepatic glycolytic gene expression and enzyme activity, along with skeletal muscle glycogen synthase protein expression, similar to RG. Furthermore, RV dose dependently decreased hepatic triglyceride content and phosphorylated I kappa B kinase (p-IKK) protein expression, while hepatic uncoupling protein (UCP) and skeletal muscle UCP expression were increased.. RV potentiates improving glycemic control, glucose uptake, and dyslipidemia, as well as protecting against pancreatic β-cell failure in a spontaneous type 2 diabetes model. Dietary RV has potential as an antidiabetic agent via activation of AMPK and its downstream targets.

Topics: Adiponectin; AMP-Activated Protein Kinases; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dietary Supplements; Dyslipidemias; Glucose Transporter Type 4; Glycated Hemoglobin; Glycogen; Insulin; Insulin Secretion; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Muscle, Skeletal; Resveratrol; Rosiglitazone; Stilbenes; Thiazolidinediones; Triglycerides

Hyper- and dyslipidemia are risk factors for cardiovascular disease, the primary cause of death in industrialized countries. Peroxisome proliferators-activated receptor (PPAR)α activation is involved in various mechanisms that improve the lipid profile. We tested various plant extracts and their compounds to determine whether they stimulated PPARα activity in vitro. Out of 34 tested plant extracts, nine exhibited low to moderate PPARα transactivation, including caraway, chili pepper, nutmeg, licorice, black and white pepper, paprika, coriander, saffron, and stevia tea. The active components of black pepper and chili pepper, piperine, and capsaicin exerted the highest transactivational activities with EC₅₀ values of 84 µM and 49 µM, respectively. The chalcones, including 2-hydroxychalcone, 2'-hydroxychalcone, 4-hydroxychalcone, and 4-methoxychalcone, moderately transactivated PPARα. Resveratrol and apigenin only slightly transactivated PPARα. These results suggest that a diet rich in fruit, herbs, and spices provides a number of PPARα agonists that might contribute to an improved lipid profile.

Topics: Apigenin; Chalcones; Dyslipidemias; Humans; Luciferases; Plant Extracts; Plants; Plasmids; PPAR alpha; Resveratrol; Spices; Stilbenes; Transcriptional Activation