Resveratrol attenuates oxidative stress and histological alterations induced by liver ischemia/reperfusion in rats

AIM： To investigate the effects of resveratrol on liver ischemia/reperfusion （I/R） injury in rats. METHODS： A total of 40 male Sprague-Dawley rats weighing 240-290 g were randomized into four groups of ten： （1） controls： data from unmanipulated animals; （2） sham group： rats subjected to the surgical procedure, except for liver I/R, and given saline; （3） I/R group： rats underwent liver ischemia for 45 rain followed by reperfusion for 45 rain; （4） I-R/Resveratrol group： rats pretreated with resveratrol （10 umol/L, iv）. Liver tissues were obtained to determine antioxidant enzyme levels and for biochemical and histological evaluation. RESULTS： Plasma aminotransferase activities were higher in the I/R group than in the I-R/Resveratrol group. Malondialdehyde levels and the hepatic injury score decreased, while superoxide dismutase, catalase, and glutathione peroxidase levels increased in group 4 compared to group 3. In group 4, histopathological changes were significantly attenuated in resveratroltreated livers. CONCLUSION： These results suggest that resveratrol has protective effects against hepatic I/R injury, and is a potential therapeutic drug for ischemia reperfusionrelated liver injury.     

Resveratrol ameliorates experimental autoimmune myocarditis.

BACKGROUND: Myosin-induced autoimmune myocarditis of rats is a model of human dilated cardiomyopathy. Resveratrol is a natural polyphenol found in grapes and wine that is reported to have cardioprotective and immunomodulatory effects. METHODS AND RESULTS: To examine the effect of resveratrol on myocarditis, vehicle or resveratrol (50 mg/kg per day) was administered to cardiac myosin immunized rats 1 day before the immunization. At 14 days after immunization, resveratrol had preserved cardiac function of myosin-immunized rats according to echocardiographic analysis. The heart weight/tibial length ratio of vehicle-treated myosin-immunized rats was increased by 1.8-fold compared with unimmunized rats, and resveratrol attenuated the heart weight increase. Resveratrol significantly decreased cellular infiltration, fibrosis, and expression of inflammatory cytokines in the myocardium. Expressions of antioxidant genes were increased in myosin-immunized hearts, and resveratrol decreased those expressions. Resveratrol also attenuated myocarditis 21 days after immunization. SIRT1, a potential effector of resveratrol, was increased in the myocardium of myosin-immunized rats compared with unimmunized rats. The SIRT1 protein was localized mainly in infiltrating mononuclear cells. CONCLUSIONS: Resveratrol significantly ameliorated myocardial injury and preserved cardiac function in a rat model of autoimmune myocarditis. Resveratrol may be a therapeutic modality for myocarditis.     

Protective effects of melatonin on myocardial ischemia/reperfusion injury in vivo

The production of oxygen free radicals has been strongly implicated as an important pathophysiological mechanism mediating myocardial ischemia/reperfusion (I/R) injury. Various antioxidants have cardioprotective effects. Melatonin, an indoleamine synthesized by the pineal gland, is a potent antioxidant and a direct free radical scavenger. This is the first in vivo study to evaluate the effect of melatonin (0.5, 1.0, and 5.0 mg/kg, i.v. bolus) on myocardial I/R injury in anesthetized Sprague-Dawley rats. Results demonstrate that pretreatment with intermediate or high doses of melatonin (1.0 and 5.0 mg/kg) at 10 min before left coronary artery occlusion markedly suppressed ventricular tachycardia (VT) and ventricular fibrillation (VF), while reducing the total number of premature ventricular contractions and total duration of VT and VF that occurred during the 45-min ischemic period. Pretreatment with melatonin dramatically improved survival rate of rats when compared with the I/R-only group. After 1-hr reperfusion, melatonin caused a significant reduction in infarct size when compared with I/R-only group. Meanwhile, pretreatment with melatonin (1.0 mg/kg) significantly reduced superoxide anion production and myeloperoxidase activity; the latter is an index of neutrophil infiltration in the ischemic myocardium. Additionally, pretreatment with melatonin (1.0 and 5.0 mg/kg) significantly attenuated ventricular arrhythmias and mortality elicited by reperfusion following 5-min ischemia. In conclusion, melatonin suppresses ischemia- and reperfusion-induced ventricular arrhythmias and reduces infarct size resulting from I/R injury. The pronounced cardioprotective activity of melatonin may be mediated by its antioxidant activity and by its capacity for neutrophil inhibition in myocardial I/R.     

Resveratrol lowers blood pressure in spontaneously hypertensive rats via calcium-dependent endothelial NO production

Objective: Resveratrol, a polyphenol of natural compounds, has beneficial cardiovascular effects, many of which are mediated by nitric oxide (NO). Resveratrol increases intracellular calcium and activates AMP-activated protein kinase (AMPK), all of which could increase NO production. We hypothesized that resveratrol via a calcium-dependent NO production lowers blood pressure (BP) in spontaneously hypertensive rats (SHR). Methods: Acetylcholine (Ach)-induced endothelium-dependent relaxations in rat aortas were examined by organ chamber. Blood pressures were determined by radiotelemetry methods. Results: Incubation of isolated aortas from SHR with resveratrol dramatically improved vasorelaxation induced by Ach. Preincubation of aortas with endothelial NO synthase (eNOS) inhibitor or calcium chelant blunted the effects of resveratrol on Ach-induced relaxation, as wells as NO production and eNOS phosphorylation. In animal studies, administration of resveratrol significantly lowered systemic BP in SHR. Conclusion: Resveratrol increases endothelial NO production to improve endothelial dysfunction and lowers BP in hypertensive rats, which depends on calcium-eNOS activation.     

Hormetic response of resveratrol against cardioprotection

Resveratrol, a grape- and red wine-derived polyphenolic phytoalexin, shows diverse health benefits including cardioprotection. Recent studies implicate that resveratrol displays hormetic action, protecting the cells at a lower dose while killing them at relatively higher doses. Because such hormetic behaviour may have a significant impact on epidemiological and clinical studies, the present study sought to determine dose-response curves for resveratrol action. In parallel, another resveratrol formulation was tested, namely, Longevinex (Resveratrol Partners LLC, USA). A group of rats were force-fed three different doses of resveratrol or Longevinex (2.5 mg/kg, 25 mg/kg and 100 mg/kg) for up to 30 days, while the control group was only given placebo. The results showed hormesis for pure resveratrol, which was cardioprotective at lower doses and detrimental for higher doses, but surprisingly Longevinex did not display any hormetic action. In the concentration range studied, Longevinex remained cardioprotective even at 100 mg/100 g body weight – a dose that killed 100% of the hearts when tested with pure resveratrol. To further test whether Longevinex doses are beneficial for other animal species, Longevinex was gavaged to a group of rabbits for six months, and showed exactly the same degree of cardioprotection. Cardioprotection was examined in isolated working hearts subjected to 30 min of ischemia followed by 2 h of reperfusion; left ventricular performance and infarct size was also examined. It appears that Longevinex does not show any hormetic action, while resveratrol clearly does.     

Potential pro-inflammatory action of resveratrol in vascular smooth muscle cells from normal and diabetic rats

BACKGROUND AND AIM: Based on the reported cardioprotective effects of resveratrol, a polyphenolic antioxidant abundant in grapes that binds to estrogen receptors, and the well-characterized anti-inflammatory properties of 17beta-estradiol, the effects of resveratrol on the functional expression of inflammatory enzymes were assessed in vascular smooth muscle cells (SMC) from normoglycaemic and streptozotocin-diabetic rats. METHODS AND RESULTS: SMC were isolated from the aorta four weeks after treating rats with streptozotocin or its vehicle. In SMC exposed to a cytokine mixture for 24h, unexpectedly, treatment with resveratrol (0.1-100microM) as well as the structurally related isoflavone genistein (1nM-1microM) enhanced expression of inducible NO synthase (iNOS). Genistein failed to mimic the elevated iNOS activity induced by resveratrol. Inhibition of estrogen receptors by the pure antiestrogen ICI 182,780 reversed the action of resveratrol on iNOS. In addition, resveratrol failed to alter cyclooxygenase-2 protein levels but reduced the accumulation of prostaglandin E(2) in the culture medium of SMC from normoglycaemic, but not diabetic rats. CONCLUSIONS: These results indicate that resveratrol, at concentrations approaching putative peak plasma levels in vivo, exhibited no anti-inflammatory properties in vascular SMC from normal and diabetic rats. By contrast, resveratrol displayed a potential pro-inflammatory activity in settings of vascular inflammation.     

Effects of resveratrol on NO secretion stimulated by insulin and its dependence on SIRT1 in high glucose cultured endothelial cells

To investigate the effects of resveratrol on the secretion of NO induced by insulin in high glucose cultured primary human umbilical vein endothelial cells (HUVEC). HUVEC were treated with 1 μmol/l resveratrol for 24 h before cultured in high glucose medium for 48 h, then all cells were stimulated by 100 nmol/l insulin for 30 min. Method based on nitric acid reductase was used to analyze the NO contents in the supernatant. Cells were collected to analyze the expression of eNOS, endothelin-1, E-selectin, and SIRT1. In order to investigate the dependence of resveratrol on SIRT1, the effects of resveratrol on cells treated by SIRT1 siRNA were also examined. Compared with control cells, high glucose decreased the secretion of NO induced by insulin. Resveratrol treatment increased the expression of SIRT1 and the secretion of NO. After interfering the expression of SIRT1 using SIRT1 siRNA, the effects of resveratrol on the NO secretion induced by insulin was impaired. Resveratrol also counteracted other pro-atherosclerotic effects of high glucose, including the up-regulating roles of high glucose on the expression of endothelin-1 mRNA and E-selectin mRNA, and the down-regulating roles of high glucose on the expression of eNOS mRNA and the basal NO secretion without the stimulating of insulin. Resveratrol can improve the NO stimulating function of insulin in high glucose cultured HUVEC in SIRT1-dependent manner. Thus, our results imply that resveratrol may have the preventive roles of atherosclerosis in diabetic patients.     

Resveratrol, a polyphenolic phytostilbene, inhibits endothelial monocyte chemotactic protein-1 synthesis and secretion

BACKGROUND/AIMS: Resveratrol is a naturally occurring polyphenol phytoestrogen and one of several constituents of red wine thought to be cardioprotective. We investigated the effect of resveratrol on the expression of the atherogenic chemokine, monocyte chemotactic protein-1 (MCP-1). METHODS: Human umbilical vein endothelial cells were stimulated with interleukin-1beta (IL-1beta) in the absence or presence of resveratrol. MCP-1 levels were determined by ELISA and MCP-1 mRNA was measured. RESULTS: Resveratrol (1-100 microM) dose-dependently inhibited IL-1beta-stimulated MCP-1 secretion, with approximately 45% inhibition at 50 microM resveratrol. This was a Gi-protein- and NO-dependent effect. Resveratrol also significantly inhibited MCP-1 gene expression in a Gi-protein-dependent but NO-independent manner. While resveratrol had no effect on MCP-1 mRNA degradation, it inhibited MCP-1 promoter activity and reduced nuclear factor kappaB and activator protein-1 binding activity induced by IL-1beta. Moreover, while hemoxygenase-1 (HO-1) expression was induced by resveratrol in human umbilical vein endothelial cells, neither treatment with the HO-1 inhibitor tin-protoporphyrin IX nor siRNA-directed knockdown of HO-1 had any effect on the inhibition of MCP-1 mRNA or protein secretion by resveratrol. CONCLUSION: These data demonstrate an inhibitory effect of resveratrol on MCP-1 synthesis and secretion, mediated via distinct signaling pathways. The inhibition of MCP-1 may represent a novel cardioprotective mechanism of resveratrol.     

Red wine ingredient resveratrol protects from beta-amyloid neurotoxicity

BACKGROUND: beta-Amyloid peptide (Abeta), a neutrotoxic substance, has been implicated to a great degree in cell death during the course of AD. Resveratrol, a natural polyphenol mainly found in red wine, has been shown to be cardioprotective and chemoprotective. Since a moderate wine intake correlates with a lower risk for Alzheimer disease (AD), an additional neuroprotective effect has been postulated for resveratrol. OBJECTIVE: The present study aimed at elucidating the possible neuroprotective effects of resveratrol against Abeta-induced neurotoxicity. METHODS: The neuroprotective capacity against Abeta-related oxidative stress was studied in a cell culture model suitable for studying such potentially neuroprotective substances. RESULTS: Resveratrol maintains cell viability and exerts an anti-oxidative action by enhancing the intracellular free-radical scavenger glutathione. CONCLUSION: Our findings suggest that red wine may be neuroprotective through the actions of resveratrol.     

苯那普利对大鼠心肌缺血再灌注心律失常的保护作用

目的　观察苯那普利对大鼠心肌缺血 /再灌注 ( I/ R)心律失常的影响。方法　选用雄性 SD大鼠 3 2只随机等分为二组 :苯那普利组 (苯那普利 10 mg· kg-1 .d-1 )和对照组 (生理盐水 2 ml/ d) ,二周后制作大鼠心肌 I/ R模型 ,观察缺血 10 min再灌注 2 0 min心律失常发生率和持续时间 ,左心室心肌超氧化物歧化酶 ( SOD)、一氧化氮 ( NO)及血压变化。结果　与对照组比苯那普利组大鼠缺血心室颤动 ( VF)发生率、再灌注室性心动过速 ( VT)、VF发生率及死亡率明显降低 ( P<0 .0 1) ;缩短缺血 /再灌注 VT持续时间 ( P<0 .0 1)。苯那普利对血压无明显影响 ( P>0 .0 5 )但可增加左心室心肌 SOD和 NO含量 ( P<0 .0 1)。结论　苯那普利具有抗大鼠 I/ R心律失常作用。     

Protective effect of resveratrol against endotoxemia-induced lung injury involves the reduction of oxidative/nitrative stress

BackgroundResveratrol, a natural plant polyphenol, has received increasing attention because its varied bioactivities, including the inhibition of tumorigenesis, lipid modification and calorie-restriction. We aimed to investigate the effect of resveratrol on oxidative/nitrative stress in endotoxemia-associated acute lung injury.MethodsMice were injected with lipopolysaccharide (LPS, 5 mg/kg, ip). Resveratrol at a dose of 0.3 mg/kg was administered alone or immediately before injection of LPS. Twenty four hours later, lung tissues were collected for histopathologic examination, and determination of malondialdehyde (MDA), H₂O₂, reduced/oxidized glutathione (GSH/GSSG) ratio, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity, inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) and peroxynitrite production.ResultsResveratrol treatment improves histopathological changes in the lung during endotoxemia. Increased oxidative stress in endotoxemic lung was reversed by resveratrol treatment, as evidenced by the decreases of pro-oxidant biomarker (MDA and H₂O₂), and the increases of anti-oxidant biomarkers (GSH/GSSG ratio, T-AOC, CAT and SOD activity). Treatment with resveratrol inhibited endotoxemia-induced iNOS expression and NO production. Moreover, peroxynitrite formation in endotoxemic lung was significantly attenuated after resveratrol treatment.ConclusionsResveratrol exerts protective effects against acute endotoxemia-associated lung injury. These beneficial effects may be due to both the anti-oxidant and anti-nitrative properties of resveratrol. These findings support the potential for resveratrol as a possible pharmacological agent to reduce acute lung injury resulting from oxidative/nitrative damage.     

白藜芦醇对大鼠心肌梗死后室性心律失常及长期存活率的影响

目的 研究白藜芦醇对大鼠心肌梗死后室性心律失常、心室重构和长期存活率的影响.方法 将SD大鼠随机分成假手术组、心肌梗死组、白藜芦醇治疗组(治疗组).心肌梗死组和治疗组开胸结扎冠状动脉左前降支,假手术组不结扎.植入性射频发射器记录24 h心电图,并分析心肌梗死后24 h内室性心律失常发病率;侵入性在体电生理检测评价室性心律失常的诱发率;全细胞膜片钳技术检测白藜芦醇对单个心室肌细胞的电生理作用;免疫荧光染色观察心肌细胞的结构改变.结果 与心肌梗死组相比,治疗组明显抑制了心肌梗死导致的室性心动过速和心室颤动发病率,治疗组室性心动过速的诱发率低于心肌梗死组,差异有统计学意义(46%vs 81%,P<0.01).14周后,治疗组心肌梗死面积和死亡率较心肌梗死组分别下降了20%和33%.膜片钳记录显示白藜芦醇抑制了L型钙电流.免疫荧光染色发现治疗组心肌细胞横断面积小于心肌梗死组.结论 白藜芦醇可以通过抑制大鼠心肌L型钙电流发挥抗心律失常作用,并抑制了左心室重构,提高了大鼠心肌梗死后的存活率.     

白藜芦醇通过激活腺苷酸活化蛋白激酶预防酒精性心肌病

目的探索白藜芦醇对酒精性心肌病的作用及其分子机制。方法将雄性Wistar大鼠随机分为对照组、酒精组和酒精+白藜芦醇组,每组10只,干预6个月后采用介入生理记录仪检测大鼠的心功能,采用常规石蜡切片和HE染色法评估心脏结构改变,采用免疫印迹法检测心肌组织中腺苷酸活化蛋白激酶和内皮型一氧化氮合酶及其磷酸化蛋白的表达,并运用硝酸还原酶法检测心肌组织中一氧化氮水平。结果 6个月酒精摄入可显著损害大鼠的心功能和心肌显微结构,添加白藜芦醇能显著削弱酒精对心脏功能和结构的损害作用。酒精摄入可显著降低心肌组织中腺苷酸活化蛋白激酶和内皮型一氧化氮合酶的磷酸化水平,并降低一氧化氮水平,而添加白藜芦醇能显著增加腺苷酸活化蛋白激酶和内皮型一氧化氮合酶的磷酸化水平,并增加心肌组织中一氧化氮水平。结论白藜芦醇能通过激活腺苷酸活化蛋白激酶/内皮型一氧化氮合酶系统和增加一氧化氮水平来预防酒精性心肌病。     

缺血后处理对再灌注大鼠胃黏膜细胞的保护作用

目的探讨缺血后处理对再灌注大鼠胃黏膜的保护作用及其抗氧化机制。方法制备胃缺血后处理模型;实验分为5组（n=6）：假手术组（S）、单纯缺血-再灌注组（I—R）、缺血预处理组（IPC）、缺血后处理组（I-post）、缺血后处理＋缺血预处理组（I-post＋IPC）。记录各组胃黏膜损伤指数并检测胃黏膜丙二醛（MDA）含量、超氧化物歧化酶（SOD）的活性变化;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）检测胃黏膜细胞的凋亡。结果 与S组相比,I—R组胃黏膜损伤指数和黏膜细胞凋亡率显著升高,胃黏膜MDA含量屁著增加,SOD活性明屁降低;在IPC组、I-post组和I-post＋IPC组,胃黏膜损伤指数与细胞凋亡率较I—R组显著降低,胃黏膜MDA含量也显著降低,而SOD活性明显升高;I-post＋IPC组对再灌注的胃黏膜损伤无叠加保护作用,分别与IPC组和I-post组相比,各项指标的差异无统计学意义。结论缺血后处理可显著减轻胃黏膜再灌注损伤,其效应与缺血预处理相似,其机制之一可能与其再灌注后氧自由基的生成减少,抑制胃黏膜细胞膜脂质过氧化、使冉灌注的胃黏膜细胞凋亡减轻有关。     

Efeito Cardioprotetor da Suplementação Materna com Resveratrol sobre a Toxicidade Induzida por Doxorrubicina em Cardiomiócitos de Neonatos

BackgroundDoxorubicin (DOX) is frequently used to treat many types of cancers, despite its dose-dependent cardiotoxicity. Alternatively, resveratrol is a polyphenol that has shown useful cardioprotective effects in many heart dysfunction models.ObjectiveThis study investigated whether resveratrol treatment in pregnant rats protects against doxorubicin-induced toxicity in offspring cardiomyocytes.MethodsWistar rats (n=8) were supplemented with dietary resveratrol during pregnancy. Upon the offspring’s birth, hearts (9-11) were used to obtain the primary culture of cardiomyocytes. DOX-induced cardiotoxicity and the effects of resveratrol supplementation were evaluated by oxidative stress markers, such as dichlorofluorescein diacetate oxidation, decrease in the activity of antioxidant enzymes, and oxidation of total sulfhydryl content, in addition to cell viability evaluation, DNA damage generation, and DNA damage repair response. A value of p<0.05 was considered statistically significant.ResultsNeonatal cardiomyocytes from resveratrol supplemented rats exhibiting an increase (p<0.01) in cell viability and lower (p<0.0001) apoptotic/necrotic cells after DOX treatment, which correlates with the activities of antioxidant enzymes and dichlorofluorescein production. Moreover, resveratrol protected cardiomyocytes from DOX-induced DNA damage, showing a decrease (p<0.05) in DNA breaks induced by oxidative stress, evaluated by the activity of DNA-repair enzymes endonuclease III and formamidopyrimidine glycosylase. Supplementation with resveratrol increased (p<0.05) the expression of the repair protein Sirt6 in the cardiomyocytes of the pups.ConclusionThis research indicates that supplementation with resveratrol during the gestational period has a notable cardioprotective effect on the offspring’s heart against DOX-induced toxicity, which may well be due to its antioxidant function, and the increase in the DNA damage repair response.     

Antiarrhythmic Effects of Some Antioxidant Vitamins in Rats Injected with Epinephrine

Since excessive amounts of catecholamines are known to produce arrhythmias and increase the plasma level of aminochrome, an oxidation product of catecholamines, we tested the hypothesis that antioxidants may reduce the formation of aminochrome and prevent the catecholamine-induced arrhythmias. For this purpose, Sprague-Dawley rats were pretreated orally, with vitamin A or vitamin C for 21 days, and their effects on ventricular arrhythmias induced by a bolus dose or cumulative doses of intravenous epinephrine were examined. Electrocardiogram recording of these animals revealed that pretreatment with either of these vitamins increased the time of onset and decreased the duration of the epinephrine-induced ventricular arrhythmias. Ventricular fibrillations due to high doses of epinephrine were also prevented by the antioxidant pretreatment. Although pretreatment with either vitamin A or vitamin C did not affect the basal malondialdehyde level in control animals, the increase in malondialdehyde level caused by epinephrine administration was significantly reduced by these agents. The elevated level of plasma aminochrome due to epinephrine was also decreased by vitamins A and C treatments. The results indicate that antioxidant may prevent catecholamine-induced arrhythmias by reducing the formation of aminochrome and thus may provide a new strategy for the management of stress-related heart disease.     

Antiplatelet Agents Sarpogrelate and Cilostazol Affect Experimentally-induced Ventricular Arrhythmias and Mortality

Antiplatelet agents, sarpogrelate (SAR), a 5-hydroxy tryptamine 2A receptor antagonist and cilostazol (CIL), a phosphodiesterase-III inhibitor, were observed to be beneficial in attenuating cardiac remodeling and improving cardiac function in congestive heart failure due to myocardial infarction in rats; however, CIL increased ventricular tachycardia and mortality. In order to study the effects of these antiplatelet agents on arrhythmias, Sprague-Dawley rats were pretreated with either SAR or CIL (5 mg/kg/day) for 2 weeks and were then either injected cumulative doses of epinephrine (Epi) or subjected to coronary occlusion. Saline-treated animals served as controls. Electrocardiographic analysis revealed that SAR pretreatment decreased the incidence and severity of ventricular arrhythmias (time of onset of arrhythmias as well as the occurrence of premature ventricular contractions, salvos, tachycardia, and fibrillations), whereas CIL treatment augmented the incidence of cardiac arrhythmias due to both Epi and coronary occlusion. None of the drugs affected the corrected QT interval significantly. Furthermore, the levels of cyclic adenosine monophosphate (cAMP) in left ventricle were markedly higher in CIL-pretreated rats when compared to SAR-pretreated or control rats. It is suggested that an excessive level of cAMP may contribute to increase incidence of ventricular arrhythmias and mortality in animals pretreated with CIL, unlike the SAR-pretreated rats.     

Inhibition of cyclic strain-induced endothelin-1 gene expression by resveratrol

Resveratrol is a phytoestrogen naturally found in grapes and is among the major constituents of wine thought to have a cardioprotective effect. Endothelin-1 (ET-1) is a potent vasopressor synthesized by endothelial cells both in culture and in vivo. The aims of this study were to test the hypothesis that resveratrol may alter strain-induced ET-1 gene expression and to identify the putative underlying signaling pathways in endothelial cells. We show that resveratrol indeed potently inhibits strain-induced ET-1 secretion, ET-1 mRNA level, and ET-1 promoter activity. Resveratrol also inhibits strain-increased NADPH oxidase activity, reactive oxygen species formation, and extracellular signal-regulated kinases1/2 (ERK1/2) phosphorylation. Furthermore, pretreating cells with resveratrol or antioxidant N-acetyl-cysteine decreases strain-increased or hydrogen peroxide-increased ET-1 secretion, ET-1 promoter activity, and ET-1 mRNA and ERK1/2 phosphorylation. Using both the electrophoretic mobility shift assay and a reporter gene assay, resveratrol and N-acetyl-cysteine also attenuated the strain-stimulated activator protein-1 binding activity and activator protein-1 reporter activity. In summary, we demonstrate for the first time that resveratrol inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK1/2 pathway through attenuation of reactive oxygen species formation. Thus, this study provides important new insights in the molecular pathways that may contribute to the proposed beneficial effects of resveratrol in the cardiovascular system.     

Effects of resveratrol therapy on glucose metabolism,insulin resistance,inflammation, and renal function in the elderly patients with type 2 diabetes mellitus: A randomized controlled clinical trial protocol

Background:Diabetes mellitus is a spectrum of metabolic disorders characterized by hyperglycemia and shows a growing global public health problem in the elderly. Resveratrol presents antiaging, anti-inflammatory, antitumor antioxidant, and cardioprotective activities. The purpose of this study was to investigate the ameliorative effects of resveratrol on blood glucose, insulin metabolism, lipid profile, renal function, inflammation, and nutrient sensing systems in the elderly patients with type 2 diabetes mellitus.Methods:The study is a single-blind, parallel-group, randomized controlled clinical trial consisting of a 6-month treatment period. A total of 472 elderly patients with type 2 diabetes mellitus were enrolled, and included participants will be randomized into 2 groups: resveratrol (n = 242) and placebo (n = 230). The clinical efficacy and changes in clinical parameters in each group will be measured at the indicated time. Clinical parameters included blood glucose, insulin resistance index, blood lipid index, proinflammatory cytokines, renal function, and nutrient sensing systems.Results:Resveratrol treatment greatly improved glucose metabolism, insulin tolerance, and insulin metabolism compared to placebo. Resveratrol relieved symptoms through enhancing nutrient sensing systems, which in turn reduced production and activity of glucose-6-phosphatase. Compared with placebo, resveratrol treatment significantly decreased proinflammatory cytokines glycated hemoglobin/hemoglobin A1c, interleukin-6, tumor necrosis factor-alpha, and interleukin-1beta in the elderly diabetes. Resveratrol treatment decreased blood glucose parameters, improved the lipid profile (total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides), and renal function compared to placebo.Conclusion:In conclusion, resveratrol treatment improves inflammation, renal function, blood glucose parameters, inflammation, insulin resistance, and nutrient sensing systems in the elderly patients with type 2 diabetes mellitus, indicating resveratrol may be a potential therapeutic drug for the treatment of the elderly patients with type 2 diabetes mellitus.     

白藜芦醇改善年龄相关自发性高血压大鼠血管功能的研究

目的：观测白藜芦醇对年龄相关自发性高血压大鼠动脉舒张功能的改善效果及年龄对动脉功能与疗效的影响。方法：雄性年轻期（8～10周龄）、中老年期（9～10月龄）的自发性高血压大鼠及健康对照大鼠,其中高血压大鼠随机分为白藜芦醇干预组和非干预组,干预组给予白藜芦醇10mg／（kg·d）灌胃,记录大鼠血压、心率,检测胸主动脉与肠系膜动脉对乙酰胆碱的舒张特性,检测肠系膜动脉中总一氧化氮（NO）及gp91phox的表达。结果：（1）与年轻期高血压大鼠相比,中老年高血压大鼠的动脉舒张功能减弱,白藜芦醇治疗后舒张功能增强。（2）白藜芦醇治疗能够增加年轻与中老年高血压大鼠的肠系膜动脉总NO量,减少gp91phox蛋白表达。结论：高血压大鼠动脉内皮依赖的舒张功能较正常大鼠减弱且存在年龄差异,摄入白藜芦醇可以通过减少gp91phox表达,增加NO量来保护血管舒张功能,该保护作用在年轻期与中老年期大鼠中均存在。