Resveratrol improves cardiovascular function and reduces oxidative organ damage in the renal, cardiovascular and cerebral tissues of two-kidney, one-clip hypertensive rats

Pleiotropic Effects of Resveratrol on Aging-Related Cardiovascular Diseases-What Can We Learn from Research in Dogs?

Resveratrol (RES) is a polyphenol with natural anti-inflammatory and antioxidant properties. It is found in abundance in plants, i.e., grapes and mulberry fruit. In addition, synthetic forms of RES exist. Since the discovery of its specific biological properties, RES has emerged as a candidate substance not only with modeling effects on the immune response but also as an important factor in preventing the onset and progression of cardiovascular disease (CVD). Previous research provided strong evidence of the effects of RES on platelets, mitochondria, cardiomyocytes, and vascular endothelial function. In addition, RES positively affects the coagulation system and vasodilatory function and improves blood flow. Not only in humans but also in veterinary medicine, cardiovascular diseases have one of the highest incidence rates. Canine and human species co-evolved and share recent evolutionary selection processes, and interestingly, numerous pathologies of companion dogs have a human counterpart. Knowledge of the impact of RES on the cardiovascular system of dogs is becoming clearer in the literature. Dogs have long been recognized as valuable animal models for the study of various human diseases as they share many physiological and genetic similarities with humans. In this review, we aim to shed light on the pleiotropic effects of resveratrol on cardiovascular health in dogs as a translational model for human cardiovascular diseases.

Diazoxide and moderate-intensity exercise improve skeletal muscle function by decreasing oxidants and enhancing antioxidant defenses in hypertensive male rats

High sodium intake is decisive in the incidence increase and prevalence of hypertension, which has an impact on skeletal muscle functionality. Diazoxide is an antihypertensive agent that inhibits insulin secretion and is an opener of KATP channels (adosine triphosphate sensitive potasium channels). For this reason, it is hypothesized that moderate-intensity exercise and diazoxide improve skeletal muscle function by reducing the oxidants in hypertensive rats. Male Wistar rats were assigned into eight groups: control (CTRL), diazoxide (DZX), exercise (EX), exercise + diazoxide (EX + DZX), hypertension (HTN), hypertension + diazoxide (HTN + DZX), hypertension + exercise (HTN + EX), and hypertension + exercise + diazoxide (HTN + EX + DZX). To induce hypertension, the rats received 8% NaCl dissolved in water orally for 30 days; in the following 8 weeks, 4% NaCl was supplied to maintain the pathology. The treatment with physical exercise of moderate intensity lasted 8 weeks. The administration dose of diazoxide was 35 mg/kg intraperitoneally for 14 days. Tension recording was performed on the extensor digitorum longus and the soleus muscle. Muscle homogenates were used to measure oxidants using fluorescent probe and the activity of antioxidant systems. Diazoxide and moderate-intensity exercise reduced oxidants and increased antioxidant defenses.

Targeting the NLRP3 inflammasome for the treatment of hypertensive target organ damage: Role of natural products and formulations

BACKGROUND AND AIM

Hypertension is a major global health problem that causes target organ damage (TOD) in the heart, brain, kidney, and blood vessels. The mechanisms of hypertensive TOD are not fully understood, and its treatment is challenging. This review provides an overview of the current knowledge on the role of Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome in hypertensive TOD and the natural products and formulations that inhibit it.

METHODS

We searched PubMed, Web of Science, Google Scholar, and CNKI for relevant articles using the keywords "hypertension," "target organ damage," "NLRP3 inflammasome," "natural products," and "formulations." We reviewed the effects of the NLRP3 inflammasome on hypertensive TOD in different organs and discussed the natural products and formulations that modulate it.

KEY RESULTS

In hypertensive TOD, the NLRP3 inflammasome is activated by various stimuli such as oxidative stress and inflammation. Activation of NLRP3 inflammasome leads to the production of pro-inflammatory cytokines that exacerbate tissue damage and dysfunction. Natural products and formulations, including curcumin, resveratrol, triptolide, and allicin, have shown protective effects against hypertensive TOD by inhibiting the NLRP3 inflammasome.

CONCLUSIONS AND IMPLICATIONS

The NLRP3 inflammasome is a promising therapeutic target in hypertensive TOD. Natural products and formulations that inhibit the NLRP3 inflammasome may provide novel drug candidates or therapies for hypertensive TOD. Further studies are needed to elucidate the molecular mechanisms and optimize the dosages of these natural products and formulations and evaluate their clinical efficacy and safety.

Vitamin E-Inhibited Phoxim-Induced Renal Oxidative Stress and Mitochondrial Apoptosis In Vivo and In Vitro of Piglets

Exposure to phoxim at low levels caused bioaccumulation with neurotoxicity but also induced oxidative stress, tissue damage, and abnormal nutrient metabolism. This study described that vitamin E ameliorates phoxim-induced nephrotoxicity via inhibiting mitochondrial apoptosis. In vivo, 24 healthy piglets were treated with phoxim (0 mg/kg and 500 mg/kg) and vitamin E + phoxim (vitamin E + phoxim: 200 mg/kg + 500 mg/kg). In vitro, PK15 cells were treated with phoxim (0 mg/L and 1 mg/L) and vitamin E + phoxim (phoxim + vitamin E: 1 mg/L + 1 mg/L) for 12 h and 24 h. Our results indicated that accumulation of ROS, oxidative stress, and renal cell injury through stimulation of mitochondrial apoptosis resulted in phoxim-induced nephrotoxicity. Phoxim resulted in swollen mitochondria, blurred internal cristae, renal glomerular atrophy, and renal interstitial fibrosis. Vitamin E alleviated the adverse effects of phoxim by reducing ROS and improving antioxidant capacity in vivo and in vitro. Vitamin E significantly increased SDH in vitro (p < 0.01), while it decreased ROS, Bad, and cyto-c in vitro and SOD and CAT in vivo (p < 0.05). Vitamin E ameliorated phoxim-induced renal histopathologic changes, and mitochondria swelled. In addition, vitamin E regulates phoxim-induced apoptosis by alleviating oxidative damage to the mitochondria.

Targeting the adenosine monophosphate-activated protein kinase signalling pathway by bempedoic acid attenuates Angiotensin II-induced cardiac remodelling in renovascular hypertension in rats

The crosstalk between the renin-angiotensin system and Adenosine monophosphate-activated protein kinase (AMPK) gained significant interest due to their involvement in the pathogenesis of several cardiovascular diseases. Angiotensin II (Ang II) plays a crucial role in developing cardiac remodelling by inducing energy imbalance, inflammation, oxidative and endoplasmic reticulum stress, and transforming growth factor-β (TGF-β)-induced fibrosis. Ang II directly or through extracellular signal-regulated kinase (ERK) activation impairs AMPK signalling with well-known antioxidant, anti-inflammatory, and anti-fibrotic effects.

AIM

This study aimed to investigate the role of bempedoic acid, a novel antihyperlipidemic drug, in attenuating hypertension-induced cardiac remodelling in rats by modulating Ang II-induced damage and activating the AMPK signalling pathway.

METHOD

Sixty adult male Sprague Dawley rats were randomly allocated into the Sham control group, Hypertensive group, Captopril group (30 mg/kg), and Bempedoic acid group (30 mg/kg). Hypertension was induced by left renal artery ligation in all groups except the Sham control group. Treatment with captopril and bempedoic acid started 14 days post-surgy and lasted two weeks. Finally, Hemodynamic measurements and electrocardiographic examination were done followed by heart tissue samples collection for biochemical, histopathological, and immunohistochemical examinations.

KEY FINDINGS

Bempedoic acid preserved the cardiac function and electrocardiogram patterns. It inhibited endoplasmic reticulum stress, exhibited antioxidant activity, and increased endothelial nitric oxide synthase activity. Bempedoic acid interfered with ERK signalling pathways, including nuclear factor-κB and TGF-β, exerting anti-inflammatory and anti-fibrotic effects.

SIGNIFICANCE

These findings indicate the cardioprotective and antihypertrophic activity of bempedoic acid, which are suggested to result from energy-independent AMPK downstream signalling activation.

Alterations in Oxidative Stress Markers and Na,K-ATPase Enzyme Properties in Kidney after Fructose Intake and Quercetin Intervention in Rats

The study aimed to characterize the consequences of a 15-week intake of 10% fructose on the kidney, with the focus on oxidative stress markers and properties of the Na,K-ATPase enzyme. Various antioxidants naturally occurring in common food were demonstrated to be protective against fructose-induced deterioration of kidneys. Therefore, we also aimed to observe the effect of 6-week quercetin administration (20 mg/kg/day) that was initiated following the 9-week period of higher fructose intake, by determining the concentration of sodium, potassium, creatinine, urea, and glucose in blood plasma and oxidative status directly in the renal tissue. Kinetic studies of renal Na,K-ATPase were utilized for a deeper insight into the molecular principles of expected changes in this enzyme activity under conditions of presumed fructose-induced renal injury. Fructose intake led to increase in body weight gain, plasma glucose and sodium levels, and deterioration of kidney properties, although some compensatory mechanisms were observable. Quercetin administration improved glycemic control in rats exposed to fructose overload. However, an increase in plasma creatinine, a decrease in GSH/GSSG ratio in renal tissue homogenate, and a controversial effect on renal Na,K-ATPase enzyme suggest that quercetin treatment may not be beneficial in the condition of pre-existing renal pathology.

Effect of bempedoic acid on angiotensin-II induced hypertension and vascular tissue remodelling in renal hypertensive rats through AMPK multiple signalling pathways modulation

Angiotensin II (Ang II), the effector of the renin-angiotensin system (RAS), is a key player in the pathogenesis of chronic hypertension, accompanied by vascular tissue resistance, remodelling, and damage. Chronic activation of Ang II receptor 1 (AT-1R) impairs multiple cellular targets implicated in cellular protection and survival, including adenosine Monophosphate-activated protein kinase (AMPK) signalling. In addition, it induces oxidative damage, endoplasmic reticulum (ER) stress, and fibrotic changes in resistance vessels. Our study investigated the antihypertensive and antifibrotic effects of bempedoic acid, a first-in-class antihyperlipidemic drug that targets adenosine triphosphate-citrate lyase enzyme to inhibit cholesterol synthesis. We also studied the modulation of multiple AMPK signalling pathways by bempedoic acid in a chronic hypertension model in rats. Sixty male Sprague-Dawley rats were divided into four groups: sham group, hypertensive group, standard captopril group, and bempedoic treated group. All groups underwent left renal artery ligation except the sham group. Fourteen days post-surgery, captopril and bempedoic acid were administered with a dose of 30 mg/kg/day orally to captopril-standard and bempedoic acid-treated groups for two weeks, respectively. In mesenteric resistance arteries, bempedoic acid activated AMPK energy independently and augmented AMPK multiple cellular targets to adapt to Ang II-induced cellular stress. It exerted antioxidant activity, increased endothelial nitric oxide synthase, and reversed the ER stress. Bempedoic acid maintained vascular integrity and prevented vascular remodelling by inhibiting extracellular signal-regulated kinase (ERK)/transforming growth factor-β fibrotic pathway. These effects were reflected in the improved hemodynamic measurements.

Nobiletin resolves left ventricular and renal changes in 2K-1C hypertensive rats

This study investigated the effects of nobiletin on cardiorenal changes and the underlying mechanisms involved in two-kidney, one-clip (2K-1C) hypertension. 2K-1C rats were treated with nobiletin (15 or 30 mg/kg/day) or losartan (10 mg/kg/day) for 4 weeks (n = 8/group). Nobiletin (30 mg/kg) reduced high levels of blood pressure and circulating angiotensin II and angiotensin-converting enzyme activity in 2K-1C rats. Left ventricular (LV) dysfunction and remodelling in 2K-1C rats were alleviated in the nobiletin-treated group (P < 0.05). Nobiletin reduced the upregulation of Ang II type I receptor (AT₁R)/JAK (Janus kinase)/STAT (signal transducer and activator of transcription) protein expression in cardiac tissue of 2K-1C rats (P < 0.05). The reduction in kidney function, and accumulation of renal fibrosis in 2K-1C rats were alleviated by nobiletin (P < 0.05). Overexpression of AT₁R and NADPH oxidase 4 (Nox4) protein in nonclipped kidney tissue was suppressed in the nobiletin-treated group (P < 0.05). The elevations in oxidative stress parameters and the reductions in antioxidant enzymes were attenuated in 2K-1C rats treated with nobiletin (P < 0.05). In summary, nobiletin had renin-angiotensin system inhibitory and antioxidant effects and attenuated LV dysfunction and remodelling via restoration of the AT₁R/JAK/STAT pathway. Nobiletin also resolved renal damage that was related to modulation of the AT₁R/Nox4 cascade in 2K-1C hypertension.

Resveratrol and regular exercise may attenuate hypertension-induced cardiac dysfunction through modulation of cellular stress responses

AIMS

Hypertension is one of the major causes of cardiac damage. In this study, the effects of resveratrol supplementation and regular exercise on hypertension-induced cellular stress responses of myocardium were compared.

MAIN METHODS

Hypertension was induced in male Wistar rats by deoxycorticosterone-acetate + salt administration for 12 weeks. Resveratrol and regular exercise were applied for the last six weeks. In addition to biochemical and molecular examinations, isoprenaline, phenylephrine and, acetylcholine-mediated contractions and sinus rate were recorded in the isolated cardiac tissues.

KEY FINDINGS

Resveratrol and regular exercise reduced systolic blood pressure in hypertensive rats. The altered adrenergic and cholinergic responses of the right atrium and left papillary muscles in hypertension were separately improved by resveratrol and regular exercise. Resveratrol and regular exercise decreased plasma and cardiac total antioxidant capacity and, augmented the expression of antioxidant genes in hypertensive rats. While regular exercise restored the increase in p-PERK expression associated with endoplasmic reticulum stress and decrease in mitophagic marker PINK1 expression, resveratrol only ameliorated PINK1 expression in hypertensive rats. Resveratrol and exercise training suppressed hypertension-induced NLRP3 inflammasome activation by reversing the increase in NLRP3, p-NF-κB expression and the mature-IL-1β/pro-IL-1β and cleaved-caspase-1/pro-caspase-1 ratio. Resveratrol and exercise enhanced mRNA expression of caspase-3, bax, and bcl-2 involved in the apoptotic pathway, but attenuated phosphorylation of stress-related mitogenic proteins p38 and JNK induced by hypertension.

SIGNIFICANCE

Our study demonstrated the protective effect of resveratrol and exercise on hypertension-induced cardiac dysfunction by modulating cellular stress responses including oxidative stress, ER stress, mitophagy, NLRP3 inflammasome-mediated inflammation, and mitogenic activation.

Effect of resveratrol on C-reactive protein: An updated meta-analysis of randomized controlled trials

We conducted a meta-analysis on the available randomized clinical trials (RCTs) to assess the role of resveratrol in lowering C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP) levels, as markers of inflammation, in various inflammatory disorders. Literature search through Medline/PubMed, Scopus, ISI Web of Science, and Cochrane Library yielded 35 RCTs (24 studies for hs-CRP and 11 studies for CRP). Pooled results revealed that resveratrol supplementation significantly reduced the hs-CRP (MWD = -0.40 mg/L; 95% CI: -0.70 to -0.09 mg/L; p = .01) and CRP (MWD = -0.31 mg/L; 95% CI: -0.47 to -0.15 mg/L; p < .001) levels in serum. Subgroup analysis revealed that resveratrol in group with ≥10 weeks significantly reduces hs-CRP levels (MWD = -0.48 mg/L; 95% CI: -0.92 to -0.04 mg/L; p = .03) and CRP (WMD = -0.47 mg/L, 95% CI = -0.69 to -0.25, p < .001). A dose of ≥500 mg/day supplementation improves the levels of CRP, but not hs-CRP. This meta-analysis demonstrates that resveratrol consumption is effective in lowering the levels of CRP and hs-CRP in inflammatory conditions, especially if supplementation takes place for ≥10 weeks with ≥500 mg/day.

Resveratrol Protects Cardiac Tissue in Experimental Malignant Hypertension Due to Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Properties

Hypertension is one of the most prevalent and powerful contributors of cardiovascular diseases. Malignant hypertension is a relatively rare but extremely severe form of hypertension accompanied with heart, brain, and renal impairment. Resveratrol, a recently described grape-derived, polyphenolic antioxidant molecule, has been proposed as an effective agent in the prevention of cardiovascular diseases. This study was designed to examine chronic resveratrol administration on blood pressure, oxidative stress, and inflammation, with special emphasis on cardiac structure and function in two models of experimental hypertension. The experiments were performed in spontaneously (SHRs) and malignantly hypertensive rats (MHRs). The chronic administration of resveratrol significantly decreased blood pressure in both spontaneously and malignant hypertensive animals. The resveratrol treatment ameliorated morphological changes in the heart tissue. The immunohistochemistry of the heart tissue after resveratrol treatment showed that both TGF-β and Bax were not present in the myocytes of SHRs and were present mainly in the myocytes of MHRs. Resveratrol suppressed lipid peroxidation and significantly improved oxidative status and release of NO. These results suggest that resveratrol prevents hypertrophic and apoptotic consequences induced by high blood pressure with more pronounced effects in malignant hypertension.

Neurological Alterations and Testicular Damages in Aging Induced by D-Galactose and Neuro and Testicular Protective Effects of Combinations of Chitosan Nanoparticles, Resveratrol and Quercetin in Male Mice

Aging is a neurological disease that is afforded by incidence of oxidative stress. Chitosan has received global interests due to its wide medical uses. Quercetin (Q) is a bioflavonoid and widely distributed in vegetables and fruits. Resveratrol is considered as a potent antioxidant and is a component of a wide range of foods. The using of either chitosan nanopartciles (CH-NPs), querectin (Q), and resveratrol (RV) to reduce the oxidative stress and biochemical alterations on brain and testicular tissues induced by D-galactose (DG) (100 mg/Kg) were the aim of the present study. This study investigated the probable protective effects of CH-NPs in two doses (140,280 mg/Kg), Q (20 mg/Kg) and RV (20 mg/Kg), against DG induced aging and neurological alterations. Brain antioxidant capacity as malonaldehyde (MDA), catalase (CAT), and glutathione reductase (GRx), as well as histopathological damages of the brain and testicular tissues were measured. The DG treated group had significantly elevated the oxidative stress markers by 96% and 91.4% in brain and testicular tissues respectively and lower significantly the antioxidant enzyme activities of both brain and testicular tissues than those of the control group by 86.95%, 69.27%, 83.07%, and 69.43%. Groups of DG that treated with a combination of CH-NPs in two doses, Q and RV, the levels of oxidative stress marker declined significantly by 68.70%, 76.64% in brain tissues and by 74.07% and 76.61% in testicular tissues, and the enzymatic antioxidants increased significantly by 75.55%, 79.24%, 62.32%, and 61.97% as compared to the DG group. The present results indicate that CH-NPs, Q, and RV have protective effects against DG-induced brain and testis tissue damage at the biochemical and histopathological levels. Mechanisms of this protective effect of used compounds against neurological and testicular toxicity may be due to the enhanced brain and testis antioxidant capacities.

Strength Training Reduces Cardiac and Renal Oxidative Stress in Rats with Renovascular Hypertension

Fundamento

O treino de força tem efeitos benéficos em doenças renais, além de ajudar a melhorar a defesa antioxidante em animais saudáveis.

Objetivo

Verificar se o treino de força reduz o dano oxidativo ao coração e rim contralateral para cirurgia de indução de hipertensão renovascular, bem como avaliar as alterações na atividade das enzimas antioxidantes endógenas superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx).

Métodos

Dezoito ratos machos foram divididos em três grupos (n=6/grupo): placebo, hipertenso e hipertenso treinado. Os animais foram induzidos a hipertensão renovascular através da ligação da artéria renal esquerda. O treino de força foi iniciado quatro semanas após a indução da hipertensão renovascular, teve 12 semanas de duração e foi realizada a 70% de 1RM. Depois do período de treino, os animais foram submetidos a eutanásia e o rim esquerdo e o coração foram retirados para realizar a quantificação de peróxidos de hidrogênio, malondialdeído e grupos sulfidrílicos, que são marcadores de danos oxidativos. Além disso, foram medidas as atividades das enzimas antioxidantes superóxido dismutase, catalase e glutationa peroxidase. O nível de significância adotado foi de 5% (p < 0,05).

Resultados

Depois do treino de força, houve redução de danos oxidativos a lipídios e proteínas, como pode-se observar pela redução de peróxidos de hidrogênio e níveis sulfidrílicos totais, respectivamente. Além disso, houve um aumento nas atividades das enzimas antioxidantes superóxido dismutase, catalase e glutationa peroxidase.

Conclusão

O treino de força tem o potencial de reduzir danos oxidativos, aumentando a atividades de enzimas antioxidantes. (Arq Bras Cardiol. 2021; 116(1):4-11)

Effects of trans- versus cis-resveratrol on adrenergic contractions of the rat tail artery and role of endothelium

The health benefits of the natural polyphenol trans‐resveratrol may play an important role in preventing a variety of diseases. Resveratrol has been shown to reduce blood pressure and improve metabolic diseases such as type 2 diabetes mellitus and obesity. Our previous studies examined the role of K⁺ channels in the vasorelaxation responses to trans‐resveratrol in the rat tail artery. During these studies, we uncovered a novel transient contraction prior to the sustained relaxation effect of trans‐resveratrol. Thus, the purpose of this study was to determine the role of the endothelium in these vascular contraction and relaxation responses to trans‐resveratrol. We additionally sought to determine if the cis‐isomer of resveratrol exerts any of the same vascular effects as the trans‐isomer. The vascular responses to trans‐resveratrol were examined in rat tail arteries with intact or denuded endothelium over a 2‐hr period. Additionally, the vascular responses to trans‐ and cis‐resveratrol were compared in rat tail arteries with intact endothelium. Both the transient contractile response and the persistent relaxation response to trans‐resveratrol were similar in the arterial rings with intact or denuded endothelium. There was a significant correlation between the initial contraction‐enhancing action of trans‐resveratrol and the magnitude of the sustained relaxation for vessels with both intact and denuded endothelium. Moreover, we demonstrated that cis‐resveratrol produced a significantly greater relaxation response as compared to trans‐resveratrol without the initial contractile response. These data demonstrate the role of the vascular smooth muscle in the vascular responses to resveratrol and the potential clinical benefits of the cis‐isomer of resveratrol as compared to the trans‐isomer.

Resveratrol reduces oxidative damage and inflammation in mice infected with Trichinella spiralis

Trichinellosis is a serious food-borne zoonotic infection of cosmopolitan distribution. Currently, treatment for trichinellosis is far from ideal. Given the important role of oxidative stress and immune-mediated inflammation in the pathogenesis of trichinellosis, this study was designed to evaluate the possible protective effects of resveratrol (RSV) during the intestinal and muscular phases of Trichinella spiralis infection in mice. The oral administration of RSV at a dose of 20 mg/kg once daily for two weeks resulted in significant reductions in both adult and larval counts; significant improvements in the redox status of the small intestine and muscles; a significant reduction in interleukin 4, pentraxin 3 and vascular endothelial growth factor expression; and the mitigation of intestinal and muscular inflammation. In conclusion, this study identifies RSV as a promising agent for the treatment of experimental trichinellosis, and more studies in experimental animals and humans are worth consideration.

Resveratrol attenuates intestinal injury in irradiated rats via PI3K/Akt/mTOR signaling pathway

Radiation-induced enteritis is one of the greatest challenges in radiotherapy. The current study was designed to evaluate the ameliorative effect of resveratrol, which exhibits anti-inflammatory property, against radiation-induced intestinal injury in rats and to explore the underlying mechanism. Rats were exposed to a single dose of 5 Gy. Resveratrol (20 mg/kg/day) was orally administered to irradiated rats over 3 weeks. Results showed that resveratrol ameliorated the intestinal oxidative stress parameters; malondialdehyde (MDA) content, glutathione (GSH) level, and catalase (CAT) activity compared to irradiated group. Furthermore, resveratrol reduced the contents of inflammatory cytokines; tumor necrosis factor α (TNF-α), nuclear factor-kappa (NF-κB), and interleukin 1β (IL-1β) in intestine. Western blotting analysis revealed that resveratrol down-regulated the proteins expression of phosphoinositide 3-kinases (PI3K), protein kinase B (Akt) as well as the mammalian target of rapamycin (mTOR) in intestinal tissues of irradiated rats and thus reduced the inflammatory mediator production. These results were confirmed by histopathological investigation. In conclusion, resveratrol attenuated intestinal inflammation following irradiation via modulating PI3K/Akt/mTOR pathway and thereby could be a promising adjuvant in radiotherapy.

Vasorelaxant effect of 3,5,4'-trihydroxy-trans-stilbene (resveratrol) and its underlying mechanism

Resveratrol is found in numerous plant-based foods and beverages and is known to have an impact on the cardiovascular system. The aim of this study was to investigate the vasorelaxant effect of resveratrol and its underlying mechanisms by employing an aortic ring assay model. Resveratrol caused relaxation of aortic rings that had been precontracted with phenylephrine in the presence of endothelium or with potassium chloride in endothelium-intact aortic rings. The vasorelaxant effect was decreased in the absence of an endothelium. The mechanisms underlying the vasorelaxant effect of resveratrol were determined through the addition of antagonists. In the presence of the endothelium, indomethacin (a nonselective cyclooxygenase inhibitor), methylene blue (cyclic guanosine monophosphate lowering agent), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, selective soluble guanylate cyclase inhibitor), Nω-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor), tetraethylammonium (TEA, nonselective calcium activator potassium channel blocker), 4-aminopyridine (4-AP, voltage-dependent K⁺ channel blocker), barium chloride (BaCl₂, inwardly rectifying K⁺ channel blocker), glibenclamide (non-specific ATP-sensitive K⁺ channel blocker) and propranolol (β-adrenergic receptor blocker) led to a significant reduction in the vasorelaxation effect induced by resveratrol. Resveratrol was also found to reduce Ca²⁺ release from the sarcoplasmic reticulum and block calcium channels. In conclusion, resveratrol targets multiple signalling pathways for exerting its vasorelaxant effects in the rat aortic ring model in both the presence and absence of endothelium.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

Resveratrol prevents the development of high blood pressure in spontaneously hypertensive rats through the inhibition of enhanced expression of Giα proteins

Resveratrol (RV), a polyphenolic component of red wine, has been shown to attenuate high blood pressure (BP) in spontaneously hypertensive rats (SHRs). We previously found that the enhanced expression of Giα proteins plays a role in the pathogenesis of hypertension in SHRs. In the present study, we investigated whether this RV-induced decrease in BP in SHRs can be attributed to the ability of RV to inhibit the enhanced expression of Giα proteins and the upstream signaling molecules implicated in the overexpression of Giα proteins. Administration of RV (50 mg/kg per day) to prehypertensive 2-week-old SHRs for 6 weeks prevented the development of high BP and inhibited the enhanced expression of Giα proteins, the enhanced levels of superoxide anion (O2−) and NADPH oxidase activity, the enhanced activation (phosphorylation) of c-Src and growth factor receptors, as well as the enhanced levels of extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) exhibited by vascular smooth muscle cells isolated from SHRs. In conclusion, these results indicate that RV attenuates the development of high BP in SHRs through the inhibition of enhanced levels of Giα proteins, oxidative stress, and the upstream signaling molecules that contribute to the overexpression of Giα proteins. These findings suggest that RV could potentially be used as a therapeutic agent in the treatment of cardiovascular complications including hypertension.

Resveratrol and Vascular Function

Resveratrol increases the production of nitric oxide (NO) in endothelial cells by upregulating the expression of endothelial NO synthase (eNOS), stimulating eNOS enzymatic activity, and preventing eNOS uncoupling. At the same time, resveratrol inhibits the synthesis of endothelin-1 and reduces oxidative stress in both endothelial cells and smooth muscle cells. Pathological stimuli-induced smooth muscle cell proliferation, vascular remodeling, and arterial stiffness can be ameliorated by resveratrol as well. In addition, resveratrol also modulates immune cell function, inhibition of immune cell infiltration into the vascular wall, and improves the function of perivascular adipose tissue. All these mechanisms contribute to the protective effects of resveratrol on vascular function and blood pressure in vivo. Sirtuin 1, AMP-activated protein kinase, and estrogen receptors represent the major molecules mediating the vascular effects of resveratrol.

Resveratrol prevents combined prenatal NG-nitro-L-arginine-methyl ester (L-NAME) treatment plus postnatal high-fat diet induced programmed hypertension in adult rat offspring: interplay between nutrient-sensing signals, oxidative stress and gut microbiota

Oxidative stress, nutrient-sensing signals, high-fat (HF) intake and dysbiosis of gut microbiota are involved in the development of hypertension, a disorder that can originate in early life. We examined whether postnatal HF diet can aggravate maternal N^G-nitro-L-arginine-methyl ester (L-NAME) treatment-induced programmed hypertension and whether resveratrol therapy can prevent it. Pregnant Sprague-Dawley rats received L-NAME administration at 60 mg/kg/day subcutaneously during pregnancy alone, or with additional resveratrol (R) 50 mg/L in drinking water during the pregnancy and lactation. The offspring were onto either regular chow or HF diet (D12331) from weaning to 16 weeks of age. Male offspring rats were assigned to five groups (N=8/group): control, L-NAME, HF, L-NAME+HF and L-NAME+HF + R at weaning at 3 weeks of age. Rats were sacrificed at 16 weeks of age. We observed that postnatal HF diet exacerbates maternal L-NAME treatment-induced programmed hypertension in male adult offspring, which resveratrol attenuated. Combined L-LAME and HF diet-induced hypertension is related to increased oxidative stress, inhibiting AMP-activated protein kinase (AMPK)/ peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) pathway and altered gut microbiota compositions. L-NAME+HF caused an increase of the Firmicutes to Bacteroidetes ratio, which resveratrol therapy prevented. Additionally, the abundances of phylum Verrucomicrobia and genus Akkermansia were amplified by resveratrol therapy. Conclusively, our data highlighted the interactions between maternal NO deficiency, HF diet, AMPK/PGC-1α pathway and gut microbiota in which the blood pressure of adult offspring can be modified by resveratrol. Resveratrol might be a useful reprogramming strategy to prevent L-NAME and HF diet-induced hypertension of developmental origin.

The natural phenolic compounds as modulators of NADPH oxidases in hypertension

BACKGROUND

Hypertension is a major public health problem worldwide. It is an important risk factor for other cardiovascular diseases such as coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral vascular disease, chronic kidney disease, and atherosclerosis.

PURPOSE

There is strong evidence that excess ROS-derived NADPH oxidase (NOX) is an important agent in hypertension. It augments blood pressure in the presence of other pro-hypertensive factors such as angiotensin II (Ang II), an important and potent regulator of cardiovascular NADPH oxidase, activates NOX via AT1 receptors. NADPH oxidase, a multi-subunit complex enzyme, is considered as a key source of ROS production in the vasculature. The activation of this enzyme is needed for assembling Rac-1, p^40phox, p^47phox and p^67phox subunits. Since, hypertensive patients need to control blood pressure for their entire life and because drugs and other chemicals often induce adverse effects, the use of natural phenolic compounds which are less toxic and potentially beneficial may be good avenues of addition research in our understand of the underlying mechanism involved in hypertension. This review focused on several natural phenolic compounds as berberine, thymoquinone, catechin, celastrol, apocynin, resveratrol, curcumin, hesperidine and G-hesperidine, and quercetin which are NOX inhibitors. In addition, structure activity relationship of these compounds eventually as the most inhibitors was discussed.

METHODS

This comprehensive review is based on pertinent papers by a selective search using relevant keywords that was collected using online search engines and databases such as ScienceDirect, Scopus and PubMed. The literature mainly focusing on natural products with therapeutic efficacies against hypertension via experimental models both in vitro and in vivo was identified.

RESULTS

It has been observed that these natural compounds prevent NADPH oxidase expression and ROS production while increasing NO bioavailability. It have been reported that they improve hypertension due to formation of a stable radical with ROS-derived NADPH oxidase and preventing the assembly of NOX subunites.

CONCLUSION

It is clear that natural phenolic compounds have some potential inhibitory effect on NADPH oxidase activity. In comparison to other phenolic plant compounds, the structural variability of the flavonoids should off different impacts on oxidative stress in hypertension including inhibition of nadph oxidase and direct scavenging of free radicals.

The Effects of Resveratrol in Patients with Cardiovascular Disease and Heart Failure: A Narrative Review

Cardiovascular disease (CVD) is the main cause of death globally and responsible for the second highest number of deaths in Canada. Medical advancements in the treatment of CVD have led to patients living longer with CVD but often progressing to another condition called heart failure (HF). As a result, HF has emerged in the last decade as a major medical concern. Fortunately, various “traditional” pharmacotherapies for HF exist and have shown success in reducing HF-associated mortality. However, to augment the treatment of patients with CVD and/or HF, alternative pharmacotherapies using nutraceuticals have also shown promise in the prevention and treatment of these two conditions. One of these natural compounds considered to potentially help treat HF and CVD and prevent their development is resveratrol. Herein, we review the clinical findings of resveratrol’s ability to be used as an effective treatment to potentially help treat HF and CVD. This will allow us to gain a more fulsome appreciation for the effects of resveratrol in the health outcomes of specific patient populations who have various disorders that constitute CVD.

Food Bioactive HDAC Inhibitors in the Epigenetic Regulation of Heart Failure

Approximately 5.7 million U.S. adults have been diagnosed with heart failure (HF). More concerning is that one in nine U.S. deaths included HF as a contributing cause. Current HF drugs (e.g., β-blockers, ACEi) target intracellular signaling cascades downstream of cell surface receptors to prevent cardiac pump dysfunction. However, these drugs fail to target other redundant intracellular signaling pathways and, therefore, limit drug efficacy. As such, it has been postulated that compounds designed to target shared downstream mediators of these signaling pathways would be more efficacious for the treatment of HF. Histone deacetylation has been linked as a key pathogenetic element for the development of HF. Lysine residues undergo diverse and reversible post-translational modifications that include acetylation and have historically been studied as epigenetic modifiers of histone tails within chromatin that provide an important mechanism for regulating gene expression. Of recent, bioactive compounds within our diet have been linked to the regulation of gene expression, in part, through regulation of the epi-genome. It has been reported that food bioactives regulate histone acetylation via direct regulation of writer (histone acetyl transferases, HATs) and eraser (histone deacetylases, HDACs) proteins. Therefore, bioactive food compounds offer unique therapeutic strategies as epigenetic modifiers of heart failure. This review will highlight food bio-actives as modifiers of histone deacetylase activity in the heart.

Boldine Improves Kidney Damage in the Goldblatt 2K1C Model Avoiding the Increase in TGF-β

Boldine, a major aporphine alkaloid found in the Chilean boldo tree, is a potent antioxidant. Oxidative stress plays a detrimental role in the pathogenesis of kidney damage in renovascular hypertension (RVH). The activation of the renin-angiotensin system (RAS) is crucial to the development and progression of hypertensive renal damage and TGF-β is closely associated with the activation of RAS. In the present study, we assessed the effect of boldine on the progression of kidney disease using the 2K1C hypertension model and identifying mediators in the RAS, such as TGF-β, that could be modulated by this alkaloid. Toward this hypothesis, rats (n = 5/group) were treated with boldine (50 mg/kg/day, gavage) for six weeks after 2K1C surgery (pressure ≥ 180 mmHg). Kidney function was evaluated by measuring of proteinuria/creatininuria ratio (U prot/U Crea), oxidative stress (OS) by measuring thiobarbituric acid reactive substances (TBARS). The evolution of systolic blood pressure (SBP) was followed weekly. Alpha-smooth muscle actin (α-SMA) and Col III were used as markers of kidney damage; ED-1 and osteopontin (OPN) were used as markers of inflammation. We also explored the effect in RAS mediators, such as ACE-1 and TGF-β. Boldine treatment reduced the UProt/UCrea ratio, plasma TBARS, and slightly reduced SBP in 2K1C hypertensive rats, producing no effect in control animals. In 2K1C rats treated with boldine the levels of α-SMA, Col III, ED-1, and OPN were lower when compared to 2K1C rats. Boldine prevented the increase in ACE-1 and TGF-β in 2K1C rats, suggesting that boldine reduces kidney damage. These results suggest that boldine could potentially be used as a nutraceutic.

Anti-inflammatory and antioxidant role of resveratrol on nicotine-induced lung changes in male rats

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Nicotine decreased the antioxidant capacities in male rats.

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The lung of nicotine-treated rats showed severe congestion of the alveolar lung tissues.

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Resveratrol exerts its protective effect by alleviating the extent of oxidative status induced by nicotine.

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Resveratrol improve the enzymatic/non-enzymatic antioxidant defense system in rats treated with combination of nicotine and resveratrol.

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Resveratrol decreases the pathological changes in animals against the lung damage caused by nicotine.

Male albino rats of Wistar strain were injected intraperitoneally with nicotine or/and resveratrol for 4 weeks. Serum Interleukin-2, Interleukin-6, alpha-fetoprotein and tumor necrosis-alpha, as well as plasma 8-hydroxydeoxyguanosine of nicotine-treated rats were increased significantly. Myeloperoxidase, xanthine oxidase, nitric oxide, lipid peroxidation and total oxidative status of the lung in nicotine-treated rats were increased significantly, which were brought down to normal in resveratrol co-treated group. Endogenous antioxidant status as the activity of superoxide dismutase, catalase, glutathione peroxidase, and glucose-6-phosphate dehydrogenases were found to be decreased significantly in the lung of the nicotine-treated group, which were significantly raised in resveratrol-administered groups. The non-enzymatic antioxidants as total antioxidant and thiol levels were decreased significantly as the effect of nicotine that was effectively enhanced by resveratrol treatment. The lung of nicotine-treated rats showed severe congestion of the alveolar lung tissues with scattered congestion per bronchiolar and perivascular cells, as well as, inflammatory cells were observed. The data suggested that resveratrol exerts its protective effect by modulating the extent of oxidative status and improving the enzymatic/non-enzymatic antioxidant defense system, moreover, decreases the pathological changes in animals against the lung damage caused by nicotine.

Resveratrol can both enhance and relax adrenergic contractions of the rat tail artery

Our aims were to determine 1) if resveratrol's vasorelaxant action is greater in the distal (resistance) versus proximal (conductance) portion of the rat tail artery, and 2) if it can be blocked by agents known to block different potassium (K) channels in arterial smooth muscle. We found that its half-maximally effective concentration values were essentially identical (25 ± 3 versus 27 ± 3 μM) for relaxing adrenergically-precontracted rings prepared from distal versus proximal tissues. This does not confirm a previous report of greater relaxation in resistance versus conductance arteries. We also found that its relaxation could not be blocked by any of seven different K channel blockers. However, we uncovered a novel unanticipated action not yet reported. In half our arterial ring preparations, resveratrol transiently enhanced adrenergically-induced precontractions beginning well before its sustained relaxant effect became apparent. This action provides the first reasonable explanation for previously unexplained increases in arterial pressures observed during acute intravenous administration of resveratrol to animal models of traumatic ischemic tissue injury, in which hypotension is often present and in need of correction. Also unanticipated, this same transient enhancement of adrenergic contraction was notably inhibited by some of the same K channel blockers (particularly tetraethylammonium and glibenclamide) that failed to influence its relaxant effect. Although we do not rule out smooth muscle as a possible site for such a paradoxical finding, we suspect resveratrol could also be acting on K-selective mechano-sensitive ion channels located in the endothelium where they may participate in release of contracting factors.

Protection of Lotus Seedpod Proanthocyanidins on Organs and Tissues under High-intensity Excercise

Lotus seedpod proanthocyanidins (LSPC) as a kind of polyphenols is widely used in medicines, cosmetics, health products. High-intensity exercise can cause damage to the body's organs and tissues. Different doses of LSPC is given to mice to check the function of protect effect to the body's organs and tissues under high-intensity exercise. The hemoglobin (HB) content, red blood cell (RBC) number and white blood cell (WBC) number were tested for mice after exercise. The activity of superoxide dismutase (SOD) and the contents of glutathione (GSH) and malondialdehyde (MDA) in muscle and viscera were evaluated. The result showed that LSPC can effectively reduce inflammation reaction in the body of mice with high intensity exercise, alleviate oxidative stress-induced injury of tissues and organs, and execute protective function on skeletal muscle and cardiac muscle. And the LSPC could enhance myocardial anti-oxygen and enzymatic activity which suggests the protective effects of resveratrol against exercise-induced myocardial damage in mice.

Phytochemical Compounds and Protection from Cardiovascular Diseases: A State of the Art

Cardiovascular diseases represent a worldwide relevant socioeconomical problem. Cardiovascular disease prevention relies also on lifestyle changes, including dietary habits. The cardioprotective effects of several foods and dietary supplements in both animal models and in humans have been explored. It was found that beneficial effects are mainly dependent on antioxidant and anti-inflammatory properties, also involving modulation of mitochondrial function. Resveratrol is one of the most studied phytochemical compounds and it is provided with several benefits in cardiovascular diseases as well as in other pathological conditions (such as cancer). Other relevant compounds are Brassica oleracea, curcumin, and berberine, and they all exert beneficial effects in several diseases. In the attempt to provide a comprehensive reference tool for both researchers and clinicians, we summarized in the present paper the existing literature on both preclinical and clinical cardioprotective effects of each mentioned phytochemical. We structured the discussion of each compound by analyzing, first, its cellular molecular targets of action, subsequently focusing on results from applications in both ex vivo and in vivo models, finally discussing the relevance of the compound in the context of human diseases.

Cholesterol Metabolism in CKD

Patients with chronic kidney disease (CKD) have a substantial risk of developing coronary artery disease. Traditional cardiovascular disease (CVD) risk factors such as hypertension and hyperlipidemia do not adequately explain the high prevalence of CVD in CKD. Both CVD and CKD are inflammatory states and inflammation adversely affects lipid balance. Dyslipidemia in CKD is characterized by elevated triglyceride levels and high-density lipoprotein levels that are both decreased and dysfunctional. This dysfunctional high-density lipoprotein becomes proinflammatory and loses its atheroprotective ability to promote cholesterol efflux from cells, including lipid-overloaded macrophages in the arterial wall. Elevated triglyceride levels result primarily from defective clearance. The weak association between low-density lipoprotein cholesterol level and coronary risk in CKD has led to controversy over the usefulness of statin therapy. This review examines disrupted cholesterol transport in CKD, presenting both clinical and preclinical evidence of the effect of the uremic environment on vascular lipid accumulation. Preventative and treatment strategies are explored.

Anti-Inflammatory and Organ-Protective Effects of Resveratrol in Trauma-Hemorrhagic Injury

Resveratrol, a natural polyphenolic compound of grape and red wine, owns potential anti-inflammatory effects, which results in the reduction of cytokines overproduction, the inhibition of neutrophil activity, and the alteration of adhesion molecules expression. Resveratrol also possesses antioxidant, anti-coagulation and anti-aging properties, and it may control of cell cycle and apoptosis. Resveratrol has been shown to reduce organ damage following traumatic and shock-like states. Such protective phenomenon is reported to be implicated in a variety of intracellular signaling pathways including the activation of estrogen receptor, the regulation of the sirtuin 1/nuclear factor-kappa B and mitogen-activated protein kinases/hemeoxygenase-1 pathway, and the mediation of proinflammatory cytokines and reactive oxygen species formation and reaction. In the recent studies, resveratrol attenuates hepatocyte injury and improves cardiac contractility due to reduction of proinflammatory mediator expression and ameliorates hypoxia-induced liver and kidney mitochondrial dysfunction following trauma and hemorrhagic injuries. Moreover, through anti-inflammatory effects and antioxidant properties, the resveratrol is believed to protect organ function in trauma-hemorrhagic injury. In this review, the organ-protective and anti-inflammatory effects of resveratrol in trauma-hemorrhagic injury will be discussed.

Resveratrol increases CD68⁺ Kupffer cells colocalized with adipose differentiation-related protein and ameliorates high-fat-diet-induced fatty liver in mice

SCOPE

Resveratrol reportedly improves fatty liver. This study purposed to elucidate the effect of resveratrol on fatty liver in mice fed a high-fat (HF) diet, and to investigate the role of liver macrophages (Kupffer cells).

METHODS AND RESULTS

C57BL/6 mice were divided into three groups, receiving either a control diet, HF diet (50% fat), or HF supplemented with 0.2% resveratrol (HF + res) diet, for 8 weeks. Compared with the HF group, the HF + res group exhibited markedly attenuated fatty liver, and reduced lipid droplets (LDs) in hepatocytes. Proteomic analysis demonstrated that the most downregulated protein in the livers of the HF + res group was adipose differentiation-related protein (ADFP), which is a major constituent of LDs and reflects lipid accumulation in cells. The HF + res group exhibited greatly increased numbers of CD68(+) Kupffer cells with phagocytic activity. Immunohistochemistry showed that several CD68(+) Kupffer cells were colocalized with ADFP immunoreaction in the HF + res group. Additionally, the HF + res group demonstrated markedly decreased TNF-alpha production, which confirmed by both liver mononuclear cells stimulated by LPS in vitro and in situ hybridization analysis, compared with the HF group.

CONCLUSION

Resveratrol ameliorated fatty liver and increased CD68-positive Kupffer cells with downregulating ADFP expression.

Lack of efficacy of resveratrol on C-reactive protein and selected cardiovascular risk factors--Results from a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Numerous studies have suggested that oral supplementation with resveratrol exerts cardioprotective effects, but evidence of the effects on C-reactive protein (CRP) plasma levels and other cardiovascular (CV) risk factors is inconclusive. Therefore, we performed a meta-analysis to evaluate the efficacy of resveratrol supplementation on plasma CRP concentrations and selected predictors of CV risk.

METHODS

The search included PUBMED, Cochrane Library, Web of Science, Scopus, and EMBASE (up to August 31, 2014) to identify RCTs investigating the effects of resveratrol supplementation on selected CV risk factors. Quantitative data synthesis was performed using a random-effects model, with weighted mean difference (WMD) and 95% confidence intervals (CI) as summary statistics.

RESULTS

Meta-analysis of data from 10 RCTs (11 treatment arms) did not support a significant effect of resveratrol supplementation in altering plasma CRP concentrations (WMD: -0.144 mg/L, 95% CI: -0.968-0.680, p = 0.731). Resveratrol supplementation was not found to alter plasma levels of total cholesterol (WMD: 1.49 mg/dL, 95% CI: -14.96-17.93, p = 0.859), low density lipoprotein cholesterol (WMD: -0.31 mg/dL, 95% CI: -9.57-8.95, p = 0.948), triglycerides (WMD: 2.67 mg/dL, 95% CI: -28.34-33.67, p = 0.866), and glucose (WMD: 1.28 mg/dL, 95% CI: -5.28-7.84, p = 0.703). It also slightly reduced high density lipoprotein cholesterol concentrations (WMD: -4.18 mg/dL, 95% CI: -6.54 to -1.82, p = 0.001). Likewise, no significant effect was observed on systolic (WMD: 0.82 mmHg, 95% CI: -8.86-10.50, p = 0.868) and diastolic blood pressure (WMD: 1.72 mm Hg, 95% CI: -6.29-9.73, p=0.674).

CONCLUSIONS

This meta-analysis of available RCTs does not suggest any benefit of resveratrol supplementation on CV risk factors. Larger, well-designed trials are necessary to confirm these results.

Metabolic effects of resveratrol: addressing the controversies

Resveratrol, a polyphenol found in a number of plant-based foods such as red wine, has received a great deal of attention for its diverse array of healthful effects. Beneficial effects of resveratrol are diverse; they include improvement of mitochondrial function, protection against obesity and obesity-related diseases such as type-2 diabetes, suppression of inflammation and cancer cell growth and protection against cardiovascular dysfunction, just to name a few. Investigations into the metabolic effects of resveratrol are furthest along and now include a number of clinical trials, which have yielded mixed results. There are a number of controversies surrounding resveratrol that have not been resolved. Here, we will review these controversies with particular emphasis on its mechanism of metabolic action and how lessons from resveratrol may help develop therapies that harness the effects of resveratrol but without the undesirable properties of resveratrol.

Resveratrol prevents pathological but not physiological cardiac hypertrophy

The mechanisms responsible for how resveratrol inhibits pathological left ventricular hypertrophy (LVH) but not physiological LVH have not been elucidated. Herein, we show that in rat cardiomyocytes, lower concentrations of resveratrol (0.1 and 1 μM) are efficient at selectively inhibiting important regulators involved in pathological LVH (such as nuclear factor of activated T cells (NFAT)) while not affecting pathways involved in physiological LVH (Akt and p70S6 kinase (p70S6K)). These differential responses are also observed in both mouse and rat models of in vivo physiological and pathological LVH. Interestingly, in all of the experiments involving a low concentration of resveratrol (1 μM), the observed effects on Akt, p70S6K, and NFAT were independent from AMP-activated protein kinase (AMPK) activation while these effects at higher concentrations of resveratrol (50 μM) were potentiated by AMPK activation. In summary, we show that resveratrol can concentration/dose selectively inhibit various pro-hypertrophic signaling pathways and that resveratrol has differential effects on the modification of these signaling cascades in response to pathological stimuli versus physiological stimuli. This has important clinical implications as our findings support the concept that resveratrol may be useful in the selective treatment of pathological LVH.

KEY MESSAGE

Resveratrol differentially regulates pathological and physiological cardiac hypertrophy. Resveratrol dose selectively inhibits pathological cardiac signaling pathways. Resveratrol inhibits NFAT-dependent transcription. At low concentrations, effects of resveratrol are AMPK-independent. Resveratrol may be used to selectively treat pathological cardiac hypertrophy.

Experimental studies of the molecular pathways regulated by exercise and resveratrol in heart, skeletal muscle and the vasculature

Regular exercise contributes to healthy aging and the prevention of chronic disease. Recent research has focused on the development of molecules, such as resveratrol, that activate similar metabolic and stress response pathways as exercise training. In this review, we describe the effects of exercise training and resveratrol on some of the organs and tissues that act in concert to transport oxygen throughout the body. In particular, we focus on animal studies that investigate the molecular signaling pathways induced by these interventions. We also compare and contrast the effects of exercise and resveratrol in diseased states.

Systemic and renal oxidative stress in the pathogenesis of hypertension: modulation of long-term control of arterial blood pressure by resveratrol

Hypertension affects over 25% of the global population and is associated with grave and often fatal complications that affect many organ systems. Although great advancements have been made in the clinical assessment and treatment of hypertension, the cause of hypertension in over 90% of these patients is unknown, which hampers the development of targeted and more effective treatment. The etiology of hypertension involves multiple pathological processes and organ systems, however one unifying feature of all of these contributing factors is oxidative stress. Once the body's natural anti-oxidant defense mechanisms are overwhelmed, reactive oxygen species (ROS) begin to accumulate in the tissues. ROS play important roles in normal regulation of many physiological processes, however in excess they are detrimental and cause widespread cell and tissue damage as well as derangements in many physiological processes. Thus, control of oxidative stress has become an attractive target for pharmacotherapy to prevent and manage hypertension. Resveratrol (trans-3,5,4'-Trihydroxystilbene) is a naturally occurring polyphenol which has anti-oxidant effects in vivo. Many studies have shown anti-hypertensive effects of resveratrol in different pre-clinical models of hypertension, via a multitude of mechanisms that include its function as an anti-oxidant. However, results have been mixed and in some cases resveratrol has no effect on blood pressure. This may be due to the heavy emphasis on peripheral vasodilator effects of resveratrol and virtually no investigation of its potential renal effects. This is particularly troubling in the arena of hypertension, where it is well known and accepted that the kidney plays an essential role in the long term regulation of arterial pressure and a vital role in the initiation, development and maintenance of chronic hypertension. It is thus the focus of this review to discuss the potential of resveratrol as an anti-hypertensive treatment via amelioration of oxidative stress within the framework of the fundamental physiological principles of long term regulation of arterial blood pressure.

Cell-permeable protein therapy for complex I dysfunction

Complex I deficiency is difficult to treat because of the size and complexity of the multi-subunit enzyme complex. Mutations or deletions in the mitochondrial genome are not amenable to gene therapy. However, animal studies have shown that yeast-derived internal NADH quinone oxidoreductase (Ndi1) can be delivered as a cell-permeable recombinant protein (Tat-Ndi1) that can functionally replace complex I damaged by ischemia/reperfusion. Current and future treatment of disorders affecting complex I are discussed, including the use of Tat-Ndi1.

Resveratrol: therapeutic potential for improving cardiometabolic health

BACKGROUND

Resveratrol, a natural polyphenol, has gained attention in recent years because of its connection with the health benefits of red wine and its anticancer activity in vitro. Studies in animal models have demonstrated beneficial effects on glucose metabolism, vascular function and anti-inflammatory and antioxidant properties. Human studies designed to understand the role of resveratrol in the prevention and treatment of age-related conditions such as diabetes, heart disease, and cancer have recently been undertaken.

METHODS

We searched PubMed for original articles that reported studies of resveratrol in humans, using search terms, including resveratrol, human studies, glucose metabolism, vascular function, and inflammation. We also searched the reference lists of identified articles for additional papers and sought expert opinion on relevant studies.

RESULTS

Resveratrol treatment has shown beneficial effects on glucose and lipid metabolism in some, but not all studies. Study population, resveratrol source, and dose have varied widely, potentially explaining inconsistent findings. Improvements were noted in endothelial function, systolic blood pressure, and markers of oxidative stress and inflammation in several studies.

CONCLUSIONS

Despite the strong preclinical evidence of positive cardiometabolic effects, studies to date have not confirmed resveratrol's benefit in humans. Study variability and methodological issues limit interpretation of available results. Additional research, focusing on subjects with defined metabolic defects and using a range of doses, is needed to advance the field.