Are the cardioprotective effects of the phytoestrogen resveratrol sex-dependent? 1.

Cardiovascular disease (CVD) is the number one cause of death in both men and women. Younger women have a lower risk for CVD, but their risk increases considerably after menopause when estrogen levels decrease. The cardiovascular protective properties of estrogen are mediated through decreasing vascular inflammation and progression of atherosclerosis, decreasing endothelial cell damage by preventing apoptosis and anti-hypertrophic mechanisms. Estrogen also regulates glucose and lipid levels, which are 2 important risk factors for CVD. Resveratrol (RES), a cardioprotective polyphenolic compound, is classified as a phytoestrogen due its capacity to bind to and modulate estrogen receptor signalling. Due to its estrogen-like property, we speculate that the cardioprotective effects of RES treatment could be sex-dependent. Based on earlier reports and more recent data from our lab presented here, we found that RES treatment may have more favourable cardiovascular outcomes in females than in males. This review will discuss estrogen- and phytoestrogen-mediated cardioprotection, with a specific focus on sex-dependent effects reported in preclinical and clinical studies.

Garlic extracts prevent oxidative stress, hypertrophy and apoptosis in cardiomyocytes: a role for nitric oxide and hydrogen sulfide.

BACKGROUND: In ancient times, plants were recognized for their medicinal properties. Later, the arrival of synthetic drugs pushed it to the backstage. However, from being merely used for food, plants are now been widely explored for their therapeutic value. The current study explores the potential of skin and flesh extracts from a hard-necked Rocambole variety of purple garlic in preventing cardiomyocyte hypertrophy and cell death. METHODS: Norepinephrine (NE) was used to induce hypertrophy in adult rat cardiomyocytes pretreated with garlic skin and flesh extracts. Cell death was measured as ratio of rod to round shaped cardiomyocytes. Fluorescent probes were used to measure apoptosis and oxidative stress in cardiomyocytes treated with and without extracts and NE. Pharmacological blockade of nitric oxide (NO) and hydrogen sulfide (H2S) were used to elucidate the mechanism of action of garlic extracts. Garlic extract samples were also tested for alliin and allicin concentrations. RESULTS: Exposure of cardiomyocytes to NE induced an increase in cell size and cell death; this increase was significantly prevented upon treatment with garlic skin and flesh extracts. Norepinephrine increased apoptosis and oxidative stress in cardiomyocytes which was prevented upon pretreatment with skin and flesh extracts; NO, and H2S blockers significantly inhibited this beneficial effect. Allicin and alliin concentration were significantly higher in garlic flesh extract when compared to the skin extract. CONCLUSION: These results suggest that both skin and flesh garlic extracts are effective in preventing NE induced cardiomyocyte hypertrophy and cell death. Reduction in oxidative stress may also play an important role in the anti-hypertrophic and anti-apoptotic properties of garlic extracts. These beneficial effects may in part be mediated by NO and H2S.

Resveratrol arrests and regresses the development of pressure overload- but not volume overload-induced cardiac hypertrophy in rats.

Cardiac hypertrophy is a compensatory enlargement of the heart due to either volume overload (VO) and/or pressure overload (PO) that develops into heart failure if left untreated. The polyphenol resveratrol has been reported to regress PO-induced cardiac hypertrophy in rats. Our aim in this study was to assess the effectiveness of resveratrol on VO-induced cardiac hypertrophy. Sprague Dawley rats were subjected to aortocaval shunt and abdominal aortic banding surgeries to create VO and PO, respectively; sham-operated rats served as controls. To arrest the development of cardiac hypertrophy, daily resveratrol treatment (2.5 mg/kg body weight) was started 2 d postsurgery for 26 d and assessed by echocardiography at 2, 14, and 28 d postsurgery. Similarly, to regress cardiac hypertrophy resveratrol treatment was started after structural and functional abnormalities developed (14 d postsurgery) for 14 d and assessed by echocardiography at 14 and 28 d postsurgery. VO surgeries induced eccentric hypertrophy characterized by increased left ventricle internal dimensions (LVID) without wall thickening. Conversely, PO induced concentric hypertrophy with increased wall thickness without change in LVID. Lipid peroxidation, a marker for oxidative stress, was significantly elevated in both PO and VO rats. Resveratrol treatment arrested the development and regressed abnormalities in cardiac structure and function in PO but not VO rats. Treatment with resveratrol also significantly reduced oxidative stress in cardiac tissue of PO and VO rats. The results on cardiac structure and function demonstrate a potential for resveratrol in the treatment of cardiac hypertrophy due to PO but not VO.

Supplementation of Type 1 Diabetic Rats with Carrot Powder Lowers Blood Glucose without Improving Cardiac Structure and Function.

Foods and food bioactives have shown to be effective in preventing some human disease conditions. In this study, we examined the effects of carrot powder, rich in carotenoids, as a dietary supplement for the prevention of cardiac anomalies in streptozotocin (STZ) induced type 1 diabetic rats. Male Wistar rats were fed either control or carrot powder containing diet for 3 weeks. Type 1 diabetes was induced with STZ injection (65 mg/kg body weight) in half of the rats in each group. All rats were continued on their respective diet for a further 9 weeks. Cardiac structural and functional parameters were measured using echocardiography at 8 weeks post STZ administration. In comparison to non-diabetic rats, diabetic rats showed significant increase in isovolumetric relaxation time and a significant decrease in systolic function parameter, cardiac output. Left ventricular internal dimension and left ventricular posterior wall thickness were significantly higher in diabetic animals. Blood glucose levels were significantly lower in carrot supplemented diabetic rats when compared with non-treated diabetic rats. Diabetic rats treated and untreated had elevated level of lipid peroxidation. Catalase levels were significantly elevated in the carrot powder supplemented diabetic rats when compared to the control rats. Carrot supplementation lowered blood glucose levels significantly but did not normalize it to control levels. It had no effect on cardiac abnormalities and anti-oxidant status in rats with type 1 diabetes.

Cyanidin 3-O-glucoside prevents the development of maladaptive cardiac hypertrophy and diastolic heart dysfunction in 20-week-old spontaneously hypertensive rats.

The present study investigated the effects of cyanidin 3-O-glucoside (C3G) in cardiomyocytes (CM) and fibroblasts exposed to endothelin 1 (ET1), as well as in the spontaneously hypertensive rat (SHR) model, alone or in combination with hydrochlorothiazide (HCT). Adult rat CM and cardiac fibroblasts (CF) were pretreated with C3G and co-incubated with ET1 (10-7 M) for 24 hours. Five-week-old male SHR and their normotensive controls, Wistar-Kyoto rats (WKY), received one of 4 treatments via oral gavage daily for 15 weeks: (1) water (control); (2) C3G (10 mg per kg per day); (3) HCT (10 mg per kg per day); (4) C3G + HCT (10 mg per kg per day each). Blood pressure (BP) was measured at 1, 8 and 15 weeks. Echocardiography measurements were performed at 15 weeks. C3G prevented ET1-induced CM death and hypertrophy. Stimulating CF with ET1 did not induce their phenoconversion; nevertheless, C3G inhibited un-stimulated CF differentiation. HCT slowed the rise of systolic BP (SBP) in the SHR over time (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs HCT = 129 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs HCT = 168 ± 7.3 mmHg), but C3G had no effect on SBP (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs C3G = 126 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs C3G = 186 ± 7.3 mmHg). SHRs treated with C3G, HCT, and C3G + HCT had lower left ventricular mass and shorter isovolumetric relaxation time compared to control SHRs. C3G ameliorated cardiac hypertrophy and diastolic dysfunction in SHRs.

Canola oil rich in oleic acid improves diastolic heart function in diet-induced obese rats.

Obesity is a leading cause of cardiovascular disease. It directly affects heart structure and function and contributes to heart failure. Diet is a major factor involved in the development of obesity along with genetic factors. We examined the effects of monounsaturated and polyunsaturated fatty acid-rich oils on cardiac structure and function in the diet-induced rodent model of obesity (DIO). Obese prone (OP) rats were fed a high-fat diet (HF; 55% of kcal) for 12 weeks; Sprague-Dawley rats fed commercial chow served as control. Echocardiography was performed to assess the cardiac structure and function in all rats at 12 weeks. OP rats fed the HF diet showed significant impairment in diastolic function compared to control rats. The HF diet containing high oleic canola oil significantly improved diastolic function of OP rats compared to the HF diet with lard. In conclusion, canola oil rich in oleic acid, when incorporated into an HF diet, prevents the development of diastolic dysfunction in DIO rats.

Resveratrol is equipotent to perindopril in attenuating post-infarct cardiac remodeling and contractile dysfunction in rats.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors improve prognosis in patients with post-myocardial infarction (MI) related cardiac dysfunction. Resveratrol is a polyphenol that has been reported to be beneficial in hypertension, ischemic heart disease, and cardiotoxicity in preclinical studies. Accordingly, we investigated the comparative and combinatorial efficacy of resveratrol and perindopril (ACE inhibitor) treatment on MI-related cardiac remodeling and contractile dysfunction. METHODS: Left anterior descending artery-ligated and sham-operated male Sprague-Dawley rats were gavaged with vehicle, resveratrol, perindopril, and combination of resveratrol+perindopril (2.5 mg/kg bodyweight/day) for 8 weeks (starting immediately after acute MI). Echocardiography was performed to assess cardiac structure and function at baseline and 8 weeks. RESULTS: At 8 weeks, vehicle-MI rats had a significantly lower left ventricular ejection fraction (LVEF) and increased LV dilatation compared to vehicle-sham rats. MI rats treated with resveratrol, perindopril and a combination of both had significantly improved LVEF and reduced LV dilatation. Vehicle-treated MI rats also had increased level of lipid peroxidation product- malondialdehyde (MDA), proinflammatory protein- tumor necrosis factor-alpha (TNF-α) and cardiac fibrosis marker- collagen and decreased enzymatic activity of superoxide dismutase and catalase compared to vehicle-sham rats. Resveratrol, perindopril and combination of both significantly prevented the /ed to determine systolic functional parameter increase in MDA, TNF-α and collagen and improved the activity of superoxide dismutase and catalase in MI rats compared to vehicle-MI rats. CONCLUSION: Treatment with resveratrol or perindopril was equivalent in significantly improving remodeling and attenuation of contractile dysfunction in MI rats. Combination treatment also attenuated the cardiac abnormalities. The improvement in cardiac abnormalities may partly be through reducing oxidative stress by preventing the decrease in the activity of superoxide dismutase and catalase, and decreasing cardiac inflammation and fibrosis.

The efficacy of resveratrol in controlling hypertension: study protocol for a randomized, crossover, double-blinded, placebo-controlled trial.

BACKGROUND: Hypertension is a global health concern for which novel treatment strategies are necessary. The aim of this study is to evaluate the efficacy of resveratrol (trans-3, 5, 4'-trihydroxystilbene, a polyphenol present in grapes) in controlling blood pressure in participants diagnosed with prehypertension and stage 1 hypertension. METHODS/DESIGN: In a randomized, crossover, double-blinded, placebo-controlled study, 50 participants with prehypertension (diastolic blood pressure and systolic blood pressure, 80-89 mmHg and 120-139 mmHg, respectively) and 50 participants with stage 1 hypertension (diastolic and systolic, 90-99 mmHg and 140-159 mmHg, respectively) will be assigned to receive resveratrol (99 % pure, from Biotivia Longevity Bioceuticals LLC Company, USA, in 500 mg capsules, twice daily for 4 weeks, orally) or placebo (500 mg neutral microcellulose capsules, twice daily for 4 weeks) in a 2 × 2 crossover design (4 weeks treatment-4 weeks washout-4 weeks treatment). The blood pressure of each participant will be recorded (a mean of two times within a 15-minute interval) every week during the study. The participants in the prehypertensive group will not receive any medication, while those in the stage 1 hypertensive group will continue to receive their routine medications during the study. Blood samples will be taken from all groups and examined for various biochemical parameters. DISCUSSION: This trial will help to establish whether resveratrol is an effective antihypertensive agent in prehypertensive and stage 1-hypertensive patients. The trial outcome will provide novel insight into the clinical efficacy of resveratrol and provide valuable information for conducting future clinical studies with resveratrol. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT201407078129N7. Registered on 15 August 2014.

Potential of resveratrol in the treatment of heart failure.

The concept of food has expanded beyond its traditional role of survival and hunger satisfaction, to include a role in the prevention and treatment of disease. Polyphenols are classes of compounds that are synthesized by plants to serve a wide variety of functions including growth pollination and defense. These compounds have recently received increased attention in medical research. In this group, one of the most studied has been resveratrol (3,5,4,-trihydroxystilbene), a polyphenol, which is found predominantly in grapes and berries. Over the past two decades, researchers have studied the ability of resveratrol to prevent or reverse the development of abnormalities in heart structure and function in animal models of heart disease and heart failure. The results from animal studies have been promising, and very recently, this knowledge has been translated into examining the efficacy of resveratrol in humans with heart disease/failure. In this review we will discuss the current status of resveratrol research on cardioprotection.

Blueberry polyphenols prevent cardiomyocyte death by preventing calpain activation and oxidative stress.

The purpose of this study was to examine the efficacy of an aqueous wild blueberry extract and five wild blueberry polyphenol fractions on an in vitro model of heart disease. Adult rat cardiomyocytes were pretreated with extract and fractions, and then exposed to norepinephrine (NE). Cardiomyocyte hypertrophy, cell death, oxidative stress, apoptosis and cardiomyocyte contractile function as well as the activities of calpain, superoxide dismutase (SOD) and catalase (CAT) were measured in cardiomyocytes treated with and without NE and blueberry fraction (BF). Four of five blueberry fractions prevented cell death and cardiomyocyte hypertrophy induced by NE. Total phenolic fraction was used for all further analysis. The NE-induced increase in oxidative stress, nuclear condensation, calpain activity and lowering of SOD and CAT activities were prevented upon pretreatment with BF. Reduced contractile function was also significantly improved with BF pretreatment. Blueberry polyphenols prevent NE-induced adult cardiomyocyte hypertrophy and cell death. The protective effects of BF may be in part attributed to a reduction in calpain activity and oxidative stress.

Reversible action of diaminothiazoles in cancer cells is implicated by the induction of a fast conformational change of tubulin and suppression of microtubule dynamics.

Diaminothiazoles are novel cytotoxic compounds that have shown efficacy toward different cancer cell lines. They show potent antimitotic and antiangiogenic activity upon binding to the colchicine-binding site of tubulin. However, the mechanism of action of diaminothiazoles at the molecular level is not known. Here, we show a reversible binding to tubulin with a fast conformational change that allows the lead diaminothiazole DAT1 [4-amino-5-benzoyl-2-(4-methoxy phenyl amino)thiazole] to cause a reversible mitotic block. DAT1 also suppresses microtubule dynamic instability at much lower concentration than its IC(50) value in cancer cells. Both growth and shortening events were reduced by DAT1 in a concentration-dependent way. Colchicine, the long-studied tubulin-binding drug, has previously failed in the treatment of cancer due to its toxicity, even though it generates a strong apoptotic response. The toxicity is attributable to its slow removal from the cell due to irreversible tubulin binding caused by a slow conformational change. DAT1 binds to tubulin at an optimal pH lower than colchicine. Tubulin conformational studies showed that the binding environments of DAT1 and colchicine are different. Molecular dynamic simulations showed a difference in the number of H-bonding interactions that accounts for the different pH optima. This study gives an insight of the action of compounds targeting tubulin's colchicine-binding site, as many such compounds have entered into clinical trials recently.

Reduced hemodynamic load aids low-dose resveratrol in reversing cardiovascular defects in hypertensive rats.

Cardiac hypertrophy and associated myocardial remodeling is one of the main complications of hypertension resulting in the development of heart failure. It is of great significance to explore novel treatments to reverse cardiac hypertrophy in hypertensives with or without affecting blood pressure. In the present study, we investigated whether low-dose resveratrol alone or in a combination with a blood pressure-lowering agent can reverse hypertension-induced cardiovascular dysfunction. Twenty-week-old male spontaneously hypertensive rats (SHRs) and Wistar-Kyoto rats were treated with resveratrol (2.5 mg kg⁻¹ per day) and/or hydralazine (25 mg kg⁻¹ per day) for 8 weeks. Blood pressure, cardiac structure and function, and electrocardiogram measurements were examined. Pressure myography of resistance arteries, histological examinations of heart tissues, oxidative stress and inflammatory measurements were also preformed to assess the efficacy of the treatment. Although resveratrol treatment alone was ineffective in reducing systolic blood pressure, diastolic blood pressure, diastolic dysfunction and vascular remodeling, it significantly prevented the systolic impairment and reduced myocardial fibrosis, and reduced oxidative stress and inflammation in hypertensive rats. Furthermore, a combination of resveratrol with hydralazine treatment significantly reduced blood pressure, improved systolic and diastolic function, decreased fibrosis and improved vascular geometry. In summary, low-dose resveratrol itself was unable to reduce systolic blood pressure, diastolic blood pressure, diastolic dysfunction and vascular remodeling. However, resveratrol alone alleviated cardiac fibrosis and some of the functional abnormalities in SHRs. And a combination of resveratrol with hydralazine was more effective than resveratrol or hydralazine alone in improving overall cardiovascular parameters.

Pro-apoptotic versus anti-apoptotic properties of dietary resveratrol on tumoral and normal cardiac cells.

Resveratrol is a natural dietary polyphenol found in grape skin, red wine, and various other food products. Resveratrol has proved to be an effective chemopreventive agent for different malignant tumors. It has also been shown to prevent vascular alterations such as atherosclerosis and inflammatory-associated events. In view of these observations, we investigated the anti-proliferative and pro-apoptotic activities of resveratrol on a tumoral cardiac cell line (HL-1 NB) derived from mouse tumoral atrial cardiac myocytes. These effects were compared with those found on normal neonatal mouse cardiomyocytes. HL-1 NB cells and neonatal cardiomyocytes were treated with resveratrol (5, 30, and/or 100 µM) for different times of culture (24, 48, and/or 72 h). Resveratrol effects were determined by various microscopical and flow cytometric methods. After resveratrol treatment, a strong inhibition of tumoral cardiac HL1-NB cell growth associated with a loss of cell adhesion was observed. This cell proliferation arrest was associated with an apoptotic process revealed by an increased percentage of cells with fragmented and/or condensed nuclei (characteristic of apoptotic cells) identified after staining with Hoechst 33342 and by the presence of cells in subG1. At the opposite, on normal cardiomyocytes, no cytotoxic effects of resveratrol were observed, and a protective effect of resveratrol against norepinephrine-induced apoptosis was found on normal cardiomyocytes. Altogether, the present data demonstrate that resveratrol (1) induces apoptosis of tumoral cardiac HL1-NB cells, (2) does not induce cell death on normal cardiomyocytes, and (3) prevents norepinephrine-induced apoptosis on normal cardiomyocytes.