EFFECTS OF PTEROSTILBENE ON HEART AND LUNG OXIDATIVE STRESS PARAMETERS IN TWO EXPERIMENTAL MODELS OF CARDIOVASCULAR DISEASE: MYOCARDIAL INFARCTION AND PULMONARY ARTERIAL HYPERTENSION.

Myocardial infarction (MI) and pulmonary artery hypertension (PAH) are two prevalent cardiovascular diseases. In both conditions, oxidative stress is associated with a worse prognosis. Pterostilbene (PTE), an antioxidant compound, has been studied as a possible therapy for cardiovascular diseases. This study aims to evaluate the effect of PTE on oxidative stress in the hearts of animals with myocardial infarction and in the lungs of animals with PAH. Male Wistar rats were used in both models. In the MI model, the experimental groups were sham, MI, and MI+PTE. In PAH model, the experimental groups were control, PAH, and PAH+PTE. Animals were exposed to MI through surgical ligation of the left coronary artery, or to PAH, by administration of monocrotaline (60 mg/kg). Seven days after undergoing cardiac injury, the MI+PTE animals were treated with PTE (100 mg/kg day) for 8 days. After this, the heart was collected for molecular analysis. The PAH+PTE animals were treated with PTE (100 mg/kg day) for 14 days, beginning 7 days after PAH induction. After this, the lungs were collected for biochemical evaluation. We found that PTE administration attenuated the decrease in ejection fraction and improved LV end-systolic volume in infarcted animals. In the PAH model, PTE improved pulmonary artery flow and decreased ROS levels in the lung. PTE administration promoted protective effects in terms of oxidative stress in two experimental models of cardiac diseases: MI and PAH. PTE also improved cardiac function in infarcted rats and pulmonary artery flow in animals with PAH.

Sulforaphane Improves Redox Homeostasis and Right Ventricular Contractility in a Model of Pulmonary Hypertension.

ABSTRACT: Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary vascular resistance (PVR), imposing overload on the right ventricle (RV) and imbalance of the redox state. Our study investigated the influence of treatment with sulforaphane (SFN), found in cruciferous vegetables, on RV remodeling and redox homeostasis in monocrotaline (MCT)-induced PAH. Male Wistar rats were separated into 4 groups: control (CTR); CTR + SFN; MCT; and MCT + SFN. PAH induction was implemented by a single dose of MCT (60 mg/kg intraperitoneally). Treatment with SFN (2.5 mg/kg/day intraperitoneally) started on the seventh day after the MCT injection and persisted for 2 weeks. After 21 days of PAH induction, echocardiographic, hemodynamic, and oxidative stress evaluation was performed. The MCT group showed an increase in RV hypertrophy, RV systolic area, RV systolic, mean pulmonary artery pressure, and PVR and exhibited a decrease in the RV outflow tract acceleration time/ejection time ratio, RV fractional shortening, and tricuspid annular plane systolic excursion compared to CTR ( P < 0.05). SFN-treated PAH attenuated detrimental changes in tricuspid annular plane systolic excursion, mean pulmonary artery pressure, and PVR parameters. Catalase levels and the glutathione/Glutathione disulfide (GSSG) ratio were diminished in the MCT group compared to CTR ( P < 0.05). SFN increased catalase levels and normalized the glutathione/GSSG ratio to control levels ( P < 0.05). Data express the benefit of SFN treatment on the cardiac function of rats with PAH associated with the cellular redox state.

Sulforaphane Effects on Cardiac Function and Calcium-Handling-Related Proteins in 2 Experimental Models of Heart Disease: Ischemia-Reperfusion and Infarction.

ABSTRACT: Sulforaphane (SFN) is a natural exogenous antioxidant from cruciferous vegetables already shown to improve cardiac function in cardiovascular diseases. The aim of this study was to analyze the effect of SFN treatment on the cardiac function in 2 experimental models of heart disease, ischemia/reperfusion (I/R) and myocardial infarction (MI), and whether an improvement of the cardiac function could be associated with a modulation of calcium-handling proteins. The study was divided into 2 main experiments: experiment 1, ex vivo with the I/R model and experiment 2, in vivo with the MI model. In the I/R model, rats were divided into control and SFN (0.5 mg/kg/d intraperitoneally for 3 days) groups, and the hearts were submitted to global ischemia (20 minutes) followed by reperfusion (20 minutes) in a Langendorff apparatus. SFN did not change left ventricle systolic and diastolic pressures but increased the contractility and relaxation indexes after 20 minutes of reperfusion. These functional changes were accompanied by a decreased protein expression of ryanodine receptor (RyR) and increased expression of p-phospholamban/phospholamban ratio, without alteration in the sarco/endoplasmic calcium ATPase expression. In the MI model, rats were randomly divided into Sham, MI (MI induced by left coronary artery ligation), Sham + SFN (5 mg/kg/d intraperitoneally for 25 days), and MI + SFN groups. Although SFN did not affect cardiac function, it led to a decreased RyR protein expression and reactive oxygen species levels in the left ventricular of the MI + SFN group. These data indicate that SFN modulates calcium-handling proteins and, thus, cardiac inotropism/lusitropism especially when administered previously to an ischemic event.

Bucindolol attenuates the vascular remodeling of pulmonary arteries by modulating the expression of the endothelin-1 A receptor in rats with pulmonary arterial hypertension.

The aim of this study was to investigate the role of the ß-adrenergic blocker bucindolol on endothelial dysfunction and pulmonary vascular remodeling in rats with pulmonary arterial hypertension (PAH). Male Wistar rats were divided into four groups: control, monocrotaline (MCT), control?+?bucindolol and monocrotaline?+?bucindolol (MCT?+?BCD). PAH was induced by an injection of monocrotaline (60?mg/kg i.p.). After two weeks, the animals were treated for seven days with bucindolol (2?mg/kg/day i.p.) or vehicle. Echocardiography was performed upon treatment completion to analyze pulmonary vascular resistance (PVR) and right ventricle (RV) myocardial performance index. Lungs were collected for oxidative stress and western blot analysis, and the pulmonary artery was analyzed for histological and immunohistochemical parameters. The MCT?+?BCD group showed a decrease (32%) in the protein expression of endothelin-1 type A receptor (ETAR) and in the ratio of ETA/endothelin-1 type B receptor (ETBR) (62%) as compared to the MCT group. Bucindolol treatment did not alter oxidative stress, as determined by lipid peroxidation analysis and antioxidant enzyme activities and expression, endothelial nitric oxide synthase immunocontent and decreased nitrotyrosine levels. Moreover, bucindolol improved vascular remodeling of the pulmonary artery in the MCT?+?BCD group by decreasing (21%) PVR and increasing RV workload in relation to MCT.

Pterostilbene reduces oxidative stress, prevents hypertrophy and preserves systolic function of right ventricle in cor pulmonale model.

BACKGROUND AND PURPOSE: In cor pulmonale, the increased afterload imposed on the right ventricle (RV) generates a maladaptive response, impairing the contractile cardiac function. Oxidative mechanisms play an important role in the pathophysiology and progression of this disease. The administration of pterostilbene (PTS), a phytophenol with antioxidant potential, may represent a therapeutic option. In the present study, we evaluated the effect of PTS complexed with hydroxypropyl-ß-cyclodextrin (HPßCD) on hypertrophy, contractile function and oxidative parameters in the RV of rats with pulmonary hypertension, induced by the administration of monocrotaline (MCT). EXPERIMENTAL APPROACH: The rats received daily doses of the PTS : HPßCD complex at 25, 50 or 100 mg·kg-1 , p.o., for 14 days. The diastolic function, E/A ratio, and systolic function, shortening fraction, fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) of the RV were determined by echocardiography. KEY RESULTS: The PTS : HPßCD complex reduced the production of NADPH oxidase-dependent superoxide anions and oxidative stress in the RV of MCT-treated rats in a dose-dependent manner. At higher doses it prevented the reduction in FAC and TAPSE in MCT-treated animals. CONCLUSIONS AND IMPLICATIONS: The PTS : HPßCD complex prevented the maladaptative remodelling and protected systolic function in the RV of rats with pulmonary hypertension. These cardioprotective mechanisms may be related, in part, to the antioxidant potential of PTS, favoured by the increased p.o. bioavailability promoted by the presence of HPßCD in the complex.