Effects of Pterostilbene on Heart and Lung Oxidative Stress Parameters in 2 Experimental Models of Cardiovascular Disease: Myocardial Infarction and Pulmonary Arterial Hypertension.

ABSTRACT: Myocardial infarction (MI) and pulmonary arterial hypertension (PAH) are 2 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 MI 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 the 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 the 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 left ventricle end-systolic volume in infarcted animals. In the PAH model, PTE improved pulmonary artery flow and decreased reactive oxygen species levels in the lung. PTE administration promoted protective effects in terms of oxidative stress in 2 experimental models of cardiac diseases: MI and PAH. PTE also improved cardiac function in infarcted rats and pulmonary artery flow in animals with PAH.

Pterostilbene improves cardiac function in a rat model of right heart failure through modulation of calcium handling proteins and oxidative stress.

This study explored the effect of pterostilbene (PTS) complexed with hydroxypropyl-ß-cyclodextrin (HPßCD) on right heart function, glutathione and glutaredoxin systems, and the expression of redox-sensitive proteins involved with regulation calcium levels in the experimental model of pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). After 7 days of PAH induction, rats received daily doses of the PTS:HPßCD complex (corresponding to 25, 50, or 100 mg·kg-1 of PTS) or vehicle (control group, CTR0) (an aqueous solution containing HPßCD; CTR0 and MCT0 (MCT group that did not receive PTS treatment)) via oral administration for 2 weeks. The results showed that the PTS:HPßCD complex increased the content of reduced glutathione and the activity of glutathione-S-transferase and glutaredoxin in the right ventricle (RV) of MCT-treated rats in a dose-dependent manner. Additionally, at higher doses, it also prevented the reduction of stroke volume and cardiac output, prevented myocardial performance index (MPI) increase, reduced lipoperoxidation, reduced total phospholamban, and increased the expression of sarcoplasmic reticulum calcium ATPase in the RV of MCT-treated rats. These results demonstrate that the PTS:HPßCD complex has a dose-dependent antioxidant mechanism that results in improved cardiac function in experimental right heart failure. Our results open a field of possibilities to PTS administration as new therapeutic approach to conventional therapy for right ventricular dysfunction. Novelty Pterostilbene complexed with hydroxypropyl-ß-cyclodextrin could be a new therapeutic approach. Pterostilbene complexed with hydroxypropyl-ß-cyclodextrin reestablishes redox homeostasis through glutathione metabolism modulation, leading to an improved MPI in pulmonary arterial hypertension-provoked right heart failure.

Carvedilol and thyroid hormones co-administration mitigates oxidative stress and improves cardiac function after acute myocardial infarction.

After acute myocardial infarction (AMI), reactive oxygen species and oxidative stress have important roles in the progression to heart failure. As a therapeutic alternative, thyroid hormones (TH) revealed cardioprotective effects after AMI, including decreasing oxidative stress. Carvedilol beta-blocker, already used in the clinical treatment of AMI, also mitigate cardiac pathological remodelling. This study assessed the effects of post-AMI carvedilol and TH co-administration on oxidative stress and cardiac function as well as whether those effects were synergistic. Male Wistar rats were divided into five groups: sham-operated (SHAM), infarcted (MI), infarcted + TH (MI + TH), infarcted + carvedilol (MI + C) and infarcted + C + TH (MI + C + TH). Two days post-surgery, the SHAM and MI groups received saline, and treated groups received their respective treatments by gavage for 12 days. The animals were submitted to echocardiographic evaluation, ventricular catheterization and euthanized for heart collection to perform oxidative stress analysis. Treated groups improved for ejection fraction compared to the MI group. Carvedilol decreased the positive chronotropic TH effects in the MI + C + TH group. The MI and MI + C groups had increased reactive oxygen species and reduced sulfhydryl levels. Carvedilol and TH co-administration showed synergic effects in the MI + C + TH group, reducing reactive oxygen species levels and improving GSH/GSSG ratio. Moreover, co-treatment attenuated NADPH oxidase activity in the MI group. Therefore, this study showed for the first time that carvedilol and TH co-administration may improve redox balance and cardiac function after AMI. Such co-administration could represent a therapeutic strategy capable of preventing cardiac dysfunction and redox unbalance after AMI.

Copaiba Oil Attenuates Right Ventricular Remodeling by Decreasing Myocardial Apoptotic Signaling in Monocrotaline-Induced Rats.

There is an increase in oxidative stress and apoptosis signaling during the transition from hypertrophy to right ventricular (RV) failure caused by pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). In this study, it was evaluated the action of copaiba oil on the modulation of proteins involved in RV apoptosis signaling in rats with PAH. Male Wistar rats (±170 g, n = 7/group) were divided into 4 groups: control, MCT, copaiba oil, and MCT + copaiba oil. PAH was induced by MCT (60 mg/kg intraperitoneally) and, 7 days later, treatment with copaiba oil (400 mg/kg by gavage) was given for 14 days. Echocardiographic and hemodynamic measurements were performed, and the RV was collected for morphometric evaluations, oxidative stress, apoptosis, and cell survival signaling, and eNOS protein expression. Copaiba oil reduced RV hypertrophy (24%), improved RV systolic function, and reduced RV end-diastolic pressure, increased total sulfhydryl levels and eNOS protein expression, reduced lipid and protein oxidation, and the expression of proteins involved in apoptosis signaling in the RV of MCT + copaiba oil as compared to MCT group. In conclusion, copaiba oil reduced oxidative stress, and apoptosis signaling in RV of rats with PAH, which may be associated with an improvement in cardiac function caused by this compound.