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.

Cardioprotective doses of thyroid hormones improve NO bioavailability in erythrocytes and increase HIF-1α expression in the heart of infarcted rats.

CONTEXT: Infarction leads to a decrease in NO bioavailability in the erythrocytes. Thyroid hormones (TH) present positive effects after infarction. However, there are no studies evaluating the effects of cardioprotective doses of TH in the erythrocytes after infarction. OBJECTIVE: This study aimed to evaluate the effects of TH in NO bioavailability and oxidative stress parameters in the erythrocytes of infarcted rats. MATERIAL AND METHODS: Wistar rats were allocated into the three groups: Sham-operated (SHAM), infarcted (AMI) and infarcted + TH (AMIT). AMIT rats received T4 and T3 for 12 days by gavage. Subsequently, the animals were evaluated by echocardiography and the LV and erythrocytes were collected. RESULTS: TH improved NO bioavailability and increased catalase activity in the erythrocytes. Besides that, TH increased HIF-1α in the heart. CONCLUSION: TH seems to be positive for erythrocytes preventing a decrease in NO bioavailability and increasing antioxidant enzymatic defense after infarction.

Effects of ovariectomy on antioxidant defence systems in the right ventricle of female rats with pulmonary arterial hypertension induced by monocrotaline.

The aim of this study was to evaluate the impact of ovariectomy on oxidative stress in the right ventricle (RV) of female rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). Rats were divided into 4 groups (n = 6 per group): sham (S), sham + MCT (SM), ovariectomized (O), and ovariectomized + MCT (OM). MCT (60 mg·kg-1 i.p.) was injected 1 week after ovariectomy or sham surgery. Three weeks later, echocardiographic analysis and RV catheterisation were performed. RV morphometric, biochemical, and protein expression analysis through Western blotting were done. MCT promoted a slight increase in pulmonary artery pressure, without differences between the SM and OM groups, but did not induce RV hypertrophy. RV hydrogen peroxide increased in the MCT groups, but SOD, CAT, and GPx activities were also enhanced. Non-classical antioxidant defenses diminished in ovariectomized groups, probably due to a decrease in the nuclear factor Nrf2. Hemoxygenase-1 and thioredoxin-1 protein expression was increased in the OM group compared with SM, being accompanied by an elevation in the estrogen receptor ß (ER-ß). Hemoxygenase-1 and thioredoxin-1 may be involved in the modulation of oxidative stress in the OM group, and this could be responsible for attenuation of PAH and RV remodeling.

Thyroid hormones decrease the proinflammatory TLR4/NF-κß pathway and improve functional parameters of the left ventricle of infarcted rats.

Myocardial infarction leads to oxidative stress and promotes activation of the TLR4/NF-κß proinflammatory pathway. Thyroid hormones (TH) are known to be cardioprotective after infarction. However, there are no studies evaluating whether TH could modulate this pathway in the heart. This study aimed to verify the effect of thyroid hormones on the TLR4/NF-κß pathway after myocardial infarction. Male Wistar rats were allocated into the following groups: Sham-operated (SHAM), sham-operated + TH (SHAMT), infarcted (AMI) and infarcted + TH (AMIT). The treated rats received T4 and T3 (8 and 2 µg 100 g-1 day-1) for 12 days by gavage. Subsequently, the animals were evaluated by echocardiography and euthanized, and the left ventricle was collected for biochemical and molecular analyses. TH modulates TLR4/NF-κß expression in the infarcted hearts of rats and decreases xanthine oxidase expression. These effects were related to cardiac functional improvement after infarction. The cardioprotective effects of T3 and T4 seem to involve an anti-inflammatory action.

Effects of thyroid hormones on aortic tissue after myocardial infarction in rats.

Studies have shown a cardioprotective role of thyroid hormones (THs) in cardiac remodeling after acute myocardial infarction (MI). However, there is no data in the literature examining the influence of TH administration on the aortic tissue in an animal model of MI. This study aimed to evaluate the effects of thyroid hormones on the aorta after MI. Male Wistar rats were divided into a sham group (SHAM), infarcted group (AMI), sham+TH (SHAMT) and AMI+TH (AMIT). After MI, the animals received T3 and T4 (2 and 8µg/100g/day, respectively) by oral gavage for 12 days. Later, the animals underwent echocardiography and euthanasia and the aorta was collected for molecular and biochemical analysis. T3 and T4 administration increased the expression of the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1α (HIF-1α) in the aorta of AMIT rats when compared with AMI. With respect to TH receptors, AMI rats presented a decrease in TRß levels, which was prevented by the hormonal administration. In AMIT rats, both TRα and TRß levels were increased when compared with the AMI group. Reactive oxygen species levels and NADPH oxidase activity were decreased in both treated groups when compared with the non-treated animals. TH administration after MI may improve angiogenic signaling in the aorta as well as the responsiveness of this vessel to T3 and T4. These positive effects in the aorta may result in additional protection for the cardiovascular system in the context of cardiac ischaemic injury.

Thyroid hormones improve cardiac function and decrease expression of pro-apoptotic proteins in the heart of rats 14 days after infarction.

Apoptosis is a key process associated with pathological cardiac remodelling in early-phase post-myocardial infarction. In this context, several studies have demonstrated an anti-apoptotic effect of thyroid hormones (TH). The aim of this study was to evaluate the effects of TH on the expression of proteins associated with the apoptotic process 14 days after infarction. Male Wistar rats (300-350 g) (n = 8/group) were divided into four groups: Sham-operated (SHAM), infarcted (AMI), sham-operated + TH (SHAMT) and infarcted + TH (AMIT). For 12 days, the animals received T3 and T4 [2 and 8 µg/(100 g day)] by gavage. After this, the rats were submitted to haemodynamic and echocardiographic analysis, and then were sacrificed and the heart tissue was collected for molecular analysis. Statistical analyses included two-way ANOVA with Student-Newman-Keuls post test. Ethics Committee number: 23262. TH administration prevented the loss of ventricular wall thickness and improved cardiac function in the infarcted rats 14 days after the injury. AMI rats presented an increase in the pro-apoptotic proteins p53 and JNK. The hormonal treatment prevented this increase in AMIT rats. In addition, TH administration decreased the Bax:Bcl-2 ratio in the infarcted rats. TH administration improved cardiac functional parameters, and decreased the expression of pro-apoptotic proteins 14 days after myocardial infarction.

T3 and T4 decrease ROS levels and increase endothelial nitric oxide synthase expression in the myocardium of infarcted rats.

UNLABELLED: Myocardial infarction leads to a reduction in nitric oxide (NO) bioavailability and an increase in reactive oxygen species (ROS) levels. This scenario has been shown to be detrimental to the heart. Recent studies have shown that thyroid hormone (TH) administration presents positive effects after ischaemic injury. Based on this, the aim of this study was to evaluate the effect of TH on NO bioavailability as well as on endothelial nitric oxide synthase (eNOS) expression after myocardial infarction. Male Wistar rats were divided into three groups: Sham-operated (SHAM), infarcted (AMI) and infarcted + TH (AMIT). During 26 days, the AMIT group received T3 and T4 (2 and 8 µg/100 g/day, respectively) by gavage, while SHAM and AMI rats received saline. After this, the rats underwent echocardiographic analysis were sacrificed, and the left ventricle was collected for biochemical and molecular analysis. STATISTICAL ANALYSIS: one-way ANOVA with Student-Newman-Keuls post test. AMI rats presented a 38% increase in ROS levels. TH administration prevented these alterations in AMIT rats. The AMIT group presented an increase in eNOS expression, in NOS activity and in nitrite levels. TH administration also increased PGC-1α expression in the AMIT group. In conclusion, TH effects seem to involve a modulation of eNOS expression and an improvement in NO bioavailability in the infarcted heart.

Aerobic Exercise Promotes a Decrease in Right Ventricle Apoptotic Proteins in Experimental Cor Pulmonale.

Pulmonary arterial hypertension is characterized by progressive increases in resistance and pressure in the pulmonary artery and Cor pulmonale. The effect of exercise on hydrogen peroxide-dependent signaling in the right ventricle (RV) of Cor pulmonale rats was analyzed. Rats were divided into sedentary control (SC), sedentary monocrotaline (SM), trained control (TC), and trained monocrotaline (TM) groups. Rats underwent exercise training (60% of VO2 max) for 5 weeks, with 3 weeks after monocrotaline injection (60 mg/kg intraperitoneally). Pulmonary resistance was enhanced in SM (2.0-fold) compared with SC. Pulmonary artery pressure was increased in SM (2.7-fold) and TM (2.6-fold) compared with their respective controls (SC and TC). RV hypertrophy indexes increased in SM compared with SC. Hydrogen peroxide was higher in SM (1.7-fold) than SC and was reduced by 47% in TM compared with SM. p-Akt was increased in TM (2.98-fold) compared with SM. The Bax/Bcl-2 ratio and caspase 3 were also increased (2.9-fold and 3.9-fold, respectively) in SM compared with SC. Caspase 3 was decreased in TM compared with SM (P < 0.05). Therefore, exercise training promoted a beneficial response by decreasing hydrogen peroxide concentrations, and consequently, apoptotic signaling in RV.

Clinical and molecular evidence of the consumption of broccoli, glucoraphanin and sulforaphane in humans / Evidencias clínicas y moleculares del consumo de brócoli, glucorafanina y sulforafano en humanos

Introduction: Sulforaphane (SFN) is an isothiocyanate derived from glucoraphanin (GRA), which is found in great amounts especially in broccoli. Its consumption has been reported to be associated with a lower risk of myocardial infarction and cancer development. Additionally, its effects have been studied in neurodegenerative diseases, diabetes, and atherosclerosis, most of the times using animal models and cell cultures. Objectives: Given the promising results of SFN, this review aimed to investigate evidence documented in human intervention studies with broccoli, GRA and SFN. Methods: A search was performed on PubMed and Virtual Health Library databases by two independent researchers using the descriptors 'broccoli' or 'glucoraphanin' or 'sulforaphane', which should appear on the study’s title or abstract. This review included randomized linical trials performed in humans that were published in English and Portuguese from 2003 to 2013 and that considered clinical and molecular parameters of cell damage as outcomes of interest. Results: Seventeen studies were selected, and the predominant type of intervention was broccoli sprouts. More consistent results were obtained for the clinical parameters blood glucose and lipid profile and for molecular parameters of oxidative stress, indicating that there was an improvement in these parameters after intervention. Less solid evidence was found with regard to decreased inflammation, Helicobacter pylori colonization, and protection against cancer. Conclusion: Although being relevant, the evidence for the use of broccoli, GRA and SFN in humans are limited; Introduction: Sulforaphane (SFN) is an isothiocyanate derived from glucoraphanin (GRA), which is found in great amounts especially in broccoli. Its consumption has been reported to be associated with a lower risk of myocardial infarction and cancer development. Additionally, its effects have been studied in neurodegenerative diseases, diabetes, and atherosclerosis, most of the times using animal models and cell cultures. Objectives: Given the promising results of SFN, this reviewaimed to investigate evidence documented in human intervention studies with broccoli, GRA and SFN. Methods: A search was performed on PubMed and Virtual Health Library databases by two independent researchers using the descriptors 'broccoli' or 'glucoraphanin' or 'sulforaphane', which should appear on the study’s title or abstract. This review included randomized clinical trials performed in humans that were published in English and Portuguese from 2003 to 2013 and that considered clinical and molecular parameters of cell damage as outcomes of interest. Results: Seventeen studies were selected, and the predominanttype of intervention was broccoli sprouts. More consistent results were obtained for the clinical parameters blood glucose and lipid profile and for molecular parameters of oxidative stress, indicating that there wasan improvement in these parameters after intervention. Less solid evidence was found with regard to decreased inflammation, Helicobacter pylori colonization, and protection against cancer. Conclusion: Although being relevant, the evidence for the use of broccoli, GRA and SFN in humans are limited thus, further intervention studies are needed to evaluate outcomes more consistently and reach better grounded conclusions (AU)

Introducción: El sulforafano (SFN) es un isotiocianato derivado de la glucorafanina (GRA), encontrada en gran cantidad especialmente en el brócolis. Su consumo está asociado a un menor riesgo de infarto del miocardio y de cáncer. Además, sus efectos están siendo estudiados en enfermedades neurodegenerativas, diabetes y aterosclerosis, casi siempre utilizando modelos animales y cultivos celulares. Objetivos: Debido a los resultados prometedores del compuesto SFN, esta revisión buscó investigar evidencias ya documentadas en intervenciones con brócoli, GRA y SFN en humanos. Métodos: Se realizó una búsqueda en las bases de datos PubMed y Biblioteca Virtual en Salud, por dos investigadores independientes, utilizando los descriptores 'broccoli' o 'glucoraphanin' o 'sulforaphane', que debían constar en el título o resumen del trabajo. Se incluyeron ensayos clínicos randomizados realizados en humanos, publicados en inglés y portugués entre 2003 y 2013, y que consideraron como desenlaces de interés parámetros clínicos y moleculares de daño celular. Resultados: Se seleccionaron 17 estudios y el tipo de intervención predominante fueron brotes de brócoli. Los resultados más consistentes fueron obtenidos con los parámetros clínicos glicemia y perfil lipídico y los parámetros moleculares de estrés oxidativo, que presentaron mejora después de la intervención. Se encontraron evidencias menos sólidas respeto a la disminución de la inflamación, de la colonización por Helicobacter pylori y protección contra cáncer. Conclusión: Aunque relevantes, las evidencias del uso Correspondence: Carolina Guerini de Souza. de brócoli, GRA y SFN en humanos son limitadas, siendo necesarios más estudios de intervención para avaluar los desenlaces de forma más consistente y producir conclusiones mejor fundamentadas (AU)

Cardioprotective effects of thyroid hormones in a rat model of myocardial infarction are associated with oxidative stress reduction.

Reactive oxygen species (ROS) are involved with progression from infarction to heart failure. Studies show that thyroid hormones (TH) present cardioprotective effects. This study aims to evaluate whether TH effects after infarction are associated to redox balance modulation. Male Wistar rats were divided into four groups: Sham-operated (SHAM), infarcted (AMI), sham-operated+TH (SHAMT), and infarcted+TH (AMIT). During 26 days, animals received T3 (2 µg/100g/day) and T4 (8 µg/100g/day) by gavage. Echocardiographic parameters were assessed and heart tissue was collected to biochemical analysis. AMIT rats presented absence of lung congestion, less cardiac dilatation, and normalization in myocardial performance index, compared with AMI. AMI rats presented an increase in hydrogen peroxide levels and in lipid peroxidation and a decrease in GSH/GSSG. TH prevented these alterations in AMIT. In conclusion, TH seem to reduce the levels of ROS, preventing oxidative stress, and improving cardiac function in infarcted rats.

Efficacy of a low dose of estrogen on antioxidant defenses and heart rate variability.

This study tested whether a low dose (40% less than the pharmacological dose of 17-ß estradiol) would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n = 9/group) were divided in three groups: (1) ovariectomized (Ovx), (2) ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg), and (3) high dose (HE; 0.5 mg) 17-ß estradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD) and catalase (CAT) activities, redox ratio (GSH/GSSG), total radical-trapping antioxidant potential (TRAP), hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

Clinical and molecular evidence of the consumption of broccoli, glucoraphanin and sulforaphane in humans.

INTRODUCTION: Sulforaphane (SFN) is an isothiocyanate derived from glucoraphanin (GRA), which is found in great amounts especially in broccoli. Its consumption has been reported to be associated with a lower risk of myocardial infarction and cancer development. Additionally, its effects have been studied in neurodegenerative diseases, diabetes, and atherosclerosis, most of the times using animal models and cell cultures. OBJECTIVES: Given the promising results of SFN, this review aimed to investigate evidence documented in human intervention studies with broccoli, GRA and SFN. METHODS: A search was performed on PubMed and Virtual Health Library databases by two independent researchers using the descriptors "broccoli" or "glucoraphanin" or "sulforaphane", which should appear on the study's title or abstract. This review included randomized clinical trials performed in humans that were published in English and Portuguese from 2003 to 2013 and that considered clinical and molecular parameters of cell damage as outcomes of interest. RESULTS: Seventeen studies were selected, and the predominant type of intervention was broccoli sprouts. More consistent results were obtained for the clinical parameters blood glucose and lipid profile and for molecular parameters of oxidative stress, indicating that there was an improvement in these parameters after intervention. Less solid evidence was found with regard to decreased inflammation, Helicobacter pylori colonization, and protection against cancer. CONCLUSION: Although being relevant, the evidence for the use of broccoli, GRA and SFN in humans are limited; thus, further intervention studies are needed to evaluate outcomes more consistently and reach better grounded conclusions.

Introducción: El sulforafano (SFN) es un isotiocianato derivado de la glucorafanina (GRA), encontrada en gran cantidad especialmente en el brócolis. Su consumo está asociado a un menor riesgo de infarto del miocardio y de cáncer. Además, sus efectos están siendo estudiados en enfermedades neurodegenerativas, diabetes y aterosclerosis, casi siempre utilizando modelos animales y cultivos celulares. Objetivos: Debido a los resultados prometedores del compuesto SFN, esta revisión buscó investigar evidencias ya documentadas en intervenciones con brócoli, GRA y SFN en humanos. Métodos: Se realizó una búsqueda en las bases de datos PubMed y Biblioteca Virtual en Salud, por dos investigadores independientes, utilizando los descriptores "broccoli" o "glucoraphanin" o "sulforaphane", que debían constar en el título o resumen del trabajo. Se incluyeron ensayos clínicos randomizados realizados en humanos, publicados en inglés y portugués entre 2003 y 2013, y que consideraron como desenlaces de interés parámetros clínicos y moleculares de daño celular. Resultados: Se seleccionaron 17 estudios y el tipo de intervención predominante fueron brotes de brócoli. Los resultados más consistentes fueron obtenidos con los parámetros clínicos glicemia y perfil lipídico y los parámetros moleculares de estrés oxidativo, que presentaron mejora después de la intervención. Se encontraron evidencias menos sólidas respeto a la disminución de la inflamación, de la colonización por Helicobacter pylori y protección contra cáncer. Conclusión: Aunque relevantes, las evidencias del uso de brócoli, GRA y SFN en humanos son limitadas, siendo necesarios más estudios de intervención para avaluar los desenlaces de forma más consistente y producir conclusiones mejor fundamentadas.