Effects of Calendula officinalis extract on liver histopathology, lipid profile, and oxidative stress in rats submitted to a diet rich in cholesterol and carbohydrates

ABSTRACT Purpose: To evaluate the modulatory properties of Calendula officinalis L. (Asteraceae) (C. officinalis) extract on cafeteria diet-fed rats. Methods: A cafeteria diet was administered ad libitum for 45 days to induce dyslipidemia. Then, the rats were treated with the formulations containing C. officinalis in the doses of 50, 100, and 150 mg/kg or only with the vehicle formulation; the control group received a commercial ration. Results: The cafeteria diet decreased glutathione S-transferase activity and high-density lipoprotein plasmatic levels and damaged the hepatic architecture. The C. officinalis extract was able to reduce lipid infiltration in liver tissue and to modulate oxidative stress and lipid profile markers. Conclusions: The correlations between the variables suggest a pathological connection between oxidative stress markers and serum lipid profile.

Role of cardiac β1-adrenergic and A1-adenosine receptors in severe arrhythmias related to Parkinson's disease

Abstract Aims Although reduced life expectancy in Parkinson's Disease (PD) patients has been related to severe cardiac arrhythmias due to autonomic dysfunctions, its molecular mechanisms remain unclear. To investigate the role of cardiac β1-Adrenergic (β1AR) and A1-Adenosine (A1R) receptors in these dysfunctions, the pharmacological effects of stimulation of cardiac β1AR (isoproterenol, ISO), in the absence and presence of cardiac β1AR (atenolol, AT) or A1R (1,3-dipropyl-8-cyclopentyl xanthine, DPCPX) blockade, on the arrhythmias induced by Ischemia/Reperfusion (CIR) in an animal PD model were studied. Methods PD was produced by dopaminergic lesions (confirmed by immunohistochemistry analysis) caused by the injection of 6-hydroxydopamine (6-OHDA, 6 μg) in rat striatum. CIR was produced by a surgical interruption for 10 min followed by reestablishment of blood circulation in the descendent left coronary artery. On the incidence of CIR-Induced Ventricular Arrhythmias (VA), Atrioventricular Block (AVB), and Lethality (LET), evaluated by Electrocardiogram (ECG) analysis, the effects of intravenous treatment with ISO, AT and DPCPX (before CIR) were studied. Results VA, AVB and LET incidences were significantly higher in 6-OHDA (83%, 92%, 100%, respectively) than in control rats (58%, 67% and 67%, respectively). ISO treatment significantly reduced these incidences in 6-OHDA (33%, 33% and 42%, respectively) and control rats (25%, 25%, 33%, respectively), indicating that stimulation of cardiac β1AR induced cardioprotection. This response was prevented by pretreatment with AT and DPCPX, confirming the involvement of cardiac β1AR and A1R. Conclusion Pharmacological modulation of cardiac β1AR and A1R could be a potential therapeutic strategy to reduce severe arrhythmias and increase life expectancy in PD patients.

Cardioprotection stimulated by resveratrol and grape products prevents lethal cardiac arrhythmias in an animal model of ischemia and reperfusion

ABSTRACT Purpose To evaluate the preventive cardioprotective effects of resveratrol and grape products, such as grape juice and red wine, in animal model of cardiac ischemia and reperfusion. Methods Male Wistar rats orally pretreated for 21-days with resveratrol and grape products were anesthetized and placed on mechanical ventilation to surgically induce cardiac ischemia and reperfusion by obstruction (ischemia) followed by liberation (reperfusion) of blood circulation in left descending coronary artery. These rats were submitted to the electrocardiogram (ECG) analysis to evaluate the effects of pretreatment with resveratrol and grape products on the incidence of ventricular arrhythmias (VA), atrioventricular block (AVB) and lethality (LET) resulting from cardiac ischemia and reperfusion. Results It was observed that the incidence of AVB was significantly lower in rats pretreated with resveratrol (25%), grape juice (37.5%) or red wine (12.5%) than in rats treated with saline solution (80%) or ethanol (80%). Similarly, incidence of LET was also significantly lower in rats pretreated with resveratrol (25%), grape juice (25%) or red wine (0%) than in rats treated with saline solution (62.5%) or ethanol (75%). Conclusions These results indicate that the cardioprotective response stimulated by resveratrol and grape products prevents the lethal cardiac arrhythmias in animal model of ischemia and reperfusion, supporting the idea that this treatment can be beneficial for prevention of severe cardiac arrhythmias in patients with ischemic heart disease.

Cardioprotective effects of pharmacological blockade of the mitochondrial calcium uniporter on myocardial ischemia-reperfusion injury

Abstract Purpose To evaluate whether the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of mitochondrial Ca2+ uniporter (MCU) protects the myocardium against injuries caused by cardiac ischemia and reperfusion (CIR). Methods CIR was induced in adult male Wistar rats (300-350 g) by occlusion of the left anterior descendent coronary artery (10 min), followed by reperfusion (120 min). Rats were treated with different doses of MCU blocker ruthenium red (RuR), administered 5 min before ischemia or reperfusion. Results In untreated rats, the incidences of ventricular arrhythmias (VA), atrioventricular block (AVB) and the lethality (LET) induced by CIR were 85%, 79% and 70%, respectively. In rats treated with RuR before ischemia, the incidences of VA, AVB and LET were significantly reduced to 62%, 25% and 25%, respectively. In rats treated with RuR after ischemia, the incidences of VA, AVB and LET were significantly reduced to 50%, 25% and 25%, respectively. Conclusion The significant reduction of the incidence of CIR-induced VA, AVB and LET produced by the treatment with RuR indicates that the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of MCU can protect the myocardium against injuries caused by CIR.

Pharmacological modulation of b-adrenoceptors as a new cardioprotective strategy for therapy of myocardial dysfunction induced by ischemia and reperfusion

Abstract Purpose: To evaluate the cardioprotective response of the pharmacological modulation of β-adrenergic receptors (β-AR) in animal model of cardiac ischemia and reperfusion (CIR), in spontaneously hypertensive (SHR) and normotensive (NWR) rats. Methods: CIR was induced by the occlusion of left anterior descendent coronary artery (10 min) and reperfusion (75 min). The SHR was treated with β-AR antagonist atenolol (AT, 10 mg/kg, IV) 5 min before CIR, and NWR were treated with β-AR agonist isoproterenol (ISO, 0.5 mg/kg, IV) 5 min before CIR. Results: The treatment with AT increased the incidence of VA, AVB and LET in SHR, suggesting that spontaneous cardioprotection in hypertensive animals was abolished by blockade of β-AR. In contrast, the treatment with ISO significantly reduced the incidence of ventricular arrhythmia, atrioventricular blockade and lethality in NWR (30%, 20% and 20%, respectively), suggesting that the activation of β-AR stimulate cardioprotection in normotensive animals. Serum CK-MB were higher in SHR/CIR and NWR/CIR compared to respective SHAM group (not altered by treatment with AT or ISO). Conclusion: The pharmacological modulation of β-AR could be a new cardioprotective strategy for the therapy of myocardial dysfunctions induced by CIR related to cardiac surgery and cardiovascular diseases.

Cardioprotective effect of preconditioning is more efficient than postconditioning in rats submitted to cardiac ischemia and reperfusion

Abstract Purpose: To investigate the cardioprotective effects of ischemic preconditioning (preIC) and postconditioning (postIC) in animal model of cardiac ischemia/reperfusion. Methods: Adult rats were submitted to protocol of cardiac ischemia/reperfusion (I/R) and randomized into three experimental groups: cardiac I/R (n=33), preCI + cardiac I/R (n=7) and postCI + cardiac I/R (n=8). After this I/R protocol, the incidence of ventricular arrhythmia (VA), atrioventricular block (AVB) and lethality (LET) was evaluated using the electrocardiogram (ECG) analysis. Results: After reestablishment of coronary blood flow, we observed variations of the ECG trace with increased incidence of ventricular arrhythmia (VA) (85%), atrioventricular block (AVB) (79%), and increase of lethality (70%) in cardiac I/R group. The comparison between I/R + preIC group with I/R group demonstrated significant reduction in VA incidence to 28%, AVB to 0% and lethality to 14%. The comparison of I/R + postIC group with I/R group was observed significance reduction in AVB incidence to 25% and lethality to 25%. Conclusion: The preconditioning strategies produce cardioprotection more efficient that postconditioning against myocardial dysfunctions and lethality by cardiac ischemia and reperfusion.

Cardioprotective effect of lipstatin derivative orlistat on normotensive rats submitted to cardiac ischemia and reperfusion

Abstract Purpose: To evaluate in vivo animal model of cardiac ischemia/reperfusion the cardioprotective activity of pancreatic lipase inhibitor of the orlistat. Methods: Adult male Wistar rats were anesthetized, placed on mechanical ventilation and underwent surgery to induce cardiac I/R by obstructing left descending coronary artery followed by reperfusion to evaluation of ventricular arrhythmias (VA), atrioventricular block (AVB) and lethality (LET) with pancreatic lipase inhibitor orlistat (ORL). At the end of reperfusion, blood samples were collected for determination of triglycerides (TG), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase-MB (CK-MB). Results: Treatment with ORL has been able to decrease the incidence of VA, AVB and LET. Besides that, treatment with ORL reduced serum concentrations of CK and LDL, but did not alter the levels of serum concentration of TG, VLDL and HDL. Conclusion: The reduction of ventricular arrhythmias, atrioventricular block, and lethality and serum levels of creatine kinase produced by treatment with orlistat in animal model of cardiac isquemia/reperfusion injury suggest that ORL could be used as an efficient cardioprotective therapeutic strategy to attenuate myocardial damage related to acute myocardial infarction.

Efeitos de um salgante isento de sódio sobre marcadores sanguíneos bioquímicos hepáticos, renais e cardíacos de ratos normo e hipertensos / Effects of a sodium-free salting agent on blood hepatic, renal and cardiac biochemical markers of normal and hypertensive rats

Introdução: A hipertensão arterial é um dos fatores de risco para doenças cardiovasculares, estando diretamente associada ao elevado consumo de sódio. Objetivo: Avaliar os níveis de marcadores de lesão hepática, renal e cardíaca em ratos hipertensos comparados aos seus controles normotensos, tratados com um salgante isento de sódio, água ou NaCl. Métodos: Ratos hipertensos (SHR) e seus controles normotensos (NWR) foram divididos em 3 grupos (n=7): G1 (água); G2 (solução aquosa contendo NaCl 70 mg/kg/dia); G3 (solução aquosa contendo salgante sem sódio 70 mg/kg/dia). Após 30 dias, o sangue dos animais foi processado. Resultados: Não houve diferença entre os níveis séricos de creatina quinase total, creatina quinase-MB, lactato desidrogenase, ácido úrico, aspartato aminotransferase e fosfatase alcalina tanto nos NWR como nos SHR tratados com NaCl ou Salgante. Houve diminuição da creatinina nos NWR e SHR tratados com NaCl e Salgante em relação aos controles (p<0,005). Conclusões: A suplementação diária com o Salgante e NaCl diminuiu os níveis séricos de creatinina nos grupos NWR e SHR. Contudo, não houve modificação nos níveis séricos de marcadores de lesão cardíaca e hepática. (AU)

Introduction: Hypertension is one of the risk factors for cardiovascular diseases, being directly associated with high consumption of sodium. Objective: To assess the levels of hepatic, renal and cardiac injury markers in hypertensive rats compared to their normotensive controls, treated with a salt free saline solution, water or NaCl. Methods: Hypertensive rats (SHR) and their normotensive controls (NWR) were divided into 3 groups (n = 7): G1 (water); G2 (aqueous solution containing NaCl 70 mg / kg / day); G3 (sodium salt-free aqueous solution 70 mg / kg / day). After 30 days, the animals' blood was processed. Results: There was no difference between serum levels of total creatine kinase, creatine kinase-MB, lactate dehydrogenase, uric acid, aspartate aminotransferase and alkaline phosphatase in both NWR and SHR1 treated NaCl or Salgante. There was a decrease in creatinine in NWR and SHR treated with NaCl and Salgante comparing to controls (p <0.005). Conclusions: Daily supplementation with sodium salt-free aqueous solution and NaCl decreases serum creatinine levels in NWR and SHR groups. However, there was no change in serum levels of cardiac and hepatic injury markers. (AU)