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Background/Aim. Mechanisms responsible for the beneficial effects of aerobic exercise training on cardiovascular function are well known, but detraining effects on myocardial parameters have not been adequately elucidated. Therefore, the study aimed to determine the occurrence and speed of cardiac adaptation reversibility after the cessation of aerobic exercise and to reveal gender differences in achieved effects of training/detraining. Methods. Fe-male and male Wistar albino rats were divided into the following groups: control, trained, and two detrained groups. Hearts were perfused according to the Langendorff technique and the following cardiodynamic parameters were determined: the maximum and minimum rate of pressure development in the left ventricle (dp/dt max and dp/dt min, respectively), systolic and diastolic left ventricular pressure (SLVP and DLVP, respectively), heart rate (HR), and coronary flow. Results. Training significantly reduced values of dp/dt max, dp/dt min, and SLVP in males and females, and coronary flow in males. Detraining caused a reversion of those changes, which was gender-specific. In females, levels of SLVP were higher after 4 weeks of detraining compred to training, and after 2 weeks of detraining. Values of SLVP were lower in both detraining periods compared to training in males. Males had higher coronary flow after 2 weeks of detraining. Simultaneously, coronary flow was reduced in the 4th week of detraining in females. Conclusion. By using a model of the isolated rat heart, the present study confirmed the existence of training-induced changes in cardiac function. Cessation of training was followed by the loss of those adaptations, faster in males than females.

The aim of our study was to assess and compare the effects of dipeptidyl peptidase 4 (DPP4) inhibitors, saxagliptin and sitagliptin, on metabolic control of disease and cardiac function in rats with diabetes mellitus type 2 (T2DM). This research would provide novel understanding into the potentially protective effects of DPP4 inhibitors in helping salvage of the heart exposed to ischaemia-reperfusion (I-R) injury. Forty-eight Wistar albino rats were randomly divided into four groups: CTRL, Control healthy group; T2DM, rats with T2DM; T2DM + Sit, rats with T2DM treated with 0.6 mg/kg of sitagliptin; T2DM + Sax, rats with T2DM treated with 0.45 mg/kg of saxagliptin for 3 weeks. At the end of the protocol, in vivo cardiac function was assessed by echocardiography, while in the blood samples glucose and insulin were determined. Additionally, ex vivo heart function was estimated on a model of I-R injury using Langendorff apparatus. Immunohistochemical analysis was used to determine the degree of myocardial apoptosis and necrosis, while DPP4 staining was performed to assess the cardiac DPP4 expression. Data were analyzed using a one-way analysis of variance (ANOVA) and the post hoc Bonferroni test for multiple comparisons. Improved glycoregulation was noticed in rats that received DPP4 inhibitors compared to untreated diabetic rats (P < .05). Moreover, better in vivo systolic function was observed in rats treated with both DPP4 inhibitors as evidenced by an increase in fractional shortening when compared to T2DM (P < .05). Most parameters of cardiac function in treated rats remained unaltered during reperfusion, thus suggesting that both drugs protected myocardium during flow restoration. Better effects on coronary circulation were achieved after sitagliptin application. Additionally, both DPP4 inhibitors showed similar potential to attenuate cardiac necrosis and apoptosis. Saxagliptin and sitagliptin might be efficient in preserving myocardial function and morphology in ex vivo induced I-R cardiac injury in rats with T2DM.

The aim of this study was to estimate the effects of natural low mineral water from the source "Sneznik-1/79" in Serbia on glycemia as well as heart function in rats with diabetes mellitus type 2 (T2DM), with the special emphasis on the role of the oxidative stress. Twenty Wistar albino rats (males, 4 weeks old at the beginning of the study, body weight 180 ± 20 g) were included in the study. Rats were divided randomly into 2 groups (10 animals per group): T2DM: rats with diabetes mellitus type 2 with free access to tap water; T2DM + SW: rats with diabetes mellitus type with free access to natural mineral water from "Sneznik-1/79". Glucose level, ex vivo cardiac function as well as systemic and cardiac redox state were assessed. At the end of the study protocol, glucose level was lower in diabetic rats who consumed mineral water. Moreover cardiac function wasn't affected by mineral water intake, however, significant antioxidant effects were observed. Our study suggests that 4-week consumption of low mineral water from the spring "Sneznik-1/79" has important role in regulation of glycemia and altering redox state in favor of elevated antioxidant capacity without affecting heart function. Based on our findings we may assume that low mineral water from the spring "Sneznik-1/79" has the potential to be used either as preventive strategy or as additional therapeutic strategy in management of T2DM.

The investigation was aimed to evaluate the effects of 3-weeks swimming exercise on blood pressure and redox status in high-salt-induced hypertensive rats. Male Wistar albino rats (n=40, 6 weeks old) were divided into 4 groups: 1. hypertensive rats that swam for 3 weeks; 2. sedentary hypertensive control rats; 3. normotensive rats that swam for 3 weeks; 4. sedentary normotensive control rats. Hypertensive animals were on high concentrated sodium (8% NaCl) solution for 4 weeks (period of induction of hypertension). After sacrificing, hearts were isolated and perfused according to Langendorff technique at gradually increased coronary per-fusion pressure from 40–120 cmH2O. The oxidative stress markers were determined in coronary venous effluent: the index of lipid peroxidation (measured as TBARS), nitrites (NO2 −), superoxide anion radical (O2 −) and hydrogen peroxide (H2O2). Swimming did not lead to significant changes in levels of TBARS, NO2 −, O2 − in any of compared groups while levels of H2O2 were significantly higher in swimming hyper-tensive group comparing to swimming normotensive group at coronary perfusion pressure of 80–120 cmH2O. Our results indicate that the short-term swimming start to reduce blood pressure. In addition it seems that this type of swimming duration does not promote cardiac oxidative stress damages.

Type 2 diabetes (T2DM) is characterized by well-preserved insulin secretion; however, the surrounding tissue is insensitive to insulin, resulting in increased blood glucose level due to the inability of tissues to convert glucose into energy. As a result of chronic non-regulation of glucose levels and high daily fluctuations in the blood, the micro- and macrovascular complications occur in these patients. Complications develop through two main mechanisms: induction of oxidative stress and innate immunity. In this regard, the aim of this study was to examine the effect of four week administration of DPP4 inhibitors (saxagliptin, sitagliptin and vildagliptin) to the parameters of oxidative stress and antioxidant defense in the group of rats with diabetes type 2 (T2DM). Sixty Wistar albino rats were divided randomly into 5 groups: group I: control healthy group; group II: rats with diabetes type 2; group III: rats with diabetes type 2 treated with 0.6 mg/kg of sitagliptin; group IV: rats with diabetes type 2 treated with 0.45 mg/kg of saxagliptin, group V: rats with diabetes type 2 treated with 9 mg/kg vildagliptin. The rats from experimental groups were fed with a high-fat diet for 4 weeks and after 6–8 h of starvation received one dose of streptozotocin (STZ) intraperitoneally (25 mg/kg body weight) to induce T2DM. Animals with fasting glucose above 7 mmol / L and insulin over 6 mmol / L were included in the study as rats with T2DM. Upon completion of the experiments, the blood was collected from the anesthetized animals and used for sphectrophotometrical determination of parameters of oxidative stress, and antioxidative defense. T2DM induced significant increase in production of reacitve oxygen species (ROS) (superoxide anion radical and hydrogen peroxide), but additional four-week administration of gliptins induced decrease in ROS values. On the other hand, T2DM induced decrease of nitric oxide, superoxide dismutase, catalaze, and reduced gluthation and concomitant therapy with gliptins induced increase of these parametars, suggesting significant antioxidant potential of this group of drugs.

This study investigated different dietary strategies, high-fat (HFd), or standard diet (Sd) alone or in combination with standardized Aronia melanocarpa extract (SAE), as a polyphenol-rich diet, and their effects on lipids and fatty acids (FA) in rats with metabolic syndrome (MetS). Wistar albino rats were randomly divided into two groups: healthy and rats with MetS, and then depending on dietary patterns on six groups: healthy rats fed with Sd, healthy rats fed with Sd and SAE, rats with MetS fed with HFd, rats with MetS fed with HFd and SAE, rats with MetS fed with Sd, and rats with MetS fed with Sd and SAE. 4 weeks later, after an overnight fast (12-14 h), blood for determination of total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), index of lipid peroxidation (measured as TBARS), and FA was collected. Increased FA and lipid concentration found in MetS rats were reduced when changing dietary habits from HFd to Sd with or without SAE consumption. Consumption of SAE slightly affects the FA profiles, mostly palmitoleic acid in healthy rats and PUFA in MetS + HFd rats. Nevertheless, in a high-fat diet, SAE supplementation significantly decreases n-6/n-3 ratio, thereby decreasing systemic inflammation. Further researches are warranted to confirm these effects in humans.

The main goal of this study was to investigate the cardioprotective properties in terms of effects on cardiodynamics of perfluorocarbon emulsion in ex vivo-induced ischemic-reperfusion injury of an isolated rat heart. The first part of the study aims to determine the dose of 10% perfluoroemulsion (PFT) that will show the best cardioprotective effect in rats on ex vivo-induced ischemic / reperfusion injury of an isolated rat heart. Depending on whether the animals received saline or PFT, the animals were divided into a control or experimental group, and depending on the application of a dose (8, 12, 16 ml / kg body weight) of saline or PFT. At a dose of 8 ml / kg, the results indicate statistically significantly lower values ​​of the maximum pressure growth rate in the group treated with 10% PFT compared to the control group treated with saline at R5 and R25 points. At a dose of 12 ml / kg, the maximum left ventricular pressure growth rate differed statistically significantly in the PFT group, ie there was an increase in this parameter at points R25 and R30, and the minimum left ventricular pressure growth rate in R15-R30 compared to saline-treated group. At a dose of 16 ml / kg, PFT also had a statistically significant effect on the change in cardiodynamic parameters in an isolated rat heart organ. Based on all the above, we can conclude that Peftoran administered immediately before ischemia (1 hour) has less positive effects on myocardial function in a model of an isolated rat heart compared to earlier administration (10 and 20 hours). Also, the effects of 10% peftoran solution are more pronounced if there is a longer period of time from application to ischemia, ie immediate application of peftoran before ischemia (1 hour) gave the weakest effects on the change of cardiodynamics of isolated rat heart.

This review aimed to provide a summary on the traditional uses, phytochemistry, and pharmacological activities in the cardiovascular system and cardiotoxicity of Melissa officinalis (MO), with the special emphasis on the protective mechanisms in different cardiovascular pathologies. MO is a perennial aromatic herb commonly known as lemon balm, honey balm, or bee balm, which belongs to Lamiaceae family. Active components are mainly located in the leaves or essential oil and include volatile compounds, terpenoid (monoterpenes, sesquiterpenes, triterpenes), and polyphenolic compounds [rosmarinic acid (RA), caffeic acid, protocatechuic acid, quercitrin, rhamnocitrin, luteolin]. For centuries, MO has been traditionally used as a remedy for memory, cognition, anxiety, depression, and heart palpitations. Up until now, several beneficial cardiovascular effects of MO, in the form of extracts (aqueous, alcoholic, and hydroalcoholic), essential oil, and isolated compounds, have been confirmed in preclinical animal studies, such as antiarrhythmogenic, negative chronotropic and dromotropic, hypotensive, vasorelaxant, and infarct size–reducing effects. Nonetheless, MO effects on heart palpitations are the only ones confirmed in human subjects. The main mechanisms proposed for the cardiovascular effects of this plant are antioxidant free radical–scavenging properties of MO polyphenols, amelioration of oxidative stress, anti-inflammatory effects, activation of M2 and antagonism of β1 receptors in the heart, blockage of voltage-dependent Ca2+ channels, stimulation of endothelial nitric oxide synthesis, prevention of fibrotic changes, etc. Additionally, the main active ingredient of MO-RA, per se, has shown substantial cardiovascular effects. Because of the vastness of encouraging data from animal studies, this plant, as well as the main ingredient RA, should be considered and investigated further as a tool for cardioprotection and adjuvant therapy in patients suffering from cardiovascular diseases.

The aim of our study was to investigate the effects of one-month consumption of polyphenol-rich standardized Aronia melanocarpa extract (SAE) on redox status in anemic hemodialysis patients. The study included 30 patients (Hb 3 months; > 3 times week). Patients were treated with commercially available SAE in a dose of 30 ml/day, for 30 days. After finishing the treatment blood samples were taken in order to evaluate the effects of SAE on redox status. Several parameters of anemia and inflammation were also followed. After the completion of the treatment, the levels of superoxide anion radical and nitrites significantly dropped, while the antioxidant capacity improved via elevation of catalase and reduced glutathione. Proven antioxidant effect was followed by beneficial effects on anemia parameters (increased hemoglobin and haptoglobin concentration, decreased ferritin and lactate dehydrogenase concentration), but SAE consumption didn`t improve inflammatory status, except for minor decrease in C-reactive protein. The consumption of SAE regulates redox status (reduce the productions of pro-oxidative molecules and increase antioxidant defense) and has beneficial effects on anemia parameters. SAE could be considered as supportive therapy in patients receiving hemodialysis which are prone to oxidative stress caused by both chronic kidney disease and hemodialysis procedure. Additionally, it could potentially be a good choice for supplementation of anemic hemodialysis patients. TRN: NCT04208451 December 23, 2019 “retrospectively registered”

This study aimed to examine the effects of diallyl trisulfide (DATS), the most potent polysulfide derived from garlic, on metabolic syndrome and myocardial function in rats with metabolic syndrome (MetS). For that purpose, we used 36 male Wistar albino rats divided into control rats, rats with MetS and MetS rats treated with 40 mg/kg of DATS every second day for 3 weeks. In the first part, we studied the impact of DATS on MetS control and found that DATS significantly raised H2S, decreased homocysteine and glucose levels and enhanced lipid and antioxidative, while reducing prooxidative parameters. Additionally, this polysulfide improved cardiac function. In the second part, we investigated the impact of DATS on ex vivo induced ischemia/reperfusion (I/R) heart injury and found that DATS consumption significantly improved cardiodynamic parameters and prevented oxidative and histo-architectural variation in the heart. In addition, DATS significantly increased relative gene expression of eNOS, SOD-1 and -2, Bcl-2 and decreased relative gene expression of NF-κB, IL-17A, Bax, and caspases-3 and -9. Taken together, the data show that DATS can effectively mitigate MetS and have protective effects against ex vivo induced myocardial I/R injury in MetS rat.

This research is designed to test the hypothesis that elevated homocysteine (Hcy) levels in vivo, caused by a deficit in vitamin B complex, promote changes in cardiac function and redox status that lead to heart failure. In order to conduct the study, we used adult male Wistar albino rats (n = 30; 4 weeks old; 100 ± 15 g body weight). Hyperhomocysteinaemia (HHcy) in these animals was achieved by dietary manipulation. For 4 weeks, the animals were fed with a standard rodent chow (control, CF), a diet enriched in methionine with no deficiency in B vitamins (i.e., folic acid, B6 and B12) (HMNV) or a diet enriched in methionine and deficient in B vitamins (HMLV). After 28 days of dietary manipulation, all animals were killed. The rat hearts were isolated and retrogradely perfused according to the Langendorff technique at a gradually increasing perfusion pressure. We found a negative correlation between elevated serum Hcy and total body and heart weight. The maximum rate of left ventricular pressure development was significantly increased in the HMNV group compared with in the other groups. Systolic left ventricular pressure was significantly changed in all groups. HHcy induces remodelling of the cardiac tissues, as moderate HHcy is associated with more prominent interstitial and perivascular fibrosis. Our results suggest that a high methionine diet without vitamin B complex causes profound negative effects associated with HHcy.

The aim of present study was to evaluate the effects of 3- and 6-week swimming exercise on cardiodynamics and coronary flow in high salt-induced hypertensive and normotensive rats. 80 male Wistar albino rats (6 weeks old) were divided into 8 groups: hypertensive animals that swam for 3 weeks; hypertensive animals that swam for 6 weeks and their respective sedentary controls; normotensive animals that swam for 3 weeks; normotensive animals that swam for 6 weeks and their respective sedentary controls. Hypertensive animals were on high sodium (8% NaCl solution) diet for 4 weeks, and these animals did not drink tap water during the experimental protocol. After sacrificing, hearts were isolated and perfused according to Langendorff technique at gradually increased coronary perfusion pressure (40–120 cmH2O). The following parameters of cardiac function were continuously recorded: maximum and minimum rate of pressure development in LV, systolic, and diastolic left ventricular pressure, and heart rate. Coronary flow was measured flowmetrically. Findings of the present study may help in better understanding of short- to medium-term exercise-induced direct effects on cardiac function and perfusion. Generally viewed, swimming of both durations did not change myocardial function and perfusion in hypertensive and normotensive conditions.

The aim of our study was to examine the effects of different dietary strategies, high-fat (HFd) or standard diet (Sd) alone or in combination with standardized oral supplementation (0.45 mL/kg/day) of Aronia melanocarpa extract (SAE) in rats with metabolic syndrome (MetS). SAE is an official product of pharmaceutical company Pharmanova (Belgrade, Serbia), however, the procedure for extraction was done by EU-Chem company (Belgrade, Serbia). Rats were divided randomly into six groups: control with Sd, control with Sd and SAE, MetS with HFd, MetS with HFd and SAE, MetS with Sd and MetS with Sd and SAE during 4 weeks. At the end of the 4-week protocol, cardiac function and liver morphology were assessed, while in the blood samples glucose, insulin, iron levels and systemic redox state were determined. Our results demonstrated that SAE had the ability to lower blood pressure and exert benefits on in vivo and ex vivo heart function. Moreover, SAE improved glucose tolerance, attenuated pathological liver alterations and oxidative stress present in MetS. Obtained beneficial effects of SAE were more prominent in combination with changing dietary habits. Promising potential of SAE supplementation alone or in combination with different dietary protocols in triggering cardioprotection should be further examined in future.