Green Tea Infusion Ameliorates Histological Damages in Testis and Epididymis of Diabetic Rats.

Green tea is a popular drink used for therapeutic purposes to mitigate the consequences of diabetes. In this study, we aimed at evaluating the potential of green tea infusion to ameliorate structural and enzymatic damages caused by hyperglycemia in the testis and epididymis of Wistar rats. For that, nondiabetic and streptozotocin-induced diabetic rats (negative control and diabetes control, respectively) received 0.6 mL of water by gavage. Another set of diabetic animals received 100 mg/kg of green tea infusion diluted in 0.6 mL of water/gavage (diabetes + green tea) daily. After 42 days of treatment, the testes and epididymides were removed and processed for histopathological analysis, micromineral determination, and enzymatic assays. The results showed that treatment with green tea infusion preserved the testicular and epididymal histoarchitecture, improving the seminiferous epithelium and the sperm production previously affected by diabetes. Treatment with green tea reduced tissue damages caused by this metabolic condition. Given the severity of hyperglycemia, there was no efficacy of the green tea infusion in maintaining the testosterone levels, antioxidant enzyme activity, and microminerals content. Thus, our findings indicate a protective effect of this infusion on histological parameters, with possible use as a complementary therapy for diabetes.

Analysis of motor performance and histomorphometry of skeletal muscles of rats exercised after cerebral ischemia.

INTRODUCTION: Cerebral ischemia causes muscle atrophy and motor incoordination in animals, impairing motor performance. OBJECTIVE: Thus, the objective of the present study was to analyze the motor performance and histomorphometry of the biceps brachii, soleus, and anterior tibialis muscles of rats submitted to a treadmill training program after induction of cerebral ischemia by the transient occlusion of the middle cerebral artery (MCAO). MATERIALS AND METHODS: To do so, twenty-four 30-day-old Wistar rats were utilized. The exercises were performed for 6 weeks on a leveled treadmill, for 30 min/day, 5 days a week, at a controlled speed of 8 m/min, and the MCAO surgery took place for 60 min. The animals were divided into the following experimental groups: SC (n = 6): control animals that underwent false surgery (operation without the induction of cerebral ischemia) and did not exercise (sedentary); CEA (n = 6): control animals exercised on the treadmill after the false surgery; SI (n = 6): sedentary ischemic animals; IEA (n = 6): animals exercised on the treadmill after the induction of cerebral ischemia. RESULTS: The type-II fibers atrophy in muscle soleo was observed in groups CEA (5125.63 ± 158.83) and SI (4982.38 ± 248.16) when compared to the SC (5927.98 ± 106.17) and IEA (6526.73 ± 195.08) groups. CONCLUSION: It is concluded that the low intensity physical exercise performed on the treadmill for six weeks after the induction of cerebral ischemia by OMCA, promoted a decrease in the atrophy of muscles important of the ischemic animals, benefiting their motor performance.

Effect of bark extract of Bathysa cuspidata on hepatic oxidative damage and blood glucose kinetics in rats exposed to paraquat.

This study investigated the effect of bark extract of Bathysa cuspidata on hepatic oxidative damage and blood glucose kinetics in rats exposed to paraquat. Wistar rats were exposed to a single dose of paraquat (30 mg/kg, i.p.) and treated with an ethanolic extract of Bathysa cuspidata (200 and 400 mg/kg). Analyses were conducted of liver edema, blood glucose, serum transaminases, alkaline phosphatase, collagen, malondialdehyde, catalase, superoxide dismutase, and histomorphometry. In the animals intoxicated with paraquat and treated with 400 mg/kg of extract, edema, hypertrophy of the nucleus of hepatocytes, serum transaminases, alkaline phosphatase, and malondialdehyde levels decreased significantly (p < .05). Catalase and superoxide dismutase activity, the number of hepatocytes per unit volume, and the glycogen proportion were maintained. The increase followed by progressive reduction of blood glucose observed in paraquat-exposed groups was significantly attenuated in the group treated with 400 mg/kg of extract (p < .05). Phytochemical analysis of the extract revealed the presence of flavonoids, proanthocyanidins, and phenolic compounds. The bark extract of Bathysa cuspidata was able to inhibit large variations in blood glucose and reduce hepatic damage in rats exposed to paraquat. This finding suggests a contribution of the extract in reducing lipid peroxidation and the morphofunctional damage to the liver parenchyma.

Green tea infusion prevents diabetic nephropathy aggravation in recent-onset type 1 diabetes regardless of glycemic control.

ETHNOPHARMACOLOGICAL RELEVANCE: Green tea, traditionally used as antidiabetic medicine, positively affects the diabetic nephropathy. It was assumed that these beneficial effects were due to the hypoglycemiant capacity of the tea, wich reduces the glycemic overload and, consequently, the advanced glycation end products rate and oxidative damage. However, these results are still controversial, since tea is not always able to exert a hypoglycemic action, as demonstrated by previous studies. AIM: Investigate if green tea infusion can generate positive outcomes for the kidney independently of glycemic control, using a model of severe type 1 diabetes. MATERIAL AND METHODS: We treated streptozotocin type 1 diabetic young rats with 100 mg/kg of green tea, daily, for 42 days, and evaluated the serum and tissue markers for stress and function. We also analyzed the ion dynamics in the organ and the morphological alterations promoted by diabetes and green tea treatment. Besides, we analyzed, by an in silico approach, the interactions of the green tea main catechins with the proteins expressed in the kidney. RESULTS: Our findings reveal that the components of green tea can interact with the proteins participating in cell signaling pathways that regulate energy metabolism, including glucose and glycogen synthesis, glucose reabsorption, hypoxia management, and cell death by apoptosis. Such interaction reduces glycogen accumulation in the organ, and protects the DNA. These results also reflect in a preserved glomerulus morphology, with improvement in pathological features, and suggesting a prevention of kidney function impairment. CONCLUSION: Our results show that such benefits are achieved regardless of the blood glucose status, and are not dependent on the reduction of hyperglycemia.

Swimming training attenuates the morphological reorganization of the myocardium and local inflammation in the left ventricle of growing rats with untreated experimental diabetes.

Diabetic cardiomyopathy is associated with cardiac remodeling, myocardial dysfunction, low-grade inflammation, and reduced cardiac adiponectin in patients with type 1 diabetes mellitus (T1DM). Alternatively, physical exercise is an important strategy for the management of diabetes. This study aimed to investigate the influence of low-intensity swimming training in cardiac cytokines, structural remodeling, and cardiomyocyte contractile dysfunction in growing rats with untreated experimental DM. Thirty-day-old male Wistar rats were divided into four groups (n=14, per group): sedentary control (SC), exercised control (EC), sedentary diabetic (SD), and exercised diabetic (ED). Diabetes was induced by streptozotocin (60 mg kg(-1), i.p.). Animals from exercised groups swam (5 days/week, 90 min/day, loading up to 5% body weight around the animal's chest) for 8 weeks. The left ventricle (LV) was removed for molecular, morphological, and cardiomyocyte mechanical analysis. Diabetic animals presented cardiac remodeling with myocardial histoarchitectural disorganization, fibrosis, and necrosis. The capillary density was lower in diabetic animals. LV cardiomyocytes from diabetic animals exhibited more prolonged time to the peak of contraction and time to half relaxation than those from control animals. The cardiac levels of interleukin 10, nitric oxide, and total and high molecular weight (HMW) adiponectin were significantly decreased in diabetic animals. Exercise training reduced the level of TNF-α, increased capillary density, and attenuated the histopathological parameters assessed in diabetic rats. In conclusion, the cardiac structural remodeling coexists with reduced levels of total and HMW adiponectin, inflammation, and cardiomyocyte contractility dysfunction in experimental DM. More important, low-intensity swimming training attenuates part of these pathological changes, indicating the beneficial role for exercise in untreated T1DM.

Exercise training prior to myocardial infarction attenuates cardiac deterioration and cardiomyocyte dysfunction in rats.

OBJECTIVES: The present study was performed to investigate 1) whether aerobic exercise training prior to myocardial infarction would prevent cardiac dysfunction and structural deterioration and 2) whether the potential cardiac benefits of aerobic exercise training would be associated with preserved morphological and contractile properties of cardiomyocytes in post-infarct remodeled myocardium. METHODS: Male Wistar rats underwent an aerobic exercise training protocol for eight weeks. The rats were then assigned to sham surgery (SHAM), sedentary lifestyle and myocardial infarction or exercise training and myocardial infarction groups and were evaluated 15 days after the surgery. Left ventricular tissue was analyzed histologically, and the contractile function of isolated myocytes was measured. Student's t-test was used to analyze infarct size and ventricular wall thickness, and the other parameters were analyzed by the Kruskal-Wallis test followed by Dunn's test or a one-way analysis of variance followed by Tukey's test (p<0.05). RESULTS: Myocardial infarctions in exercise-trained animals resulted in a smaller myocardial infarction extension, a thicker infarcted wall and less collagen accumulation as compared to myocardial infarctions in sedentary animals. Myocardial infarction-induced left ventricular dilation and cardiac dysfunction, as evaluated by +dP/dt and -dP/dt, were both prevented by previous aerobic exercise training. Moreover, aerobic exercise training preserved cardiac myocyte shortening, improved the maximum shortening and relengthening velocities in infarcted hearts and enhanced responsiveness to calcium. CONCLUSION: Previous aerobic exercise training attenuated the cardiac dysfunction and structural deterioration promoted by myocardial infarction, and such benefits were associated with preserved cardiomyocyte morphological and contractile properties.

Grape extract and α-Tocopherol effect in cardiovascular disease model of Apo E -/- Mice.

PURPOSE: To verify the effect of consumption of grape extract isolated or combined with α-tocopherol supplementation on atherosclerosis model with Apo E -/- mice. METHODS: After six weeks of atherogenic diet, Apo E -/- mice were divided into the following groups: Control, Grape, Tocopherol and Grape plus Tocopherol. The treatment progressed for 11 weeks when animals were submitted to euthanasia. RESULTS: All the treatments presented hypocholesterolemic effect with reduction of serum and liver cholesterol levels. This effect was parallel to an increase in the fecal excretion of cholesterol. There was also a higher fecal excretion of saturated fatty acids in groups receiving grape extract or α-tocopherol. All the groups treated presented a tendency to show higher levels of vitamin E. The fatty acid profile showed a tendency for monounsaturated fatty acid preservation after grape extract and α-tocopherol consumption. Morphological analysis revealed a lower degree of evolution of the atherosclerotic plaque of the animals that were fed α-tocopherol combined with grape extract, even when no difference was found in the size of the largest lesion. CONCLUSION: A synergistic effect between the polyphenols and α-tocopherol was observed, resulting in diminished evolution of atherosclerosis and a greater beneficial effect on atherosclerosis than the isolated consumption of antioxidants.

Grape extract and α-Tocopherol effect in cardiovascular disease model of Apo E -/- Mice / Efeito do extrato de uva e α-Tocoferol em camundongos Apo E -/-, modelo de doença cardiovascular

PURPOSE: To verify the effect of consumption of grape extract isolated or combined with α-tocopherol supplementation on atherosclerosis model with Apo E -/- mice. METHODS: After six weeks of atherogenic diet, Apo E -/- mice were divided into the following groups: Control, Grape, Tocopherol and Grape plus Tocopherol. The treatment progressed for 11 weeks when animals were submitted to euthanasia. RESULTS: All the treatments presented hypocholesterolemic effect with reduction of serum and liver cholesterol levels. This effect was parallel to an increase in the fecal excretion of cholesterol. There was also a higher fecal excretion of saturated fatty acids in groups receiving grape extract or α-tocopherol. All the groups treated presented a tendency to show higher levels of vitamin E. The fatty acid profile showed a tendency for monounsaturated fatty acid preservation after grape extract and α-tocopherol consumption. Morphological analysis revealed a lower degree of evolution of the atherosclerotic plaque of the animals that were fed α-tocopherol combined with grape extract, even when no difference was found in the size of the largest lesion. CONCLUSION: A synergistic effect between the polyphenols and α-tocopherol was observed, resulting in diminished evolution of atherosclerosis and a greater beneficial effect on atherosclerosis than the isolated consumption of antioxidants.

OBJETIVO: Verificar o efeito do consumo de extrato de uva isolada ou combinada com a suplementação de α-tocoferol em modelo de aterosclerose, utilizando camundongos Apo E -/-. MÉTODOS: Os camundongos Apo E -/- foram tratados com dieta aterogênica por seis semanas e foram divididos em quatro grupos: Controle, Uva, Tocoferol e Uva e Tocoferol. Após 11 semanas de tratamento os animais foram submetidos à eutanasia. RESULTADOS: Todos os tratamentos apresentaram efeito hipocolesterolêmico, com redução de colesterol plasmático e hepático. Este efeito foi acompanhado de um aumento na excreção fecal de colesterol. Houve também uma maior excreção fecal de ácidos graxos saturados nos grupos que receberam extrato de uva ou de α-tocoferol. Todos os grupos apresentaram uma tendência a apresentar níveis mais elevados de vitamina E. O perfil de ácidos graxos mostrou uma tendência para a preservação de ácidos graxos monoinsaturados, após consumo de extrato de uva e α-tocoferol. A análise morfológica revelou um menor grau de evolução da placa aterosclerótica dos animais que foram alimentados com α-tocoferol combinado com extrato de uva, mesmo quando não houve diferença no tamanho da lesão. CONCLUSÃO: Foi observado um efeito sinergístico entre os polifenóis e α-tocoferol, resultando na redução na evolução da aterosclerose e um maior de efeito benéfico na aterosclerose do que o consumo isolado de antioxidantes sobre a aterosclerose do que o consumo isolado de antioxidantes.

Treinamento em natação com baixa intensidade não protege músculo esquelético contra lesões induzidas por exercício exaustivo em ratos / Low-intensity swimming training does not protect the skeletal muscle

Enquanto o exercício aeróbico regular promove adaptações benéficas ao músculo esquelético, o exercício físico exaustivo induz lesões musculares. O objetivo deste estudo foi verificar se um programa de natação com baixa intensidade é capaz de proteger músculos esqueléticos contra lesões induzidas por exercício exaustivo. Ratos Wistar (peso: 376,50 ± 4,36g; idade: 90 dias) foram divididos aleatoriamente em quatro grupos: controle sedentário (CS); sedentário submetido a teste de exaustão (SE); treinado em natação (TN); treinado em natação submetido a teste de exaustão (TNE). Animais dos grupos TN e TNE foram submetidos a um programa de natação sem sobrecarga por 90 minutos/dia, cinco dias/semana, durante 17 semanas. Após este período, os grupos SE e TNE foram submetidos a um teste de exaustão em natação. Após eutanásia, fragmentos dos músculos sóleo e reto femoral foram coletados e submetidos à análise histológica e de proteínas de choque térmico (HSP70). Os resultados mostraram que o tempo até a exaustão foi maior no grupo TNE que no SE (125,0 ± 6,0 vs. 90,0 ± 8,5min, respectivamente, P < 0,05). Os níveis de lactato sanguíneo durante o teste e exaustão foram menores no grupo TNE que no SE (5,31 ± 0,22 vs. 8,76 ± 0,59mmol/L, respectivamente, P < 0,05). A frequência de fibras lesadas nos músculos foi maior nos grupos SE (sóleo: 34,86 ± 0,04; reto femoral: 37,57 ± 0,07) e TNE (sóleo: 41,57 ± 0,08; reto femoral: 39,57 ± 0,05), comparada aos grupos CS (sóleo: 13,88 ± 0,81; reto femoral: 16,75 ± 0,79) e TN (sóleo: 24,14 ± 0,06; reto femoral: 24,0 ± 0,05), respectivamente (P < 0,05). Não houve diferença significativa nos níveis de HSP70 dos músculos analisados entre os quatro grupos. Concluimos que apesar do treinamento em natação melhorar o desempenho dos animais no teste de exaustão, não promoveu proteção aos seus músculos esqueléticos contra as lesões induzidas pelo exercício exaustivo.

While regular aerobic exercise promotes beneficial adaptations to the skeletal muscle, acute exhaustive exercise causes structural damage to the skeletal muscle cells. The aim of this study was to verify whether a low-intensity swimming program protects the skeletal muscles against damage induced by exhaustive exercise. Male Wistar rats (weight: 376.50 4.36g; age: 90 days) were randomly divided into four groups: sedentary control (SC, N=8); sedentary submitted to exhaustive test (SE, N=7); swimming trained (TN, N=7); swimming trained submitted to exhaustive test (TNE, N=7). Animals of TN and TNE groups were submitted to a swimming regimen without overload for 90 min/day, 5 days/wk, during 17 weeks. Forty-eight hours after the last training session, animals from SE and TNE groups were submitted to an exhaustive exercise protocol. At sacrifice, fragments of soleus and rectus femoris muscles were collected and submitted to histological analysis and heat shock protein (HSP70) expression measurement. The results showed that the time until exhaustion was greater in the STE than in SE group (125.0 6.00 vs. 90.0 8.48 min, respectively, P<0.05). The levels of blood lactate during exhaustive exercise were lower in animals from TNE than SE (5.31 ± 0.22 vs. 876 ± 0.59 mmol/L, respectively, P<0.05)The frequency of damaged fibers in the muscles was greater in SE (soleus: 34.86±0.04; rectus femoris: 37.57 ± 0.07) and STE (soleus: 41.57±0.08; rectus femoris: 39.57 ± 0.05), compared to groups SC (soleus: 13.88±0.81; rectus femoris: 16.75 ± 0.79) and ST (soleus: 24.14±0.06; rectus femoris: 24.0 ± 0.05), respectively (P<0.05). There was no significant difference at the HSP70 levels of the analyzed muscles among the four groups (P>0.05). In conclusion, although a low-intensity swimming training increased the animals' performance in the exhaustive exercise test, it did not protect their skeletal muscles against damage induced by exhaustive exercise.