Graziele Freitas de Bem

Relaxant Effects of Sildenafil on the Human Isolated Bladder Neck

OBJECTIVE To evaluate potential in vitro relaxant actions of sildenafil on human isolated bladder neck smooth muscle. METHODS Bladder neck strips were sampled from patients (aged 55-77 years) submitted to prostatic surgery (6 adenomectomies and 1 radical prostatectomy). These were carefully dissected into 1-2 x 0.5-cm pieces and suspended in an organ bath containing 30 mL of a modified Krebs Henseleit solution, bubbled with 95% O(2)/5% CO(2). After tissue stabilization and viability test with KCl, the tissue was precontracted with phenylephrine, and a concentration-response relaxant curve to sildenafil was constructed. The effect of sildenafil was also assessed in tissues treated with N(omega)-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one (ODQ) (inhibitors of nitric oxide synthase and guanylyl cyclase, respectively). RESULT Sildenafil induced significant bladder neck relaxation at all concentrations tested. The maximum relaxation was 86.97% +/- 6.69%, obtained with a high concentration of sildenafil (5.1 x 10(-4) M). Both L-NAME and ODQ significantly reduced sildenafil-induced relaxation. CONCLUSIONS Sildenafil was effective in inducing bladder neck smooth muscle relaxation in vitro. This effect was almost abolished by L-NAME and ODQ, clearly demonstrating a dependence of the nitric oxide-cyclic guanosine monophosphate pathway. Our in-vitro results suggest that sildenafil might be useful in improving lower urinary tract symptoms due to benign prostatic hyperplasia.

Protective effect of Euterpe oleracea Mart (açaí) extract on programmed changes in the adult rat offspring caused by maternal protein restriction during pregnancy

This study examined the effect of açaí (Euterpe oleracea Mart.) seed extract (ASE) on cardiovascular and renal alterations in adult offspring, whose mothers were fed a low‐protein (LP) diet during pregnancy.

Euterpe oleracea Mart.-Derived Polyphenols Protect Mice from Diet-Induced Obesity and Fatty Liver by Regulating Hepatic Lipogenesis and Cholesterol Excretion

The aim of this study was to investigate the effect of a polyphenol-rich Açaí seed extract (ASE, 300 mg/kg-1d-1) on adiposity and hepatic steatosis in mice that were fed a high-fat (HF) diet and its underlying mechanisms based on hepatic lipid metabolism and oxidative stress. Four groups were studied: C57BL/6 mice that were fed with standard diet (10% fat, Control), 10% fat + ASE (ASE), 60% fat (HF), and 60% fat + ASE (HF + ASE) for 12 weeks. We evaluated the food intake, body weight gain, serum glucose and lipid profile, hepatic cholesterol and triacyglycerol (TG), hepatic expression of pAMPK, lipogenic proteins (SREBP-1c, pACC, ACC, HMG-CoA reductase) and cholesterol excretion transporters, ABCG5 and ABCG8. We also evaluated the steatosis in liver sections and oxidative stress. ASE reduced body weight gain, food intake, glucose levels, accumulation of cholesterol and TG in the liver, which was associated with a reduction of hepatic steatosis. The increased expressions of SREBP-1c and HMG-CoA reductase and reduced expressions of pAMPK and pACC/ACC in HF group were antagonized by ASE. The ABCG5 and ABCG8 transporters expressions were increased by the extract. The antioxidant effect of ASE was demonstrated in liver of HF mice by restoration of SOD, CAT and GPx activities and reduction of the increased levels of malondialdehyde and protein carbonylation. In conclusion, ASE substantially reduced the obesity and hepatic steatosis induced by HF diet by reducing lipogenesis, increasing cholesterol excretion and improving oxidative stress in the liver, providing a nutritional resource for prevention of obesity-related adiposity and hepatic steatosis.

Effects of an extract obtained from fruits of Euterpe oleracea Mart. in the components of metabolic syndrome induced in C57BL/6J mice fed a high-fat diet.

Previously, we have demonstrated that the seed of Euterpe oleracea Mart. (açaí) from the Amazon region exerts vasodilator and antihypertensive actions. The aim of our study was to assess the effects of oral chronic treatment with açaí seed extract (ASE, 300 mg·kg−1·d−1) on high-fat (HF) diet-induced metabolic syndrome (MS) in C57BL/6J mice. Four groups of C57BL/6 mice were fed with control diet (10% fat), ASE (10% fat), HF (60% fat), and HF + ASE (60% fat plus ASE) for 12 weeks. The vasodilator effects of acetylcholine (ACh) and nitroglycerine (NG) were studied in perfused mesenteric arterial bed. Body weight, plasma total cholesterol, triglyceride, glucose and insulin levels, oral glucose tolerance test, and oxidative damage were determined, and the insulin resistance measured by Homeostatic Model Assessment (HOMA) index. Vasodilator response to ACh but not to NG was reduced in HF mice, and ASE restored the response. Increased plasma malondialdehyde levels, body weight, plasma triglyceride, total cholesterol, glucose levels, and insulin resistance were observed in HF mice and reduced by ASE. Treatment with ASE also reduced glucose intolerance observed by oral glucose tolerance test in HF mice. In conclusion, ASE protected C57BL/6J mice fed HF diet from phenotypic and metabolic characteristics of MS, providing an alternative nutritional resource for prevention of MS.

Grape skin extract protects against programmed changes in the adult rat offspring caused by maternal high-fat diet during lactation.

Maternal overnutrition during suckling period is associated with increased risk of metabolic disorders in the offspring. We aimed to assess the effect of Vitis vinifera L. grape skin extract (ACH09) on cardiovascular and metabolic disorders in adult male offspring of rats fed a high-fat (HF) diet during lactation. Four groups of female rats were fed: control diet (7% fat), ACH09 (7% fat plus 200 mg kg(-1) d(-1) ACH09 orally), HF (24% fat), and HF+ACH09 (24% fat plus 200 mg kg(-1) d(-1) ACH09 orally) during lactation. After weaning, all male offspring were fed a control diet and sacrificed at 90 or 180 days old. Systolic blood pressure was increased in adult offspring of HF-fed dams and ACH09 prevented the hypertension. Increased adiposity, plasma triglyceride, glucose levels and insulin resistance were observed in offspring from both ages, and those changes were reversed by ACH09. Expression of insulin cascade proteins IRS-1, AKT and GLUT4 in the soleus muscle was reduced in the HF group of both ages and increased by ACH09. The plasma oxidative damage assessed by malondialdehyde levels was increased, and nitrite levels decreased in the HF group of both ages, which were reversed by ACH09. In addition, ACH09 restored the decreased plasma and mesenteric arteries antioxidant activities of superoxide dismutase, catalase and glutathione peroxidase in the HF group. In conclusion, the treatment of HF-fed dams during lactation with ACH09 provides protection from later-life hypertension, body weight gain, insulin resistance and oxidative stress. The protective effect ACH09 may involve NO synthesis, antioxidant action and activation of insulin-signaling pathways.

Defective nitric oxide-cyclic guanosine monophosphate signaling in patients with bipolar disorder: a potential role for platelet dysfunction.

Objective Bipolar disorder (BD) is associated with elevated cardiovascular mortality rates. We investigated the modulation of L-arginine–nitric oxide (NO) signaling in platelets from patients with BD at different phases. Methods Platelets obtained from 28 patients with BD and 10 healthy volunteers were analyzed for L-arginine transport, NO synthase (NOS) activity, cyclic guanosine monophosphate content, and biomarkers of oxidative stress. Expressions of NOS isoforms, soluble guanylyl cyclase, and arginase were also measured in platelets. Amino acid and C-reactive protein levels in plasma were assessed. Results Plasma concentrations of L-arginine (mean [M] ± standard error of the mean [SEM] = 97 ± 10 versus 121 ± 10 µM) and its transport into platelets (median [interquartile range] = 26.0 [28.6] versus 26.5 [43.9] pmol/109 cells per minute) did not differ between patients with BD and controls (p > .05). Patients with BD showed reduced NOS activity (M ± SEM = 0.037 ± 0.003 versus 0.135 ± 0.022 pmol/108 cells, p < .001), but not endothelial NOS, inducible NOS, and arginase expression, compared with controls (p > .05). Cyclic guanosine monophosphate content was reduced (M ± SEM = 0.022 ± 0.003 versus 0.086 ± 0.020 pmol/108 cells, p < .05) despite the absence of changes in soluble guanylyl cyclase expression (median [interquartile range] = 21.6 [15.5] versus 9.5 [9.4] arbitrary units, p > .05) in patients with BD. Superoxide dismutase activity, but not catalase activity, was increased in patients with BD in the manic phase (M ± SEM = 2094 ± 335 versus 172 ± 17 U/mg protein, p < .001). C-reactive protein was elevated only in manic episodes (M ± SEM = 0.8 ± 0.2 versus 0.1 ± 0.02 mg/L, p < .001). Conclusions Impaired NO generation from platelets, inflammation, and oxidative stress may play pivotal roles in the multifaceted process of cardiovascular events in BD. Abbreviations NO = nitric oxide NOS = nitric oxide synthase BD = bipolar disorder

The Beneficial Effect of Anthocyanidin‐Rich Vitis vinifera L. Grape Skin Extract on Metabolic Changes Induced by High‐Fat Diet in Mice Involves Antiinflammatory and Antioxidant Actions

We hypothesized that a polyphenol‐rich extract from Vitis vinifera L. grape skin (GSE) may exert beneficial effects on obesity and related metabolic disorders induced by a high‐fat diet (HFD). C57/BL6 mice were fed a standard diet (10% fat, control, and GSE groups) or an HFD (60% fat, high fat (HF), and HF + GSE) with or without GSE (200 mg/kg/day) for 12 weeks. GSE prevented weight gain; dyslipidemia; insulin resistance; the alterations in plasma levels of leptin, adiponectin, and resistin; and the deregulation of leptin and adiponectin expression in adipose tissue. These beneficial effects of GSE may be related to a positive modulation of insulin signaling proteins (IR, pIRS, PI3K, pAKT), pAMPK/AMPK ratio, and GLUT4 expression in muscle and adipose tissue. In addition, GSE prevented the oxidative damage, evidenced by the restoration of antioxidant activity and decrease of malondialdehyde and carbonyl levels in muscle and adipose tissue. Finally, GSE showed an anti‐inflammatory action, evidenced by the reduced plasma and adipose tissue inflammatory markers (TNF‐α, IL‐6). Our results suggest that GSE prevented the obesity and related metabolic disorders in HF‐fed mice by regulating insulin sensitivity and GLUT4 expression as well as by preventing the oxidative stress and inflammation in skeletal muscle and adipose tissue. Copyright

Supplementation with Vitis vinifera L. skin extract improves insulin resistance and prevents hepatic lipid accumulation and steatosis in high-fat diet–fed mice

Nonalcoholic fatty liver disease is one of the most common complications of obesity. The Vitis vinifera L. grape skin extract (ACH09) is an important source of polyphenols, which are related to its antioxidant and antihyperglycemic activities. We hypothesized that ACH09 could also exert beneficial effects on metabolic disorders associated with obesity and evaluated ACH09s influence on high-fat (HF) diet-induced hepatic steatosis and insulin resistance in C57BL/6 mice. The animals were fed a standard diet (10% fat, control) or an HF diet (60% fat, HF) with or without ACH09 (200mg/[kg d]) for 12weeks. Our results showed that ACH09 reduced HF diet-induced body weight gain, prevented hepatic lipid accumulation and steatosis, and improved hyperglycemia and insulin resistance. The underlying mechanisms of these beneficial effects of ACH09 may involve the activation of hepatic insulin-signaling pathway because the expression of phosphorylated insulin receptor substrate-1, phosphatidylinositol 3-kinase, phosphorylated Akt serine/threonine kinase 1, and glucose transporter 2 was increased by ACH09 and correlated with improvement of hyperglycemia, hyperinsulinemia, and insulin resistance. ACH09 reduced the expression of the lipogenic factor sterol regulatory-element binding protein-1c in the liver and upregulated the lipolytic pathway (phosphorylated liver kinase B1/phosphorylated adenosine-monophosphate-activated protein kinase), which was associated with normal hepatic levels of triglyceride and cholesterol and prevention of steatosis. ACH09 prevented the hepatic oxidative damage in HF diet-fed mice probably by restoration of antioxidant activity. In conclusion, ACH09 protected mice from HF diet-induced obesity, insulin resistance, and hepatic steatosis. The regulation of hepatic insulin signaling pathway, lipogenesis, and oxidative stress may contribute to ACH09s protective effect.

Antidiabetic effect of Euterpe oleracea Mart. (açaí) extract and exercise training on high-fat diet and streptozotocin-induced diabetic rats: A positive interaction

A growing body of evidence suggests a protective role of polyphenols and exercise training on the disorders of type 2 diabetes mellitus (T2DM). We aimed to assess the effect of the açaí seed extract (ASE) associated with exercise training on diabetic complications induced by high-fat (HF) diet plus streptozotocin (STZ) in rats. Type 2 diabetes was induced by feeding rats with HF diet (55% fat) for 5 weeks and a single dose of STZ (35 mg/kg i.p.). Control (C) and Diabetic (D) animals were subdivided into four groups each: Sedentary, Training, ASE Sedentary, and ASE Training. ASE (200 mg/kg/day) was administered by gavage and the exercise training was performed on a treadmill (30min/day; 5 days/week) for 4 weeks after the diabetes induction. In type 2 diabetic rats, the treatment with ASE reduced blood glucose, insulin resistance, leptin and IL-6 levels, lipid profile, and vascular dysfunction. ASE increased the expression of insulin signaling proteins in skeletal muscle and adipose tissue and plasma GLP-1 levels. ASE associated with exercise training potentiated the reduction of glycemia by decreasing TNF-α levels, increasing pAKT and adiponectin expressions in adipose tissue, and IR and pAMPK expressions in skeletal muscle of type 2 diabetic rats. In conclusion, ASE treatment has an antidiabetic effect in type 2 diabetic rats by activating the insulin-signaling pathway in muscle and adipose tissue, increasing GLP-1 levels, and an anti-inflammatory action. Exercise training potentiates the glucose-lowering effect of ASE by activating adiponectin-AMPK pathway and increasing IR expression.

Tempol, a superoxide dismutase-mimetic drug, prevents chronic ischemic renal injury in two-kidney, one-clip hypertensive rats

ABSTRACT Tempol, a superoxide dismutase-mimetic drug, has been shown to attenuate radical-induced damage, exerting beneficial effects in the animal models of oxidative stress and hypertension. This study evaluated the effect of Tempol on renal structural and functional alterations in two-Kidney, one-Clip hypertensive rats. In this study, young male Wistar rats had the left kidney clipped (2K1C), and sham-operated animals (Sham) were used as controls. Animals received Tempol (1mmol/L in drinking water) or vehicle for 5 weeks. Systolic blood pressure was evaluated once a week. At the end of the experimental protocol, the animals were placed in metabolic cages to collect urine (24h) and then anesthetized with thiopental (70mg/kg i.p.) to collect blood by puncturing the descending aorta for biochemical analysis, and the clipped kidney for morphological and immunohistochemical analyses. The vasodilator effect of Tempol was evaluated in mesenteric arterial bed (MAB) isolated from adult Wistar rats. The chronic treatment with Tempol prevented the development of hypertension and the increased plasma levels of urea, creatinine, and 8-isoprostane in 2K1C animals. Tempol also improved both glomeruli number and kidney volume to normal levels in the 2K1C+Tempol group. In addition, the treatment prevented the increased collagen deposition and immunostaining for renin, caspase-3, and 8-isoprostane in the stenotic kidney of 2K1C animals. Moreover, Tempol induced a dose-dependent vasodilator response in MAB from Wistar rats. These results suggest that Tempol protects the stenotic kidney against chronic ischemic renal injury and prevents renal dysfunction in the 2K1C model, probably through its antioxidant, vasodilator and antihypertensive actions.