Endocannabinoid System: Chemical Characteristics and Biological Activity.

The endocannabinoid system (eCB) has been studied to identify the molecular structures present in Cannabis sativa. eCB consists of cannabinoid receptors, endogenous ligands, and the associated enzymatic apparatus responsible for maintaining energy homeostasis and cognitive processes. Several physiological effects of cannabinoids are exerted through interactions with various receptors, such as CB1 and CB2 receptors, vanilloid receptors, and the recently discovered G-protein-coupled receptors (GPR55, GPR3, GPR6, GPR12, and GPR19). Anandamide (AEA) and 2-arachidoylglycerol (2-AG), two small lipids derived from arachidonic acid, showed high-affinity binding to both CB1 and CB2 receptors. eCB plays a critical role in chronic pain and mood disorders and has been extensively studied because of its wide therapeutic potential and because it is a promising target for the development of new drugs. Phytocannabinoids and synthetic cannabinoids have shown varied affinities for eCB and are relevant to the treatment of several neurological diseases. This review provides a description of eCB components and discusses how phytocannabinoids and other exogenous compounds may regulate the eCB balance. Furthermore, we show the hypo- or hyperfunctionality of eCB in the body and how eCB is related to chronic pain and mood disorders, even with integrative and complementary health practices (ICHP) harmonizing the eCB.

Açaí seed extract (ASE) rich in proanthocyanidins improves cardiovascular remodeling by increasing antioxidant response in obese high-fat diet-fed mice.

Obesity is recognized as an independent risk factor for cardiovascular diseases and is an important contributor to cardiac mortality. Açaí seed extract (ASE), rich in proanthocyanidins, has been shown to have potential anti-obesity effects. This study aimed to investigate the therapeutic effect of ASE in cardiovascular remodeling associated with obesity and compare it with that of rosuvastatin. Male C57BL/6 mice were fed a high-fat diet or a standard diet for 12 weeks. The ASE (300 mg/kg/day) and rosuvastatin (20 mg/kg/day) treatments started in the 8th week until the 12th week, totaling 4 weeks of treatment. Our data showed that treatment with ASE and rosuvastatin reduced body weight, ameliorated lipid profile, and improved cardiovascular remodeling. Treatment with ASE but not rosuvastatin reduced hyperglycemia and oxidative stress by reducing immunostaining of 8-isoprostane and increasing SOD-1 and GPx expression in HFD mice. ASE and rosuvastatin reduced NOX4 expression, increased SIRT-1 and Nrf2 expression and catalase and GPx activities, and improved vascular and cardiac remodeling in HFD mice. The therapeutic effect of ASE was similar to that of rosuvastatin in reducing dyslipidemia and cardiovascular remodeling but was superior in reducing oxidative damage and hyperglycemia, suggesting that ASE was a promising natural product for the treatment of cardiovascular alterations associated with obesity.

Therapeutic effects of açaí seed extract on hepatic steatosis in high-fat diet-induced obesity in male mice: a comparative effect with rosuvastatin.

OBJECTIVES: Obesity is considered a risk factor for the development of non-alcoholic fatty liver disease (NAFLD). The hydroalcoholic extract obtained from the açai seed (ASE), rich in proanthocyanidins, has been shown a potential body weight regulator with antioxidant properties. This study aimed to investigate the therapeutic effect of ASE in obesity-associated NAFLD and compare it with Rosuvastatin. METHODS: Male C57BL/6 mice received a high-fat diet or standard diet for 12 weeks. The treatments with ASE (300 mg/kg per day) or rosuvastatin (20 mg/kg per day) began in the eighth week until the 12th week. KEY FINDINGS: Our data show that the treatments with ASE and rosuvastatin reduced body weight and hyperglycaemia, improved lipid profile and attenuated hepatic steatosis in HFD mice. ASE and Rosuvastatin reduced HMGCoA-Reductase and SREBP-1C and increased ABGC8 and pAMPK expressions in the liver. Additionally, ASE, but not Rosuvastatin, reduced NPC1L1 and increased ABCG5 and PPAR-α expressions. ASE and rosuvastatin increased SIRT-1 expression and antioxidant defence, although only ASE was able to decrease the oxidative damage in hepatic tissue. CONCLUSIONS: The therapeutic effect of ASE was similar to that of rosuvastatin in reducing dyslipidemia and hepatic steatosis but was better in reducing oxidative damage and hyperglycaemia.

Açaí (Euterpe oleracea Mart.) seed extract improves aerobic exercise performance in rats.

The purpose of this study was to examine whether the supplementation with an açai (Euterpe oleracea Mart.) seed extract (ASE) would affect the aerobic exercise performance in rats and correlate with the vascular function, muscle oxidative stress and mitochondrial biogenesis. Male Wistar rats were divided into five groups: Sedentary, Sedentary with chronic supplementation of ASE, Training, Training with chronic (200 mg/Kg/day intragastric gavage for 5 weeks) or acute (30 min before the maximal treadmill stress test (MST) supplementation with ASE. The exercise training was performed on a treadmill (30 min/day; 5 days/week) for 4 weeks. The chronic supplementation with ASE increased the exercise time (58%) and the running distance (129%) in relation to the MST, while the Training group increased 40% and 78% and the Training with acute ASE group increased 30% and 63%, respectively. The training-induced increase of ACh vasodilation was not changed by ASE, but the norepinephrine-induced vasoconstriction was reduced by chronic and acute supplementation with ASE. The increased levels of malondialdehyde in soleus muscle homogenates from the Training group was reduced only by chronic supplementation with ASE. The muscle antioxidant defense, NO2 levels, and expression of the mitochondrial biogenesis-related proteins (PGC1α, SIRT-1, p-AMPK/AMPK, Nrf-2) were not different between Training and Sedentary groups, but all these parameters were increased in the Training with Chronic ASE compared with the Sedentary groups. In conclusion, chronic supplementation with ASE improves aerobic physical performance by increasing the vascular function, reducing the oxidative stress, and up-regulating the mitochondrial biogenesis key proteins.

Açaí seed extract prevents the renin-angiotensin system activation, oxidative stress and inflammation in white adipose tissue of high-fat diet-fed mice.

The role of the renin-angiotensin system (RAS), oxidative stress, and inflammation on the development of obesity and its comorbidities has been extensively addressed. Euterpe oleracea Mart. (açaí) seed extract (ASE), with antioxidant and anti-inflammatory properties and capable to modulate plasma renin levels, has been evidenced as a potential regulator of body mass. We hypothesized that the supplementation with ASE might exert beneficial effects on obesity-related white adipose tissue changes and metabolic disorders by interfering with the local adipose tissue overexpression of RAS, inflammation, and oxidative stress in C57BL/6 mice fed a high-fat (HF) diet. The animals were fed a standard diet (10% fat, control), 60% fat (HF), HF + ASE (300 mg/kg per day) and HF + ENA (enalapril, 30 mg/kg per day) for 12 weeks. ASE and ENA prevented weight gain and adiposity, adipocyte hypertrophy, dyslipidemia, and insulin resistance. In adipose tissue, ASE increased the insulin receptor expression and reduced renin and AT1 receptor expression, which was associated with decreased plasma levels of renin and angiotensin II. Differently, ENA increased the expression of angiotensin-conversing enzyme 2, AT2, B2, and Mas receptors in adipose tissue. Also, ASE but not ENA decreased malondialdehyde and 8-isoprostane levels in adipose tissue. Finally, ASE and ENA reduced the adipose tissue inflammatory markers tumor necrosis factor alpha and interleukin 6. These results demonstrate that ASE prevented the adipocyte hypertrophy, obesity, hyperlipidemia, hyperglycemia, and insulin resistance in HF diet-fed mice. The downregulation of RAS in adipose tissue, reducing oxidative stress and inflammation, may contribute to the prevention of obesity-related disorders.

Anxiolytic and antioxidant effects of Euterpe oleracea Mart. (açaí) seed extract in adult rat offspring submitted to periodic maternal separation.

Many studies suggest a protective role of phenolic compounds in mood disorders. We aimed to assess the effect of Euterpe oleracea (açaí) seed extract (ASE) on anxiety induced by periodic maternal separation (PMS) in adult male rats. Animals were divided into 6 groups: control, ASE, fluoxetine (FLU), PMS, PMS+ASE, and PMS+FLU. For PMS, pups were separated daily from the dam for 3 h between postnatal day (PN) 2 and PN21. ASE (200 mg·kg-1·day-1) and FLU (10 mg·kg-1·day-1) were administered by gavage for 34 days after stress induction, starting at PN76. At PN106 and PN108, the rats were submitted to open field (OF) and forced swim tests, respectively. At PN110, the rats were sacrificed by decapitation. ASE increased time spent in the center area in the OF test, glucocorticoid receptors in the hypothalamus, tropomyosin receptor kinase B (TRKB) levels in the hippocampus, and nitrite levels and antioxidant activity in the brain stem (PMS+ASE group compared with PMS group). ASE also reduced plasma corticotropin-releasing hormone levels, adrenal norepinephrine levels, and oxidative damage in the brain stem in adult male offspring submitted to PMS. In conclusion, ASE treatment has an anti-anxiety effect in rats submitted to PMS by reducing hypothalamic-pituitary-adrenal axis reactivity and increasing the nitric oxide (NO)-brain-derived neurotrophic factor (BDNF)-TRKB pathway and antioxidant defense in the central nervous system. Novelty ASE has anti-anxiety and antioxidant effects in early-life stress. ASE reduces hypothalamic-pituitary-adrenal axis reactivity. The anxiolytic effect of ASE may involve activation of the NO-BDNF-TRKB pathway in the central nervous system.

Açaí (Euterpe oleracea Mart) seed extract protects against maternal vascular dysfunction, hypertension, and fetal growth restriction in experimental preeclampsia.

Objective: To investigate whether Euterpe oleracea Mart. (açaí) seed extract (ASE) prevents maternal cardiovascular changes and intrauterine growth restriction (IUGR) in experimental preeclampsia (PE).Methods: ASE administration (200 mg/kg/day) during mid to late pregnancy in a rat model of L-NAME-induced PE.Results: ASE impaired the maternal hypertension and microalbuminuria as well as the lower fetal and placental weight in experimental PE. ASE also prevented the maternal vascular dysfunction and lipoperoxidation in this model.Conclusion: ASE protected against maternal cardiovascular changes and IUGR in the L-NAME-induced PE. The protective effect of ASE may be partly explained by its antioxidant property.

Uraemic toxin-induced inflammation and oxidative stress in human endothelial cells: protective effect of polyphenol-rich extract from açaí.

NEW FINDINGS: What is the central question of this study? Does a polyphenol-rich extract from açaí have a potential role in preventing uraemic toxin-induced endothelial cell dysfunction? What is the main finding and its importance? Polyphenols from açaí prevented cell death, restored migratory capacity, protected from inflammation and contributed to the restoration of the antioxidant response in endothelial cells exposed to uraemic toxins. The protective role of açaí against toxic effects exerted by uraemic toxins presents a potential new therapeutic target in endothelial cells. ABSTRACT: In chronic kidney disease (CKD), progressive loss of kidney function results in the accumulation of protein-bound uraemic toxins such as p-cresyl sulfate (pCS) and indoxyl sulfate (IS). Among strategies to ameliorate the harmful actions of uraemic toxins, phenolic compounds have been extensively studied. The main goal of this work was to evaluate the antioxidant and anti-inflammatory actions of phenolic-rich açaí seed extract (ASE) in response to endothelial dysfunction induced by IS and pCS, in human umbilical vein endothelial cells (HUVECs). Cells were treated with ASE (10 µg ml-1 ) in the presence or absence of IS (61 µg ml-1 ) and pCS (40 µg ml-1 ). Cell viability, cell death, cell migratory capacity and inflammatory biomarker expression were evaluated. Cellular antioxidant response was measured through the activity and expression of antioxidant enzymes, and oxidative damage was evaluated. IS and pCS lowered cell viability, triggered cell death and lowered the migratory capacity in endothelial cells (P < 0.05). ASE prevented cell death and restored the migratory capacity in cells exposed to IS. Both toxins up-regulated pro-inflammatory cytokine expression, and ASE was able to beneficially counteract this effect. Tumour necrosis factor-α secretion was greater in uraemic toxin-treated cells and ASE reversed this phenomenon in cells treated with both toxins concomitantly (P < 0.05). With regard to the antioxidant response, superoxide dismutase expression was strikingly lower in cells treated with both toxins, and ASE inhibited this harmful effect (P < 0.05). From the results, we conclude that ASE exerted protective effects on inflammation and oxidative stress caused by uraemic toxins (particularly by IS) in human endothelial cells.

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.

Euterpe oleracea Mart. seed extract protects against renal injury in diabetic and spontaneously hypertensive rats: role of inflammation and oxidative stress.

PURPOSE: Euterpe oleracea Mart. (açaí) seed extract (ASE), through its anti-hypertensive, antioxidant and anti-inflammatory properties, may be useful to treat or prevent human diseases. Several evidences suggest that oxidative stress and inflammation contribute to the pathogenesis of diabetic nephropathy; therefore, we tested the hypothesis that ASE (200 mg/kg-1day-1) prevents diabetes and hypertension-related oxidative stress and inflammation, attenuating renal injury. METHODS: Male rats with streptozotocin (STZ)-induced diabetes (D), and spontaneously hypertensive rats with STZ-induced diabetes (DH) were treated daily with tap water or ASE (D + ASE and DH + ASE, respectively) for 45 days. The control (C) and hypertensive (H) animals received water. RESULTS: The elevated serum levels of urea and creatinine in D and DH, and increased albumin excretion in HD were reduced by ASE. Total glomeruli number in D and DH, were increased by ASE that also reduced renal fibrosis in both groups by decreasing collagen IV and TGF-ß1 expression. ASE improved biomarkers of renal filtration barrier (podocin and nephrin) in D and DH groups and prevented the increased expression of caspase-3, IL-6, TNF-α and MCP-1 in both groups. ASE reduced oxidative damage markers (TBARS, carbonyl levels and 8-isoprostane) in D and DH associated with a decrease in Nox 4 and p47 subunit expression and increase in antioxidant enzyme activity in both groups (SOD, catalase and GPx). CONCLUSION: ASE substantially reduced renal injury and prevented renal dysfunction by reducing inflammation, oxidative stress and improving the renal filtration barrier, providing a nutritional resource for prevention of diabetic and hypertensive-related nephropathy.

Euterpe oleracea Mart. (açaí) seed extract associated with exercise training reduces hepatic steatosis in type 2 diabetic male rats.

Type 2 diabetes mellitus contributes to an increased risk of metabolic and morphological changes in key organs, such as the liver. We aimed to assess the effect of the açaí seed extract (ASE) associated with exercise training on hepatic steatosis 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, followed by a single low dose of STZ (35 mg/kg i.p.). Control and diabetic groups were subdivided into four groups that were fed with standard chow diet for 4 weeks. Control (C) group was subdivided into Sedentary C, Training C, ASE Sedentary C and ASE Training C. Diabetic (D) group was subdivided into Sedentary D, Training D, ASE Sedentary D and ASE Training D. ASE (200 mg/kg/day) was administered by intragastric gavage, and the exercise training was performed on a treadmill (30 min/day; 5 days/week). Treatment with ASE associated with exercise training reduced the blood glucose (70.2%), total cholesterol (81.2%), aspartate aminotransferase (51.7%) and hepatic triglyceride levels (66.8%) and steatosis (72%) in ASE Training D group compared with the Sedentary D group. ASE associated with exercise training reduced the hepatic lipogenic proteins' expression (77.3%) and increased the antioxidant defense (63.1%), pAMPK expression (70.2%), cholesterol transporters (71.1%) and the pLKB1/LKB1 ratio (57.1%) in type 2 diabetic rats. In conclusion, ASE treatment associated with exercise training protects against hepatic steatosis in diabetic rats by reducing hepatic lipogenesis and increasing antioxidant defense and cholesterol excretion.

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 © 2017 John Wiley & Sons, Ltd.

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 ACH09's 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 ACH09's protective effect.

Effect of Euterpe oleracea Mart. Seeds Extract on Chronic Ischemic Renal Injury in Renovascular Hypertensive Rats.

Previously, we have demonstrated that the seeds of Euterpe oleracia Mart. (açaí) are rich in polyphenols with antihypertensive and antioxidant properties. This study evaluated the renal protective effects of the hydroalcoholic extract obtained from the seeds of açaí (ASE) fruits in two-kidney, one-clip (2K1C) renovascular hypertension. Young male Wistar rats were used to obtain 2K1C and sham groups. Animals received ASE (200 mg/(kg·day) in drinking water) or vehicle for 40 days. We evaluated serum and urinary parameters, renal structural changes, and oxidative status. The increase in systolic blood pressure of the 2K1C group was accompanied by a decrease in left kidney volume and number of glomeruli, as well as an increase in glomerular volume and collagen deposition. ASE prevented the alterations of these parameters, except the reduced kidney volume. Serum levels of urea and creatinine and urinary protein excretion were increased in the 2K1C group and treatment with ASE improved all these functional parameters. The increased oxidative damage in the 2K1C group, assessed by lipid and protein oxidation, was prevented by ASE. The nitrite content and both expression and activity of antioxidant enzymes (superoxide dismutase-1, catalase, and glutathione peroxidase) were lower in the 2K1C group and restored by ASE. ASE substantially reduced renal injury and prevented renal dysfunction in 2K1C rats probably through its antihypertensive and antioxidant effects, providing a natural resource for treatment and prevention of renovascular hypertension-related abnormalities.

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

OBJECTIVES: 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. METHODS: Four groups of rats were fed: control diet (20% protein); ASE (200 mg/kg per day); and LP (6% protein); LP + ASE (6% protein + ASE) during pregnancy. After weaning, all male offspring were fed a control diet and sacrificed at 4 months old. We evaluated the blood pressure, vascular function, serum and urinary parameters, plasma and kidney oxidative damage, and antioxidant activity and renal structural changes. KEY FINDINGS: Hypertension and the reduced acetylcholine-induced vasodilation in the LP group were prevented by ASE. Serum levels of urea, creatinine and fractional excretion of sodium were increased in LP and reduced in LP + ASE. ASE improved nitrite levels and the superoxide dismutase and glutathione peroxidase activity in LP, with a corresponding decrease of malondialdehyde and protein carbonyl levels. Kidney volume and glomeruli number were reduced and glomerular volume was increased in LP. These renal alterations were prevented by ASE. CONCLUSIONS: Treatment of protein-restricted dams with ASE provides protection from later-life hypertension, oxidative stress, renal functional and structural changes, probably through a vasodilator and antioxidant activity.

Euterpe oleracea Mart.-derived polyphenols prevent endothelial dysfunction and vascular structural changes in renovascular hypertensive rats: role of oxidative stress.

The consumption of polyphenol-rich foods is associated with a decreased risk of mortality from cardiovascular diseases. Previously, we have demonstrated that the stone of Euterpe oleracea Mart. (açaí) from the Amazon region exerts vasodilator and antioxidant actions. This study examined the effect of açaí stone extract (ASE) on the vascular functional and structural changes and oxidative stress associated with the two-kidney, one-clip (2K-1C) renovascular hypertension. 2K-1C and sham-operated rats were treated with ASE 200 mg/kg/day (or vehicle) for 40 days. Blood pressure was measured by tail plethysmography, and the vascular reactivity was evaluated in the rat isolated mesenteric arterial bed. Mesenteric protein expression of endothelial nitric oxide synthase (eNOS), superoxide dismutase 1 and 2 (SOD1 and SOD2), metalloproteinase 2 (MMP-2), and tissue inhibitor of MMPs (TIMP)-1 was assessed by Western blot; oxidative damage and antioxidant activity by spectrophotometry; MMP-2 levels by gelatin zymography; and structural changes by histological analysis. ASE prevented 2K-1C hypertension and the reduction of acetylcholine-induced vasodilation. The increased levels of malondialdehyde and carbonyl protein were reduced by ASE. SOD, catalase, and glutathione peroxidase activities and the expressions of SOD1 and SOD2, eNOS, and TIMP-1 were decreased in 2K-1C rats and recovered by ASE. In 2K-1C rats, ASE prevented vascular remodeling and the increased expression/levels of MMP-2. These findings indicate that ASE produces antihypertensive effect and prevents the endothelial dysfunction and vascular structural changes in 2K-1C hypertension, probably through mechanisms involving antioxidant effects, NOS activation, and inhibition of MMP-2 activation.

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) diet­induced 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.