In Vivo Nutritional Assessment of the Microalga Nannochloropsis gaditana and Evaluation of the Antioxidant and Antiproliferative Capacity of Its Functional Extracts.

Nannochloropsis gaditana is a microalga with interesting nutritional and functional value due to its high content of protein, polyunsaturated fatty acids, and bioactive compounds. However, the hardness of its cell wall prevents accessibility to these components. This work aimed to study the effect of a treatment to increase the fragility of the cell wall on the bioavailability of its nutrients and functional compounds. The antioxidant and antiproliferative capacity of functional extracts from treated and untreated N. gaditana was assessed, and the profile of bioactive compounds was characterized. Furthermore, to study the effect of treatment on its nutrient availability and functional capacity, an in vivo experiment was carried out using a rat experimental model and a 20% dietary inclusion level of microalgae. Functional extracts from treated N. gaditana exhibited higher antioxidant activity than the untreated control. Furthermore, the treated microalga induced hypoglycemic action, higher nitrogen digestibility, and increased hepatic antioxidant activity. In conclusion, N. gaditana has interesting hepatoprotective, antioxidant, and anti-inflammatory potential, thus proving itself an ideal functional food candidate, especially if the microalga is treated to increase the fragility of its cell wall before consumption.

The combined treatment with lentil protein hydrolysate and a mixed training protocol is an efficient lifestyle intervention to manage cardiovascular and renal alterations in obese Zucker rats.

PURPOSE: Functional and structural changes in cardiovascular and renal systems resulting from obesity and metabolic syndrome represent a severe risk to human health. Lifestyle interventions such as combining healthy diet with adequate physical exercise protocols are good strategies to manage these pathologies. In this research, the effects of lentil protein hydrolysate administration, combined or not with a mixed training protocol, on insulin resistance, cardiovascular and renal functionality were studied in the obese Zucker rat experimental model. METHODS: Thirty-two rats (16 lean and 16 obese subdivided in sedentary and trained animals) were administered lentil protein hydrolysate, whereas another 32 subdivided in the same experimental design were administered placebo. The experiment lasted for 8 weeks. At the end of the experimental period, insulin resistance and different parameters of cardiovascular and renal functionality were measured. RESULTS: The individual or combined interventions with lentil protein hydrolysate and mixed training protocol were efficient at counteracting some of the metabolic, cardiovascular and renal alterations characterizing the obese Zucker rat. Specifically, lentil protein hydrolysate decreased hyperphagia, amplitude of QRS complex, plasma ACE and selectin E expression in aorta, while increasing urinary volume and pH. Exercise showed beneficial actions on HOMA-IR, QRS amplitude, QTc interval, urinary volume, kidney weight and Mn-SOD activity. Interestingly, most of the mentioned benefits of exercise were more consistent when protein hydrolysate was also administered. CONCLUSION: The interesting synergies between the two interventions assessed qualify them as alternative therapeutic strategies to treat cardiovascular and kidney diseases associated to the metabolic syndrome.

Aerobic interval exercise improves renal functionality and affects mineral metabolism in obese Zucker rats.

Obesity, metabolic syndrome, and renal injury are considered risk factors for type 2 diabetes, as well as kidney disease. Functional and structural changes in the kidney as consequence of obesity and metabolic syndrome may lead to impaired mineral metabolism in what is known as chronic kidney disease-mineral and bone disorder. Lifestyle interventions such as physical activity are good strategies to manage these pathologies and therefore, prevent the loss of kidney functionality and related complications in mineral metabolism. In this study, we have used 40 male Zucker rats that were randomly allocated into four different experimental groups, two of them (an obese and a lean one) performed an aerobic interval training protocol, and the other two groups were sedentary. At the end of the experimental period (8 wk), urine, plasma, and femur were collected for biochemical and mineral composition analysis, whereas the kidney was processed for histological studies. The obese rats exhibited albuminuria, glomerulosclerosis, and hypertrophy in glomeruli and renal tubule in some areas, together with alterations in mineral content of plasma but not of femur. The training protocol prevented the generation of albuminuria and glomerulosclerosis, showing a significant action on plasma and bone mineral levels. Therefore, the specific training protocol used in this study was able to prevent the development of diabetic nephropathy and affected the metabolism of certain minerals.

Improvement of the antioxidant and hypolipidaemic effects of cowpea flours (Vigna unguiculata) by fermentation: results of in vitro and in vivo experiments.

BACKGROUND: The antioxidant capacity and hypolipidaemic effects of Vigna unguiculata, as well as their potential improvement by different fermentation and thermal processes were studied using in vitro and in vivo methods. RESULTS: Phenolic content and reducing capacity of legume acetone extract were significantly increased by different fermentation processes, and by the thermal treatment of fermented legume flours. TBARS inhibiting capacity was increased by fermentation but not by thermal treatment. A higher ability to decrease Cu(2+)/H2O2-induced electrophoretic mobility of LDL was found in fermented when compared to raw legume extracts, and a higher protective effect on short term metabolic status of HT-29 cells was found for raw and lactobacillus-fermented Vigna followed by naturally fermented Vigna extracts. Significant improvements in plasma antioxidant capacity and hepatic activity of antioxidant enzymes were observed in rats that consumed fermented legume flours when compared to the untreated legume or a casein-methionine control diet. In addition, liver weight and plasma levels of cholesterol and triglycerides were also positively affected by untreated or naturally fermented Vigna. CONCLUSION: V. unguiculata has demonstrated its potential as a functional food with interesting antioxidant and lipid lowering properties, which can be further augmented by fermentation processes associated or not to thermal processing.

Novel insights and mechanisms of diet-induced obesity: Mid-term versus long-term effects on hepatic transcriptome and antioxidant capacity in Sprague-Dawley rats.

AIMS: The study of molecular mechanisms related to obesity and associated pathologies like type 2-diabetes and non-alcoholic fatty liver disease requires animal experimental models in which the type of obesogenic diet and length of the experimental period to induce obesity deeply affect the metabolic alterations. Therefore, this study aimed to test the influence of aging along a rat model of diet-induced obesity in gene expression of the hepatic transcriptome. MAIN METHODS: A high-fat/high-fructose diet to induce obesity was used. Mid- (13 weeks) and long-term (21 weeks) periods were established. Caloric intake, bodyweight, hepatic fat, fatty acid profile, histological changes, antioxidant activity, and complete transcriptome were analyzed. KEY FINDINGS: Excess bodyweight, hepatic steatosis and altered lipid histology, modifications in liver antioxidant activity, and dysregulated expression of transcripts related to cell structure, glucose & lipid metabolism, antioxidant & detoxifying capacity were found. Modifications in obese and control rats were accounted for by the different lengths of the experimental period studied. SIGNIFICANCE: Main mechanisms of hepatic fat accumulation were de novo lipogenesis or altered fatty acid catabolism for mid- or long-term study, respectively. Therefore, the choice of obesity-induction length is a key factor in the model of obesity used as a control for each specific experimental design.

Bioavailability and biotransformation of linolenic acid from basil seed oil as a novel source of omega-3 fatty acids tested on a rat experimental model.

Basil is an aromatic herb with a high concentration of bioactive compounds. The oil extracted from its seeds is a good source of α-linolenic acid (ALA) and also provides substantial amounts of linoleic acid (LA). This study aimed to test the bioavailability of the oil derived from basil seeds and its effects on different physiological parameters using 7-15% dietary inclusion levels. Furthermore, the assimilation of LA and ALA and their transformation in long-chain polyunsaturated fatty acids (LC-PUFAs) have been studied. Digestive utilization of total fat from basil seed oil (BSO) was high and similar to that of olive oil used as a control. Consumption of BSO resulted in increased LA and ALA levels of the plasma, liver, and erythrocyte membrane. In addition, the transformation of LA to arachidonic acid (ARA) was decreased by the high dietary intake of ALA which redirected the pathway of the Δ-6 desaturase enzyme towards the transformation of ALA into eicosapentaenoic acid (EPA). No alterations of hematological and plasma biochemical parameters were found for the 7 and 10% dietary inclusion levels of BSO, whereas a decrease in the platelet count and an increase in total- and HDL-cholesterol as well as plasma alkaline phosphatase (ALP) were found for a 15% BSO dose. In conclusion, BSO is a good source of ALA to be transformed into EPA and decrease the precursor of the pro-inflammatory molecule ARA. This effect on the levels of EPA in different tissues offers potential for its use as a dietary supplement, novel functional food, or a constituent of nutraceutical formulations to treat different pathologies.

Anemonia sulcata and Its Symbiont Symbiodinium as a Source of Anti-Tumor and Anti-Oxoxidant Compounds for Colon Cancer Therapy: A Preliminary in Vitro Study.

Recently, invertebrate marine species have been investigated for the presence of natural products with antitumor activity. We analyzed the invertebrate Anemonia sulcata with (W) and without (W/O) the presence of its microalgal symbiont Symbiodinium as a source of bioactive compounds that may be applied in the therapy and/or prevention of colorectal cancer (CRC). Animals were mechanically homogenized and subjected to ethanolic extraction. The proximate composition and fatty acid profile were determined. In addition, an in vitro digestion was performed to study the potentially dialyzable fraction. The antioxidant and antitumor activity of the samples and the digestion products were analyzed in CRC cells in vitro. Our results show a high concentration of polyunsaturated fatty acid in the anemone and a great antioxidant capacity, which demonstrated the ability to prevent cell death and a high antitumor activity of the crude homogenates against CRC cells and multicellular tumor spheroids, especially W/O symbiont. These preliminary results support that Anemonia sulcata could be a source of bioactive compounds with antioxidant and antitumor potential against CRC and that the absence of its symbiont may enhance these properties. Further studies will be necessary to define the bioactive compounds of Anemonia sulcata and their mechanisms of action.

Antitumor Effect of the Ethanolic Extract from Seeds of Euphorbia lathyris in Colorectal Cancer.

The seeds of Euphorbia lathyris have been used in traditional medicine to treat various medical conditions. However, neither all of their active biocompounds nor the molecular mechanisms underlying their therapeutic effects have been described. A new ethanolic extract of defatted flour from mature seeds of Euphorbia lathyris showed a high total polyphenol content and significant antioxidant activity. Chromatographic analysis showed that esculetin, euphorbetin, gaultherin, and kaempferol-3-rutinoside were the most abundant polyphenolic bioactive compounds. Antiproliferative assays showed a high and selective antitumor activity against colon cancer cell lines (T84 and HCT-15). In addition, a significant antiproliferative activity against glioblastoma multiforme cells was also demonstrated. Its mechanism of action to induce cell death was mediated by the overexpression of caspases 9, 3, and 8, and by activation of autophagy. Interestingly, a reduction in the migration capacity of colon cancer cells and a significant antiangiogenic effect on human umbilical vein endothelial cells were also demonstrated. Finally, the extract significantly reduced the subpopulations of cancer stem cells. This extract could be the basis to develop new therapeutic strategies for the treatment of colon cancer, although further experiments will be necessary to determine its in vivo effects.

Caloric restriction, physical exercise, and CB1 receptor blockade as an efficient combined strategy for bodyweight control and cardiometabolic status improvement in male rats.

Obesity is critically associated with the development of insulin resistance and related cardiovascular and kidney diseases. Several strategies for weight loss have been developed but most of them exhibit a post-intervention rebound effect. Here, we aimed to design combined weight-loss strategies of caloric restriction, physical exercise, and administration of a CB1 receptor blocker to inhibit food intake that also accomplish the objectives of lost-weight maintenance and improvement of cardiovascular and renal function. Diet-induced obesity (DIO) was generated in Sprague Dawley rats for 12 weeks to test the effects of single or combined strategies (i.e. caloric restriction, mixed training protocol, and/or administration of appetite suppressant) on caloric intake, body weight, cardiovascular and renal functionality resulting from a weight-loss intervention period of 3 weeks followed by 6 weeks of weight maintenance. Consumption of a high-fat diet (HFD) caused a significant increase in body weight (5th week of the experimental period) and led to the development of insulin resistance, cardiovascular, and renal alterations. The different interventions tested, resulted in a significant body weight loss and improved glucose metabolism, aerobic capacity, electrocardiographic parameters, vascular expression of adhesion molecules and inflammatory mediators, and renal functionality, reaching values similar to the control normocaloric group or even improving them. Successful maintenance of lost weight was achieved along a 6-week maintenance period in addition to adequate health status. In conclusion, the weight-loss and maintenance intervention strategies tested were efficient at reversing the obesity-related alterations in body weight, glucose metabolism, aerobic capacity, cardiovascular and renal functionality. The beneficial action was very consistent for caloric restriction and physical exercise, whereas administration of a CB1 receptor blocker complemented the effects of the prior interventions in some parameters like body weight or aerobic capacity, and showed specific actions in renal status, increasing glomerular filtration rate and diuresis. Overall, the novelty of our study relies on the easy implementation of combined strategies for effective weight management that resulted in significant health benefits.

A combined healthy strategy for successful weight loss, weight maintenance and improvement of hepatic lipid metabolism.

Obesity is critically related with the development of metabolic and pathophysiological alterations among which non-alcoholic fatty liver disease (NAFLD) is of especial relevance. Although there are numerous strategies to successfully treat obesity, the prevention of weight regain still remains challenging for individuals who have undergone weight loss programs. In such context, diet and physical activity are considered essential for the regulation of body weight and lipid metabolism. In this study, rats were fed a high-fat diet (HFD) to induce obesity and alterations in hepatic lipid metabolism. Obese rats were then treated with single or combined strategies of caloric restriction, physical exercise, and/or pharmacological treatment with an appetite suppressant, to lose weight, reverse the obesity-related alterations in hepatic morphology and lipid metabolism and maintain the beneficial effects of the interventions used. HFD induced excess body weight, hepatic steatosis, altered fatty acid profile, dysregulated gene expression of lipogenic and lipolytic enzymes, as well as plasma markers of liver damage, and modifications in liver antioxidant enzyme activity. Such alterations were ameliorated by caloric restriction in combination with a mixed training protocol and/or food-intake inhibitor administration during a weight loss intervention period of 3 weeks, and the beneficial effects remained after 6 weeks of weight maintenance, with some interesting interactions observed. In conclusion, weight loss strategies assayed were efficient at correcting the obesogenic action of a HFD and related alterations in hepatic functionality through different molecular mechanisms. The beneficial effects were also evident along the post-intervention maintenance period to avoid body weight regain.

Effects of dietary fibers on disturbances clustered in the metabolic syndrome.

Because of its growing prevalence in Western countries, the metabolic syndrome, a common metabolic disorder that clusters a constellation of abnormalities, including central obesity, hypertension, dyslipidemia and insulin resistance, is emerging as one of the most important public health problems in the world, taking into account that it is a major risk factor mainly for type 2 diabetes and cardiovascular diseases, and also for many types of cancer. Although the pathogenesis of this syndrome is complex and not fully understood, obesity and insulin resistance, accompanied by an altered profile of number of hormones and cytokines produced by the adipose tissue, seem to be the main causative agents. A prime therapeutic approach to the prevention and treatment of this syndrome involves lifestyle changes. Among dietary modifications, dietary fiber intake could play an interesting role in the management of metabolic syndrome through different mechanisms related to its dietary sources, specific chemical structure and physical properties, or fermentability in the gut. According to all of these variables, the different types of dietary fibers have been reported to take part in the control of body weight, glucose and lipid homeostasis, insulin sensitivity and in the regulation of many inflammation markers involved in the pathogenesis of metabolic syndrome, and which are also considered to be among its features.

Baseline glutathione peroxidase activity affects prognosis after acute coronary syndromes.

Oxidative stress is associated with atherosclerosis and plaque lesions in experimental in vitro models. Few in vivo studies have examined the association between redox status and the prognosis of acute coronary syndromes.We undertook a prospective, observational study of 137 patients who had been admitted because of an acute coronary syndrome. We determined glutathione peroxidase activity (a marker of systemic antioxidant status) and recorded clinical and angiographic features and cardiovascular events (cardiovascular death, reinfarction, readmission with a new ischemic event, or need for coronary revascularization).The mean age of the patients (78% of whom were men) was 61.7 +/- 10.9 years; 76% were admitted with non-ST-segment-elevation acute coronary syndrome. Left ventricular ejection fraction was normal in 61%. In the 23.4% who experienced cardiovascular events, glutathione peroxidase activity was higher (mean, 2.38 vs 1.76 mU/mg of protein; P < 0.01). Two-year event-free survival was lower in patients whose glutathione peroxidase activity was higher than the 50th percentile (63% vs 82%; P = 0.01). Multivariate analysis showed a direct independent relationship between glutathione peroxidase activity and cardiovascular events (hazard ratio, 3.72; 95% confidence interval, 1.53-9.02; P < 0.01).We conclude that patients who experienced acute coronary syndromes and events during follow-up had higher plasma glutathione peroxidase activity, and that glutathione peroxidase activity was an independent predictor of events during follow-up.

Effects of a combined intervention with a lentil protein hydrolysate and a mixed training protocol on the lipid metabolism and hepatic markers of NAFLD in Zucker rats.

Metabolic syndrome is a cluster of metabolic alterations characterized by central obesity, dyslipidemia, elevated plasma glucose, insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD). In this study, a combined intervention of a lentil protein hydrolysate and a mixed training protocol was assessed in an animal experimental model of genetic obesity and metabolic syndrome. Thirty-two male obese and 32 lean Zucker rats were divided into eight different experimental groups. Rats performed a mixed exercise protocol or had a sedentary lifestyle and were administered a lentil protein hydrolysate or placebo. Daily food intake, weekly body weight gain, plasma parameters of glucose and lipid metabolisms, body composition, hepatic weight, total fat content and fatty acid profile, as well as gene expression of lipogenic and lipolytic nuclear transcription factors and their target genes were measured. Obese Zucker rats exhibited higher body and liver weight and fat content than did their lean counterparts. Such alterations were related to modifications in aerobic capacity, plasma biochemical parameters of glucose and lipid metabolisms, hepatic fatty acid profile and gene expression of nuclear transcription factors SREBP1c, PPARα, LXR and associated lipogenic and lipolytic enzymes. The interventions tested did not affect body weight gain but improved aerobic capacity, reduced hepatomegalia and steatosis associated with NAFLD and relieved the adverse effects produced by this condition in glucose and lipid metabolisms through the modulation in the expression of different genes involved in diverse metabolic pathways.

Genistein restores caveolin-1 and AT-1 receptor expression and vascular function in large vessels of ovariectomized hypertensive rats.

OBJECTIVE: The soy-derived phytoestrogen genistein improves endothelial function in postmenopausal women and ovariectomized (OVX) normotensive rats. We hypothesized that genistein would improve vascular reactivity involving changes in endothelial nitric oxide synthase (NOS) expression and its regulatory proteins (caveolin and calmodulin), angiotensin II receptor, and/or oxidative status in OVX spontaneously hypertensive rats (SHRs). DESIGN: After ovariectomy or sham operation, 23-week-old female SHRs received either 17beta-estradiol (2 mg/kg/wk SC), genistein (10 mg/kg/d by gavage), or placebo. RESULTS: In OVX rats, final body weight was increased and uterus weight was decreased, and these values were reduced and increased, respectively, by 17beta-estradiol but unaffected by genistein. Acetylcholine-induced endothelium-dependent vasorelaxation was significantly blunted in aortas from OVX placebo SHRs. The contractions induced by the NOS inhibitor L-NAME and angiotensin II in OVX placebo were lower and higher, respectively, than in sham rats. Estradiol and genistein restored these functional changes. Aortic endothelial NOS and calmodulin-1 expression were unchanged, whereas caveolin-1 and angiotensin II receptor expression was increased in OVX rats. Estradiol and genistein treatment did not modify endothelial NOS, but normalized caveolin-1 and angiotensin II receptor and increased calmodulin-1 expression. Vascular superoxide production was increased in OVX placebo and normalized by both estradiol and genistein. CONCLUSIONS: Genistein prevented all cardiovascular changes induced by estrogen depletion in SHRs to a similar extent as estradiol but had no uterotrophic effect. The present findings may help to explain the potential benefits of genistein as a therapeutic agent for preventing menopausal vascular complications, especially in hypertensive women.

Chronic administration of genistein improves endothelial dysfunction in spontaneously hypertensive rats: involvement of eNOS, caveolin and calmodulin expression and NADPH oxidase activity.

The soya-derived phytoestrogen genistein has been suggested to be protective in cardiovascular diseases. In the present study, we have analysed whether chronic oral genistein might influence endothelial function in male SHRs (spontaneously hypertensive rats) via ERs (oestrogen receptors), changes in eNOS (endothelial NO synthase) activity and vascular O(2)(-) (superoxide) production. Rats (23-weeks old) were divided into the following groups: WKY (Wistar-Kyoto)-vehicle, SHR-vehicle, WKY-genistein (10 mg.kg(-1) of body weight.day(-1)); SHR-genistein; SHR-genistein-faslodex (ICI 182780; 2.5 mg.kg(-1) of body weight.day(-1)). Vascular expression of eNOS, caveolin-1 and calmodulin-1 were analysed by Western blotting, eNOS activity by conversion of [(3)H]arginine into L-[(3)H]citrulline and O(2)(-) production by chemoluminescence of lucigenin. In SHRs, after 5 weeks of treatment, genistein reduced systolic blood pressure and enhanced endothelium-dependent aortic relaxation to acetylcholine, but had no effect on the vasodilator responses to sodium nitroprusside. Compared with WKY rats, SHRs had up-regulated eNOS and down-regulated caveolin-1 and calmodulin-1 expression, increased NADPH-induced O(2)(-) production, but reduced eNOS activity. Genistein increased aortic calmodulin-1 protein abundance and eNOS activity, and reduced NADPH-induced O(2)(-) production in SHRs. The pure ERalpha and ERbeta antagonist faslodex did not modify any of the changes induced by genistein in SHRs, suggesting that these effects are unrelated to ER stimulation. In conclusion, genistein reduced the elevated blood pressure and endothelial dysfunction in SHRs. This latter effect appears to be related to increased eNOS activity associated with increased calmodulin-1 expression and decreased O(2)(-) generation.

Protective vascular effects of quercitrin in acute TNBS-colitis in rats: the role of nitric oxide.

Quercitrin (quercetin 3-rhamnoside) is a bioflavonoid with anti-inflammatory activity in experimental colitis. Several studies have suggested that vascular injury might be a primary process in Crohn's disease, but there is no information about the function of the mesenteric bed in the experimental models of colitis. The aims of this study were to analyse whether the reactivity to vasoconstrictor agents is altered in the mesenteric vascular bed from animals with colitis induced by administration of trinitrobenzenesulfonic acid (TNBS) in the early stages of this pathology, and to determine the effects of quercitrin on such vascular alterations. Contraction of mesenteric beds produced by vasoconstrictor agents such as noradrenaline and KCl is reduced in rats in the early stages of experimental TNBS-induced colitis. This alteration was partially reverted by non-selective nitric oxide synthase (NOS) inhibition with N-nitro-l-arginine methylester, and enhanced by non-selective cyclooxygenase (COX) inhibition with indomethacin. However, the endothelium-dependent relaxant responses to acetylcholine were not significantly altered. iNOS, COX-2, NOX-1, tumor necrosis factor α (TNFα) and interleukin 1ß (IL1ß) expressions were higher in the mesenteric arteries from TNBS-treated rats, without changes in both eNOS expression and eNOS-Ser1177 phosphorylation. The in vivo pre-treatment with 5 mg kg-1 of the flavonoid quercitrin reverts both the early hyporesponse of mesenteric arteries to noradrenaline and the up-regulation of iNOS, COX2, NOX1, TNFα and IL1ß in colitic rats. In conclusion, quercitrin improves the impaired mesenteric vascular reactivity in the acute phase of this colitis model, at least in part by reducing NO overproduction from iNOS.

The Combined Intervention with Germinated Vigna radiata and Aerobic Interval Training Protocol Is an Effective Strategy for the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) and Other Alterations Related to the Metabolic Syndrome in Zucker Rats.

Metabolic syndrome (MetS) is a group of related metabolic alterations that increase the risk of developing non-alcoholic fatty liver disease (NAFLD). Several lifestyle interventions based on dietary treatment with functional ingredients and physical activity are being studied as alternative or reinforcement treatments to the pharmacological ones actually in use. In the present experiment, the combined treatment with mung bean (Vigna radiata), a widely used legume with promising nutritional and health benefits that was included in the experimental diet as raw or 4 day-germinated seed flour, and aerobic interval training protocol (65-85% VO2 max) has been tested in lean and obese Zucker rats following a 2 × 2 × 2 (2 phenotypes, 2 dietary interventions, 2 lifestyles) factorial ANOVA (Analysis of Variance) statistical analysis. Germination of V. radiata over a period of four days originated a significant protein hydrolysis leading to the appearance of low molecular weight peptides. The combination of 4 day-germinated V. radiata and aerobic interval training was more efficient compared to raw V. radiata at improving the aerobic capacity and physical performance, hepatic histology and functionality, and plasma lipid parameters as well as reverting the insulin resistance characteristic of the obese Zucker rat model. In conclusion, the joint intervention with legume sprouts and aerobic interval training protocol is an efficient treatment to improve the alterations of glucose and lipid metabolism as well as hepatic histology and functionality related to the development of NAFLD and the MetS.

Quercetin downregulates NADPH oxidase, increases eNOS activity and prevents endothelial dysfunction in spontaneously hypertensive rats.

BACKGROUND AND OBJECTIVE: Several studies have found that chronic treatment with the dietary flavonoid quercetin lowers blood pressure and restores endothelial dysfunction in hypertensive animal models. We hypothesized that increased endothelial nitric oxide synthase (eNOS) and/or decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase protein expression and activity, and reduced reactive oxygen species might be involved in the improvement of endothelial function induced by quercetin in spontaneously hypertensive rats (SHR). DESIGN AND METHODS: Male SHR and Wistar-Kyoto (WKY) rats (5 weeks old) were treated with quercetin (10 mg/kg) or vehicle for 13 weeks. Changes in vascular expression of eNOS, caveolin-1 and p47 were analysed by Western blot, eNOS activity by conversion of [H]arginine to L-[H]citrulline, and NADPH oxidase activity by NADPH-enhanced chemoluminescence of lucigenin. RESULTS: In SHR, quercetin reduced the increase in blood pressure and heart rate and enhanced the endothelium-dependent aortic vasodilation induced by acetylcholine, but had no effect on the endothelium-independent response induced by nitroprusside. However, quercetin had no effect on endothelium-dependent vasoconstriction and aortic thromboxane B2 production. Compared to WKY, SHR showed upregulated eNOS and p47 protein expression, downregulated caveolin-1 expression, increased NADPH-induced superoxide production but, paradoxically, eNOS activity was reduced. Chronic quercetin treatment prevented all these changes in SHR. In WKY, quercetin had no effect on blood pressure, endothelial function or the expression or activity of the proteins analysed. CONCLUSIONS: Enhanced eNOS activity and decreased NADPH oxidase-mediated superoxide anion (O2) generation associated with reduced p47 expression appear to be essential mechanisms for the improvement of endothelial function and the antihypertensive effects of chronic quercetin.

Increased NADPH oxidase activity mediates spontaneous aortic tone in genetically hypertensive rats.

NADPH oxidase is critically involved in increased blood pressure, vascular hypertrophy, inflammation and endothelial dysfunction in experimental and clinical hypertension. We hypothesized that NADPH oxidase might also play a role in the development of spontaneous aortic tone in spontaneously hypertensive rats (SHR). Wistar Kyoto rats (WKY) were used as normotensive controls. Tone was recorded under isometric conditions. NADPH oxidase activity was measured by both lucigenin luminescence and dihydroethidium fluorescence. p47phox protein was localized by immunohistochemistry. SHR (but not WKY rat) aortae showed spontaneous tone in the absence of exogenous vasoconstrictors as evidenced by a stronger relaxant effect of Ca2+-free sodium nitroprusside solution. This tone was enhanced in endothelium-denuded arteries and was inhibited by superoxide dismutase, apocynin, diphenylene iodonium and quercetin. Aortic NADPH oxidase activity, measured by both lucigenin luminescence and dihydroethidium fluorescence, was increased in SHR compared with WKY rats. Immunohistochemical analysis revealed a strong increase in p47phox expression in the medial layer in SHR. Taken together, the present results indicate that enhanced NADPH oxidase activity and, hence, NADPH driven O2- production, is involved in the spontaneous aortic tone in SHR. This was associated with an increased expression of p47phox in the medial layer of the aorta.

Aerobic interval exercise improves parameters of nonalcoholic fatty liver disease (NAFLD) and other alterations of metabolic syndrome in obese Zucker rats.

Metabolic syndrome (MS) is a group of metabolic alterations that increase the susceptibility to cardiovascular disease and type 2 diabetes. Nonalcoholic fatty liver disease has been described as the liver manifestation of MS. We aimed to test the beneficial effects of an aerobic interval training (AIT) protocol on different biochemical, microscopic, and functional liver alterations related to the MS in the experimental model of obese Zucker rat. Two groups of lean and obese animals (6 weeks old) followed a protocol of AIT (4 min at 65%-80% of maximal oxygen uptake, followed by 3 min at 50%-65% of maximal oxygen uptake for 45-60 min, 5 days/week, 8 weeks of experimental period), whereas 2 control groups remained sedentary. Obese rats had higher food intake and body weight (P < 0.0001) and suffered significant alterations in plasma lipid profile, area under the curve after oral glucose overload (P < 0.0001), liver histology and functionality, and antioxidant status. The AIT protocol reduced the severity of alterations related to glucose and lipid metabolism and increased the liver protein expression of PPARγ, as well as the gene expression of glutathione peroxidase 4 (P < 0.001). The training protocol also showed significant effects on the activity of hepatic antioxidant enzymes, although this action was greatly influenced by rat phenotype. The present data suggest that AIT protocol is a feasible strategy to improve some of the plasma and liver alterations featured by the MS.