Showing papers in "Journal of Nutritional Biochemistry in 2013"

Benefits of polyphenols on gut microbiota and implications in human health.

Abstract: The biological properties of dietary polyphenols are greatly dependent on their bioavailability that, in turn, is largely influenced by their degree of polymerization. The gut microbiota play a key role in modulating the production, bioavailability and, thus, the biological activities of phenolic metabolites, particularly after the intake of food containing high-molecular-weight polyphenols. In addition, evidence is emerging on the activity of dietary polyphenols on the modulation of the colonic microbial population composition or activity. However, although the great range of health-promoting activities of dietary polyphenols has been widely investigated, their effect on the modulation of the gut ecology and the two-way relationship "polyphenols ↔ microbiota" are still poorly understood. Only a few studies have examined the impact of dietary polyphenols on the human gut microbiota, and most were focused on single polyphenol molecules and selected bacterial populations. This review focuses on the reciprocal interactions between the gut microbiota and polyphenols, the mechanisms of action and the consequences of these interactions on human health.

Recent advances in understanding the anti-diabetic actions of dietary flavonoids

Abstract: Flavonoids are polyphenolic compounds that are abundant in fruits and vegetables, and increasing evidence demonstrates a positive relationship between consumption of flavonoid-rich foods and disease prevention. Epidemiological, in vitro and animal studies support the beneficial effects of dietary flavonoids on glucose and lipid homeostasis. It is encouraging that the beneficial effects of some flavonoids are at physiological concentrations and comparable to clinically-used anti-diabetic drugs; however, clinical research in this field and studies on the anti-diabetic effects of flavonoid metabolites are limited. Flavonoids act on various molecular targets and regulate different signaling pathways in pancreatic β-cells, hepatocytes, adipocytes and skeletal myofibers. Flavonoids may exert beneficial effects in diabetes by (i) enhancing insulin secretion and reducing apoptosis and promoting proliferation of pancreatic β-cells; (ii) improving hyperglycemia through regulation of glucose metabolism in hepatocytes; (iii) reducing insulin resistance, inflammation and oxidative stress in muscle and fat and (iv) increasing glucose uptake in skeletal muscle and white adipose tissue. This review highlights recent findings on the anti-diabetic effects of dietary flavonoids, including flavan-3-ols, flavanones, flavonols, anthocyanidins, flavones and isoflavones, with particular emphasis on the studies that investigated the cellular and molecular mechanisms involved in the beneficial effects of the compounds.

Modulation of adipose tissue inflammation by bioactive food compounds

Abstract: Adipose tissue has an important endocrine function in the regulation of whole-body metabolism. Obesity leads to a chronic low-grade inflammation of the adipose tissue, which disrupts this endocrine function and results in metabolic derangements, such as type-2 diabetes. Dietary bioactive compounds, such as polyphenols and certain fatty acids, are known to suppress both systemic and adipose tissue inflammation and have the potential to improve these obesity-associated metabolic disorders. Mechanistically, polyphenolic compounds including non-flavonoids, such as curcumin and resveratrol, and flavonoids, such as catechins (tea-polyphenols), quercetin and isoflavones, suppress nuclear factor-κB (NF-κB) and mitogen-activated protein (MAP) kinases (MAPK) pathways while activating the 5′ adenosine monophosphate-activated protein kinase (AMPK) pathway in adipose tissue. Dietary polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), conjugated linoleic acid (CLA) and monounsaturated fatty acids (MUFA), such as oleic acid, also impart anti-inflammatory effects through several mechanisms. These include activation of AMPK and peroxisome proliferator-activated receptor gamma (PPAR-γ), as well as suppression of toll-like receptors (TLRs) and NF-κB pathway. This review discusses the major molecular mechanisms of dietary polyphenols and fatty acids, alone or in combination, which are responsible for adipose tissue-associated anti-inflammatory effects.

Nutritional modulation of cognitive function and mental health.

Abstract: The important role of diet in cardiometabolic health is generally well recognised; for mental health, it is not so well understood. However, lifestyle risk factors for poor physical health are the same risk factors for mental illness, including poor diet. This is reflected by the high level of poor physical health in people with mental illness. Mediterranean, whole food diets have been associated with reduced risk for chronic disease, but very little research has investigated their mental health benefits. We provide a model for the pathways by which food components provided by a Mediterranean-style diet can facilitate healthy brain function. We then review evidence for the role of selected nutrients/food components - antioxidants, omega-3 fatty acids and B vitamins - in the brain and, hence, modulation of cognitive function and mental health. Converging evidence indicates multiple pathways by which these nutrients can assist in brain function, drawing from studies investigating them in isolation. There is very little work done on synergistic actions of nutrients and whole diets, highlighting a need for human intervention studies investigating benefits of Mediterranean-style diets for mental, as well as cardiometabolic health.

Biochemical and metabolic mechanisms by which dietary whey protein may combat obesity and Type 2 diabetes

Abstract: Consumption of milk and dairy products has been associated with reduced risk of metabolic disorders and cardiovascular disease. Milk contains two primary sources of protein, casein (80%) and whey (20%). Recently, the beneficial physiological effects of whey protein on the control of food intake and glucose metabolism have been reported. Studies have shown an insulinotropic and glucose-lowering properties of whey protein in healthy and Type 2 diabetes subjects. Whey protein seems to induce these effects via bioactive peptides and amino acids generated during its gastrointestinal digestion. These amino acids and peptides stimulate the release of several gut hormones, such as cholecystokinin, peptide YY and the incretins gastric inhibitory peptide and glucagon-like peptide 1 that potentiate insulin secretion from β-cells and are associated with regulation of food intake. The bioactive peptides generated from whey protein may also serve as endogenous inhibitors of dipeptidyl peptidase-4 (DPP-4) in the proximal gut, preventing incretin degradation. Indeed, recently, DPP-4 inhibitors were identified in whey protein hydrolysates. This review will focus on the emerging properties of whey protein and its potential clinical application for obesity and Type 2 diabetes.

Lifestyle and nutritional imbalances associated with Western diseases: causes and consequences of chronic systemic low-grade inflammation in an evolutionary context.

Abstract: In this review, we focus on lifestyle changes, especially dietary habits, that are at the basis of chronic systemic low grade inflammation, insulin resistance and Western diseases. Our sensitivity to develop insulin resistance traces back to our rapid brain growth in the past 2.5 million years. An inflammatory reaction jeopardizes the high glucose needs of our brain, causing various adaptations, including insulin resistance, functional reallocation of energy-rich nutrients and changing serum lipoprotein composition. The latter aims at redistribution of lipids, modulation of the immune reaction, and active inhibition of reverse cholesterol transport for damage repair. With the advent of the agricultural and industrial revolutions, we have introduced numerous false inflammatory triggers in our lifestyle, driving us to a state of chronic systemic low grade inflammation that eventually leads to typically Western diseases via an evolutionary conserved interaction between our immune system and metabolism. The underlying triggers are an abnormal dietary composition and microbial flora, insufficient physical activity and sleep, chronic stress and environmental pollution. The disturbance of our inflammatory/anti-inflammatory balance is illustrated by dietary fatty acids and antioxidants. The current decrease in years without chronic disease is rather due to "nurture" than "nature," since less than 5% of the typically Western diseases are primary attributable to genetic factors. Resolution of the conflict between environment and our ancient genome might be the only effective manner for "healthy aging," and to achieve this we might have to return to the lifestyle of the Paleolithic era as translated to the 21st century culture.

Polychlorinated biphenyl 153 is a diet-dependent obesogen that worsens nonalcoholic fatty liver disease in male C57BL6/J mice.

Abstract: Background Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that are detectable in the serum of all American adults. Amongst PCB congeners, PCB 153 has the highest serum level. PCBs have been dose-dependently associated with obesity, metabolic syndrome and nonalcoholic fatty liver disease (NAFLD) in epidemiological studies. Objective The purpose of this study is to determine mechanisms by which PCB 153 worsens diet-induced obesity and NAFLD in male mice fed a high-fat diet (HFD). Methods Male C57BL6/J mice were fed either control or 42% milk fat diet for 12 weeks with or without PCB 153 coexposure (50 mg/kg ip ×4). Glucose tolerance test was performed, and plasma and tissues were obtained at necropsy for measurements of adipocytokine levels, histology and gene expression. Results In control diet-fed mice, addition of PCB 153 had minimal effects on any of the measured parameters. However, PCB 153 treatment in high-fat-fed mice was associated with increased visceral adiposity, hepatic steatosis and plasma adipokines including adiponectin, leptin, resistin and plasminogen activator inhibitor-1 levels. Likewise, coexposure reduced expression of hepatic genes implicated in β-oxidation while increasing the expression of genes associated with lipid biosynthesis. Regardless of diet, PCB 153 had no effect on insulin resistance or tumor necrosis factor alpha levels. Conclusion PCB 153 is an obesogen that exacerbates hepatic steatosis, alters adipocytokines and disrupts normal hepatic lipid metabolism when administered with HFD but not control diet. Because all US adults have been exposed to PCB 153, this particular nutrient–toxicant interaction potentially impacts human obesity/NAFLD.

Epigallocatechin-3-gallate prevents systemic inflammation-induced memory deficiency and amyloidogenesis via its anti-neuroinflammatory properties.

Abstract: Neuroinflammation has been known to play a critical role in the pathogenesis of Alzheimer's disease (AD) through amyloidogenesis. In a previous study, we found that systemic inflammation by intraperitoneal (ip) injection of lipopolysaccharide (LPS) induces neuroinflammation and triggers memory impairment. In this present study, we investigated the inhibitory effects of epigallocatechin-3-gallate (EGCG) on the systemic inflammation-induced neuroinflammation and amyloidogenesis as well as memory impairment. ICR mice were orally administered with EGCG (1.5 and 3 mg/kg) for 3 weeks, and then the mice were treated by ip injection of LPS (250 μg/kg) for 7 days. We found that treatment of LPS induced memory-deficiency-like behavior and that EGCG treatment prevented LPS-induced memory impairment and apoptotic neuronal cell death. EGCG also suppressed LPS-induced increase of the amyloid beta-peptide level and the expression of the amyloid precursor protein (APP), β-site APP cleaving enzyme 1 and its product C99. In addition, we found that EGCG prevented LPS-induced activation of astrocytes and elevation of cytokines including tumor necrosis factor-α, interleukin (IL)-1β, macrophage colony-stimulating factor, soluble intercellular adhesion molecule-1 and IL-16, and the increase of inflammatory proteins, such as inducible nitric oxide synthase and cyclooxygenase-2, which are known factors responsible for not only activation of astrocytes but also amyloidogenesis. In the cultured astrocytes, EGCG also inhibited LPS-induced cytokine release and amyloidogenesis. Thus, this study shows that EGCG prevents memory impairment as well as amyloidogenesis via inhibition of neuroinflammatory-related cytokines released from astrocytes and suggests that EGCG might be a useful intervention for neuroinflammation-associated AD.

Nobiletin improves obesity and insulin resistance in high-fat diet-induced obese mice.

Abstract: Nobiletin (NOB) is a polymethoxylated flavone present in citrus fruits and has been reported to have antitumor and anti-inflammatory effects. However, little is known about the effects of NOB on obesity and insulin resistance. In this study, we examined the effects of NOB on obesity and insulin resistance, and the underlying mechanisms, in high-fat diet (HFD)-induced obese mice. Obese mice were fed a HFD for 8 weeks and then treated without (HFD control group) or with NOB at 10 or 100mg/kg. NOB decreased body weight gain, white adipose tissue (WAT) weight and plasma triglyceride. Plasma glucose levels tended to decrease compared with the HFD group and improved plasma adiponectin levels and glucose tolerance. Furthermore, NOB altered the expression levels of several lipid metabolism-related and adipokine genes. NOB increased the mRNA expression of peroxisome proliferator-activated receptor (PPAR)-γ, sterol regulatory element-binding protein-1c, fatty acid synthase, stearoyl-CoA desaturase-1, PPAR-α, carnitine palmitoyltransferase-1, uncoupling protein-2 and adiponectin, and decreased the mRNA expression of tumor necrosis factor-α and monocyte chemoattractant protein-1 in WAT. NOB also up-regulated glucose transporter-4 protein expression and Akt phosphorylation and suppressed IκBα degradation in WAT. Taken together, these results suggest that NOB improves adiposity, dyslipidemia, hyperglycemia and insulin resistance. These effects may be elicited by regulating the expression of lipid metabolism-related and adipokine genes, and by regulating the expression of inflammatory makers and activity of the insulin signaling pathway.

Effects of ALA, EPA and DHA in high-carbohydrate, high-fat diet-induced metabolic syndrome in rats

Abstract: We compared the cardiovascular, hepatic and metabolic responses to individual dietary n-3 fatty acids (α-linolenic acid, ALA; eicosapentaenoic acid, EPA; and docosahexaenoic acid, DHA) in a high-carbohydrate, high-fat diet-induced model of metabolic syndrome in rats. Additionally, we measured fatty acid composition of plasma, adipose tissue, liver, heart and skeletal muscle in these rats. The same dosages of ALA and EPA/DHA produced different physiological responses to decrease the risk factors for metabolic syndrome. ALA did not reduce total body fat but induced lipid redistribution away from the abdominal area and favorably improved glucose tolerance, insulin sensitivity, dyslipidemia, hypertension and left ventricular dimensions, contractility, volumes and stiffness. EPA and DHA increased sympathetic activation, reduced the abdominal adiposity and total body fat and attenuated insulin sensitivity, dyslipidemia, hypertension and left ventricular stiffness but not glucose tolerance. However, ALA, EPA and DHA all reduced inflammation in both the heart and the liver, cardiac fibrosis and hepatic steatosis. These effects were associated with complete suppression of stearoyl-CoA desaturase 1 activity. Since the physiological responses to EPA and DHA were similar, it is likely that the effects are mediated by DHA with EPA serving as a precursor. Also, ALA supplementation increased DHA concentrations but induced different physiological responses to EPA and DHA. This result strongly suggests that ALA has independent effects in metabolic syndrome, not relying on its metabolism to DHA.

Lactobacillus rhamnosus GG reduces hepatic TNFα production and inflammation in chronic alcohol-induced liver injury.

Abstract: The therapeutic effects of probiotic treatment in alcoholic liver disease (ALD) have been studied in both patients and experimental animal models. Although the precise mechanisms of the pathogenesis of ALD are not fully understood, gut-derived endotoxin has been postulated to play a crucial role in hepatic inflammation. Previous studies have demonstrated that probiotic therapy reduces circulating endotoxin derived from intestinal gram-negative bacteria in ALD. In this study, we investigated the effects of probiotics on hepatic tumor necrosis factor-α (TNFα) production and inflammation in response to chronic alcohol ingestion. Mice were fed Lieber DeCarli liquid diet containing 5% alcohol for 8weeks, and Lactobacillus rhamnosus GG (LGG) was supplemented in the last 2 weeks. Eight-week alcohol feeding caused a significant increase in hepatic inflammation as shown by histological assessment and hepatic tissue myeloperoxidase activity assay. Two weeks of LGG supplementation reduced hepatic inflammation and liver injury and markedly reduced TNFα expression. Alcohol feeding increased hepatic mRNA expression of Toll-like receptors (TLRs) and CYP2E1 and decreased nuclear factor erythroid 2-related factor 2 expression. LGG supplementation attenuated these changes. Using human peripheral blood monocytes-derived macrophages, we also demonstrated that incubation with ethanol primes both lipopolysaccharide- and flagellin-induced TNFα production, and LGG culture supernatant reduced this induction in a dose-dependent manner. In addition, LGG treatment also significantly decreased alcohol-induced phosphorylation of p38 MAP kinase. In conclusion, probiotic LGG treatment reduced alcohol-induced hepatic inflammation by attenuation of TNFα production via inhibition of TLR4- and TLR5-mediated endotoxin activation.

Nutritional protective mechanisms against gut inflammation

Abstract: Inflammatory bowel disease (IBD) is a debilitating and widespread immune-mediated illness characterized by excessive inflammatory and effector mucosal responses leading to tissue destruction at the gastrointestinal tract. Interactions among the immune system, the commensal microbiota and the host genotype are thought to underlie the pathogenesis of IBD. However, the precise etiology of IBD remains unknown. Diet-induced changes in the composition of the gut microbiome can modulate the induction of regulatory versus effector immune responses at the gut mucosa and improve health outcomes. Therefore, manipulation of gut microbiota composition and the local production of microbial-derived metabolites by using prebiotics, probiotics and dietary fibers is being explored as a promising avenue of prophylactic and therapeutic intervention against gut inflammation. Prebiotics and fiber carbohydrates are fermented by resident microflora into short chain fatty acids (SCFAs) in the colon. SCFAs then activate peroxisome proliferator-activated receptor (PPAR)γ, a nuclear transcription factor with widely demonstrated anti-inflammatory efficacy in experimental IBD. The activation of PPARγ by naturally ocurring compounds such as conjugated linoleic acid, pomegranate seed oil-derived punicic acid, eleostearic acid and abscisic acid has been explored as nutritional interventions that suppress colitis by directly modulating the host immune response. The aim of this review is to summarize the status of innovative nutritional interventions against gastrointestinal inflammation, their proposed mechanisms of action, preclinical and clinical efficacy as well as bioinformatics and computational modeling approaches that accelerate discovery in nutritional and mucosal immunology research.

Pomegranate reverses methotrexate-induced oxidative stress and apoptosis in hepatocytes by modulating Nrf2-NF-κB pathways.

Abstract: The clinical efficacy of the widely used chemotherapeutic drug methotrexate (MTX) is limited due to its associated hepatotoxicity. Pomegranate polyphenols are of huge health benefits and known to possess remarkable antioxidant properties capable of protecting normal cells from various stimuli-induced oxidative stress and cell death. In this study, we explored the protective role of pomegranate fruit extract (PFE) in ameliorating MTX-induced hepatic damage. Male Swiss albino mice exposed to MTX (20 mg/kg body weight) exhibited distinct markers of toxicity such as increased activities of enzymes alanine transaminase, aspartate transaminase, lactate dehydrogenase and alkaline phosphatase and also increased oxidative stress in liver evidenced by increased ROS generation and lipid peroxidation. Decrease in reduced glutathione levels, superoxide dismutase, catalase, hepatic heme oxygenase 1 and NQO-1 activities were also observed. Tracing the signal transduction pathways, it was seen that MTX exposure significantly increased nuclear translocation of NF-κB coupled with increase in phosphorylated Iκ-B and down-regulation of NF-kappaB-dependent antiapoptotic protein Bcl-2. Treatment with MTX increased the expression of the apoptotic enhancer Rho/Cdc42 as well as the phosphorylation of SAPK/JNK. A shift in the Bax/Bcl-2 ratio towards apoptosis and increase in the caspase 3 level was also evident. Administration of PFE for 7 consecutive days before and after MTX challenge suppressed MTX-induced cell death, mitigated the injurious effects of MTX and offered protection against apoptosis. PFE was shown to reduce ROS generation in hepatocytes by activating the Nrf2-ARE pathway and inhibiting NF-κB as a consequence of which the antioxidant defense mechanism in the liver was up-regulated, thereby conferring protection against MTX-induced hepatotoxicity and apoptosis.

Docosahexaenoic acid inhibition of inflammation is partially via cross-talk between Nrf2/heme oxygenase 1 and IKK/NF-κB pathways

Abstract: We examined the underlying mechanisms involved in n-3 docosahexaenoic acid (DHA) inhibition of inflammation in EA.hy926 cells. The present results demonstrated that pretreatment with DHA (50 and 100 μM) inhibited tumor necrosis factor-alpha (TNF-α)-induced intercellular adhesion molecule 1 (ICAM-1) protein, mRNA expression and promoter activity. In addition, TNF-α-stimulated inhibitory kappa B (IκB) kinase (IKK) phosphorylation, IκB phosphorylation and degradation, p65 nuclear translocation, and nuclear factor-κB (NF-κB) and DNA binding activity were attenuated by pretreatment with DHA. DHA triggered early-stage and transient reactive oxygen species (ROS) generation and significantly increased the protein expression of heme oxygenase 1 (HO-1), induced nuclear factor erythroid 2-related factor 2 (Nrf2) translocation to the nucleus and up-regulated antioxidant response element (ARE)-luciferase reporter activity. Moreover, DHA inhibited Nrf2 ubiquitination and proteasome activity. DHA activated Akt, p38 and ERK1/2 phosphorylation, and specific inhibitors of respective pathways attenuated DHA-induced Nrf2 nuclear translocation and HO-1 expression. Transfection with HO-1 siRNA knocked down HO-1 expression and partially reversed the DHA-mediated inhibition of TNF-α-induced p65 nuclear translocation and ICAM-1 expression. Importantly, we show for the first time that HO-1 plays a down-regulatory role in NF-κB nuclear translocation, and inhibition of Nrf2 ubiquitination and proteasome activity are involved in increased cellular Nrf2 level by DHA. In this study, we show that HO-1 plays a down-regulatory role in NF-κB nuclear translocation and that the protective effect of DHA against inflammation is partially via up-regulation of Nrf2-mediated HO-1 expression and inhibition of IKK/NF-κB signaling pathway.

Zinc deficiency induces production of the proinflammatory cytokines IL-1β and TNFα in promyeloid cells via epigenetic and redox-dependent mechanisms

Abstract: The deprivation of zinc, caused by malnutrition or as a consequence of aging or disease, strongly affects immune cell functions, causing higher frequency of infections. Among other effects, an increased production of reactive oxygen species (ROS) and proinflammatory cytokines has been observed in zinc-deficient patients, but the underlying mechanisms were unknown. The aim of the current study was to define mechanisms explaining the increase in proinflammatory cytokine production during zinc deficiency, focusing on the role of epigenetic and redox-mediated mechanisms. Interleukin (IL)-1β and tumor necrosis factor (TNF)α production was increased in HL-60 cells under zinc deficiency. Analyses of the chromatin structure demonstrated that the elevated cytokine production was due to increased accessibilities of IL-1β and TNFα promoters in zinc-deficient cells. Moreover, the level of nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) oxidase-produced ROS was elevated under zinc deficiency, subsequently leading to p38 mitogen-activated protein kinase (MAPK) phosphorylation. The increased activation of p38 MAPK appeared to be necessary for posttranscriptional processes in IL-1β and TNFα synthesis. These data demonstrate that IL-1β and TNFα expression under zinc deficiency is regulated via epigenetic and redox-mediated mechanisms. Assuming an important role of zinc in proinflammatory cytokine regulation, this should encourage research in the use of zinc supplementation for treatment of inflammatory diseases.

Extra-virgin olive oil diet and mild physical activity prevent cartilage degeneration in an osteoarthritis model: an in vivo and in vitro study on lubricin expression.

Abstract: Mediterranean diet includes a relatively high fat consumption mostly from monounsaturated fatty acids mainly provided by olive oil, the principal source of culinary and dressing fat. The beneficial effects of olive oil have been widely studied and could be due to its phytochemicals, which have been shown to possess anti-inflammatory properties. Lubricin is a chondroprotective glycoprotein and it serves as a critical boundary lubricant between opposing cartilage surfaces. A joint injury causes an initial flare of cytokines, which decreases lubricin expression and predisposes to cartilage degeneration such as osteoarthritis. The aim of this study was to evaluate the role of extra-virgin olive oil diet and physical activity on inflammation and expression of lubricin in articular cartilage of rats after injury. In this study we used histomorphometric, histological, immunocytochemical, immunohistochemical, western blot and biochemical analysis for lubricin and interleukin-1 evaluations in the cartilage and in the synovial fluid. We report the beneficial effect of physical activity (treadmill training) and extra-virgin olive oil supplementation, on the articular cartilage. The effects of anterior cruciate ligament transection decrease drastically the expression of lubricin and increase the expression of interleukin-1 in rats, while after physical activity and extra-virgin olive oil supplemented diet, the values return to a normal level compared to the control group. With our results we can confirm the importance of the physical activity in conjunction with extra-virgin olive oil diet in medical therapy to prevent osteoarthritis disease in order to preserve the articular cartilage and then the entire joint.

Dietary extra virgin olive oil polyphenols supplementation modulates DSS-induced chronic colitis in mice

Abstract: We evaluated the protective effect of dietary extra virgin olive oil (EVOO) polyphenol extract (PE) supplementation in the inflammatory response associated to chronic colitis model. Six-week-old mice were randomized in four dietary groups: standard diet (SD), EVOO diet and both enriched with PE (850 ppm) (SD+PE and EVOO+PE). After 30 days, animals that were exposed to dextran sodium sulfate (DSS) (3%) followed by 3 weeks of drinking water developed chronic colitis, which was evaluated by disease activity index (DAI) and histology. Cell proliferation was analyzed by immunohistochemical and changes in monocyte chemotactic protein (MCP)-1 and tumor necrosis factor (TNF)-α mRNA expression by quantitative real-time polymerase chain reaction. Colonic expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, mitogen-activated protein kinases (MAPKs), IκBα inhibitory and peroxisome proliferator-activated receptor gamma (PPARγ) were determined by western blotting. SD-DSS group showed a significant increase of DAI, histological damage and cell proliferation, as well as an up-regulation of TNF-α, MCP-1, COX-2 and iNOS proteins. p38 and JNK MAPKs phosphorylation, IκBα degradation and PPARγ deactivation were also observed. However, in DSS-treated and EVOO+PE-fed mice, DAI and cell proliferation were significantly reduced, as well as MCP-1, TNF-α, COX-2 and iNOS expression levels. In addition, this dietary group, notably down-regulated JNK phosphorylation, prevented IκBα degradation and PPARγ deactivation. These results demonstrated, for the first time, that EVOO-PE supplementation possessed marked protective effects on experimental colitis through PPARγ up-regulation and nuclear transcription factor-kappa B and MAPK signaling pathway inhibition, decreasing the inflammatory cascade. We concluded that PE-enriched EVOO diet could be a beneficial functional food on ulcerative colitis.

Anti-apoptotic and anti-inflammatory effect of Piperine on 6-OHDA induced Parkinson's rat model.

Abstract: In the present study, we examined the molecular mechanism by which Piperine (bioactive compound of Piper nigrum) inhibits neuronal cell apoptosis. We further investigated the anti-inflammatory effect of Piperine on 6-OHDA induced Parkinson's disease. Consistent with its antioxidant properties, Piperine (10 mg/kg bwt) reduced 6-OHDA-induced lipid peroxidation and stimulated glutathione levels in striatum of rats. Furthermore, Piperine treatment diminished cytochrome-c release from mitochondria and reduced caspase-3 and caspase-9 activation induced by 6-OHDA. Treatment with Piperine markedly inhibited poly(ADP-ribose) polymerase activation, pro-apoptotic Bax levels and elevation of Bcl-2 levels. Piperine reduces contralateral rotations induced by apomorphine. Further narrow beam test and rotarod also showed improvement in motor coordination and balance behavior in rats treated with Piperine. In addition Piperine depletes inflammatory markers, TNF-α and IL-1β in 6-OHDA-induced Parkinson's rats. We propose that, in addition to its antioxidant properties Piperine exerts a protective effect via anti-apoptotic and anti-inflammatory mechanism on 6-OHDA induced Parkinson's disease.

Anthocyanin-enriched bilberry and blackcurrant extracts modulate amyloid precursor protein processing and alleviate behavioral abnormalities in the APP/PS1 mouse model of Alzheimer's disease☆

Abstract: A growing body of epidemiological evidence suggests that fruit and vegetable juices containing various phenolic compounds can reduce the risk of Alzheimer's disease (AD). As the altered amyloid precursor protein (APP) processing leading to increased β-amyloid (Aβ) production is a key pathogenic feature of AD, we elucidated the effects of different polyphenols on neuroprotection and APP processing under different in vitro stress conditions. The effects of these compounds were also investigated in transgenic AD mice (APdE9). Free radical toxicity and apoptosis were induced in human SH-SY5Y neuroblastoma cells overexpressing APP751. Menadione-induced production of reactive oxygen species was significantly decreased upon treatment with myricetin, quercetin or anthocyanin-rich extracts in a dose-dependent manner. However, these extracts did not affect caspase-3 activation, APP processing or Aβ levels upon staurosporine-induced apoptosis. APdE9 mice fed with anthocyanin-rich bilberry or blackcurrant extracts showed decreased APP C-terminal fragment levels in the cerebral cortex as compared to APdE9 mice on the control diet. Soluble Aβ40 and Aβ42 levels were significantly decreased in bilberry-fed mice as compared to blackcurrant-fed mice. Conversely, the ratio of insoluble Aβ42/40 was significantly decreased in blackcurrant-fed mice relative to bilberry-fed mice. Both berry diets alleviated the spatial working memory deficit of aged APdE9 mice as compared to mice on the control diet. There were no changes in the expression or phosphorylation status of tau in APdE9 mice with respect to diet. These data suggest that anthocyanin-rich bilberry and blackcurrant diets favorably modulate APP processing and alleviate behavioral abnormalities in a mouse model of AD.

The renin-angiotensin system in adipose tissue and its metabolic consequences during obesity.

Abstract: Obesity is a worldwide disease that is accompanied by several metabolic abnormalities such as hypertension, hyperglycemia and dyslipidemia. The accelerated adipose tissue growth and fat cell hypertrophy during the onset of obesity precedes adipocyte dysfunction. One of the features of adipocyte dysfunction is dysregulated adipokine secretion, which leads to an imbalance of pro-inflammatory, pro-atherogenic versus anti-inflammatory, insulin-sensitizing adipokines. The production of renin-angiotensin system (RAS) components by adipocytes is exacerbated during obesity, contributing to the systemic RAS and its consequences. Increased adipose tissue RAS has been described in various models of diet-induced obesity (DIO) including fructose and high-fat feeding. Up-regulation of the adipose RAS by DIO promotes inflammation, lipogenesis and reactive oxygen species generation and impairs insulin signaling, all of which worsen the adipose environment. Consequently, the increase of circulating RAS, for which adipose tissue is partially responsible, represents a link between hypertension, insulin resistance in diabetes and inflammation during obesity. However, other nutrients and food components such as soy protein attenuate adipose RAS, decrease adiposity, and improve adipocyte functionality. Here, we review the molecular mechanisms by which adipose RAS modulates systemic RAS and how it is enhanced in obesity, which will explain the simultaneous development of metabolic syndrome alterations. Finally, dietary interventions that prevent obesity and adipocyte dysfunction will maintain normal RAS concentrations and effects, thus preventing metabolic diseases that are associated with RAS enhancement.

Maternal fat intake in rats alters 20:4n-6 and 22:6n-3 status and the epigenetic regulation of Fads2 in offspring liver

Abstract: Poor prenatal nutrition, acting through epigenetic processes, induces persistent changes in offspring phenotype. We investigated the effect of maternal fat intake on polyunsaturated fatty acid (PUFA) status and on the epigenetic regulation of Fads2, encoding Δ6 desaturase (rate limiting in PUFA synthesis), in the adult offspring. Rats (n=6 per dietary group) were fed either 3.5% (w/w), 7% (w/w) or 21% (w/w) butter or fish oil (FO) from 14 days preconception until weaning. Offspring (n=6 males and females per dietary group) were fed 4% (w/w) soybean oil until postnatal day 77. 20:4n-6 and 22:6n-3 levels were lower in liver phosphatidylcholine (PC) and phosphatidylethanolamine and plasma PC (all P<.0001) in offspring of dams fed 21% than 3.5% or 7% fat regardless of type. Hepatic Fads2 expression related inversely to maternal dietary fat. Fads2 messenger RNA expression correlated negatively with methylation of CpGs at −623, −394, −84 and −76 bases relative to the transcription start site (all P<.005). Methylation of these CpGs was higher in offspring of dams fed 21% than 3.5% or 7% fat; FO higher than butter. Feeding adult female rats 7% fat reduced 20:4n-6 status in liver PC and Fads2 expression and increased methylation of CpGs −623, −394, −84 and −76 that reversed in animals switched from 7% to 4% fat diets. These findings suggest that fat exposure during development induces persistent changes, while adults exhibit a transient response, in hepatic PUFA status in offspring through epigenetic regulation of Fads2. Thus, epigenetic regulation of Fads2 may contribute to short- and long-term regulation of PUFA synthesis.

Effect of olive oil phenols on the production of inflammatory mediators in freshly isolated human monocytes

Abstract: Recent in vitro and in vivo studies suggest that the anti-inflammatory properties of extra virgin olive oil may be involved in the prevention of chronic degenerative diseases. In this study, the ability of olive oil phenols to influence the release of superoxide anions (O2-), prostaglandin E2 (PGE2) and tumor necrosis factor α (TNFα) and the expression of cyclooxygenase2 (COX2) in human monocytes, freshly isolated from healthy donors, was investigated. O2- were measured by superoxide dismutase-inhibitable cytochrome c reduction and PGE2 and TNFα production were determined in culture medium with appropriate enzyme immunoassay kits. COX2 mRNA and protein were evaluated by quantitative reverse transcription-polymerase chain reaction and Western immunoblotting, respectively. Treatment of monocytes for 24 h with 100 μM of hydroxytyrosol (3,4-DHPEA), tyrosol (p-HPEA) and their secoiridoid derivatives (3,4-DHPEA and p-HPEA linked to the dialdehydic form of elenolic acid: 3,4-DHPEA-EDA and p-HPEA-EDA, respectively) significantly (P<.05) inhibited the production of O2(-) as follows: 3,4-DHPEA (40%,), p-HPEA (9%), 3,4-DHPEA-EDA (25%) and p-HPEA-EDA (36%). Hydroxytyrosol also considerably reduced the expression of COX2 at both the mRNA and protein level (P<.05) and caused a clear dose-dependent reduction of PGE2 released into the culture medium (45% and 71% at 50 and 100 μM, respectively, P<.05). The COX2 mRNA was also efficiently inhibited by the secoiridoids. Moreover, it was shown that hydroxytyrosol increased the monocytes TNFα production. In addition to other chemopreventive properties, these results suggest that the health effects of olive oil phenols may be related to their ability to modulate the production of pro-inflammatory molecules, a property common to non-steroidal anti-inflammatory drugs.

Chlorogenic acid, a dietary polyphenol, protects acetaminophen-induced liver injury and its mechanism.

Abstract: Chlorogenic acid (CGA) is one of the most abundant dietary polyphenols, possessing well-known antioxidant capacity. The present study is designed to observe the protection provided by CGA against acetaminophen (AP)-induced liver injury in mice in vivo and the underlying mechanisms engaged in this process. Serum transaminases analysis and liver histological evaluation demonstrated the protection of CGA against AP-induced liver injury. CGA treatment decreased the increased number of liver apoptotic cells induced by AP in a dose-dependent manner. CGA also inhibited AP-induced cleaved activation of caspase-3, 7. Moreover, CGA reversed AP-decreased liver reduced glutathione (GSH) levels, glutamate-cysteine ligase (GCL) and glutathione reductase activity. Further results showed that CGA increased mRNA and protein expression of the catalytic subunit of GCL (GCLC), thioredoxin (Trx) 1/2 and thioredoxin reductase (TrxR) 1. Furthermore, CGA abrogated AP-induced phospholyated activation of ERK1/2, c-Jun N-terminal kinase (JNK), p38 kinases and molecular signals upstream. The results of this study demonstrate that CGA counteracts AP-induced liver injury at various levels by preventing apoptosis and oxidative stress damage, and more specifically, both the GSH and Trx antioxidant systems and the mitogen-activated protein kinase (MAPK) signaling cascade appear to be engaged in this protective mechanism.

Anti-cancer effects of naturally occurring compounds through modulation of signal transduction and miRNA expression in human colon cancer cells.

Abstract: Much evidence indicates that various naturally occurring compounds have an anti-cancer effect, but the detailed mechanisms are not well understood. In this study, we selected anti-cancer phytochemicals such as epigallocatechin-3-gallate (EGCG), resveratrol (RES) and α-mangostin (α-M), all of which are well-characterized chemopreventive agents. We sought to elucidate the mechanism of their anti-cancer effects and the synergistic effects obtained by combined treatment with the anti-cancer drug 5-fluorouracil (5-FU) in three human colon cancer cell lines. The numbers of viable cells were consistently decreased by the treatment with EGCG, RES or α-M at more than 10 μM in all three cell lines tested. All compounds mainly induced apoptosis and suppressed the PI3K/Akt signaling pathway. Additionally, α-M, which had the greatest PI3K/Akt-suppressing activity, also suppressed MAP kinase (MAPK)/Erk1/2 signaling. Importantly, the combination treatment with RES and 5-FU induced a remarkably synergistic enhancement of growth inhibition and apoptosis through the additional suppression of the MAPK/Erk1/2 signaling pathway in colon cancer DLD-1 cells. Interestingly, RES increased the intracellular expression level of miR-34a, which down-regulated the target gene E2F3 and its downstream Sirt1, resulting in growth inhibition. These findings indicate that these compounds functioned as chemosensitizers when combined with anti-cancer drugs through the modulation of apoptotic and growth-related signaling pathways. Also, RES exerted its anti-cancer activity in part through a newly defined mechanism, i.e., the miR-34a/E2F3/Sirt1 cascade.

Epithelial-mesenchymal transition, a novel target of sulforaphane via COX-2/MMP2, 9/Snail, ZEB1 and miR-200c/ZEB1 pathways in human bladder cancer cells.

Abstract: Metastasis and recurrence of bladder cancer are the main reasons for its poor prognosis and high mortality rates. Because of its biological activity and high metabolic accumulation in urine, sulforaphane, a phytochemical exclusively occurring in cruciferous vegetables, has a powerful and specific potential for preventing bladder cancer. In this paper, sulforaphane is shown to significantly suppress a variety of biochemical pathways including the attachment, invasion, migration and chemotaxis motion in malignant transitional bladder cancer T24 cells. Transfection with cyclooxygenase-2 (COX-2) overexpression plasmid largely abolished inhibition of MMP2/9 expression as well as cell invasive capability by sulforaphane. Moreover, sulforaphane inhibited the epithelial-to-mesenchymal transition (EMT) process which underlies tumor cell invasion and migration mediated by E-cadherin induction through reducing transcriptional repressors, such as ZEB1 and Snail. Under conditions of over-expression of COX-2 and/or MMP2/9, sulforaphane was still able to induce E-cadherin or reduce Snail/ZEB1 expression, suggesting that additional pathways might be involved. Further studies indicated that miR-200c played a role in the regulation of E-cadherin via the ZEB1 repressor but not by the Snail repressor. In conclusion, the EMT and two recognized signaling pathways (COX-2/MMP2,9/ ZEB1, Snail and miR-200c/ZEB1) are all targets for sulforaphane. This study indicated that sulforaphane may possess therapeutic potential in preventing recurrence of human bladder cancer.

Maternal high-fat intake during pregnancy programs metabolic-syndrome-related phenotypes through liver mitochondrial DNA copy number and transcriptional activity of liver PPARGC1A

Abstract: In this study, we contrasted the hypothesis that maternal diet during pregnancy has an impact on fetal metabolic programming through changes in liver mitochondrial DNA (mtDNA) content and transcriptional activity of Ppargc1a and that these effects are sex specific. Methods Rats were fed either high-fat (HFD) or standard chow diet (SCD) during gestation and lactation. The resulting adult male and female offspring were fed either HFD or SCD for an 18-week period, generating eight experimental groups. Results Maternal HFD feeding during pregnancy is associated with a decreased liver mtDNA copy number ( P P Ppargc1a mRNA ( P Ppargc1a was inversely correlated with HOMA-IR ( R =−0.53, P Tfam , Nrf1 , Hnf4a , Pepck and Ppparg mRNA was not associated with maternal programming. In conclusion, maternal high-fat diet feeding during pregnancy programs liver mtDNA content and the transcriptional activity of Ppargc1a , which strongly modulates, in a sex-specific manner, glucose homeostasis and organ fat accumulation in adult life after exposure to a nutritional insult.

Circulating matrix Gla protein is associated with coronary artery calcification and vitamin K status in healthy women

Abstract: Matrix Gla protein (MGP) is a vitamin K-dependent protein and an inhibitor of vascular calcification. Vitamin K is required for the carboxylation of MGP and can thereby reduce calcification. Circulating MGP species with different conformations have been investigated as markers for coronary artery calcification (CAC). In high-risk populations, high total uncarboxylated MGP (t-ucMGP) was associated with decreased CAC, while high non-phosphorylated uncarboxylated MGP (dp-ucMGP) was associated with a poor vitamin K status. This cross-sectional study investigated the association of MGP species with CAC, vitamin K status among 200 healthy women. Circulating dp-ucMGP, t-ucMGP and, non-phosphorylated carboxylated MGP (dp-cMGP) levels were measured by ELISA techniques and Agatston score by multi-detector computed tomography. The ratio of uncarboxylated to carboxylated osteocalcin was used as proxy of vitamin K status. A borderline significant (P=.06) association between higher circulating dp-ucMGP levels and high CAC was observed (β=0.091, 95% CI-0.01; 0.19). In the entire study population, high t-ucMGP levels tended to be associated (P=.09) with lower CAC (β=-0.36, 95% CI:-0.78; 0.06). This association strengthened amongst women with CAC to a significant relation between high t-ucMGP levels and lower CAC (β=-0.55, 95% CI-1.01;-0.10). Dp-cMGP was not associated with CAC. Low vitamin K-status was associated with high dp-ucMGP concentrations (β=0.138, 95% CI 0.09; 0.19) but not with other MGP species. These results show that dp-ucMGP may serve as a biomarker of vitamin K status. Circulating dp-ucMGP and t-ucMGP may serve as markers for the extent of CAC, but these findings need to be confirmed.

Maternal dietary folate and/or vitamin B12 restrictions alter body composition (adiposity) and lipid metabolism in Wistar rat offspring

Abstract: Maternal vitamin deficiencies are associated with low birth weight and increased perinatal morbidity and mortality. We hypothesize that maternal folate and/or vitamin B12 restrictions alter body composition and fat metabolism in the offspring. Female weaning Wistar rats received ad libitum for 12 weeks a control diet (American Institute of Nutrition-76A) or the same with restriction of folate, vitamin B12 or both (dual deficient) and, after confirming vitamin deficiency, were mated with control males. The pregnant/lactating mothers and their offspring received their respective diets throughout. Biochemical and body composition parameters were determined in mothers before mating and in offspring at 3, 6, 9 and 12 months of age. Vitamin restriction increased body weight and fat and altered lipid profile in female Wistar rats, albeit differences were significant with only B12 restriction. Offspring born to vitamin-B12-restricted dams had lower birth weight, while offspring of all vitamin-restricted dams weighed higher at/from weaning. They had higher body fat (specially visceral fat) from 3 months and were dyslipidemic at 12 months, when they had high circulating and adipose tissue levels of tumor necrosis factor α, leptin and interleukin 6 and low levels of adiponectin and interleukin 1β. Vitamin-restricted offspring had higher activities of hepatic fatty acid synthase and acetyl-CoA-carboxylase and higher plasma cortisol levels. In conclusion, maternal and peri-/postnatal folate and/or vitamin B12 restriction increased visceral adiposity (due to increased corticosteroid stress), altered lipid metabolism in rat offspring perhaps by modulating adipocyte function and may thus predispose them to high morbidity later.

Dietary pyrroloquinoline quinone (PQQ) alters indicators of inflammation and mitochondrial-related metabolism in human subjects.

Abstract: Pyrroloquinoline quinone (PQQ) influences energy-related metabolism and neurologic functions in animals. The mechanism of action involves interactions with cell signaling pathways and mitochondrial function. However, little is known about the response to PQQ in humans. Using a crossover study design, 10 subjects (5 females, 5 males) ingested PQQ added to a fruit-flavored drink in two separate studies. In study 1, PQQ was given in a single dose (0.2 mg PQQ/kg). Multiple measurements of plasma and urine PQQ levels and changes in antioxidant potential [based on total peroxyl radical-trapping potential and thiobarbituric acid reactive product (TBAR) assays] were made throughout the period of 48 h. In study 2, PQQ was administered as a daily dose (0.3 mg PQQ/kg). After 76 h, measurements included indices of inflammation [plasma C-reactive protein, interleukin (IL)-6 levels], standard clinical indices (e.g., cholesterol, glucose, high-density lipoprotein, low-density lipoprotein, triglycerides, etc.) and (1)H-nuclear magnetic resonance estimates of urinary metabolites related in part to oxidative metabolism. The standard clinical indices were normal and not altered by PQQ supplementation. However, dietary PQQ exposure (Study 1) resulted in apparent changes in antioxidant potential based on malonaldehyde-related TBAR assessments. In Study 2, PQQ supplementation resulted in significant decreases in the levels of plasma C-reactive protein, IL-6 and urinary methylated amines such as trimethylamine N-oxide, and changes in urinary metabolites consistent with enhanced mitochondria-related functions. The data are among the first to link systemic effects of PQQ in animals to corresponding effects in humans.

Lycopene intervention reduces inflammation and improves HDL functionality in moderately overweight middle-aged individuals.

Abstract: The management of overweight subjects by interventions aimed at reducing inflammation is highly desirable. To date, observational studies have identified a link between increased dietary antioxidant intake and reduced cardiovascular morbidity. However, direct trial evidence regarding the ability of antioxidants to influence inflammation is lacking. Therefore, this study examined lycopene's ability to lower systemic and high-density lipoprotein (HDL)-associated inflammation in moderately overweight middle-aged subjects. Serum was collected before and after a 12-week intervention from 54 moderately overweight, middle-aged individuals. Subjects were randomised to one of three groups: control diet (<10 mg lycopene/week), lycopene-rich diet (224-350 mg lycopene/week) and lycopene supplement (70 mg lycopene/week). HDL was subfractionated into HDL(2&3) by rapid ultracentrifugation. Compliance was monitored by assessing lycopene concentration in serum and HDL(2&3). Systemic and HDL-associated inflammation was assessed by measuring serum amyloid A (SAA) levels. HDL functionality was determined by monitoring the activities of paraoxonase-1 (PON-1), cholesteryl ester transfer protein (CETP) and lecithin cholesterol acyltransferase (LCAT). Lycopene increased in serum and HDL(2&3) following both lycopene interventions (P<.001, for all), while SAA decreased in serum following the lycopene supplement and in HDL(3) following both lycopene interventions (P<.05 for all). PON-1 activity increased in serum and HDL(2&3) in both lycopene groups (P<.05, for all). Furthermore, the activity of CETP decreased in serum following the lycopene supplement, while the activity of LCAT increased in serum and HDL(3) following both lycopene interventions (P<.05 for all). These results demonstrate that in moderately overweight, middle-aged subjects, increasing lycopene intake leads to changes to HDL(2&3), which we suggest enhanced their antiatherogenic properties. Overall, these results show the heart-protective properties of increased lycopene intake.