Showing papers in "Journal of Clinical Biochemistry and Nutrition in 2014"

The role of lipid peroxidation in neurological disorders

Abstract: There has been much evidence demonstrating the involvement of oxidative stress in the pathology of neurological disorders. Moreover, the vulnerability of the central nervous system to reactive oxygen species mediated injury is well established since neurons consume large amounts of oxygen, the brain has many areas containing high iron content, and neuronal mitochondria generate large amounts of hydrogen peroxide. Furthermore, neuronal membranes are rich in polyunsaturated fatty acids, which are particularly susceptible to oxidative stress. Recently, the biological roles of products produced by lipid peroxidation have received much attention, not only for their pathological mechanisms associated with neurological disorders, but also for their practical clinical applications as biomarkers. Here, we discuss the production mechanisms of reactive oxygen species in some neurological disorders, including Alzheimer’s disease, Down syndrome, Parkinson’s disease, and stroke. We also describe lipid peroxidation biomarkers for evaluating oxidative stress.

Scavenging rate constants of hydrophilic antioxidants against multiple reactive oxygen species.

Abstract: Scavenging rate constants of eight hydrophilic antioxidants, including caffeic acid, chlorogenic acid, genistein, glutathione, N-acetylcysteine, rutin, trolox, and uric acid against multiple ROS, namely superoxide anion, hydroxyl radical, singlet oxygen, and alkoxyl radical were determined with the electron spin resonance method. Direct flash photolysis measurement of the second-order rate constant in the reaction of alkoxyl radical plus the spin trap 5,5-dimethyl-pyrroline N-oxide made it possible to evaluate scavenging rate constants in antioxidants. The magnitudes of scavenging rate constants were notably dependent on the character of each ROS and the overall rate constants were highest in hydroxyl radical scavenging and the lowest in superoxide anion. The highest scavenging rate constant against superoxide anion was obtained by chlorogenic acid (2.9 × 10(5) M(-1) s(-1)) and the lowest was by N-acetylcysteine (5.0 × 10(2) M(-1) s(-1)). For singlet oxygen, the highest was by glutathione (9.4 × 10(8) M(-1) s(-1)) and the lowest was by uric acid (2.3 × 10(6) M(-1) s(-1)). All other numbers are listed and illustrated. Redox potential measurements of the antioxidants indicated that the antioxidants are likely to react with superoxide anion and singlet oxygen through electron transfer processes.

Effect of eating vegetables before carbohydrates on glucose excursions in patients with type 2 diabetes

Abstract: The aim of this review was to evaluate whether eating vegetables before carbohydrates could reduce the postprandial glucose, insulin, and improve long-term glycemic control in Japanese patients with type 2 diabetes. We studied the effect of eating vegetables before carbohydrates on postprandial plasma glucose, insulin, and glycemic control for 2.5 y in patients with type 2 diabetes. The postprandial glucose and insulin levels decreased significantly when the patients ate vegetables before carbohydrates compared to the reverse regimen, and the improvement of glycemic control was observed for 2.5 y. We also compared the postprandial glucose and glucose fluctuations assessed by continuous glucose monitoring system for 72-h in patients with type 2 diabetes and subjects with normal glucose tolerance when subjects ate vegetables before carbohydrates and carbohydrates before vegetables in a randomized crossover design. The glycemic excursions and incremental glucose peak were significantly lower when the subjects ate vegetables before carbohydrates compared to the reverse regimen. This evidence supports the effectiveness of eating vegetables before carbohydrates on glucose excursions in the short-term and glycemic control in the long-term in patients with type 2 diabetes.

Lipopolysaccharides accelerate hepatic steatosis in the development of nonalcoholic fatty liver disease in Zucker rats.

Abstract: Nonalcoholic fatty liver disease (NAFLD) can develop into end-stage disease that includes cryptogenic cirrhosis and hepatocellular carcinoma. Bacterial endotoxin, for example lipopolysaccharide (LPS), plays an important role in the pathogenesis of NAFLD. The aim of this study was to assess the role of LPS in the development of NAFLD. Twenty-one male Zucker (fa/fa) rats were divided into three groups: rats fed for twelve weeks on a diet rich in disaccharide (D12 group), rats similarly managed but treated with LPS (LPS group), and those on the same diet for 24 weeks (D24 group). Histological examination demonstrated that this protocol induced hepatic steatosis in the LPS and D24 groups. Significant, marked accumulation of lipid droplets was observed in the LPS group, compared with the D24 group. Rats from the LPS group showed a decrease in plasma adiponectin levels, an increase in plasma leptin levels, and greater expression of FAS and SREBP-1c mRNA in the liver, compared with rats from the D24 group. These finding coincided with histological findings. We therefore suggest that LPS may accelerate the progression of hepatic steatosis.

Oxidized DJ-1 as a possible biomarker of Parkinson's disease.

Abstract: Parkinson's disease is a progressive, age-related, neurodegenerative disorder, and oxidative stress is an important mediator in its pathogenesis. DJ-1 is a causative gene of a familial form of Parkinson's disease, namely PARK7, and plays a significant role in antioxidative defense to protect the cells from oxidative stress. DJ-1 undergoes preferential oxidation at the cysteine residue at position 106, Cys-106, under oxidative stress. The critical role of Cys-106 in the biological function of DJ-1 has been demonstrated, and recent studies indicate that DJ-1 acts as a sensor of oxidative stress by regulating the gene expression of antioxidative defense. Specific antibodies against Cys-106-oxidized DJ-1 have been developed, and the generation of oxidized DJ-1 in cellular and animal models of Parkinson's disease has been investigated. This review focuses on the role of DJ-1 in antioxidative defense and the importance of oxidizable Cys-106 in its function. The significance of the identification of early-phase Parkinson's disease biomarkers and the nature of oxidized DJ-1 as a biomarker for Parkinson's disease are discussed here.

Direct exposure of non-equilibrium atmospheric pressure plasma confers simultaneous oxidative and ultraviolet modifications in biomolecules

Abstract: Thermal plasmas and lasers are used in medicine to cut and ablate tissues and for coagulation. Non-equilibrium atmospheric pressure plasma (NEAPP) is a recently developed, non-thermal technique with possible biomedical applications. Although NEAPP reportedly generates reactive oxygen/nitrogen species, electrons, positive ions, and ultraviolet radiation, little research has been done into the use of this technique for conventional free radical biology. Recently, we developed a NEAPP device with high electron density. Electron spin resonance spin-trapping revealed (•)OH as a major product. To obtain evidence of NEAPP-induced oxidative modifications in biomolecules and standardize them, we evaluated lipid peroxidation and DNA modifications in various in vitro and ex vivo experiments. Conjugated dienes increased after exposure to linoleic and α-linolenic acids. An increase in 2-thiobarbituric acid-reactive substances was also observed after exposure to phosphatidylcholine, liposomes or liver homogenate. Direct exposure to rat liver in saline produced immunohistochemical evidence of 4-hydroxy-2-nonenal- and acrolein-modified proteins. Exposure to plasmid DNA induced dose-dependent single/double strand breaks and increased the amounts of 8-hydroxy-2'-deoxyguanosine and cyclobutane pyrimidine dimers. These results indicate that oxidative biomolecular damage by NEAPP is dose-dependent and thus can be controlled in a site-specific manner. Simultaneous oxidative and UV-specific DNA damage may be useful in cancer treatment.

Brazilian green propolis improves immune function in aged mice

Abstract: Aging weakened innate and adaptive immunity both quantitatively and qualitatively. Some components in propolis could stimulate immune function in young animals or cultured immune cells in vitro. Few studies had been carried out in the aged. The present study was to evaluate the effects of Brazilian green propolis supplementation on the immunological parameters in aged mice. Eighty Kunming mice, aged 15–18 months, were randomly assigned to the control and three experimental groups supplemented with different doses (83.3, 157.4 and 352.9 mg/kg.bw respectively) of Brazilian green propolis. The experiment lasted for 4 weeks. Contents of total polyphenol, flavonoid, cinnamic acid and artepillin-C in Brazilian green propolis were analyzed. Splenic NK cytotoxic, T lymphocyte proliferation and antibody generation cells, as well as the phagocytosis of peritoneal macrophages, ear swelling, and serum contents of IgG, IgM, hemolysin and cytokines were measured. After 4 weeks of treatment, the phagocytosis of peritoneal macrophages was enhanced in 157.4 mg/kg and 352.9 mg/kg groups. Ear swelling increased in all propolis treatmented groups. Antibodies specific to sheep erythrocytes were higher in the groups receiving 157.4 and 352.9 mg/kg.bw than that of control group. IgG level dramatically increased in the groups receiving 83.3 and 157.4 mg/kg.bw in comparison to the control group. These results indicate that administration of Brazilian green propolis have a positive effect on innate and adaptive immunity in aged mice.

Propensity to high-fat diet-induced obesity in mice is associated with the indigenous opportunistic bacteria on the interior of Peyer’s patches

Abstract: Indigenous opportunistic bacteria on the interior of the Peyer's patches play a key role in the development of the mucosal immune, but their population composition has been ignored. The present study was conducted to test the hypothesis that the changes in the composition of indigenous opportunistic bacteria in the Peyer's patches are associated with obesity. C57BL/6J-male mice had been fed either a control diet or a high-fat diet. After 25 weeks, mice in high-fat diet exhibit either an obesity-prone (OP) or an obesity-resistant (OR) phenotype. Control diet group (CT) and OR group had a significant larger bacteria diversity than that in the OP group. Allobaculum and Lactobacillus were significantly decreased in high-fat diet induced OP mice compared with CT and OR mice, whereas Rhizobium and Lactococcus was significantly increased. The result of quantitative real-time PCR was consistent with that of 454 pyrosequencing. Significant correlations between mRNA expression of inflammation marks and the top 5 abundance genera bacteria on the interior of Peyer's patches were observed by Pearson's correlation analysis. Taken together, the indigenous opportunistic bacteria on the interior of Peyer's patches plays a major role in the development of inflammation for an occurrence of obesity.

The impact of non-steroidal anti-inflammatory drugs on the small intestinal epithelium.

Abstract: The small intestine has been called as a dark continent of digestive tract and it had been very difficult to diagnose or treat the disease of small intestine. However recent technological development including video capsule endoscopy or balloon-assisted endoscopy has made us to aware the various diseases of small intestine. By using capsule endoscopy, many researchers reported that more than 70% of patients treated continuously with non-steroidal anti-inflammatory drugs (NSAID) exhibit the mucosal damage of small intestine. In some cases, NSAID not only causes mucosal damage but also results in life threatening bleeding from small intestine, which had not been prevented or cured by gastro-protective drug or anti-gastric acid secretion drug administration. Therefore to investigate and identify the effective drug that protects small intestine from mucosal damage is urgently expected. In spite of extensive investigation in clinical field, only a few drugs such as misoprostol, a synthetic prostaglandin E1 analogue, has been reported as an effective one but is not satisfactory enough to fulfill the requirement of patients who suffer from NSAID-induced mucosal damage of small intestine. And now, extensive study is being performed using several gastro-mucoprotective drugs by many researchers. In this review, we introduce the current clinical situation in small intestinal injury of patients under NSAID treatment, and to summarize the molecular mechanism by which NSAID, including acetyl salicylic acid, cause small intestinal damage. In addition, we present results of clinical trials performed so far, and refer the possible preventive method or treatment in the near future.

The astaxanthin-induced improvement in lipid metabolism during exercise is mediated by a PGC-1α increase in skeletal muscle.

Abstract: Astaxanthin, a xanthophyll carotenoid, accelerates lipid utilization during aerobic exercise, although the underlying mechanism is unclear. The present study investigated the effect of astaxanthin intake on lipid metabolism associated with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) in mice. Mice were divided into 4 groups: sedentary, sedentary and astaxanthin-treated, exercised, and exercised and astaxanthin-treated. After 2 weeks of treatment, the exercise groups performed treadmill running at 25 m/min for 30 min. Immediately after running, intermuscular pH was measured in hind limb muscles, and blood was collected for measurements. Proteins were extracted from the muscle samples and PGC-1α and its downstream proteins were measured by western blotting. Levels of plasma fatty acids were significantly decreased after exercise in the astaxanthin-fed mice compared with those fed a normal diet. Intermuscular pH was significantly decreased by exercise, and this decrease was inhibited by intake of astaxanthin. Levels of PGC-1α and its downstream proteins were significantly elevated in astaxanthin-fed mice compared with mice fed a normal diet. Astaxanthin intake resulted in a PGC-1α elevation in skeletal muscle, which can lead to acceleration of lipid utilization through activation of mitochondrial aerobic metabolism.

Detection of AGEs as markers for carbohydrate metabolism and protein denaturation

Abstract: Approximately 100 years have passed since the Maillard reaction was first reported in the field of food chemistry as a condensation reaction between reducing sugars and amino acids. This reaction is thought to progress slowly primarily from glucose with proteins in vivo. An early-stage product, called the ”Amadori product”, is converted into advanced glycation end products. Those accumulate in the body in accordance with age, with such accumulation being enhanced by lifestyle-related diseases that result in the denaturation of proteins. Recent studies have demonstrated that intermediate carbonyls are generated by several pathways, and rapidly generate many glycation products. However, accurate quantification of glycation products in vivo is difficult due to instability and differences in physicochemical properties. In this connection, little is known about the relationship between the structure of glycation products and pathology. Furthermore, the interaction between proteins modified by glycation and receptors for advanced glycation end products is also known to induce the production of several inflammatory cytokines. Therefore, those inhibitors have been developed over the world to prevent lifestyle-related diseases. In this review, we describe the process of protein denaturation induced by glycation and discuss the possibility of using the process as a marker of age-related diseases.

The involvement of endoplasmic reticulum stress in bile acid-induced hepatocellular injury.

Abstract: Secondary bile acids produced by enteric bacteria accumulate to high levels in the enterohepatic circulation and may contribute to the pathogenesis of hepatocellular injury. Relative hydrophobicity has been suggested to be an important determinant of the biological properties of these compounds, although the mechanism by which bile acids induce pathogenesis is not fully understood. On the other hand, endoplasmic reticulum stress has been shown to be involved in the induction and development of various pathogenic conditions. In this report, we demonstrated that the intensities of cytotoxicity and endoplasmic reticulum stress in HepG2 cells triggered by the bile acids tested were largely dependent on their hydrophobicity. The activation of caspase-3 and DNA fragmentation by treatment with chenodeoxycholic acid showed the contribution of apoptosis to cytotoxicity. Increases in intracellular calcium levels and the generation of reactive oxygen species stimulated by treatment with chenodeoxycholic acid contributed to endoplasmic reticulum stress. Bile acids also induced transforming growth factor-β, a potent profibrogenic factor, which is known to induce hepatocyte apoptosis and ultimately liver fibrosis. In conclusion, our study demonstrated that bile acids induced endoplasmic reticulum stress, which in turn stimulated apoptosis in HepG2 cells, in a hydrophobicity-dependent manner.

Bactericidal effect of hydroxyl radicals generated from a low concentration hydrogen peroxide with ultrasound in endodontic treatment

Abstract: One approach to enhance the disinfection of root canals in end� odontic treatment is ultrasonic irrigation with sodium hypochlo� rite. Reactive oxygen species, such as hydroxyl radical, are generated by biological defense systems to kill invading bacteria. Ultrasonic irrigation with hydrogen peroxide may be a promising option to increase hydroxyl radical generation. We examined the bactericidal effects of hydroxyl radical generated from low con� centration hydrogen peroxide with ultrasound in vitro. An ultra� sonic tip was submerged in 0.5 or 1.0 M hydrogen peroxide in a microfuge tube. hydrogen peroxide was irradiated with the ultra� sound, the tip of which was maintained centered in the tube to mimic ultrasonic irrigation. Hydroxyl radical generation was assessed by electron spin resonance spectroscopy. Subsequently, Enterococcus faecalis suspension in hydrogen peroxide was pre� pared and irradiated as described above. Bactericidal effects were assessed by viable counting. Electron spin resonance measure� ments showed that hydroxyl radical generation increased signifi�

Consumption of strawberries on a daily basis increases the non-urate 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity of fasting plasma in healthy subjects.

Abstract: Strawberries contain anthocyanins and ellagitanins which have antioxidant properties. We determined whether the consumption of strawberries increase the plasma antioxidant activity measured as the ability to decompose 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) in healthy subjects. The study involved 10 volunteers (age 41 ± 6 years, body weight 74.4 ± 12.7 kg) that consumed 500 g of strawberries daily for 9 days and 7 matched controls. Fasting plasma and spot morning urine samples were collected at baseline, during fruit consumption and after a 6 day wash-out period. DPPH decomposition was measured in both deproteinized native plasma specimens and pretreated with uricase (non-urate plasma). Twelve phenolics were determined with HPLC. Strawberries had no effect on the antioxidant activity of native plasma and circulating phenolics. Non-urate plasma DPPH decomposition increased from 5.7 ± 0.6% to 6.6 ± 0.6%, 6.5 ± 1.0% and 6.3 ± 1.4% after 3, 6 and 9 days of supplementation, respectively. The wash-out period reversed this activity back to 5.7 ± 0.8% (p<0.01). Control subjects did not reveal any changes of plasma antioxidant activity. Significant increase in urinary urolithin A and 4-hydroxyhippuric (by 8.7- and 5.9-times after 6 days of supplementation with fruits) was noted. Strawberry consumption can increase the non-urate plasma antioxidant activity which, in turn, may decrease the risk of systemic oxidants overactivity.

Different sucrose-isomaltase response of Caco-2 cells to glucose and maltose suggests dietary maltose sensing

Abstract: Using the small intestine enterocyte Caco-2 cell model, sucrase-isomaltase (SI, the mucosal α-glucosidase complex) expression and modification were examined relative to exposure to different mono- and disaccharide glycemic carbohydrates. Caco-2/TC7 cells were grown on porous supports to post-confluence for complete differentiation, and dietary carbohydrate molecules of glucose, sucrose (disaccharide of glucose and fructose), maltose (disaccharide of two glucoses α-1,4 linked), and isomaltose (disaccharide of two glucoses α-1,6 linked) were used to treat the cells. qRT-PCR results showed that all the carbohydrate molecules induced the expression of the SI gene, though maltose (and isomaltose) showed an incremental increase in mRNA levels over time that glucose did not. Western blot analysis of the SI protein revealed that only maltose treatment induced a higher molecular weight band (Mw ~245 kDa), also at higher expression level, suggesting post-translational processing of SI, and more importantly a sensing of maltose. Further work is warranted regarding this putative sensing response as a potential control point for starch digestion and glucose generation in the small intestine.

Mitochondrial reactive oxygen species accelerate gastric cancer cell invasion

Abstract: Tumor invasion is the most important factor to decide patient's prognosis. The relation between reactive oxygen species and tumor invasion is mainly reported that nicotinamide adenine dinucleotide phosphate oxidase in the cell membrane is a reactive oxygen species producer for formulating an invadopodia. On the other hand, mitochondrion was known as one of the most important reactive oxygen species-producer in the cell via an energy transfer system. However, the relation between mitochondrial reactive oxygen species and the tumor invasion was not well clarified. In this study, we evaluated the relation between mitochondrial reactive oxygen species and tumor invasion using a normal gastric mucosal cell-line (RGM-1) and a cancerous mutant RGM-1 cell-line (RGK-1). Manganese superoxide dismutase-expressing RGK-1 cell-lines were used for a scavenging mitochondrial reactive oxygen species. The cells have been evaluated their movement ability as follows; cellular ruffling frequencies, wound healing assay to evaluate horizontal cellular migration, and invasion assay using matrigel to analyze vertical cellular migration. All cellular movement abilities were inhibited by scavenging mitochondrial reactive oxygen species with manganese superoxide dismutase. Therefore mitochondrial reactive oxygen species was one of factors enhancing the tumor invasion in gastric cancer.

Sesamol suppresses cyclooxygenase-2 transcriptional activity in colon cancer cells and modifies intestinal polyp development in ApcMin/+ mice

Abstract: Excessive prostaglandin production by cyclooxygenase-2 in stromal and epithelial cells is a causative factor of colorectal carcinogenesis. Thus, compounds which inhibit cyclooxygenase-2 transcriptional activity in colon epithelial cells could be candidates for anti-carcinogenic agents. A cyclooxygenase-2 transcriptional activity in the human colon cancer cell line DLD-1 has been measured using a β-galactosidase reporter gene system. Using this system, we demonstrated that the decrease in basal cyclooxygenase-2 transcriptional activities at 100 µM sesamol, one of the lignans in sesame seeds, was 50%. Other compounds in sesame seeds such as sesamin, sesamolin, ferulic acid, and syringic acid did not exhibit significant suppression of cyclooxygenase-2 transcriptional activity at up to 100 µM. In a following experiment, 6-week-old male Min mice, Apc-deficient mice, were divided into a non-treated and 500 ppm sesamol groups. At the age of 15 weeks, it was found that treatment with sesamol decreased the number of polyps in the middle part of small intestine to 66.1% of the untreated value. Moreover, sesamol suppressed cyclooxygenase-2 and cytosolic prostaglandin E2 synthase mRNA in the polyp parts. The present findings may demonstrate the novel anti-carcinogenetic property of sesamol, and imply that agents that can suppress cyclooxygenase-2 expression may be useful cancer chemopreventive agents.

β-Glucuronidase activity and mitochondrial dysfunction: the sites where flavonoid glucuronides act as anti-inflammatory agents.

Abstract: Epidemiological and experimental studies suggest that the consumption of flavonoid-rich diets decreases the risk of various chronic diseases such as cardiovascular diseases. Although studies on the bioavailability of flavonoids have been well-characterized, the tissue and cellular localizations underlying their biological mechanisms are largely unknown. The development and application of novel monoclonal antibodies revealed that macrophages could be the major target of dietary flavonoids in vivo. Using macrophage-like cell lines in vitro, we examined the molecular basis of the interaction between the macrophages and flavonoids, especially the glucuronide metabolites. We have found that extracellular β-glucuronidase secreted from macrophages is essential for the bioactivation of the glucuronide conjugates into the aglycone, and that the enzymatic activity, which requires an acidic pH, is promoted by the increased secretion of lactate in response to the mitochondrial dysfunction. This review describes our recent findings indicating the molecular mechanisms responsible for the anti-inflammatory activity of dietary flavonoids within the inflammation sites. We propose that the extracellular activity of β-glucuronidase associated with the status of the mitochondrial function in the target cells might be important biomarkers for the specific sites where the glucuronides of dietary flavonoids can act as anti-atherosclerotic and anti-inflammatory agents in vivo.

Estimate of dietary phosphorus intake using 24-h urine collection.

Abstract: Increases in serum phosphorus levels and dietary phosphorus intake induces vascular calcification, arterial sclerosis and cardiovascular diseases. Limiting phosphorus intake is advisable, however, no assessment methods are capable of estimating dietary phosphorus intake. We hypothesized that urinary phosphorus excretion can be translated into estimation of dietary phosphorus intake, and we evaluated whether a 24-h urine collection method could estimate dietary phosphorus intake. Thirty two healthy subjects were recruited for this study. Subjects collected urine samples over 24 h and weighed dietary records. We calculated dietary protein intake and phosphorus intake from dietary records and urine collection, and investigated associations between the two methods in estimating protein and phosphorus intake. Significant positive correlations were observed between dietary records and UC for protein and phosphorus intake. The average intakes determined from dietary records were significantly higher than from urine collection for both protein and phosphorus. There was a significant positive correlation between both the phosphorus and protein difference in dietary records and urine collection. The phosphorus-protein ratio in urine collection was significantly higher than in dietary records. Our data indicated that the 24-h urine collection method can estimate the amount of dietary phosphorus intake, and the results were superior to estimation by weighed dietary record.

Serum zinc value in patients with hepatitis virus-related chronic liver disease: association with the histological degree of liver fibrosis and with the severity of varices in compensated cirrhosis

Abstract: The relationships between the serum mineral concentrations and the endoscopic findings of esophageal varices have been poorly investigated. In this study, we investigated hepatitis virus-positive patients who had undergone a liver biopsy (n = 576) and 75 patients with compensated cirrhosis in order to evaluate the association of the zinc value with the severity of liver fibrosis and esophageal varices. The mean zinc values decreased with the progression of fibrosis (METAVIR score; F0-1: 71.3 ± 11.3, F2: 68.9 ± 11.7, F3: 66.3 ± 11.8, F4: 63.9 ± 15.0). In the hepatitis virus-related compensated cirrhosis, the mean zinc value decreased with the severity of varices (patients without varices: 66.3 ± 12.6, patients with low-risk varices: 62.5 ± 13.7, patients with high-risk varices: 55.6 ± 13.0). The zinc value was significantly lower in patients with varices than in those without varices (59.3 ± 13.6 vs 66.3 ± 12.6, p<0.05). The zinc value was also significantly lower in the patients with a high risk of bleeding than in those with a low risk (55.6 ± 13.0 vs 64.6 ± 13.1, p<0.01). These findings suggest that the zinc value is not only an indicator of an abnormal metal metabolism, but is also a simple parameter associated with hepatitis virus-related various conditions, including the degree of liver fibrosis and the severity of esophageal varices in compensated cirrhosis.

Role of Nrf2 in the alteration of cholesterol and bile acid metabolism-related gene expression by dietary cholesterol in high fat-fed mice.

Abstract: Nuclear factor-E2-related factor 2 (Nrf2) is a regulator of lipid metabolism as well as various cytoprotective enzymes and may be involved in the pathogenesis of non-alcoholic fatty liver disease. Although, bile acids affect lipid metabolism, the role of Nrf2 in bile acid metabolism remains unclear. In this study, it was tested how Nrf2 modulates lipid and bile acid homeostasis in liver in response to changes of cholesterol absorption under high-fat diet using Nrf2-null mice. Eight-week-old male wild-type and Nrf2-null mice (n = 6/group) were divided into three groups fed the following diets: 1) control diet containing 4% soybean oil and 16% lard, 2) control diet plus ezetimibe, 3) control diet plus cholesterol. Blood and livers were removed after 4 weeks feeding. High cholesterol diet increased hepatic expression of liver X receptor α target genes related to fatty acid metabolism (FAS, ACC1, SREBP-1c, SCD-1c and CD36), cholesterol transport (Abcg5/abcg8) and bile acid synthesis (Cyp7a1) in wild type mice. However, these genes were not induced in Nrf2-null mice. These findings suggest that Nrf2 has a relation to liver X receptor α and controls the regulation of gene expressions related to lipid and bile acid metabolism.

Maternal protein restriction induces alterations in hepatic tumor necrosis factor-α/CYP7A1 signaling and disorders regulation of cholesterol metabolism in the adult rat offspring

Abstract: It is well recognized that adverse events in utero impair fetal development and lead to the development of obesity and metabolic syndrome in adulthood. To investigate the mechanisms linking impaired fetal growth to increased cholesterol, an important clinical risk factor characterizing the metabolic syndrome and cardiovascular disease, we examined the impact of maternal undernutrition on tumor necrosis factor-α (TNF-α)/c-jun N-terminal kinase (JNK) signaling pathway and the cholesterol 7α-hydroxylase (CYP7A1) expression in the livers of the offspring with a protein restriction model. The male offspring with intrauterine growth restriction (IUGR) caused by the isocaloric low-protein diet showed decreased liver weight at birth and augmented circulation and hepatic cholesterol levels at 40 weeks of age. Maternal undernutrition significantly upregulated cytokine TNF-α expression and JNK phospholytion levels in the livers from fetal age to adulthood. Elevated JNK phospholytion could be linked to downregulated hepatocyte nuclear factor-4α and CYP7A1 expression, subsequently led to higher hepatic cholesterol. This work demonstrated that intrauterine malnutrition-induced IUGR might result in intrinsic disorder in hepatic TNF-α/CYP7A1 signaling, and contribute to the development of hypercholesterolemia in later life.

Coffee consumption is inversely associated with depressive status in Japanese patients with type 2 diabetes

Abstract: Depression has been reported to be more prevalent among diabetic patients than non-diabetic individuals. Although depression and diabetes are causally and bi-directionally related, the influence of food intake frequency on depressive symptoms in diabetic patients has not been fully evaluated. This cross-sectional study analyzed data obtained from 89 patients with type 2 diabetes who completed self-administered questionnaires regarding food intake frequency, diabetic variables, physical activity and depressive states. The prevalence of a "definite" depressive state was 16.9%. The duration of diabetes, hemoglobin A1c levels, diabetic microvascular complications and physical activity levels were similar between depressed and non-depressed patients. Daily intakes of total lipids, n-6 polyunsaturated fatty acids and lipid energy ratios were significantly lower, and the carbohydrate energy ratio was significantly higher in depressed than in non-depressed patients. Coffee consumption was inversely associated with depressive symptoms, but no significant association was found between tea or green tea consumption and depressive symptoms. The logistic regression analysis showed that coffee consumption was an independent predictor of non-depressed status in diabetic patients. This might be due to biologically active compounds containing in coffee other than caffeine.

The behavior of ROS-scavenging nanoparticles in blood.

Abstract: Here, we report an interaction between blood and redox nanoparticles, prepared by self-assembly of amphiphilic block copolymers possessing 2,2,6,6-tetramethylpiperidine-N-oxyls as a side chain of hydrophobic segment. When 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl was added to rat whole blood, its electron spin resonance signal disappeared rapidly. In contrast, the signal from redox nanoparticles remained for a long period of time, indicating that nitroxide radicals were protected in the blood by their compartmentalization in the core of nanoparticle. Although most 2,2,6,6-tetramethylpiperidine-N-oxyls were located in the nanoparticle core, reactive oxygen species-scavenging activity was found outside of blood cells. For example, redox nanoparticles suppressed superoxide anion-induced hemolysis effectively, while 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl did not. It was revealed that redox nanoparticles were not internalized into the healthy blood cells, which was in sharp contrast to 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl. Due to its internalization into healthy platelets, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl induced mitochondrial dysfunction, while redox nanoparticles did not. Redox nanoparticles suppressed platelet adhesion and extended blood coagulation time, in contrast to 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl. These results indicate that redox nanoparticles scavenge reactive oxygen species outside of cells, but do not interfere with normal redox reactions inside of the cell. Based on these results, we determine that an anti-oxidative strategy based on nanotechnology is a rational and safe therapeutic approach.

Acetaldehyde is an oxidative stressor for gastric epithelial cells.

Abstract: Alcohol drinking and smoking contain the risk of a carcinogenesis. Acetaldehyde is content in cigarette smoke and an ethanol metabolite. However the clear evidence for reactive oxygen species (ROS) generation by acetaldehyde in gastric cells in vitro is none. In this study, we elucidated acetaldehyde is an oxidative stress inducer on rat gastric epithelial cells by electron paramagnetic resonance measurement in living cells. We also confirmed whether acetaldehyde-induced cellular ROS was derived from mitochondria or not. The results of cellular ROS determination showed that an increment of cellular ROS was shown for 15 min in living cells from exposing 0.1% (v/v) acetaldehyde. Lipid peroxidation in cellular membrane also induced by 0.1% ethanol and the tendency is same in the results of cellular ROS determination. JC-1 stained showed the decrement of mitochondrial membrane potential. These results indicated that acetaldehyde is not merely a necrotizing factor for gastric epithelial cells, but also an oxidative stress inducer via injured mitochondria.

The effects of Lactobacillus pentosus strain b240 and appropriate physical training on salivary secretory IgA levels in elderly adults with low physical fitness: a randomized, double-blind, placebo-controlled trial

Abstract: The purpose of the study was to evaluate the effects of Lactobacillus pentosus strain b240 (b240) intake and appropriate physical training on salivary secretory immunoglobulin A secretion in elderly adults with low physical fitness. Elderly adults with low physical fitness (daily step count below 3,500 steps) were divided into 2 groups: a b240 intake + exercise group (b240 group) and a placebo intake + exercise group (placebo group). Each subject continued intake of b240 or placebo and moderate-intensity resistance exercise for 12 weeks. Before and 4, 8, and 12 weeks after the start of intervention, each subject underwent saliva sampling. Before and after intervention, physical fitness tests and step count were measured. Our results showed that secretory immunoglobulin A secretion in 57 subjects during the b240/placebo intake period was significantly greater in the b240 group than in the placebo group (p<0.05). There were no significant changes in physical fitness tests before and after intervention in the 2 groups. The daily amount of walking increased significantly after intervention in both groups (p<0.05). These results suggest that in elderly adults with low physical activity and fitness, intake of b240 with appropriate physical exercise elevate salivary secretory immunoglobulin A secretion.

Cooperative effects of soy isoflavones and carotenoids on osteoclast formation

Abstract: Osteoclasts play a major role in bone resorption. Several functional food components, such as soy isoflavones and carotenoids, are reported to inhibit osteoclast formation. However, the cooperative effect of functional foods or their constituents on bone metabolism has not been clarified. This study aimed to investigate the cooperative effect of soy isoflavones and carotenoids on osteoclast formation in vitro using cultures of RAW264 and bone marrow cells in the presence of receptor activator of nuclear factor κ-B ligand. In RAW264 cells, treatment with soy isoflavones (genistein or equol) or carotenoids (β-carotene) suppressed osteoclast formation. At 10 µM, genistein and equol inhibited RAW264 cell proliferation but did not affect cell viability. When 10 µM genistein or equol was combined with 0.1 µM β-carotene, we observed an additive suppressive effect on osteoclast differentiation. Similar results were observed with bone marrow cell cultures. We found that 10 µM of zeaxanthin or lutein suppressed osteoclast formation singly, and further enhanced the suppressive effects of daidzein or genistein when administered in combination. These results suggest that the combination of soy isoflavones and carotenoids have an enhanced suppressive effect on osteoclast formation. This knowledge might be important in planning diet for bone health.

Identification of novel omega-3 fatty acid-derived bioactive metabolites based on a targeted lipidomics approach.

Abstract: Omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid have beneficial effects in many inflammatory disorders. Although the mechanism of eicosapentaenoic acid and docosahexaenoic acid action is still not fully defined in molecular terms, recent studies have revealed that, during the course of acute inflammation, omega-3 polyunsaturated fatty acid-derived anti-inflammatory mediators including resolvins and protectins are produced. This review presents recent advances in understanding the formation and action of these mediators, especially focusing on the LC-MS/MS-based lipidomics approach and recently identified bioactive products with potent anti-inflammatory property.

Structural specificity of electric potentials in the coulometric-array analysis of catechins and theaflavins.

Abstract: We have established a novel method to evaluate the redox properties of tea polyphenols by HPLC-coulometric-array analysis. We plotted the quantity of electricity (µC) on the vertical axis and the electric potential (mV), adjusted with the associated palladium reference electrode, on the horizontal axis to provide "quantity versus potential (QP) plot". The patterns of the plots correspond to the derivative of a hydrodynamic voltammogram or a current-voltage curve, with the electric potentials of the peaks in the QP plot corresponding to the half-wave potentials in the current-voltage curve. We confirmed that catechins and theaflavins are oxidized depending on the electric potentials of their partial structures, and found that all compounds showing a peak at 0 mV in the QP plots produce hydrogen peroxide (H2O2) during the autoxidation process.

α-Lipoic acid suppresses migration and invasion via downregulation of cell surface β1-integrin expression in bladder cancer cells.

Abstract: Our previous study showed α-lipoic acid (LA) downregulated cell surface β1-integrin expression of v-H-ras-transformed derivative of rat fibroblast with amelioration of their malignant phenotype. Here, we evaluated the ameliorating effect of LA on the malignant characters in H-ras-transformed bladder cancer cells. H-ras mutated bladder cancer line, T24 cells were incubated with LA to evaluate the inhibitory effect on proliferation, migration, invasion and β1-integrin expression. Fluorescence staining of F-actin and western blotting analyses of the related signaling pathways were also performed. LA inhibited the proliferation of T24 cells. Cell adhesion to collagen IV and fibronectin was strikingly inhibited by LA treatment accompanied by downregulation of cell surface but not whole cell β1-integrin expression. LA clearly inhibited cell migration and invasion of T24 cells, which were mimicked by extracellular signal-regulated kinase (ERK) and Akt pathway inhibition. Actually, LA significantly downregulated the phosphorylated ERK and Akt levels. Moreover, LA downregulated phosphorylated focal adhesion kinase level with disappearance of stress fiber formation. Finally, although LA induced the internalization of cell surface β1-integrin, disruption of the raft did not affect the action of LA. Taken together, LA is a promising agent to improve malignant character of bladder cancer cells through regulation of cellular β1-integrin localization.