Exogenously-Sourced Ethylene Positively Modulates Photosynthesis, Carbohydrate Metabolism, and Antioxidant Defense to Enhance Heat Tolerance in Rice.

The effect of exogenously-applied ethylene sourced from ethephon (2-chloroethyl phosphonic acid)was studied on photosynthesis, carbohydrate metabolism, and high-temperature stress tolerance in Taipei-309 and Rasi cultivars of rice (Oryza sativa L.). Heat stress increased the content of H2O2 and thiobarbituric acid reactive substances (TBARS)more in Rasi than Taipei-309. Further, a significant decline in sucrose, starch, and carbohydrate metabolism enzyme activity and photosynthesis was also observed in response to heat stress. The application of ethephon reduced H2O2 and TBARS content by enhancing the enzymatic antioxidant defense system and improved carbohydrate metabolism, photosynthesis, and growth more conspicuously in Taipei-309 under heat stress. The ethephon application enhanced photosynthesis by up-regulating the psbA and psbB genes of photosystem II in heat-stressed plants. Interestingly, foliar application of ethephoneffectively down-regulated high-temperature-stress-induced elevated ethylene biosynthesis gene expression. Overall, ethephon application optimized ethylene levels under high-temperature stress to regulate the antioxidant enzymatic system and carbohydrate metabolism, reducing the adverse effects on photosynthesis. These findings suggest that ethylene regulates photosynthesis via carbohydrate metabolism and the antioxidant system, thereby influencing high-temperature stress tolerance in rice.

Impact of the antioxidant quercetin on morphological integrity and follicular development in the in vitro culture of Bos indicus female ovarian fragments.

We evaluated the effect of quercetin on the in vitro culture of bovine ovarian fragments in relation to morphology, development, and oxidative stress. Ovaries (n = 12) from Nelore heifers (n = 6) were used. Each pair of ovaries was divided into nine fragments, and one fragment from each animal was fixed in Bouin solution for 24 h (histology control) or frozen (- 80°C; control for oxidative stress). Other ovarian fragments (n = 8) were distributed into concentrations of 0, 10, 25, and 50 µg/mL of quercetin added to the culture medium for 5 or 10 d. Data were analyzed by chi-square test or ANOVA followed by Tukey's test (P < 0.05). Treatment with 25 µg/mL quercetin resulted in the highest proportion of total intact follicles for 5 (67.3%) and 10 d (57.1%); the concentration of 25 µg/mL also presented the best proportion of developing follicles for 5 d (68.7%) and 10 d (62.8%). Treatment with 25 µg/mL quercetin resulted in significant ferric reduction for 10 d of culture, but not for 5 d. No difference (P > 0.1) was observed in the production of reactive oxygen species or in the oxidative degradation of lipids between treatments and non-cultivated controls. Treatment with 25 µg/mL quercetin preserved the morphological integrity of the developing follicles for 5 and 10 d of culture, in addition to promoting the best antioxidant potential after 10 d of culture in bovine ovarian fragments.

Day and blue light modify growth, cell physiology and indole-3-acetic acid production of Azospirillum brasilense Az39 under planktonic growth conditions.

AIM: In this work, we evaluated the effects of light on growth, cell physiology and stress response of Azospirillum brasilense Az39, a non-photosynthetic rhizobacteria, under planktonic growth conditions. METHODS AND RESULTS: Exponential cultures of Az39 were exposed to blue (BL), red (RL) and daylight (DL) or maintained in darkness for 24, 48 and 72 h. The biomass production and indole 3-acetic acid (IAA) biosynthesis increased by exposition to DL. Conversely, BL decreased IAA concentration through a direct effect on the molecule. The DL increased superoxide dismutase activity, hydrogen peroxide and thiobarbituric acid reactive substances levels, but the last one was also increased by BL. Both DL and BL increased cell aggregation but only BL increased biofilm formation. CONCLUSIONS: We demonstrated that both BL and DL are stress effectors for A. brasilense Az39 under planktonic growth conditions. The DL increased biomass production, IAA biosynthesis and bacterial response to stress, whereas BL induced cell aggregation and biofilms formation, but decreased the IAA concentration by photooxidation. SIGNIFICANCE AND IMPACT OF THE STUDY: Blue light and DL changes growth capacity, cell physiology and plant growth promotion ability of A. brasilense Az39 and these changes could be considered to improve the production and functionality of biofertilizers.

Levels of the oxidative stress biomarker malondialdehyde in tears of patients with central serous chorioretinopathy relate to disease activity.

Purpose: Central serous chorioretinopathy (CSCR) has been associated with oxidative stress-related risk factors. The objective of this study was to optimize an analytical method for evaluating the oxidative stress biomarker malondialdehyde (MDA) in human tears and determine its level in the tears of patients with CSCR. Methods: In this pilot study, tear samples were obtained from 34 healthy donors and 31 treatment-naïve CSCR male patients (eight with acute CSCR and 23 with chronic CSCR). Two analytical methods based on high-performance liquid chromatography followed by fluorescence detection were evaluated, with either 2-thiobarbituric derivative (TBA) or 2-aminoacridone (2-AA). Activity of CSCR was defined by the serous retinal detachment (SRD) height, which was measured by two independent observers on spectral-domain optical coherence tomography. Results: The 2-AA method showed higher sensitivity and precision compared to the TBA method. When the 2-AA method was applied to tears from healthy donors, the levels of MDA were statistically significantly higher in men compared to women (mean ± standard deviation, SD: 9,914 nM ± 6,126 versus 4,635 nM ± 1,173, p = 0.006). No difference was found in tear MDA levels between male patients with CSCR and age-matched control men (p = 0.17). However, MDA levels were statistically significantly higher in acute compared to chronic CSCR cases (mean ± SD: 12,295 nM ± 8,495 versus 6,790 ± 3,969 nM, p = 0.03). Additionally, there was a correlation between MDA levels and RPE leakage, quantified by the height of the serous retinal detachment (p = 0.02, r = 0.40). Conclusions: Levels of MDA in tears, measured with an optimized analytical method, correlate with RPE leakage in CSCR.

Novel thiobarbiturates as potent urease inhibitors with potential antibacterial activity: Design, synthesis, radiolabeling and biodistribution study.

Urease enzyme is a virulence factor that helps in colonization and maintenance of highly pathogenic bacteria in human. Hence, the inhibition of urease enzymes is well-established to be a promising approach for preventing deleterious effects of ureolytic bacterial infections. In this work, novel thiobarbiturate derivatives were synthesized and evaluated for their urease inhibitory activity. All tested compounds effectively inhibited the activity of urease enzyme. Compounds 1, 2a, 2b, 4 and 9 displayed remarkable anti-urease activity (IC50 = 8.21-16.95 µM) superior to that of thiourea reference standard (IC50 = 20.04 µM). Moreover, compounds 3a, 3g, 5 and 8 were equipotent to thiourea. Among the tested compounds, morpholine derivative 4 (IC50 = 8.21 µM) was the most potent one, showing 2.5 folds the activity of thiourea. In addition, the antibacterial activity of the synthesized compounds was estimated against both standard strains and clinical isolates of urease producing bacteria. Compound 4 explored the highest potency exceeding that of cephalexin reference drug. Moreover, biodistribution study using radiolabeling approach revealed a remarked uptake of 99mTc-compound 4 into infection induced in mice. Furthermore, a molecular docking analysis revealed proper orientation of title compounds into the urease active site rationalizing their potent anti-urease activity.

Poaceae Type II Galactinol Synthase 2 from Antarctic Flowering Plant Deschampsia antarctica and Rice Improves Cold and Drought Tolerance by Accumulation of Raffinose Family Oligosaccharides in Transgenic Rice Plants.

Deschampsia antarctica is a Poaceae grass that has adapted to and colonized Antarctica. When D. antarctica plants were subjected to cold and dehydration stress both in the Antarctic field and in laboratory experiments, galactinol, a precursor of raffinose family oligosaccharides (RFOs) and raffinose were highly accumulated, which was accompanied by upregulation of galactinol synthase (GolS). The Poaceae monocots have a small family of GolS genes, which are divided into two distinct groups called types I and II. Type II GolSs are highly expanded in cold-adapted monocot plants. Transgenic rice plants, in which type II D. antarctica GolS2 (DaGolS2) and rice GolS2 (OsGolS2) were constitutively expressed, were markedly tolerant to cold and drought stress as compared to the wild-type rice plants. The RFO contents and GolS enzyme activities were higher in the DaGolS2- and OsGolS2-overexpressing progeny than in the wild-type plants under both normal and stress conditions. DaGolS2 and OsGolS2 overexpressors contained reduced levels of reactive oxygen species (ROS) relative to the wild-type plants after cold and drought treatments. Overall, these results suggest that Poaceae type II GolS2s play a conserved role in D. antarctica and rice in response to drought and cold stress by inducing the accumulation of RFO and decreasing ROS levels.

Docking- and pharmacophore-based virtual screening for the identification of novel Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) inhibitor with a thiobarbiturate scaffold.

Mycobacterium tuberculosis (Mtb) protein tyrosine phosphatase B (MptpB) is an important virulence factor for Mtb that contributes to survival of the bacteria in macrophages. The absence of a human ortholog makes MptpB an attractive target for new therapeutics to treat tuberculosis. MptpB inhibitors could be an effective treatment to overcome emerging TB drug resistance. Adopting a structure-based virtual screening strategy, we successfully identified thiobarbiturate-based drug-like MptpB inhibitor 15 with an IC50 of 22.4 µM, and as a non-competitive inhibitor with a Ki of 24.7 µM. Importantly, not only did it exhibit moderate cell membrane permeability, compound 15 also displayed potent inhibition of intracellular TB growth in the macrophage, making it an excellent lead compound for anti-TB drug discovery. To the best of our knowledge, this novel thiobarbiturate is the first class of MptpB inhibitor reported so far that leveraged docking- and pharmacophore-based virtual screening approaches. The results of preliminary structure-activity relationship demonstrated that compound 15 identified herein was not a singleton and may inspire the design of novel selective and drug-like MptpB inhibitors.

Dietary supplementation of vitamin C: an effective measure for protection against UV-B irradiation using fish as a model organism.

The development of UV-B protective mechanisms in aquacultural species is essential for the sustainable production of healthy aqua crop. Freshwater carp Catla catla larvae (13.5 ± 1.12 mg) were fed with a diet containing 0.5% vitamin C (D1) and a control diet (D2) for 40 days. Each group was exposed to two doses of UV-B irradiation: 360 (5 min, D15 min and D25 min) and 720 mJ cm-2 (10 min, D110 min and D210 min) for 15 days. Significantly (p < 0.05) higher survival and average weight were recorded in D1 compared to D2 exposed to the same dose. Also, significantly (p < 0.001) higher nitric oxide synthase and lower thiobarbituric acid reactive substances and heat shock protein 70 levels were recorded in D15 min compared to the other groups. A direct relationship was found between the dose of UV-B and DNA fragmentation in muscles. DNA damage indices such as tail DNA, tail extent moment and olive tail moment were significantly (p < 0.01) lower in D15 min. Thus, supplementation of vitamin C in the diet provides UV-B protection to larvae.

Synthesis, Molecular Modeling and Biological Evaluation of 5-arylidene-N,N-diethylthiobarbiturates as Potential α-glucosidase Inhibitors.

BACKGROUND: Barbituric acid derivatives are a versatile group of compounds which are identified as potential pharmacophores for the treatment of anxiety, epilepsy and other psychiatric disorders. They are also used as anesthetics and have sound effects on the motor and sensory functions. Barbiturates are malonylurea derivatives with a variety of substituents at C-5 position showing resemblance with nitrogen and sulfur containing compounds like thiouracil which exhibited potent anticancer and antiviral activities. Recently, barbituric acid derivatives have also received great interest for applications in nanoscience. OBJECTIVE: Synthesis of 5-arylidene-N,N-diethylthiobarbiturates, biological evaluation as potential α-glucosidase inhibitors and molecular modeling. METHODS: In the present study, N,N-Diethylthiobarbituric acid derivatives were synthesized by refluxing of N,N-diethylthiobarbituric acid and different aromatic aldehydes in distilled water. In a typical reaction; a mixture of N,N-diethylthiobarbituric acid 0.20 g (1 mmol) and 5-bromo-2- hydroxybenzaldehyde 0.199 g (1 mmol) mixed in 10 mL distilled water and reflux for 30 minutes. After completion of the reaction, the corresponding product 1 was filtered and dried and yield calculated. It was crystallized from ethanol. The structures of synthesized compounds 1-25 were carried out by using 1H, 13C NMR, EI spectroscopy and CHN analysis used for the determination of their structures. The α-glucosidase inhibition assay was performed as given by Chapdelaine et al., with slight modifications and optimization. RESULTS: Our newly synthesized compounds showed a varying degree of α-glucosidase inhibition and at least four of them were found as potent inhibitors. Compounds 6, 5, 17, 11 exhibited IC50 values (Mean±SEM) of 0.0006 ± 0.0002, 18.91 ± 0.005, 19.18 ± 0.002, 36.91 ± 0.003 µM, respectively, as compared to standard acarbose (IC50, 38.25 ± 0.12 µM). CONCLUSION: Our present study has shown that compounds 6, 5, 17, 11 exhibited IC50 values of 0.0006 ± 0.0002, 18.91 ± 0.005, 19.18 ± 0.002, 36.91 ± 0.003 µM, respectively. The studies were supported by in silico data analysis.

Effects of Redox Disturbances on Intestinal Contractile Reactivity in Rats Fed with a Hypercaloric Diet.

Few studies have associated the effects of changes in caloric intake and redox disturbances in the gastrointestinal tract. Therefore, the present study aimed at evaluating the hypercaloric diet consumption influence on the contractile reactivity of intestinal smooth muscle, morphology, and oxidative stress of rat ileum. Wistar rats were randomly divided into groups that received a standard diet and fed with a hypercaloric diet for 8 weeks. Animals were euthanized, and the ileum was isolated to isotonic contraction monitoring. Morphology was evaluated by histological staining and oxidative stress by quantification of malondialdehyde levels and total antioxidant activity. Cumulative concentration-response curves to KCl and carbachol were attenuated in rats fed with a hypercaloric diet compared to those that received a standard diet. In addition, an increase in caloric intake promotes a rise in the thickness of the longitudinal smooth muscle layer of rat ileum and tissue malondialdehyde levels, characterizing lipid peroxidation, as well as a decrease in the antioxidant activity. Thus, it was concluded that the consumption of a hypercaloric diet impairs rat intestinal contractility due to mechanisms involving modifications in the intestinal smooth muscle architecture triggered by redox disturbances.

Antidiabetic, Antihyperlipidemic, and Antioxidant Activities of Mulberry Lees Fermented Products in Diabetic Mice.

Mulberry lees are the sediment in the bottom of the barrel, which can be obtained from the processing of mulberry wine, and they are considered as low-value byproducts. In this study, mulberry lees were extracted with ethanol, and then fermented with Monascus pilosus to obtain fermented products (M × M). Male ICR mice were diabetes induced by STZ, and then oral administration of fermented products. The results showed that fermented products could reduce 31.9% to 47.9% plasma glucose, 25.8% to 48.2% total cholesterol, and 16.7% to 25% triglyceride levels in diabetic mice, and it can greatly lower the malondialdehyde (MDA) content by 26.4% to 59.7% but raise antioxidant enzyme activity in the liver of the mice. Moreover, fermented products not only could reduce AST and ALT activity of the diabetic mice, thereby alleviating liver inflammation, but also lowered the urea nitrogen and creatinine levels, improved glomerulus volume, and reduced swelling and inflammation in the kidneys. It was concluded that mulberry lees fermented products could be served as a value-added resource for human health.

Effect of lithocholic acid on biologically active α,ß-unsaturated aldehydes induced by H2O2 in glioma mitochondria for use in glioma treatment.

Lithocholic acid (LCA) is known to kill glioma cells while sparing normal neuronal cells. However, the anti-glioma mechanism of LCA is unclear at present. Although malondialdehyde (MDA) is not specific to detect tumors, biologically active α,ß-unsaturated aldehydes can be used to detect the outcome of gliomas, especially the mitochondria, as a research tool. The purpose of this research was to determine the optimum conditions for a lipid peroxidation model, according to changes in the aldehydes formed from the reaction between 2-thiobarbituric acid and biologically active α,ß-unsaturated aldehydes. Experimental methods and procedures were successfully established for a model of lipid peroxidation induced by H2O2 in glioma mitochondria for glioma treatment and optimum conditions for LCA treatment were determined. The optimal conditions for the model were a glioma mitochondrial concentration of 1.5 mg/ml, H2O2 concentration of 0.3 mg/ml, duration of action of 30 min, and addition of 4.0 ml of 46 mM thiobarbituric acid. The effect of LCA, as determined by changes in the UV peaks at 450, 495, and 532 nm, was optimal at a concentration of 100 µM, a duration of action of 15 min, and in an acidic microenvironment. The study concluded that a suitable concentration of LCA has anti-glioma effects as determined by the effect on changes in the UV peaks at 450, 495 and 532 nm and the mitochondrial model developed should be conducive to further in-depth research.

Chinese olive extract ameliorates hepatic lipid accumulation in vitro and in vivo by regulating lipid metabolism.

Chinese olive contains plenty of polyphenols, which possess a wide range of biological actions. In this study, we aimed to investigate the role of the ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc) in the modulation of lipid accumulation in vitro and in vivo. In cellular studies, CO-EtOAc attenuated oleic acid-induced lipid accumulation; we then elucidated the molecular mechanisms of CO-EtOAc in FL83B mouse hepatocytes. CO-EtOAc suppressed the mRNA levels of fatty acid transporter genes (CD36 and FABP) and lipogenesis genes (SREBP-1c, FAS, and ACC1), but upregulated genes that govern lipolysis (HSL) and lipid oxidation (PPARα, CPT-1, and ACOX). Moreover, CO-EtOAc increased the protein expression of phosphorylated AMPK, ACC1, CPT-1, and PPARα, but downregulated the expression of mature SREBP-1c and FAS. AMPK plays an essential role in CO-EtOAc-mediated amelioration of lipid accumulation. Furthermore, we confirmed that CO-EtOAc significantly inhibited body weight gain, epididymal adipose tissue weight, and hepatic lipid accumulation via regulation of the expression of fatty acid transporter, lipogenesis, and fatty acid oxidation genes and proteins in C57BL/6 mice fed a 60% high-fat diet. Therefore, Chinese olive fruits may have the potential to improve the metabolic abnormalities associated with fatty liver under high fat challenge.

Enzymatic System of Antioxidant Protection of Erythrocytes in Diabetic Rats Treated with Medicinal Mushrooms Agaricus brasiliensis and Ganoderma lucidum (Agaricomycetes).

Excessive glucose concentrations in blood and cells promote the intensification of auto-oxidation. This is one of the mechanisms through which free radicals form in hyperglycemia. As a result of hyperglycemia, oxidative stress develops and lipid peroxidation (LPO) is enhanced. Erythrocytes are particularly susceptible to reactive oxygen species and LPO, which can violate cell functions. This article describes the analysis of the influence of mycelia from the medicinal mushrooms Agaricus brasiliensis and Ganoderma lucidum on the enzymatic link of the antioxidant system in rat erythrocytes under streptozotocin-induced diabetes mellitus. Oxidative stress was strengthened in red blood cells of diabetic rats, as evidenced by decreased activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, and by increased amounts of thiobarbituric acid-positive products, which are markers of LPO. Administration of A. brasiliensis and G. lucidum submerged cultivated mycelial powder to animals with streptozotocin-induced diabetes restored superoxide dismutase, catalase, and glutathione peroxidase activity and reduced the amounts of thiobarbituric acid-positive products to control values, but did not affect the activity of glutathione reductase.

Cultivar and Metal-Specific Effects of Endophytic Bacteria in Helianthus tuberosus Exposed to Cd and Zn.

Plant growth promoting endophytic bacteria (PGPB) isolated from Brassica napus were inoculated in two cultivars of Helianthus tuberosus (VR and D19) growing on sand supplemented with 0.1 mM Cd or 1 mM Zn. Plant growth, concentrations of metals and thiobarbituric acid (TBA) reactive compounds were determined. Colonization of roots of H. tuberosus D19 by Pseudomonas sp. 262 was evaluated using confocal laser scanning microscopy. Pseudomonas sp. 228, Serratia sp. 246 and Pseudomonas sp. 262 significantly enhanced growth of H. tuberosus D19 exposed to Cd or Zn. Pseudomonas sp. 228 significantly increased Cd concentrations in roots. Serratia sp. 246, and Pseudomonas sp. 256 and 228 resulted in significantly decreased contents of TBA reactive compounds in roots of Zn exposed D19 plants. Growth improvement and decrease of metal-induced stress were more pronounced in D19 than in VR. Pseudomonas sp. 262-green fluorescent protein (GFP) colonized the root epidermis/exodermis and also inside root hairs, indicating that an endophytic interaction was established. H. tuberosus D19 inoculated with Pseudomonas sp. 228, Serratia sp. 246 and Pseudomonas sp. 262 holds promise for sustainable biomass production in combination with phytoremediation on Cd and Zn contaminated soils.

Synthesis of thiobarbituric acid derivatives: In vitro α-glucosidase inhibition and molecular docking studies.

Synthesis, structure, and evaluation of in vitro α-glucosidase enzyme inhibition of a new class of diethylammonium salts of aryl substituted thiobarbituric acid is described. This protocol is straight, environmentally benign and efficient, involving Aldol-Michael addition reaction in one pot fashion. The 3D chemical structures of the synthesized compounds were assigned based on spectroscopic methods and X-ray single crystal diffraction analyses. All synthesized compounds 3a-3n were evaluated for their in vitro α-glucosidase enzyme inhibitory activity, whereas acarbose was used as the standard drug (IC50=840±1.73µM). All tested compounds were found to possess varying degree of α-glucosidase enzyme inhibition activity with (IC50=19.46±1.84-415.8±4.0µM). Compound3i(IC50=19.4±1.84µM) exhibited the highest activity. To the best of knowledge this is the first report of the in vitro α-glucosidase enzyme inhibition by the diethylamonium salts of aryl substituted thiobarbituric acid. Furthermore, molecular docking studies of selected compounds were also performed to see interactions between active compounds and binding sites.

Temporal changes in plasma markers of oxidative stress following laparoscopic sleeve gastrectomy in subjects with impaired glucose regulation.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity and associated metabolic complications. Obesity and type 2 diabetes are associated with increased oxidative stress. Previous studies have examined changes in plasma oxidative stress after laparoscopic Roux-en-Y gastric bypass, but there is limited evidence of the effects of LSG. OBJECTIVES: To examine the effects of LSG on plasma thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAOS) at 1 and 6 months after LSG in patients with obesity and impaired glucose regulation. SETTING: University hospital, United Kingdom. METHODS: Twenty-two participants with impaired glucose homeostasis undergoing LSG (body mass index 50.1 kg/m2, glycated hemoglobin 53 mmol/mol) were studied. Measurements of fasting and 120-minute TBARS and TAOS were performed during an oral glucose tolerance test preoperatively and postoperatively. RESULTS: Compared with preoperative levels, significant decreases were seen 6 months postoperatively in fasting TBARS (61.0±17.9 versus 39.4±13.8 ng/mL, P = .04) and 120-minute TBARS (76.0±29.5 versus 46.5±16.3 ng/mL, P = .02). No significant changes were observed in plasma TAOS. No significant association was observed between changes in TBARS and other clinical or biochemical measures. CONCLUSION: We observed a significant reduction in TBARS, a global measure of lipid peroxidation 6 months after LSG in participants with obesity and impaired glucose regulation.

The effects of walnut supplementation on hippocampal NMDA receptor subunits NR2A and NR2B of rats.

OBJECTIVES: Walnuts contain numerous selected dietary factors that have an impact on brain functions, especially learning and memory formation in the hippocampus. Hippocampal N-methyl d-aspartate receptors (NMDARs) are involved in the formation of cognitive functions. In this study, we aimed to investigate the molecular effects of walnut supplementation on the hippocampal expressions of NMDARs involved in cognitive functions and lipid peroxidation levels in rats. METHODS: The male Sprague-Dawley rats (6 months old, n = 24) were fed with a walnut-supplemented diet (6% walnut diet, n = 12) and a control diet (rat food, n = 12) as ad libitum for 8 weeks. At the end of this period, NMDAR subunits NR2A and NR2B in the hippocampi were assayed by western blotting. Lipid peroxidation levels were measured using the thiobarbituric acid. RESULTS: The expression of NR2A and NR2B was elevated in the walnut-supplemented rats compared with the control group (P < 0.05). In addition, the levels of lipid peroxidation in the walnut-supplemented group were significantly decreased compared with the control group. DISCUSSION: We suggested that walnut supplementation may have protective effects against the decline of cognitive functions by regulating NMDAR and lipid peroxidation levels in the hippocampus. The study provides evidence that selected dietary factors (polyunsaturated fatty acids, melatonin, vitamin E, and flavonoids) within walnut may help to trigger hippocampal neuronal signal transduction for the formation of learning and memory.

Influence of 12-week Nordic Walking training on biomarkers of endothelial function in healthy postmenopausal women.

BACKGROUND: The aim of this study was to evaluate the effects of a 12-week Nordic Walking (NW) intervention on nitric oxide synthase activity (eNOS), levels of antibodies against oxidatively modified low-density lipoproteins (oLAb), plasma antioxidant capacity (TAC), thiobarbituric acid reactive substance (TBARS) concentration, carbohydrate and lipid metabolism, and atherosclerosis risk factors (AIP) in postmenopausal women. METHODS: A sample of 39 women, divided into two comparable groups: training (N.=20) and control (N.=19), took part in the study. Participants in the training group performed a 12-week supervised NW training: 60-minute sessions of exercise, repeated three times per week. The biochemical and anthropometric data were obtained before and after the intervention. During the first and the last training sessions, the individual walking distance in trained group was measured. RESULTS: After the intervention, significant differences in covered distance, body mass, BMI, fat mass, insulin level (P<0.01), systolic blood pressure and TBARS concentration (P<0.05) were found in trained women. CONCLUSIONS: Applied training was able to improve functional capacity and body composition in healthy postmenopausal women. It appears to be no direct link between a significant decrease in the level of systolic blood pressure, the level of eNOS activity, TAC, oLAb and plasma TBARS concentration in trained women. It seems probable that NW training would be more effective for postmenopausal women with more severely impaired endothelial function.

VPO1 mediates oxidation of LDL and formation of foam cells.

Deposition of oxidized-LDL in vascular walls is essential in the initiation of atherosclerosis. Oxidation of LDL has been attributed to myeloperoxidase as its generation of potent oxidants. However, the exact mechanism of LDL oxidation and foam cell formation in atherosclerosis remains to be elucidated. Vascular peroxidase-1 (VPO1), a newly-identified heme-containing peroxidase, is primarily expressed in cardiovascular systems, and secreted into the circulation. The present study evaluates VPO1-mediated LDL oxidation and its role in atherosclerosis. VPO1 was first demonstrated binding to LDL. VPO1-mediated oxidation of proteins and lipids in LDL was verified by a variety of methods including immunoblot analysis, free tryptophan assay, UV absorbance, and thiobarbituric acid assay. VPO1-oxidized LDL caused accumulation of LDL in monocyte-like cells and promoted formation of foam cells. Administration of inflammation factors, LPS or TNF-α, induced increasing expression of VPO1 in aorta and secretion to plasma. TNF-α also promoted formation and retention of VPO1-oxidized LDL in aortic walls. Our data suggest that VPO1 contributes to oxidation and retention of LDL in vessel walls, and formation foam cells, indicating VPO1 as a novel potential mediator of atherosclerosis.