Effects of Biotin Supplementation in the Diet on Adipose Tissue cGMP Concentrations, AMPK Activation, Lipolysis, and Serum-Free Fatty Acid Levels

Several studies have shown that pharmacological concentrations of biotin decrease hyperlipidemia. The molecular mechanisms by which pharmacological concentrations of biotin modify lipid metabolism are largely unknown. Adipose tissue plays a central role in lipid homeostasis. In the present study, we analyzed the effects of biotin supplementation in adipose tissue on signaling pathways and critical proteins that regulate lipid metabolism, as well as on lipolysis. In addition, we assessed serum fatty acid concentrations. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (control: 1.76 mg biotin/kg; supplemented: 97.7 mg biotin/kg diet) over 8 weeks postweaning. Compared with the control group, biotin-supplemented mice showed an increase in the levels of adipose guanosine 3',5'-cyclic monophosphate (cGMP) (control: 30.3±3.27 pmol/g wet tissue; supplemented: 49.5±3.44 pmol/g wet tissue) and of phosphorylated forms of adenosine 5'-monophosphate-activated protein kinase (AMPK; 65.2%±1.06%), acetyl-coenzyme A (CoA), carboxylase-1 (196%±68%), and acetyl-CoA carboxylase-2 (78.1%±18%). Serum fatty acid concentrations were decreased (control: 1.12±0.04 mM; supplemented: 0.91±0.03 mM), and no change in lipolysis was found (control: 0.29±0.05 μmol/mL; supplemented: 0.33±0.08 μmol/mL). In conclusion, 8 weeks of dietary biotin supplementation increased adipose tissue cGMP content and protein expression of the active form of AMPK and of the inactive forms of acetyl-CoA carboxylase-1 and acetyl-CoA carboxylase-2. Serum fatty acid levels fell, and no change in lipolysis was observed. These findings provide insight into the effects of biotin supplementation on adipose tissue and support its use in the treatment of dyslipidemia.

Targeted metabolomic analysis reveals the association between the postprandial change in palmitic acid, branched-chain amino acids and insulin resistance in young obese subjects

Obesity is the result of a positive energy balance and often leads to difficulties in maintaining normal postprandial metabolism. The changes in postprandial metabolites after an oral glucose tolerance test (OGTT) in young obese Chinese men are unclear. In this work, the aim is to investigate the complex metabolic alterations in obesity provoked by an OGTT using targeted metabolomics. We used gas chromatography-mass spectrometry and ultra high performance liquid chromatography-triple quadrupole mass spectrometry to analyze serum fatty acids, amino acids and biogenic amines profiles from 15 control and 15 obese subjects at 0, 30, 60, 90 and 120 min during an OGTT. Metabolite profiles from 30 obese subjects as independent samples were detected in order to validate the change of metabolites. There were the decreased levels of fatty acid, amino acids and biogenic amines after OGTT in obesity. At 120 min, percent change of 20 metabolites in obesity has statistical significance when comparing with the controls. The obese parameters was positively associated with changes in arginine and histidine (P<0.05) and the postprandial change in palmitic acid (PA), branched-chain amino acids (BCAAs) and phenylalanine between 1 and 120 min were positively associated with fasting insulin and HOMA-IR (all P<0.05) in the obese group. The postprandial metabolite of PA and BCAAs may play important role in the development and onset of insulin resistance in obesity. Our findings offer new insights in the complex physiological regulation of the metabolism during an OGTT in obesity.

In vivo and in vitro evidences of dehydroepiandrosterone protective role on the cardiovascular system

CONTEXT

Dehydroepiandrosterone (DHEA) and its sulfate ester, Dehydroepiandrosterone Sulfate (DHEA-S) have been considered as putative anti-aging hormones for many years. Indeed, while DHEAS is the most abundant circulating hormone, its concentration is markedly decreased upon aging and early epidemiologic trials have revealed a strong inverse correlation between the hormone concentrations and the occurrence of several dysfunctions frequently encountered in the elderly. Naturally, hormonal supplementation has been rapidly suggested to prevent DHEA (S) deficiency and therefore, age-related development of these pathologies, using the same strategy as estrogen replacement therapy proposed in postmenopausal women.

EVIDENCE ACQUISITION

All references were searched using PubMed and the following strategy: our initial selection included all articles in English and we sorted them with the following keywords: "DHEA or DHEA-S" and "heart or vascular or endothelium or cardiovascular disease". The search was limited to neither the publication date nor specific journals. The final selection was made according to the relevance of the article content with the aims of the review. According to these criteria, fewer than 10% of the articles retrieved at the first step were discarded.

RESULTS

In this short review, we have focused on the cardiovascular action of DHEA. We started by analyzing evidences in favor of a strong inverse association between DHEA (S) levels and the cardiovascular risk as demonstrated in multiple observational epidemiologic studies for several decades. Then we discussed the different trials aimed at supplementing DHEA (S), both in animals and human, for preventing cardiovascular diseases and we analyzed the possible reasons for the discrepancy observed among the results of some studies. Finally, we presented putative molecular mechanisms of action for DHEA (S), demonstrated in vitro in different models of vascular and cardiac cells, highlighting the complexity of the involved signaling pathways.

CONCLUSIONS

The identification of the beneficial cardiovascular effects of DHEA (S) and a better understanding of the involved mechanisms should be helpful to develop new strategies or pharmacologic approaches for many lethal diseases in Western countries.

Curcumin triggers apoptosis via upregulation of Bax/Bcl-2 ratio and caspase activation in SW872 human adipocytes

Induction of adipocyte apoptosis has been postulated as a novel strategy with which to treat obesity. The effects of curcumin, a polyphenol compound, on the apoptotic signaling pathway in SW872 adipocytes were investigated in the present study. The results showed that cell viability decreased following curcumin treatment in a time- and dose-dependent manner. The results from a single-stranded DNA ELISA assay indicated that curcumin causes the number of apoptotic cells to increase in a concentration-dependent manner. In addition, curcumin treatment resulted in an increased expression of Bax, and a decrease in that of of Bcl-2, with a concomitant upregulation of the Bax/Bcl-2 ratio. Curcumin treatment also led to the release of cytochrome c from mitochondria into the cytosol. Similarly, caspase-dependent poly (ADP) ribose polymerase (PARP) cleavage by curcumin was observed in the current study. In conclusion the results indicate that curcumin is an effective therapeutic agent with which to induce apoptosis in adipocytes. This effect is, in part, mediated through the mitochondrial pathway, which involves upregulation of the Bax/Bcl-2 ratio, cytochrome c release, activation of caspase-3 and the cleavage of PARP.

Mangiferin inhibits endoplasmic reticulum stress-associated thioredoxin-interacting protein/NLRP3 inflammasome activation with regulation of AMPK in endothelial cells

BACKGROUND

Endothelial dysfunction is tightly associated with cardiovascular complications in diabetic patients. This study aims to investigate the effects of mangiferin on the regulation of endothelial homeostasis under endoplasmic reticulum stress (ER stress) conditions.

RESULTS

High glucose (25 mmol/L) exposure induced ER stress and promoted ROS production in endothelial cells. Mangiferin effectively inhibited ER stress-associated oxidative stress by attenuating IRE1α phosphorylation and reducing ROS production. In response to ER stress, thioredoxin-interacting protein (TXNIP) expression increased, followed by NLRP3 inflammasome activation and increased IL-1β secretion. Mangiferin treatment attenuated the expressions of TXNIP and NLRP3 and reduced IL-1β and IL-6 production, demonstrating its inhibitory effects on TXNIP/NLRP3 inflammasome activation. NLRP3 inflammasome activation is responsible for mitochondrial cell death. Mangiferin restored the loss of the mitochondrial membrane potential (Δψm) and inhibited caspase-3 activity, and thereby protected cells from high glucose-induced apoptosis. Moreover, mangiferin inhibited ET-1 secretion and restored the loss of NO production when cells were exposed to high glucose. Mangiferin enhanced AMPK phosphorylation and AMPK inhibitor compound C diminished its beneficial effects, indicating the potential role of AMPK in its action.

CONCLUSION

Our work showed the beneficial effects of mangiferin on the improvement of endothelial homeostasis and elucidated the molecular pathway through which mangiferin ameliorated endothelial dysfunction by inhibition of ER stress-associated TXNIP/NLRP3 inflammasome activation in endothelial cells.

SIGNIFICANCE

These findings demonstrated the beneficial effects of mangiferin on the regulation of endothelial homeostasis and indicated its potential application in the management of diabetic cardiovascular complications.

Vitamin D-enhanced duodenal calcium transport

For humans and rodents, duodenum is a very important site of calcium absorption since it is exposed to ionized calcium released from dietary complexes by gastric acid. Calcium traverses the duodenal epithelium via both transcellular and paracellular pathways in a vitamin D-dependent manner. After binding to the nuclear vitamin D receptor, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] upregulates the expression of several calcium transporter genes, e.g., TRPV5/6, calbindin-D9k, plasma membrane Ca(2+)-ATPase1b, and NCX1, thereby enhancing the transcellular calcium transport. This action has been reported to be under the regulation of parathyroid-kidney-intestinal and bone-kidney-intestinal axes, in which the plasma calcium and fibroblast growth factor-23 act as negative feedback regulators, respectively. 1,25(OH)2D3 also modulates the expression of tight junction-related genes and convective water flow, presumably to increase the paracellular calcium permeability and solvent drag-induced calcium transport. However, vitamin D-independent calcium absorption does exist and plays an important role in calcium homeostasis under certain conditions, particularly in neonatal period, pregnancy, and lactation as well as in naturally vitamin D-impoverished subterranean mammals.

Rapid identification of erythrocyte phospholipids in Sprague-Dawley rats by ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

A rapid, sensitive, and reliable approach for analyzing five kinds of erythrocyte phospholipids in Sprague-Dawley rats was provided by ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry with MassLynx(TM) MassFragment. Improving conventional high performance liquid chromatography techniques, ultra high performance liquid chromatography integrated with quadrupole time-of-flight tandem mass spectrometry offers high sensitivity and increased analytical speed by using columns packed with sub-2 μm particles (1.7 μm), which allows a faster separation to be achieved. Through this method, 83 phospholipids were tentatively characterized based on their mass spectra and tandem mass spectra, as well as by matching the in-house formula database within a mass error of 5 ppm, including 40 phosphatidylcholines, 24 phosphatidyl ethanolamines, three phosphatidylinositols, six phosphatidylserines, and ten sphingomyelins. Our present results proved that the established method could be used to qualitatively analyze complex erythrocyte phospholipids in Sprague-Dawley rats and provide a useful data base for pharmacology and phospholipidomics to seek potential biomarkers of disease prediction.

Beneficial effects of neomangiferin on high fat diet-induced nonalcoholic fatty liver disease in rats

This study was carried out to determine the effect and mechanism of action of neomangiferin (NG) on high-fat diet-induced nonalcoholic fatty liver disease (NAFLD) in rats. NAFLD rats were randomly assigned into several groups of equal number. NG (50, 25mg/kg·day(-1) BW) and lipanthyl (PT, 5mg/kg·day(-1) BW) were given to the NAFLD rats, respectively. In the study, serum lipids, metabolic rate, liver fat, liver lipids and histology were examined. To further investigate the molecular mechanism of the effect of NG on NAFLD, expression levels of mRNA and protein for peroxisome proliferator-activated receptor α (PPARα), fatty acid transport protein 2 (FATP2), long-chain-fatty-acid - CoA ligase 1 (ACSL1) and carnitine palmitoyltransferase 1a (CPT1a) in the liver were determined by Real Time-PCR and western blot analysis, respectively. NG administration significantly reduced the final body weight, liver fat accumulation, and serum triglyceride (TG), total cholesterol (TC) concentrations, low-density lipoprotein cholesterol (LDL-C), glucose (GLU) levels, and hepatic TG, TC, malondialdehyde (MDA) levels, but increased serum high-density lipoprotein cholesterol (HDL-C) and hepatic superoxide dismutase (SOD) levels. NG upregulated the mRNA and protein expression of PPARα and CPT1a, but downregulated the mRNA and protein expression of FATP2 and ACSL1 in the liver. These results suggested that NG can regulate NAFLD partly by modulating the expression levels of genes involved in FFA uptake and lipid oxidation.

Prospective association of fatty acids in the de novo lipogenesis pathway with risk of type 2 diabetes: the Cardiovascular Health Study

BACKGROUND

Experimental evidence suggests that hepatic de novo lipogenesis (DNL) affects insulin homeostasis via synthesis of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Few prospective studies have used fatty acid biomarkers to assess associations with type 2 diabetes.

OBJECTIVES

We investigated associations of major circulating SFAs [palmitic acid (16:0) and stearic acid (18:0)] and MUFA [oleic acid (18:1n-9)] in the DNL pathway with metabolic risk factors and incident diabetes in community-based older U.S. adults in the Cardiovascular Health Study. We secondarily assessed other DNL fatty acid biomarkers [myristic acid (14:0), palmitoleic acid (16:1n-7), 7-hexadecenoic acid (16:1n-9), and vaccenic acid (18:1n-7)] and estimated dietary SFAs and MUFAs.

DESIGN

In 3004 participants free of diabetes, plasma phospholipid fatty acids were measured in 1992, and incident diabetes was identified by medication use and blood glucose. Usual diets were assessed by using repeated food-frequency questionnaires. Multivariable linear and Cox regression were used to assess associations with metabolic risk factors and incident diabetes, respectively.

RESULTS

At baseline, circulating palmitic acid and stearic acid were positively associated with adiposity, triglycerides, inflammation biomarkers, and insulin resistance (P-trend < 0.01 each), whereas oleic acid showed generally beneficial associations (P-trend < 0.001 each). During 30,763 person-years, 297 incident diabetes cases occurred. With adjustment for demographics and lifestyle, palmitic acid (extreme-quintile HR: 1.89; 95% CI: 1.27, 2.83; P-trend = 0.001) and stearic acid (HR: 1.62; 95% CI: 1.09, 2.41; P-trend = 0.006) were associated with higher diabetes risk, whereas oleic acid was not significantly associated. In secondary analyses, vaccenic acid was inversely associated with diabetes (HR: 0.56; 95% CI: 0.38, 0.83; P-trend = 0.005). Other fatty acid biomarkers and estimated dietary SFAs or MUFAs were not significantly associated with incident diabetes.

CONCLUSIONS

In this large prospective cohort, circulating palmitic acid and stearic acid were associated with higher diabetes risk, and vaccenic acid was associated with lower diabetes risk. These results indicate a need for additional investigation of biological mechanisms linking specific fatty acids in the DNL pathway to the pathogenesis of diabetes.

Curcumin Attenuates Oxidative Stress and Activation of Redox-Sensitive Kinases in High Fructose- and High-Fat-Fed Male Wistar Rats

The present study was carried out to investigate the effects of curcumin on oxidative stress and redox-sensitive kinases in high fructose- and high-fat-fed rats. Sixty rats were randomly divided into six groups with ten animals each. Rats were fed with a standard rodent diet, high fructose diet (60%), and high-fat diet (30%). Curcumin was administered to control, high fructose and high fat diet groups for ten weeks. At the end of the study, body weight and blood glucose levels were measured. The antioxidant enzymes GSH (reduced glutathione), GPx (glutathione peroxidase), and catalase activities were estimated in the blood. MDA, TAS, and TOS were estimated in the plasma, liver, and kidney. Curcumin treatment decreased body weight and blood glucose levels in the rats fed with fructose and high-fat diet. Antioxidant enzymes and plasma TAS were significantly improved by curcumin treatment in high fructose-fed rats, whereas in high-fat-fed rats, there was an increase only in the GPx activity. Curcumin significantly attenuated the elevation of plasma MDA and TOS in both diet groups. Hepatic MDA and TOS were found to be decreased upon curcumin supplementation in both diet groups, whereas a decrease in the renal MDA levels was observed only in fructose-treated rats, not in fat-fed rats. Curcumin treatment elevated liver TAS in rats fed only with the fructose-rich diet. Curcumin showed a significant decrease in the oxidative stress index (OSI) in plasma, liver, and kidney tissues in both diet groups. ERK phosphorylation was significantly decreased in both diet groups by curcumin treatment. Similarly, curcumin reduced the phosphorylation of p38 MAPK only in the high fructose-fed rats, not in the high-fat-fed rats. No significant changes were found in JNK phosphorylation in both diet groups. Thus, curcumin may be effective in the management of diet-induced oxidative stress and could be explored as a therapeutic adjuvant against complications associated with obesity and diabetes.

Sex Hormones and Their Receptors Regulate Liver Energy Homeostasis

The liver is one of the most essential organs involved in the regulation of energy homeostasis. Hepatic steatosis, a major manifestation of metabolic syndrome, is associated with imbalance between lipid formation and breakdown, glucose production and catabolism, and cholesterol synthesis and secretion. Epidemiological studies show sex difference in the prevalence in fatty liver disease and suggest that sex hormones may play vital roles in regulating hepatic steatosis. In this review, we summarize current literature and discuss the role of estrogens and androgens and the mechanisms through which estrogen receptors and androgen receptors regulate lipid and glucose metabolism in the liver. In females, estradiol regulates liver metabolism via estrogen receptors by decreasing lipogenesis, gluconeogenesis, and fatty acid uptake, while enhancing lipolysis, cholesterol secretion, and glucose catabolism. In males, testosterone works via androgen receptors to increase insulin receptor expression and glycogen synthesis, decrease glucose uptake and lipogenesis, and promote cholesterol storage in the liver. These recent integrated concepts suggest that sex hormone receptors could be potential promising targets for the prevention of hepatic steatosis.

Untargeted metabolic profiling identifies altered serum metabolites of type 2 diabetes mellitus in a prospective, nested case control study

BACKGROUND

Application of metabolite profiling could expand the etiological knowledge of type 2 diabetes mellitus (T2D). However, few prospective studies apply broad untargeted metabolite profiling to reveal the comprehensive metabolic alterations preceding the onset of T2D.

METHODS

We applied untargeted metabolite profiling in serum samples obtained from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort comprising 300 individuals who developed T2D after a median follow-up time of 6 years and 300 matched controls. For that purpose, we used ultraperformance LC-MS with a protocol specifically designed for large-scale metabolomics studies with regard to robustness and repeatability. After multivariate classification to select metabolites with the strongest contribution to disease classification, we applied multivariable-adjusted conditional logistic regression to assess the association of these metabolites with T2D.

RESULTS

Among several alterations in lipid metabolism, there was an inverse association with T2D for metabolites chemically annotated as lysophosphatidylcholine(dm16:0) and phosphatidylcholine(O-20:0/O-20:0). Hexose sugars were positively associated with T2D, whereas higher concentrations of a sugar alcohol and a deoxyhexose sugar reduced the odds of diabetes by approximately 60% and 70%, respectively. Furthermore, there was suggestive evidence for a positive association of the circulating purine nucleotide isopentenyladenosine-5'-monophosphate with incident T2D.

CONCLUSIONS

This study constitutes one of the largest metabolite profiling approaches of T2D biomarkers in a prospective study population. The findings might help generate new hypotheses about diabetes etiology and develop further targeted studies of a smaller number of potentially important metabolites.

Metabolite profiling for the identification of altered metabolic pathways in Alzheimer's disease

Gas chromatography coupled to mass spectrometry is the most frequent tool for metabolomic profiling of low molecular weight metabolites. Its suitability in health survey is beyond doubt, given that primary metabolites involved in central pathways of metabolism are usually altered in diseases. The objective of this work is to investigate metabolic differences in serum between Alzheimer's disease patients and healthy controls in order to elucidate pathological mechanisms underlying to disease. Alterations in levels of 23 metabolites were detected, including increased lactic acid, α-ketoglutarate, isocitric acid, glucose, oleic acid, adenosine and cholesterol, as well as decreased urea, valine, aspartic acid, pyroglutamate, glutamine, phenylalanine, asparagine, ornithine, pipecolic acid, histidine, tyrosine, palmitic and uric acid, tryptophan, stearic acid and cystine. Metabolic pathway analysis revealed the involvement of multiple affected pathways, such as energy deficiencies, oxidative stress, hyperammonemia, and others. Moreover, it is noteworthy that some of these compounds have not been previously described in AD research, such as α-ketoglutarate, isocitrate pipecolic acid, pyroglutamate and adenosine, confirming the potential of this metabolomic approach in the search of novel potential markers for early detection of Alzheimer's disease.

Piperine, a natural bioenhancer, nullifies the antidiabetic and antioxidant activities of curcumin in streptozotocin-diabetic rats

Knowing that curcumin has low bioavailability when administered orally, and that piperine has bioenhancer activity by inhibition of hepatic and intestinal biotransformation processes, the aim of this study was to investigate the antidiabetic and antioxidant activities of curcumin (90 mg/kg) and piperine (20 or 40 mg/kg), alone or co-administered, incorporated in yoghurt, in streptozotocin (STZ)-diabetic rats. The treatment for 45 days of STZ-diabetic rats with curcumin-enriched yoghurt improved all parameters altered in this experimental model of diabetes: the body weight was increased in association with the weight of skeletal muscles and white adipose tissues; the progressive increase in the glycemia levels was avoided, as well as in the glycosuria, urinary urea, dyslipidemia, and markers of liver (alanine and aspartate aminotransferases and alkaline phosphatase) and kidney (urinary protein) dysfunction; the hepatic oxidative stress was decreased, since the activities of the antioxidant enzymes superoxide dismutase, catalase and gluthatione peroxidase were increased, and the levels of malondialdehyde and protein carbonyl groups were reduced. The dose of 20 mg/kg piperine also showed antidiabetic and antioxidant activities. The treatment of STZ-diabetic rats with both curcumin and 20 mg/kg piperine in yoghurt did not change the antidiabetic and antioxidant activities of curcumin; notably, the treatment with both curcumin and 40 mg/kg piperine abrogated the beneficial effects of curcumin. In addition, the alanine aminotransferase levels were further increased in diabetic rats treated with curcumin and 40 mg/kg piperine in comparison with untreated diabetic rats. These findings support that the co-administration of curcumin with a bioenhancer did not bring any advantage to the curcumin effects, at least about the antidiabetic and antioxidant activities, which could be related to changes on its biotransformation.

Dynamic analysis of the endogenous metabolites in depressed patients treated with TCM formula Xiaoyaosan using urinary (1)H NMR-based metabolomics

ETHNOPHAMACOLOGICAL RELEVANCE

Xiaoyaosan (XYS), one of the best-known traditional Chinese medicine prescriptions with a long history of use, is composed of Bupleurum chinense DC., Paeonia lactiflora Pall., Poria cocos (Schw.) Wolf, Angelica sinensis (Oliv.) Diels, Zingiber officinale Rosc., Atractylodes macrocephala Koidz., Glycyrrhiza uralensis Fisch., and Mentha haplocalyx Briq. For centuries, XYS has been widely used in China for the treatment of mental disorders such as depression. However, the complicated mechanism underlying the antidepressant activity of XYS is not yet well-understood. This understanding is complicated by the sophisticated pathophysiology of depression and by the complexity of XYS, which has multiple constituents acting on different metabolic pathways. The variations of endogenous metabolites in depressed patients after administration of XYS may help elucidate the anti-depressant effect and mechanism of action of XYS. The aim of this study is to establish the metabolic profile of depressive disorder and to investigate the changes of endogenous metabolites in the depressed patients before and after the treatment of Xiaoyaosan using the dynamic analysis of urine metabolomics profiles based on (1)H NMR.

MATERIALS AND METHODS

Twenty-one depressed patients were recruited from the Traditional Chinese Medicine Department of the First Affiliated Hospital of Shanxi Medical University. Small endogenous metabolites present in urine samples were measured by nuclear magnetic resonance (NMR) and analyzed by multivariate statistical methods. The patients then received XYS treatment for six weeks, after which their Hamilton Depression Scale (HAMD) scores were significantly decreased compared with their baseline scores (p≤0.01). Eight components in urine specimens were identified that enabled discrimination between the pre- and post-XYS-treated samples.

RESULTS

Urinary of creatinine, taurine, 2-oxoglutarate and xanthurenic acid increased significantly after XYS treatment (p≤0.05), while the urinary levels of citrate, lactate, alanine and dimethylamine decreased significantly (p≤0.05) compared with pre-treatment urine samples. These statistically significant perturbations are involved in energy metabolism, gut microbes, tryptophan metabolism and taurine metabolism.

CONCLUSIONS

The symptoms of depression had been improved after 6 weeks׳ treatment of XYS according to evaluation of HAMD scores. The dynamic tendency of the 8 metabolites that changed significantly during the treatment of XYS is consistent with the improvement in symptoms of depression. These metabolites may be used as biomarkers for the diagnosis of depressive disorders or the evaluation of the antidepressant as well as the exploration of the mechanism of depression.

Current state-of-the-art of nontargeted metabolomics based on liquid chromatography-mass spectrometry with special emphasis in clinical applications

Metabolomics, as a part of systems biology, has been widely applied in different fields of life science by studying the endogenous metabolites. The development and applications of liquid chromatography (LC) coupled with high resolution mass spectrometry (MS) greatly improve the achievable data quality in non-targeted metabolic profiling. However, there are still some emerging challenges to be covered in LC-MS based metabolomics. Here, recent approaches about sample collection and preparation, instrumental analysis, and data handling of LC-MS based metabolomics are summarized, especially in the analysis of clinical samples. Emphasis is put on the improvement of analytical techniques including the combination of different LC columns, isotope coded derivatization methods, pseudo-targeted LC-MS method, new data analysis algorithms and structural identification of important metabolites.

Magnolia officinalis attenuates free fatty acid-induced lipogenesis via AMPK phosphorylation in hepatocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis (MO) is a traditional Chinese herbal medicine that has been used in clinical practice to treat liver disease. The aim of this study is to examine the effects of MO on the development of nonalcoholic fatty liver in hepatocytes.

MATERIALS AND METHODS

Human hepatoma-derived HepG2 cells and mouse normal FL83B hepatocytes were exposed to 0.5mM free fatty acids (FFAs; oleate:palmitate, 2:1) for 24h to simulate conditions of nonalcoholic fatty liver in vitro. The cells were treated with a standardized MO extract 1h prior to FFA exposure.

RESULTS

MO pretreatment attenuated the increases in intracellular lipid accumulation and triglyceride content in FFA-exposed hepatocytes in a dose-dependent manner. MO pretreatment significantly inhibited both sterol regulatory element-binding protein (SREBP)-1c activation and increases in fatty acid translocase, fatty acid synthase, and stearoyl CoA desaturase-1 protein expression in FFA-exposed hepatocytes in a dose-dependent manner. MO pretreatment markedly induced adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in hepatocytes. Compound C, an AMPK inhibitor, blocked the inhibitory effect of MO on the increases in intracellular lipid accumulation and triglyceride content induced by FFAs. In hepatocytes pretreated with compound C, MO failed to inhibit SREBP-1c activation and the increases in fatty acid translocase, fatty acid synthase, and stearoyl-CoA desaturase-1 protein expression induced by FFAs.

CONCLUSIONS

Our results indicate that MO attenuates triglyceride biosynthesis and accumulation induced by FFAs in hepatocytes, suggesting its pharmacological potential for the prevention of nonalcoholic fatty liver disease. These effects may be mediated by the inhibition of SREBP-1c via AMPK phosphorylation.

Mangiferin stimulates carbohydrate oxidation and protects against metabolic disorders induced by high-fat diets

Excessive dietary fat intake causes systemic metabolic toxicity, manifested in weight gain, hyperglycemia, and insulin resistance. In addition, carbohydrate utilization as a fuel is substantially inhibited. Correction or reversal of these effects during high-fat diet (HFD) intake is of exceptional interest in light of widespread occurrence of diet-associated metabolic disorders in global human populations. Here we report that mangiferin (MGF), a natural compound (the predominant constituent of Mangifera indica extract from the plant that produces mango), protected against HFD-induced weight gain, increased aerobic mitochondrial capacity and thermogenesis, and improved glucose and insulin profiles. To obtain mechanistic insight into the basis for these effects, we determined that mice exposed to an HFD combined with MGF exhibited a substantial shift in respiratory quotient from fatty acid toward carbohydrate utilization. MGF treatment significantly increased glucose oxidation in muscle of HFD-fed mice without changing fatty acid oxidation. These results indicate that MGF redirects fuel utilization toward carbohydrates. In cultured C2C12 myotubes, MGF increased glucose and pyruvate oxidation and ATP production without affecting fatty acid oxidation, confirming in vivo and ex vivo effects. Furthermore, MGF inhibited anaerobic metabolism of pyruvate to lactate but enhanced pyruvate oxidation. A key target of MGF appears to be pyruvate dehydrogenase, determined to be activated by MGF in a variety of assays. These findings underscore the therapeutic potential of activation of carbohydrate utilization in correction of metabolic syndrome and highlight the potential of MGF to serve as a model compound that can elicit fuel-switching effects.

The Structural Basis of Action of Vanadyl (VO2+) Chelates in Cells

Much emphasis has been given to vanadium compounds as potential therapeutic reagents for the treatment of diabetes mellitus. Thus far, no vanadium compound has proven efficacious for long-term treatment of this disease in humans. Therefore, in review of the research literature, our goal has been to identify properties of vanadium compounds that are likely to favor physiological and biochemical compatibility for further development as therapeutic reagents. We have, therefore, limited our review to those vanadium compounds that have been used in both in vivo experiments with small, laboratory animals and in in vitro studies with primary or cultured cell systems and for which pharmacokinetic and pharmacodynamics results have been reported, including vanadium tissue content, vanadium and ligand lifetime in the bloodstream, structure in solution, and interaction with serum transport proteins. Only vanadyl (VO²⁺) chelates fulfill these requirements despite the large variety of vanadium compounds of different oxidation states, ligand structure, and coordination geometry synthesized as potential therapeutic agents. Extensive review of research results obtained with use of organic VO²⁺-chelates shows that the vanadyl chelate bis(acetylacetonato)oxidovanadium(IV) [hereafter abbreviated as VO(acac)₂], exhibits the greatest capacity to enhance insulin receptor kinase activity in cells compared to other organic VO²⁺-chelates, is associated with a dose-dependent capacity to lower plasma glucose in diabetic laboratory animals, and exhibits a sufficiently long lifetime in the blood stream to allow correlation of its dose-dependent action with blood vanadium content. The properties underlying this behavior appear to be its high stability and capacity to remain intact upon binding to serum albumin. We relate the capacity to remain intact upon binding to serum albumin to the requirement to undergo transcytosis through the vascular endothelium to gain access to target tissues in the extravascular space. Serum albumin, as the most abundant transport protein in the blood stream, serves commonly as the carrier protein for small molecules, and transcytosis of albumin through capillary endothelium is regulated by a Src protein tyrosine kinase system. In this respect it is of interest to note that inorganic VO²⁺ has the capacity to enhance insulin receptor kinase activity of intact 3T3-L1 adipocytes in the presence of albumin, albeit weak; however, in the presence of transferrin no activation is observed. In addition to facilitating glucose uptake, the capacity of VO²⁺- chelates for insulin-like, antilipolytic action in primary adipocytes has also been reviewed. We conclude that measurement of inhibition of release of only free fatty acids from adipocytes stimulated by epinephrine is not a sufficient basis to ascribe the observations to purely insulin-mimetic, antilipolytic action. Adipocytes are known to contain both phosphodiesterase-3 and phosphodiesterase-4 (PDE3 and PDE4) isozymes, of which insulin antagonizes lipolysis only through PDE3B. It is not known whether the other isozyme in adipocytes is influenced directly by VO²⁺- chelates. In efforts to promote improved development of VO²⁺- chelates for therapeutic purposes, we propose synergism of a reagent with insulin as a criterion for evaluating physiological and biochemical specificity of action. We highlight two organic compounds that exhibit synergism with insulin in cellular assays. Interestingly, the only VO²⁺- chelate for which this property has been demonstrated, thus far, is VO(acac)₂.

Lysophosphatidylcholine and amide as metabolites for detecting alzheimer disease using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabonomics

Alzheimer disease (AD) can be diagnosed by clinical and neuropsychologic tests and at autopsy, but there are no simple effective diagnostic methods for detecting biomarkers in patients at early stages of cognitive impairment. Early metabolic alterations that may facilitate AD diagnosis have not been thoroughly explored. We applied a nontargeted metabonomic approach using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to analyze serum and urine samples from 46 patients with AD and 36 healthy controls. Metabolite profiles were processed using multivariate analysis to identify potential metabolites, which were further confirmed using tandem mass spectrometry. Ultrahigh-performance liquid chromatography mass spectrometry methods were additionally used to quantify potentially important biomarkers. Independent samples were then selected to validate the identified biomarkers. There was a clear separation between healthy controls and AD patients; AD patient samples had disordered amino acid and phospholipid metabolism and dysregulated palmitic amide. Receiver operator characteristic curve and quantification suggested that palmitic amide, lysophosphatidylcholine (LysoPC, 18:0), LysoPC(18:2), L-glutamine, and 5-L-glutamylglycine were the optimal metabolites. In addition, areas under the curve from the palmitic amide, LysoPC(18:2), and 5-L-glutamylglycine in the validation study were 0.714, 0.996, and 0.734, respectively. These data elucidate the metabolic alterations associated with AD and suggest new biomarkers for AD diagnosis, thereby permitting early intervention designed to prevent disease progression.

Anti-hyperglycemic and insulin sensitizer effects of turmeric and its principle constituent curcumin

CONTEXT

Turmeric is obtained from the plant Curcuma longa L; its major constituent, curcumin, is a polyphenol with multiple effects which can modulate some signaling pathways.

EVIDENCE ACQUISITION

Insulin resistance is a major risk factor for chronic diseases such as type 2 diabetes, atherosclerotic, metabolic syndrome and cardiovascular disease. In addition, Insulin resistance in peripheral tissue is one of the most important reasons of hyperglycemia which can cause global or systemic effects. The present study reviewed studies published in PubMed from 1998 to 2013, indicating the role of curcumin in attenuation of many pathophysiological processes involved in development and progression of hyperglycemia and insulin resistance.

RESULTS

Curcumin can reduce blood glucose level by reducing the hepatic glucose production, suppression of hyperglycemia-induced inflammatory state, stimulation of glucose uptake by up-regulation of GLUT4, GLUT2 and GLUT3 genes expressions, activation of AMP kinase, promoting the PPAR ligand-binding activity, stimulation of insulin secretion from pancreatic tissues, improvement in pancreatic cell function, and reduction of insulin resistance.

CONCLUSIONS

Curcumin has antihyperglycemic and insulin sensitizer effects. Thereby, more studies evaluating the effects of curcumin on hyperglycemic state and insulin resistance in related disorders such as diabetes are recommended.

High-throughput and high-sensitivity quantitative analysis of serum unsaturated fatty acids by chip-based nanoelectrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry: early stage diagnostic biomarkers of pancreatic cancer

In this study, Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) coupled with chip-based direct-infusion nanoelectrospray ionization source (CBDInanoESI) in a negative ion mode is first employed to evaluate the effect of serum and its corresponding supernatant matrixes on the recoveries of serum free fatty acids (FFAs) based on spike-and-recovery experimental strategy by adding analytes along with analog internal standard (IS). The recoveries between serum (69.8-115.6%) and the supernatant (73.6-99.0%) matrixes are almost identical. Multiple point internal standard calibration curves between the concentration ratios of individual fatty acids to ISs, (C(17:1) as IS of C(16:1), C(18:3), C(18:2), or C(18:1) or C(21:0) as IS of C(20:4) or C(22:6)) versus their corresponding intensity ratios were constructed for C(16:1), C(18:3), C(18:2), C(18:1), C(20:4) and C(22:6), respectively, with correlation coefficients of greater than 0.99, lower limits of detection between 0.3 and 1.8 nM, and intra- and inter-day precision (relative standard deviations <18%), along with the linear dynamic range of three orders of magnitude. Sequentially, this advanced analytical platform was applied to perform simultaneous quantitative and qualitative analysis of multiple targets, e.g., serum supernatant unsaturated FFAs from 361 participants including 95 patients with pancreatic cancer (PC), 61 patients with pancreatitis and 205 healthy controls. Experimental results indicate that the levels of C(18:1), C(18:2), C(18:3), C(20:4) and C(22:6), as well as the level ratios of C(18:2)/C(18:1) and C(18:3)/C(18:1) of the PC patients were significantly decreased compared with those of healthy controls and the patients with pancreatitis (p < 0.01). It is worth noting that the ratio of C(18:2)/C(18:1), polyunsaturated fatty acids (PUFAs) (C(18:2), C(18:3), C(20:4), and C(22:6)), panel a (C(16:1), C(18:3), C(18:2), C(20:4) and C(22:6)) and panel b (C(18:2)/C(18:1) and C(18:3)/C(18:1)) performed excellent diagnostic ability, with an area under the receiver operating characteristic curve of ≥0.869, sensitivity of ≥85.7%, and specificity of ≥86.7% for differentiating the early stage PC from non-cancer subjects, which are greatly higher than those of clinically used serum biomarker CA 19-9. More importantly, this platform can also provide a fast and easy way to quantify the levels of FFAs in less than 30 s per sample.

PubChem applications in drug discovery: a bibliometric analysis

A bibliometric analysis of PubChem applications is presented by reviewing 1132 research articles. The massive volume of chemical structure and bioactivity data in PubChem and its online services have been used globally in various fields including chemical biology, medicinal chemistry and informatics research. PubChem supports drug discovery in many aspects such as lead identification and optimization, compound-target profiling, polypharmacology studies and unknown chemical identity elucidation. PubChem has also become a valuable resource for developing secondary databases, informatics tools and web services. The growing PubChem resource with its public availability offers support and great opportunities for the interrogation of pharmacological mechanisms and the genetic basis of diseases, which are vital for drug innovation and repurposing.

Biomarkers identified by urinary metabonomics for noninvasive diagnosis of nutritional rickets

Nutritional rickets is a worldwide public health problem; however, the current diagnostic methods retain shortcomings for accurate diagnosis of nutritional rickets. To identify urinary biomarkers associated with nutritional rickets and establish a noninvasive diagnosis method, urinary metabonomics analysis by ultra-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry and multivariate statistical analysis were employed to investigate the metabolic alterations associated with nutritional rickets in 200 children with or without nutritional rickets. The pathophysiological changes and pathogenesis of nutritional rickets were illustrated by the identified biomarkers. By urinary metabolic profiling, 31 biomarkers of nutritional rickets were identified and five candidate biomarkers for clinical diagnosis were screened and identified by quantitative analysis and receiver operating curve analysis. Urinary levels of five candidate biomarkers were measured using mass spectrometry or commercial kits. In the validation step, the combination of phosphate and sebacic acid was able to give a noninvasive and accurate diagnostic with high sensitivity (94.0%) and specificity (71.2%). Furthermore, on the basis of the pathway analysis of biomarkers, our urinary metabonomics analysis gives new insight into the pathogenesis and pathophysiology of nutritional rickets.

Cyclooxygenase-2-dependent oxidative stress mediates palmitate-induced impairment of endothelium-dependent relaxations in mouse arteries

Palmitic acid, one of the saturated free fatty acids, impairs cardiovascular function as manifested by inducing vascular inflammation, apoptosis and over-production of reactive oxygen species (ROS) although the origin for ROS remains unclear. The present study investigated the cellular mechanisms underlying palmitate-induced impairment of endothelial function. Ex vivo treatment in tissue culture with palmitate concentration-dependently attenuated acetylcholine-induced endothelium-dependent relaxations, up-regulated the expression of cyclooxygenase-2 (COX-2) and elevated superoxide formation in mouse aortic endothelial cells (MAECs) measured by dihydroethidium (DHE) staining and electron paramagnetic resonance (EPR) spectroscopy. Superoxide scavengers, COX-2 inhibitor and thromboxane prostanoid (TP) receptor antagonist, but not COX-1 inhibitor reversed the harmful effects of palmitate. Furthermore, palmitate impaired acetylcholine-induced relaxations and raised superoxide in en face endothelium of aortas only from COX-1(-/-) mice but not from COX-2(-/-) mice. Palmitate increased the production and release of TXB2, a stable thromboxane A2 metabolite in mouse aortas, which was abolished by COX-2 inhibitor. Superoxide scavenger did not affect palmitate-induced up-regulated expression of COX-2 in MAECs. Both real time PCR and luciferase reporter gene assay confirmed COX-2 up-regulation in palmitate-treated MAECs and NF-κB was substantially involved in this up-regulation. The present study provides novel evidence that palmitate up-regulates COX-2 through NF-κB-dependent mechanism and resultant COX-2-associated oxidative stress impairs endothelium-dependent relaxations in mouse aortas.

Changes in urinary metabolic profile after oral administration of curcuma extract in rats

The diffusion of phytochemicals in health promoting products is growing, but studies related to their effects on healthy subjects are still lacking despite the large consumption of natural products as nutraceuticals or food supplements. In many cases, research supports the in vitro antioxidant activity of phytochemicals, but the health claims attributed to the final marketed nutraceutical products have dubious scientific foundation. Also, studies focussed on the definition of their biological targets and mechanisms of action can be useful to assess their efficacy and safety. In this study, the effect of oral administration of 80mg/kg of Curcuma longa Linn. extract to 12 healthy rats over 25 days was evaluated by monitoring the changes of urinary composition. 24-h urine was collected during the animal experiment and the composition was analyzed by (1)H NMR and HPLC-MS. The two datasets were studied individually through a metabolomic approach and the multivariate analysis revealed significant differences between the control and the treated group. Curcumin levels were also measured in 24-h urine samples by HPLC-MS. Both the (1)H NMR and the HPLC-MS dataset showed that the administration of 80mg/kg of Curcuma longa extract to healthy animals induces changes in urinary composition. Decreased allantoin urinary levels can be considered a partial demonstration of the in vivo effect of curcumin on oxidative stress in a healthy animal model.

Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation.

Minireview: hey U(PS): metabolic and proteolytic homeostasis linked via AMPK and the ubiquitin proteasome system

One of the master regulators of both glucose and lipid cellular metabolism is 5'-AMP-activated protein kinase (AMPK). As a metabolic pivot that dynamically responds to shifts in nutrient availability and stress, AMPK dysregulation is implicated in the underlying molecular pathology of a variety of diseases, including cardiovascular diseases, diabetes, cancer, neurological diseases, and aging. Although the regulation of AMPK enzymatic activity by upstream kinases is an active area of research, less is known about regulation of AMPK protein stability and activity by components of the ubiquitin-proteasome system (UPS), the cellular machinery responsible for both the recognition and degradation of proteins. Furthermore, there is growing evidence that AMPK regulates overall proteasome activity and individual components of the UPS. This review serves to identify the current understanding of the interplay between AMPK and the UPS and to promote further exploration of the relationship between these regulators of energy use and amino acid availability within the cell.

Serum free fatty acids level in senile cataract

PURPOSE

To evaluate and compare the levels of free fatty acids between senile cataract patients and normal controls.

METHODS

Fifty consecutive patients with newly diagnosed senile cataract and 50 age- and gender-matched controls were evaluated. Subjects/patients were randomized according to selection criteria. The levels of free fatty acids (FFAs) in serum were measured by gas chromatography-mass spectrometry (GC-MS). Sixteen fatty acids from 14:0 to 24:1 were identified. The values were compared between cataract and control groups by parametric independent sample test and Mann-Whitney U tests.

RESULTS

A significant decrease was observed in arachidonic acid (C20:4n-6, ARA), cis-4,7,10,13,16,19-docosahexaenoic acid (C22:6n-3, DHA), tetracosanoic acid (C24: 0), cis-7,10,13,16,19-docosapentaenoic acid (C22:5n-6, DPA), total n-3 long-chain polyunsaturated fatty acids (LC-PUFAs), total n-6 LC-PUFAs, total fatty acids, unsaturated fatty acids (USFAs), polyunsaturated fatty acids (PUFAs), and nonessential fatty acid levels in patients with senile cataract in comparison with healthy persons (p < 0.05).

CONCLUSIONS

The levels of FFA including DPA, tetracosanoic acid, ARA, and DHA were significantly lower in the senile cataract group compared to that in the normal controls. FFA may be helpful in preventing senile cataract.

Evaluation of the effect of curcumin capsules on glyburide therapy in patients with type-2 diabetes mellitus

This study aimed to assess the possible beneficial effects of curcumin capsules as lipid-lowering effects and as a permeability glycoprotein (P-gp) inhibitor on the pharmacokinetics and pharmacodynamics of glyburide and as a P-gp substrate with glyburide in patients with type-2 diabetes mellitus. Open-label, randomized control trial was carried out for 11 days on eight type-2 diabetic patients on glyburide therapy. On the first day of the study, following the administration of 5 mg of glyburide, blood samples were collected from the patients at various time intervals ranging from 0.5 to 24 h. Blood sampling was repeated on the 11th day of the study, after treating the patients with curcumin for ten consecutive days. Glyburide concentrations changed at the second hour, Cmax was unchanged, the glucose levels were decreased, Area Under first Movement Curre (AUMC) was increased, and no patient has experienced the hypoglycaemia. The low-density lipoprotein, very-low-density lipoprotein and triglycerides were decreased significantly, and the high-density lipoprotein content increased. The co-administration of curcumin capsules with glyburide may be beneficial to the patients in better glycaemic control. The lipid lowering and antidiabetic properties of the curcumin show as a potential future drug molecule.

Decreased serum levels of free fatty acids are associated with breast cancer

BACKGROUND

Changes in the levels of lipids are associated with breast cancer (BC).

METHODS

Disease-specific serum free fatty acids (FFAs) were quantified using chip-based direct-infusion nanoelectrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (CBDInanoESI-FTICR MS) in the negative ion mode. Multiple point internal standard calibration curves between the concentration ratios of fatty acids (i.e., C16:1, C18:3, C18:2, C18:1, C20:4, and C22:6) to internal standards (C17:1 for C16:1, C18:3, C18:2, and C18:1, C21:0 for C20:4 and C22:6) and their corresponding intensity ratios were established with a correlation coefficient of greater than 0.986.

RESULTS

Data from 342 serum samples including 202 healthy controls and 140 BC patients indicate that serum concentrations of FFAs in patients with BC were significantly decreased compared with those in healthy controls. A panel of C16:1, C18:3, C18:2, C20:4, and C22:6 showed an excellent diagnostic ability to differentiate the patients with early stage BC from healthy controls, with the area under the receiver operating characteristics (ROC) curve of 0.953, a sensitivity of 83.3%, and a specificity of 87.1%.

CONCLUSION

Our findings suggest that these FFAs may be a valuable biomarker panel for the early-stage detection of BC.

Application of proteomics in diagnosis of ADHD, schizophrenia, major depression, and suicidal behavior

This report focuses on the application of different proteomic techniques in diagnosis and treatment of psychiatric disorders such as major depression, suicidal behavior, schizophrenia, and attention deficit/hyperactivity disorder (ADHD). Firstly, we briefly describe different analytic approaches that can be applied for the discovery of specific biomarkers for diagnosing the above disorders, as well as for monitoring the effect of their treatment. Secondly, we discussed the types of biomarkers in general used in biomedicine for characterizing different disorders and diseases. Next, the potential applications of these biomarkers for diagnosing and managing major depression, suicidal behavior, schizophrenia, and ADHD are discussed in details. Forensic aspects of these biomarkers for the above disorders are also considered. Finally, we discuss the potential of specific biomarkers for distinguishing between comorbid psychiatric disorders in clinical setup as well as their potential for understanding mechanisms underlying the disorders and in discovery of new treatment strategies.

Inhibitory potential of Grifola frondosa bioactive fractions on α-amylase and α-glucosidase for management of hyperglycemia

This study examined the inhibitory effects of Grifola frondosa (GF), a medicinal mushroom popularly consumed in traditional medicine and health food, on digestive enzymes related to type 2 diabetes; chemical profiles and inhibitory kinetics of its bioactive fractions were also analyzed. Results showed that all GF extracts showed weak anti-α-amylase activity; however, strong anti-α-glucosidase activity was noted on GF n-hexane extract (GF-H). Further fractionation confirmed that compared with acarbose (a commercial α-glucosidase inhibitor), the nonpolar fraction of GF possessed a stronger anti-α-glucosidase activity but a weaker anti-α-amylase activity. These activities were not derived from ergosterol and ergosterol peroxide, two major compounds of this fraction. The inhibitory kinetics of GF-H on α-glucosidase was competitive inhibition. GF-H was as good as acarbose in inhibiting the starch digestion in vitro. Oleic acid and linoleic acid could be the major active constituents that have contributed to the potency of GF in inhibiting α-glucosidase activity.

Fish oil and fenofibrate prevented phosphorylation-dependent hepatic sortilin 1 degradation in Western diet-fed mice

Obesity and diabetes are associated with hepatic triglyceride overproduction and hypertriglyceridemia. Recent studies have found that the cellular trafficking receptor sortilin 1 (Sort1) inhibits hepatic apolipoprotein B secretion and reduces plasma lipid levels in mice, and its hepatic expression was negatively associated with plasma lipids in humans. This study investigated the regulation of hepatic Sort1 under diabetic conditions and by lipid-lowering fish oil and fenofibrate. Results showed that hepatic Sort1 protein, but not mRNA, was markedly lower in Western diet-fed mice. Knockdown of hepatic Sort1 increased plasma triglyceride in mice. Feeding mice a fish oil-enriched diet completely restored hepatic Sort1 levels in Western diet-fed mice. Fenofibrate also restored hepatic Sort1 protein levels in Western diet-fed wild type mice, but not in peroxisome proliferator-activated receptor α (PPARα) knock-out mice. PPARα ligands did not induce Sort1 in hepatocytes in vitro. Instead, fish oil and fenofibrate reduced circulating and hepatic fatty acids in mice, and n-3 polyunsaturated fatty acids prevented palmitate inhibition of Sort1 protein in HepG2 cells. LC/MS/MS analysis revealed that Sort1 phosphorylation at serine 793 was increased in obese mice and in palmitate-treated HepG2 cells. Mutations that abolished phosphorylation at Ser-793 increased Sort1 stability and prevented palmitate inhibition of Sort1 ubiquitination and degradation in HepG2 cells. In summary, therapeutic strategies that prevent posttranslational hepatic Sort1 down-regulation in obesity and diabetes may be beneficial in improving dyslipidemia.

Adaptive cellular stress pathways as therapeutic targets of dietary phytochemicals: focus on the nervous system

During the past 5 decades, it has been widely promulgated that the chemicals in plants that are good for health act as direct scavengers of free radicals. Here we review evidence that favors a different hypothesis for the health benefits of plant consumption, namely, that some phytochemicals exert disease-preventive and therapeutic actions by engaging one or more adaptive cellular response pathways in cells. The evolutionary basis for the latter mechanism is grounded in the fact that plants produce natural antifeedant/noxious chemicals that discourage insects and other organisms from eating them. However, in the amounts typically consumed by humans, the phytochemicals activate one or more conserved adaptive cellular stress response pathways and thereby enhance the ability of cells to resist injury and disease. Examplesof such pathways include those involving the transcription factors nuclear factor erythroid 2-related factor 2, nuclear factor-κB, hypoxia-inducible factor 1α, peroxisome proliferator-activated receptor γ, and forkhead box subgroup O, as well as the production and action of trophic factors and hormones. Translational research to develop interventions that target these pathways may lead to new classes of therapeutic agents that act by stimulating adaptive stress response pathways to bolster endogenous defenses against tissue injury and disease. Because neurons are particularly sensitive to potentially noxious phytochemicals, we focus on the nervous system but also include findings from other cell types in which actions of phytochemicals on specific signal transduction pathways have been more thoroughly studied.

G-protein-coupled estrogen receptor as a new therapeutic target for treating coronary artery disease

Coronary heart disease (CHD) continues to be the greatest mortality risk factor in the developed world. Estrogens are recognized to have great therapeutic potential to treat CHD and other cardiovascular diseases; however, a significant array of potentially debilitating side effects continues to limit their use. Moreover, recent clinical trials have indicated that long-term postmenopausal estrogen therapy may actually be detrimental to cardiovascular health. An exciting new development is the finding that the more recently discovered G-protein-coupled estrogen receptor (GPER) is expressed in coronary arteries-both in coronary endothelium and in smooth muscle within the vascular wall. Accumulating evidence indicates that GPER activation dilates coronary arteries and can also inhibit the proliferation and migration of coronary smooth muscle cells. Thus, selective GPER activation has the potential to increase coronary blood flow and possibly limit the debilitating consequences of coronary atherosclerotic disease. This review will highlight what is currently known regarding the impact of GPER activation on coronary arteries and the potential signaling mechanisms stimulated by GPER agonists in these vessels. A thorough understanding of GPER function in coronary arteries may promote the development of new therapies that would help alleviate CHD, while limiting the potentially dangerous side effects of estrogen therapy.