Decreased Glucose Utilization Research Articles

Acclimation to hypercarbia protects cardiac contractility and alters tissue carbohydrate metabolism in the Amazonian armored catfish Pterygoplichthys pardalis

The armored catfish Pterygoplichthys pardalis tolerates environmental hypercarbia, high partial pressures of CO2 (\(P_{{{\text{CO}}_{ 2} }}\)), by preferentially protecting intracellular pH (pHi) in the face of extracellular acidosis. This response is associated with ionic changes which may disrupt contractility in cardiac muscle, and it is not known whether acclimation to hypercarbia provides protection against these changes. We studied the influence of different \(P_{{{\text{CO}}_{ 2} }}\) acclimation histories on cardiac muscle function using isometrically contracting ventricular strip preparations. Fish were held for >4 months at 21 mmHg \(P_{{{\text{CO}}_{ 2} }}\) and then exposed to normocarbia (6 mmHg \(P_{{{\text{CO}}_{ 2} }}\)) for either 15 h or 5–6 days. Acclimation to chronic hypercarbia eliminated the negative inotropic effects of in vitro hypercarbia, decreased extracellular Ca2+ sensitivity, and reduced maximum pacing frequency in ventricular strip preparations. Fish acclimated to chronic hypercarbia also exhibited hepatic glycogen and plasma glucose accumulation, and lower plasma lactate levels compared to fish acclimated to normocarbia for 5–6 days. We suggest chronic hypercarbia may induce cardiac remodeling to protect contractility and reduce the energetic demands of pHi regulation. The activation of HCO3− synthesis pathways may decrease glucose utilization and enhance carbohydrate stores, potentially providing protection against hypoxia, a stressor frequently encountered in conjunction with hypercarbia in the Amazon.

METABOLIC ARREST DURING HIBERNATION! CARDIAC REGULATION OF PYRUVATE DEHYDROGENASE (PDH) IN A HIBERNATING GROUND SQUIRREL (ICTIDOMYS TRIDECEMLINEATUS)

Many mammals use hibernation to survive freezing temperatures and lack of food during winter months by cycling through periods of torpor-arousal. Hibernating 13-line ground squirrels (Ictidomys tridecemlineatus) native to the North American prairies utilize variety of physiological adaptations to survive the harsh winter conditions. Pyruvate dehydrogenase (PDH) is a vital regulatory enzyme that links glycolysis and tricarboxylic acid cycle. Inhibition of PDH activity via three serine phosphorylation sites (p-S293, p-S300, and p-S232) regulates the metabolic flux through the TCA cycle, decrease glucose utilization, facilitate lipid metabolism, and overall provide metabolic adaptation to nutrient availability. The purpose of this study was to explore the post-translational regulation of pyruvate dehydrogenase mediated by mitochondrial serine/threonine kinases, PDHKs (1-4) during topor-arousal cycle in cardiac tissues of 13-line ground squirrels. Liver and muscle tissues were also included in the study for multi-tissue comparison purpose. A combination of Luminex Multiplex Assay and western immunoblotting were used to measure the protein expression levels of total PDH, three phospho-PDH modifications, and four PDH kinases in euthermic control, entrance, late torpor, and interbout arousal cycles (n=4, p<0.05). Heart showed significant 2-3 fold upregulation in PDH-pS293 and PDH-pS300 levels during torpor compared to the euthermic-control, indicating a possible shut down of PDH activity during hibernation. Subsequently, cardiac PDHK4 (with high affinity for pS293 and pS300) showed a 2-fold increase during torpor. Liver showed 30-fold increase in PDH-pS300 during torpor with PDHK1 showing 2-fold increase during torpor and arousal. As expected skeletal muscle showed limited PDH regulation during torpor-arousal cycle. Overall, heart and liver showed strong inhibitory PDH regulation, indicating a possible decrease in glucose utilization through glycolysis and an increase in β-oxidation of lipids during times of extended starvation in 13-line ground squirrels. This study provides us with greater insight into the biochemical mechanisms controlling the teeter-totter between glucose oxidation and β-oxidation of fatty acids, a central theme behind recent cardiac hypertension and type-II diabetes studies.

Enzymatic passaging of human embryonic stem cells alters central carbon metabolism and glycan abundance.

To realize the potential of human embryonic stem cells (hESCs) in regenerative medicine and drug discovery applications, large numbers of cells that accurately recapitulate cell and tissue function must be robustly produced. Previous studies have suggested that genetic instability and epigenetic changes occur as a consequence of enzymatic passaging. However, the potential impacts of such passaging methods on the metabolism of hESCs have not been described. Using stable isotope tracing and mass spectrometry-based metabolomics, we have explored how different passaging reagents impact hESC metabolism. Enzymatic passaging caused significant decreases in glucose utilization throughout central carbon metabolism along with attenuated de novo lipogenesis. In addition, we developed and validated a method for rapidly quantifying glycan abundance and isotopic labeling in hydrolyzed biomass. Enzymatic passaging reagents significantly altered levels of glycans immediately after digestion but surprisingly glucose contribution to glycans was not affected. These results demonstrate that there is an immediate effect on hESC metabolism after enzymatic passaging in both central carbon metabolism and biosynthesis. HESCs subjected to enzymatic passaging are routinely placed in a state requiring re-synthesis of biomass components, subtly influencing their metabolic needs in a manner that may impact cell performance in regenerative medicine applications.

Diabetes Mellitus: An Ayurvedic View

Diabetes Mellitus refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. Several distinct types of DM are caused by a complex interaction of genetics and environmental factors. Depending on the aetiology of the DM factors contributing to hyperglycemia include reduced insulin secretion, decreased glucose utilization, and increased glucose production. Diabetes is known as Prameha, which has been discussed in Ayurveda since antiquity. Caraka has given exhaustive description of the disease Prameha which ultimately progresses towards Madhumeha or the sweetness of urine in addition to Polyurea.

Distinct Changes in Adipose Tissue and Muscle in Response to Excess Systemic Glucose in Rats

Objective: Excess nutrients can cause insulin resistance in skeletal muscle in vivo. However, the response of white adipose tissue is less clear. In a chronic glucose infusion model (1 and 4 days), distinct adaptations in muscle and white adipose tissue have been described. Muscle developed sustained insulin resistance after 1 day of glucose infusion but adipose tissue did not. Exactly what distinguishes adipose tissue from muscle in response to glucose oversupply remains to be determined. The aim of the present study was to investigate the early (3-8 h) metabolic and signaling changes that take place in epididymal fat pads, and to a lesser extent, red quadriceps muscle, using an acute glucose infusion model. Methods: Hyperglycemia (~11 mM) and hyperinsulinemia were generated by infusing glucose into rats for 3, 5, or 8 h. Results: We found that similar to red quadriceps muscle, AMPactivated protein kinase (AMPK) activity was diminished in epididymal fat pads of the glucose infused rats. Yet, both glucose uptake and triglyceride synthesis were increased in epididymal fat whereas muscle showed a progressive decrease in glucose utilization and glycogen synthesis after 5 h. Insulin signaling, as determined by Akt phosphorylation (Ser473), remained intact in epididymal fat but not in red quadriceps muscle. Furthermore, unlike muscle, there was no evidence of PKC activation in epididymal fat. Conclusion: The results confirmed and extend findings that suggest white adipose tissue responds very differently than muscle when exposed to sustained elevated concentration of glucose.

Ethanol production by a Paenibacillus species isolated from an Icelandic hot spring – Production yields from complex biomass

Ethanol production using Paenibacillus strain J2 was studied on carbohydrates and lignocellulosic biomass hydrolysates including grass (Phleum pratense) and barley straw (Hordeum vulgare). The strain has a broad substrate spectrum; fermentation of glucose yielded ethanol (major product), acetate, butyrate (minor), hydrogen, and carbon dioxide. At glucose concentrations below 30 mM fermentation was not inhibited. Higher substrate loadings resulted in decreased glucose utilization and a shift of end products towards butyrate. The maximum yields of ethanol were 1.45 mol ethanol mol glucose -1 . The end products from lignocellulosic (4.5 g L -1 dw) biomass hydrolysates pretreated with 0.5% HCl or NaOH (control was unpretreated) prior to cellulase treatment were investigated. Ethanol production from cellulose hydrolysates without chemical pre-treatment yielded 5.5 mM ethanol g -1 with lower yields from paper and lignocellulosic biomasses (1.2-1.7 mM g -1 ). Ethanol production was enhanced by dilute acid or base pre-treatment combined with enzymatic treatment with the highest yields from grass (3.2 mM ethanol g -1

Hypoxia decreases glucagon-like peptide-1 secretion from the GLUTag cell line.

Glucagon-like peptide-1 (GLP-1), an incretin hormone, is secreted from L cells located in the intestinal epithelium. It is known that intestinal oxygen tension is decreased postprandially. In addition, we found that the expression of hypoxia-inducible factor-1α (HIF-1α), which accumulates in cells under hypoxic conditions, was significantly increased in the colons of mice with food intake, indicating that the oxygen concentration is likely reduced in the colon after eating. Therefore, we hypothesized that GLP-1 secretion is affected by oxygen tension. We found that forskolin-stimulated GLP-1 secretion from GLUTag cells, a model of intestinal L cells, is suppressed in hypoxia (1% O2). Forskolin-stimulated elevations of preproglucagon (ppGCG) and proprotein convertase 1/3 (PC1/3) mRNA expression were decreased under hypoxic conditions. The finding that H89, a protein kinase A (PKA) inhibitor, inhibited the forskolin-stimulated increase of ppGCG and PC1/3 indicated that the cAMP-PKA pathway is involved in the hypoxia-induced suppression of the genes. Hypoxia decreased hexokinase 2 mRNA and protein expression and increased lactate dehydrogenase A mRNA and protein expression. Concomitantly, lactate production was increased and ATP production was decreased. Together, the results indicate that hypoxia decreases glucose utilization for ATP production, which probably causes a decrease in cAMP production and in subsequent GLP-1 production. Our findings suggest that the postprandial decrease in oxygen tension in the intestine attenuates GLP-1 secretion.

Antidiabetic activity of Randia dumetorum against streptozotocin (STZ) induced diabetics in rats

In the present investigates the antidiabetic activity of Randia dumetorum against streptozotocin (stz) induced diabetics in rats. The rats treated with Streptozotocin showed a significant increased in glucose level and altered level of lipid profile, heamoglobin and insulin were observed. The mechanism underlying STZ hyperglycemia in diabetes mellitus involves over-production (excessive hepatic glycogenolysis and gluconeogenesis) and decreased utilization of glucose by the tissues. Fifteen days administration of ethanolic extract of leaf of the Randia dumetorum (500mg/kg b.wt.) and standard as glibenclamide (0.25mg/kg ) to diabetic rats resulted in significant reduction in blood glucose level, restored heamoglobin, and lipid profile as compared to diabetic rats. The present study suggests that the Randia dumetorum leaves extracts had synergetic hypoglycemic and hypolipidemic effect revealed by decreased glucose, lipid levels and heamoglobin therefore attribute to therapeutic value of the Randia dumetorum extracts of leaves to combat the diabetic condition in rats. The effect of Randia dumetorum leaves was better than glibenclamide. The potential activity of Randia dumetorum leaves may due to the presence of phytochemicals.

Reduced glucose utilization underlies seizure protection with dietary therapy in epileptic EL mice

Dietary therapy has been used to treat many individuals with epilepsy whose seizures are refractory to antiepileptic drugs. The mechanisms for how dietary therapy confers seizure protection are currently not well understood. We evaluated the acute effects of glucose and β-hydroxybutyrate (the major circulating ketone body) in conferring seizure protection to the EL mouse, a model of multifactorial idiopathic generalized epilepsy. EL mice were fed either an unrestricted standard diet or a calorie-restricted standard diet to achieve a body weight reduction of 20–23%. d-Glucose, 2-deoxy-d-glucose, and β-hydroxybutyrate were supplemented in the drinking water of calorie-restricted mice for 2.5h prior to seizure testing to simulate the effect of increased glucose availability, decreased glucose utilization, and increased ketone availability, respectively. Seizure susceptibility, body weight, plasma glucose, and β-hydroxybutyrate were measured over a nine-week treatment period. Additionally, excitatory and inhibitory amino acids were measured in the brains of mice using 1H NMR. Glutamate decarboxylase activity was also measured to evaluate the connection between dietary therapy and brain metabolism. We found that lowering of glucose utilization is necessary to confer seizure protection with long-term (>4weeks) calorie restriction, whereas increased ketone availability did not affect seizure susceptibility. In the absence of long-term calorie restriction, however, reduced glucose utilization and increased ketone availability did not affect seizure susceptibility. Brain excitatory and inhibitory amino acid content did not change with treatment, and glutamate decarboxylase activity was not associated with seizure susceptibility. We demonstrated that reduced glucose utilization is necessary to confer seizure protection under long-term calorie restriction in EL mice, while acute ketone supplementation did not confer seizure protection. Further studies are needed to uncover the mechanisms by which glucose utilization influences seizure susceptibility.

Spatial memory impairment is associated with hippocampal insulin signals in ovariectomized rats.

Estrogen influences memory formation and insulin sensitivity. Meanwhile, glucose utilization directly affects learning and memory, which are modulated by insulin signals. Therefore, this study investigated whether or not the effect of estrogen on memory is associated with the regulatory effect of this hormone on glucose metabolism. The relative expression of estrogen receptor β (ERβ) and glucose transporter type 4 (GLUT4) in the hippocampus of rats were evaluated by western blot. Insulin level was assessed by ELISA and quantitative RT-PCR, and spatial memory was tested by the Morris water maze. Glucose utilization in the hippocampus was measured by 2-NBDG uptake analysis. Results showed that ovariectomy impaired the spatial memory of rats. These impairments are similar as the female rats treated with the ERβ antagonist tamoxifen (TAM). Estrogen blockade by ovariectomy or TAM treatment obviously decreased glucose utilization. This phenomenon was accompanied by decreased insulin level and GLUT4 expression in the hippocampus. The female rats were neutralized with hippocampal insulin with insulin antibody, which also impaired memory and local glucose consumption. These results indicated that estrogen blockade impaired the spatial memory of the female rats. The mechanisms by which estrogen blockade impaired memory partially contributed to the decline in hippocampal insulin signals, which diminished glucose consumption.

Long-chain acylcarnitine content determines the pattern of energy metabolism in cardiac mitochondria

In the heart, a nutritional state (fed or fasted) is characterized by a unique energy metabolism pattern determined by the availability of substrates. Increased availability of acylcarnitines has been associated with decreased glucose utilization; however, the effects of long-chain acylcarnitines on glucose metabolism have not been previously studied. We tested how changes in long-chain acylcarnitine content regulate the metabolism of glucose and long-chain fatty acids in cardiac mitochondria in fed and fasted states. We examined the concentrations of metabolic intermediates in plasma and cardiac tissues under fed and fasted states. The effects of substrate availability and their competition for energy production at the mitochondrial level were studied in isolated rat cardiac mitochondria. The availability of long-chain acylcarnitines in plasma reflected their content in cardiac tissue in the fed and fasted states, and acylcarnitine content in the heart was fivefold higher in fasted state compared to the fed state. In substrate competition experiments, pyruvate and fatty acid metabolites effectively competed for the energy production pathway; however, only the physiological content of acylcarnitine significantly reduced pyruvate and lactate oxidation in mitochondria. The increased availability of long-chain acylcarnitine significantly reduced glucose utilization in isolated rat heart model and in vivo. Our results demonstrate that changes in long-chain acylcarnitine contents could orchestrate the interplay between the metabolism of pyruvate-lactate and long-chain fatty acids, and thus determine the pattern of energy metabolism in cardiac mitochondria.

Rol del Magnesio en la Eficacia de Fármacos Hipoglicemiantes

El objetivo de este trabajo fue el de demostrar que la deficiencia de magnesio inhibe el uso de glucosa, estimulada por la insulina, basal y exógena, e hipoglicemiantes orales. Se utilizaron 21 ratas albinas (250 - 300 g) a las cuales se les extrajo el muscúlo sóleo, para incubación en medio Ringer-Krebs, con presencia o ausencia de magnesio y con una cantidad conocida de glucosa (6 x 10-3 mol/L). El dosaje de las muestras obtenidas de los medios se realizó antes y después de la incubación, con una prueba de glucosa enzimática, realizándose las lecturas en espectrofotómetro. El estudio se dividió en tres etapas: en la primera, se vió la interacción con calcio y magnesio; en la segunda, la inleracción con insulina a una concentración de 1 mU/L; y en la tercera, la interacción con hipoglicemiantes orales: cIorpropamida y glibencIamida. Observamos mayor utilización de glucosa por parte del músculo en los medios que contenían tanto calcio como magnesio, que en los que no tenían magnesio pero sí calcio; esto se vió tanto con la insulina basal como exógena. En la interacción con sulfonilúreas existió una disminución del uso de glucosa en el medio sin magnesio; siendo mayor ésta con la sulfonilúrea de primera generación que con la de segunda generación. Estos resultados nos sugieren que los niveles de utilización tisular de glucosa basal y estimulada por hipoglicemiantes son dependientes de la concentración de magnesio, encontrándose disminuída en situaciones de hipomagnesemia.

The Furan Fatty Acid Metabolite CMPF Is Elevated in Diabetes and Induces β Cell Dysfunction

Gestational diabetes (GDM) results from failure of the β cells to adapt to increased metabolic demands; however, the cause of GDM and the extremely high rate of progression to type 2 diabetes (T2D) remains unknown. Using metabolomics, we show that the furan fatty acid metabolite 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF) is elevated in the plasma of humans with GDM, as well as impaired glucose-tolerant and T2D patients. In mice, diabetic levels of plasma CMPF induced glucose intolerance, impaired glucose-stimulated insulin secretion, and decreased glucose utilization. Mechanistically, we show that CMPF acts directly on the β cell, causing impaired mitochondrial function, decreasing glucose-induced ATP accumulation, and inducing oxidative stress, resulting in dysregulation of key transcription factors and ultimately reduced insulin biosynthesis. Importantly, specifically blocking its transport through OAT3 or antioxidant treatment could prevent CMPF-induced β cell dysfunction. Thus, CMPF provides a link between β cell dysfunction and GDM/T2D that could be targeted therapeutically.

Laboratory protocols in the diagnosis of gestational diabetes

Gestational diabetes (GD) represents any degree of glucose intolerance that is first detected during the pregnancy. The sensitivity of muscle and adipose tissues to insulin decreases during the pregnancy (at the end of the second trimester for 50%), leading to the decreased glucose utilization and increased degradation of the maternal fat and protein. GD occurs in 2-3% of all pregnancies and it accounts for 90% of all forms of diabetes during the pregnancy, and subsequently the risk of diabetes occurrence in these women is 30 to 60% higher. Adequate glycemic control, especially during organogenesis, helps to reduce the frequency of macrosomia, difficult and premature deliveries, abortions, congenital malformations, perinatal mortality, diabetic nephropathy mother preeclampsia and eclampsia. There are different recommendations for blood glucose values for the diagnosis of GD in the world and in our country. The aim of this study is to present the protocols and recommendations which are used by us for the diagnosis of GD.

Neuropsychiatric disorders and cognitive dysfunction in patients with Cushing's disease

Objective To review the main neuropsychiatric disorders and cognitive deficits in patients with Cushing's disease (CD) and the associated pathophysiological mechanisms underlying CD. These mechanistic details may provide recommendations for preventing or treating the cognitive impairments and mood disorders in patients with CD. Data sources Data were obtained from papers on psychiatric and cognitive complications in CD published in English within the last 20 years. To perform the PubMed literature search, the following keywords were input: cushing's disease, cognitive, hippocampal, or glucocorticoids. Study selection Studies were selected if they contained data relevant to the topic addressed in the particular section. Because of the limited length of this article, we have frequently referenced recent reviews that contain a comprehensive amalgamation of literature rather than the actual source papers. Results Patients with active CD not only suffer from many characteristic clinical features, but also show some neuropsychiatric disorders and cognitive impairments. Among the psychiatric manifestations, the common ones are emotional instability, depressive disorder, anxious symptoms, impulsivity, and cognitive impairment. Irreversible effects of previous glucocorticoid (GC) excess on the central nervous system, such as hippocampal and the basal ganglia, is the most reasonable reason. Excess secretion of cortisol brings much structural and functional changes in hippocampal, such as changes in neurogenesis and morphology, signaling pathway, gene expression, and glutamate accumulation. Hippocampal volume loss can be found in most patients with CD, and decreased glucose utilization caused by GCs may lead to brain atrophy, neurogenesis impairment, inhibition of long-term potentiation, and decreased neurotrophic factors; these may also explain the mechanisms of GC-induced brain atrophy and hippocampal changes. Conclusions Brain atrophy and hippocampal changes caused by excess secretion of cortisol are thought to play a significant pathophysiological role in the etiology of changes in cognitive function and psychiatric disturbances. The exact mechanisms by which GCs induce hippocampal volume loss are not very clear till now. So, further investigations into the mechanisms by which GCs affect the brain and the effective coping strategy are essential.

Genetic Inactivation of Pyruvate Dehydrogenase Kinases Improves Hepatic Insulin Resistance Induced Diabetes

Pyruvate dehydrogenase kinases (PDK1-4) play a critical role in the inhibition of the mitochondrial pyruvate dehydrogenase complex especially when blood glucose levels are low and pyruvate can be conserved for gluconeogenesis. Under diabetic conditions, the Pdk genes, particularly Pdk4, are often induced, and the elevation of the Pdk4 gene expression has been implicated in the increased gluconeogenesis in the liver and the decreased glucose utilization in the peripheral tissues. However, there is no direct evidence yet to show to what extent that the dysregulation of hepatic Pdk genes attributes to hyperglycemia and insulin resistance in vivo. To address this question, we crossed Pdk2 or Pdk4 null mice with a diabetic model that is deficient in hepatic insulin receptor substrates 1 and 2 (Irs1/2). Metabolic analyses reveal that deletion of the Pdk4 gene had better improvement in hyperglycemia and glucose tolerance than knockout of the Pdk2 gene whereas the Pdk2 gene deletion showed better insulin tolerance as compared to the Pdk4 gene inactivation on the Irs1/2 knockout genetic background. To examine the specific hepatic effects of Pdks on diabetes, we also knocked down the Pdk2 or Pdk4 gene using specific shRNAs. The data also indicate that the Pdk4 gene knockdown led to better glucose tolerance than the Pdk2 gene knockdown. In conclusion, our data suggest that hepatic Pdk4 may be critically involved in the pathogenesis of diabetes.

Overexpression of AQP7 improves insulin resistance in 3T3-L1 adipocytes

Objective To investigate the role of aquaglyceroporin 7 (AQP7) played in insulin resistance of adipocytes.Methods 3T3-L1 preadipocyte cells were induced to be fully differentiated adipocytes and then insulin resistance was induced by dexamethasone (DXM).Adenovirus vector over-expressing AQP7 (Ad-AQP7) was constructed and transfected into adipocytes.Expression levels of AQP7,glycerol release from adipocytes,changes in glucose consumption,and phosphorylated protein kinase B (p-PKB) were measured.Results 48 h-treatment of dexamethasone significantly inhibited the expression level of p-PKB (P＜0.01) and decreased glucose utilization,as well as down-regulation of AQP7 (P＜0.01).Over-expression of AQP7 by transfecting Ad-AQP7 to dexamethasone (DXM)-induced insulin resistant adipocytes could improve glycerol secretion of adipocytes,being consistent with the restoration of p-PKB expression levels and glucose consumption.Conclusions AQP7 may improve in molecular mechanism of insulin resistance in adipocytes.Overexpression of AQP7 may contribute to the improvement of insulin resistance in adipocytes and might be correlated with better phosphorylation of PKB. Key words: Aquaglyceroporin 7 ; Insulin resistance ; Protein kinase B

Abstract 3714: Metabolomics and proteomics reveal inhibition of glycolysis in withaferin A-mediated prevention of mammary carcinogenesis in MMTV-neu mice.

Abstract Plants used in Ayurvedic medicine, which has been practiced for centuries in India for the treatment of different ailments, continue to draw attention for identification of novel small molecule cancer chemopreventive agents. Withaferin A (WA) is one such promising small molecule constituent of the medicinal plant Withania somnifera (also known as Ashwagandha) with in vivo activity against xenografted human breast cancer cells. We have also shown recently that mammary cancer development and pulmonary metastasis in MMTV-neu transgenic mice is inhibited significantly by WA administration. In the present study, we performed metabolomics profiling using plasma and tumor tissues (n=8) and proteomics profiling using tumor tissues (n=3) from control and WA-treated MMTV-neu mice to gain insights into the mechanism underlying in vivo preventive effect of WA. A total of 320 and 328 biochemicals of known identity were detectable in the plasma and tumor tissue, respectively. The WA-mediated mammary cancer prevention in MMTV-neu mice was associated with a statistically significant alteration (P≤0.05) in the levels of 76 biochemicals in the plasma (24 increase, 52 decrease). Metabolomics using tumor tissues revealed alterations in the levels of 24 biochemicals (2 increase, 24 decrease) upon WA administration. One change that was highly consistent in the plasma and tumor tissue from WA-treated mice compared to controls was a decrease in glucose utilization, glycolysis, and TCA cycle activity. Proteomics using tumor tissues confirmed downregulation of many glycolysis-related proteins in the tumor of WA-treated mice compared with control, including M2-type pyruvate kinase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase A isoform 2. Downregulation of TCA cycle-related proteins in the tumor of WA-treated mice compared with control included pyruvate carboxylase and isocitrate dehydrogenase. Other altered biochemicals were reflective of changes in arginine metabolism, polyamine biosynthesis, glutathione metabolism, lipid metabolism, and catabolism of branched-chain amino acids. These observations indicate that WA treatment prevents mammary cancer in MMTV-neu mice by suppressing glycolysis (Warburg effect) and TCA cycle. This study was supported by the grant CA142604 awarded by the National Cancer Institute. Citation Format: Shivendra V. Singh, Eun-Ryeong Hahm, Joomin Lee, Su-Hyeong Kim, Anuradha Sehrawat, Julie A. Arlotti. Metabolomics and proteomics reveal inhibition of glycolysis in withaferin A-mediated prevention of mammary carcinogenesis in MMTV-neu mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3714. doi:10.1158/1538-7445.AM2013-3714

Defects in Free Fatty Acid Oxidation and Glucose Oxidation Coexist in the Failing Heart

Purpose Abnormalities of energy substrate utilization exist in the failing heart and contribute to disease progression. These abnormalities are attributed by some to decreased glucose utilization and by others to reduced free fatty acid (FFA) oxidation. In the normal heart, recruitment of the glucose transport proteins GLUT-1 and -4 is a mechanism by which the heart increases glucose transport for metabolism while up- or down-expression of muscle carnitine palmitoyl transferase (mCPT-1) provides directionally concordant regulation of FFA oxidation. In the present study we tested the hypothesis that defects of both GLUT-1 and -4 and mCPT-1 coexist in the failing LV myocardium. Methods and Materials Studies were performed in LV tissue homogenate obtained from 6 normal (NL) donor human hearts, 6 explanted failing human hearts with dilated cardiomyopathy (DCM) and 6 failing human hearts with ischemic cardiomyopathy (ICM) and from 6 NL and 7 coronary microembolization-induced heart failure (HF) dogs. Protein levels of the glucose transporters, GLUT-1 and -4 where measured in human and dog hearts and mCPT-1 in dog hearts using specific antibodies and Western blotting and bands quantified in densitometric units (du). Results Compared to NL, protein levels of GLUT-1 and -4 were significantly decreased in DCM, ICM and HF dogs and mCPT-1 was significantly decreased in HF dogs (Table). Conclusions Abnormalities of key regulators of FFA oxidation and glucose oxidation coexist in the failing heart regardless of HF etiology and favor energy deprivation. Coexistence of these abnormalities in the failing heart can act to limit the benefits that may be derived from therapies that target. Protein Expression in LV MyocardiumNL-Human DonorDCMICMGLUT-1 (du)15.7 ± 0.910.6 ± 0.3 * 0.41 ± 0.02 * GLUT-4 (du)31.7 ± 1.719.5 ± 1.8 * 16.6 ± 1.4 * NL-DogHF-DogGLUT-1 (du)20.1 ± 3.04.7 ± 0.5 † GLUT-4 (du)24.5 ± 3.116.2 ± 0.8 † mCPT-1 (du)1.40 ± 0.070.53 ± 0.06 † *=p

Anti diabetic effect of ethanolic extract of leaves of Ocimum sanctum in alloxan induced diabetes in rats

Background: Diabetes mellitus refers to a group of common metabolic disorders that share the phenotype of hyperglycemia resulting from defects of reduced insulin secretion, decreased glucose utilization and increase in glucose production. It is estimated that there are currently 285 million people worldwide and this number is set to increase to 438 million by the year 2030. India has the highest number of patients with known diabetes worldwide, with a prevalence of 11.6%. The aim of the study was to evaluate the anti diabetic activity of ethanolic extract of leaves of plant Ocimum sanctum in alloxan induced diabetes in rats. Methods: The study was conducted on 4 groups of 6 rats each to evaluate the hypoglycaemic effect of ethanolic extract of Ocimum sanctum. Glibenclamide was used as a standard drug and the results were compared in reference to it. Tween 80 was given for both normal and diabetic control groups. The fasting blood sugar levels were recorded on 1 st , 3 rd , 5 th , 7 th , 10 th days by glucometer. Resul ts: The results indicate that the test compound ethanolic extract of Ocimum sanctum has significant and sustained oral hypoglycaemic activity, comparable with the hypoglycaemic effect of glibenclamide, a sulfonylurea. Conclusion: The hy poglycaemic potential of the test compound is found to be comparable with that of the standard drug glibenclamide.