2-(n-(7-nitrobenz-2-oxa-1-3-diazol-4-yl)amino)-2-deoxyglucose and Body-Weight

Obesity may cause several metabolic complications, including insulin resistance and type 2 diabetes mellitus. Despite great advances in medicine, people still keep exploring novel and effective drugs for treatment of obesity and insulin resistance. The aim of this study was to survey if baicalin might ameliorate obesity-induced insulin resistance and to explore its signal mechanisms in skeletal muscles of mice. Diet-induced obese (DIO) mice were given 50 mg/kg baicalin intraperitoneally (i.p.) once a day for 21 days, and C2C12 myotubes were treated with 100, 200, 400 μM baicalin for 12 h in this study. Then insulin resistance indexes and insulin signal protein levels in skeletal muscles were examined. We discovered that administration of baicalin decreased food intake, body weight, HOMA-IR and NT-PGC-1α levels, but enhanced GLUT4, PGC-1α, pP38MAPK, pAKT and pAS160 contents, as well as GLUT4 mRNA, PGC-1α mRNA, PPARγ mRNA, GLUT1 mRNA expression in skeletal muscles of obese mice and myotubes of C2C12 cells, and reversed high fat diet-induced glucose and insulin intolerance, hyperglycemia and insulin resistance in the mice. These results suggest that baicalin is a powerful and promising agent for treatment of obesity and insulin resistance via Akt/AS160/GLUT4 and P38MAPK/PGC1α/GLUT4 pathway.

Topics: 4-Chloro-7-nitrobenzofurazan; Animals; Blood Glucose; Body Weight; Cell Line; Cell Membrane; Deoxyglucose; Feeding Behavior; Flavonoids; Glucose Tolerance Test; Glucose Transporter Type 1; Glucose Transporter Type 4; GTPase-Activating Proteins; Homeostasis; Injections, Intraperitoneal; Insulin Resistance; Male; Mice, Inbred C57BL; Muscle, Skeletal; Obesity; Phosphorylation; PPAR gamma; Proto-Oncogene Proteins c-akt; RNA, Messenger; Signal Transduction

In this paper, we investigated the effects of Coptis chinensis polysaccharide (CCP) on hyperglycemia and glucose intolerance in high-fat diet (HFD)-induced diabetic C57BL/6J mice. CCP was prepared by extraction from Coptis chinensis and oral given to the mice. C57BL/6J mice in each of the 5 groups (eight mice per group) were given either the normal diet (ND) (D12450B, 10% kcal% fat; Research diet, New Brunswick, NJ, USA), HFD (D12451, 45% kcal% fat; Research diet, New Brunswick, NJ, USA), or HFD with CCP of differing hardness (500, 1000, and 2000ppm) for 20 weeks. Mice given an HFD with CCP showed lowered fasting plasma glucose levels compared to HFD-fed mice. Oral and intraperitoneal glucose tolerance tests showed that CCP improves impaired glucose tolerance in HFD-fed mice. Histopathological evaluation of the pancreas showed that CCP recovers the size of the pancreatic islets of Langerhans, and increases the secretion of insulin and glucagon in HFD-fed mice. Quantitative reverse transcription polymerase chain reaction results revealed that the expression of hepatic genes involved in glucogenesis, glycogenolysis and glucose oxidation were suppressed, while those in glucose uptake, β-oxidation, and glucose oxidation in muscle were increased in mice fed HFD with CCP. CCP increased AMP-dependent kinase (AMPK) phosphorylation in 3T3-L1 pre- and mature adipocytes and improved impaired AMPK phosphorylation in the muscles and livers of HFD-induced diabetic mice. CCP stimulated phosphoinositol-3-kinase and AMPK pathway-mediated glucose uptake in 3T3-L1 adipocytes. Taken together, these results suggest that CCP has potential as an anti-diabetic agent, given its ability to suppress hyperglycemia and improve glucose intolerance by increasing glucose uptake.

Topics: 3T3-L1 Cells; 4-Chloro-7-nitrobenzofurazan; Adenylate Kinase; Adipocytes; Adipokines; Animals; Blood Glucose; Body Weight; Coptis; Cytokines; Deoxyglucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Fasting; Feeding Behavior; Gene Expression Regulation; Gluconeogenesis; Insulin; Lipids; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Polysaccharides

Evidence indicates that central galanin is involved in regulation of insulin resistance in animals. This study investigates whether type 1 galanin receptor (GAL1) in the brain mediates the ameliorative effect of galanin on insulin resistance in skeletal muscles of type 2 diabetic rats. Rats were intracerebroventricularly (i.c.v.) injected with galanin(1-13)-bradykinin(2-9) amide (M617), a GAL1 agonist, and/or Akti-1/2, an Akt inhibitor, via caudal veins once per day for 10 days. Insulin resistance in muscle tissues was evaluated by glucose tolerance and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) tests, peroxisome proliferator-activated receptor-γ (PPARγ), glucose transporter 4 (GLUT4) mRNA expression levels, Akt phosphorylation, and GLUT4 and vesicle-associated membrane protein 2 (VAMP2) concentration at plasma membranes in muscle cells. The results show that i.c.v. treatment with M617 increased glucose tolerance, 2-NBDG uptake, PPARγ levels, Akt phosphorylation, GLUT4 protein, and GLUT4 mRNA expression levels as well as GLUT4 and VAMP2 concentration at plasma membranes. All increases may be blocked by pretreatment with Akti-1/2. These results suggest that activated central GAL1 may trigger the Akt signaling pathway to alleviate insulin resistance in muscle cells. Therefore, the impact of galanin on insulin resistance is mediated mainly by GAL1 in the brain, and the GAL1 agonist may be taken as a potential antidiabetic agent for treatment of type 2 diabetes mellitus. © 2016 Wiley Periodicals, Inc.

Topics: 4-Chloro-7-nitrobenzofurazan; Animals; Blood Glucose; Body Weight; Bradykinin; Deoxyglucose; Diabetes Mellitus, Experimental; Disease Models, Animal; Galanin; Glucose Tolerance Test; Glucose Transporter Type 4; Insulin; Insulin Resistance; Male; Muscle, Skeletal; Peptide Fragments; PPAR gamma; Rats; Rats, Wistar; Receptor, Galanin, Type 1; Subcellular Fractions; Vesicle-Associated Membrane Protein 2

Alarin, a regulatory peptide, belongs to the galanin family and plays the same regulatory roles as galanin in orexigenic activity and energy metabolism. Our previous studies had found that galanin might facilitate insulin sensitivity via activation of its central receptors. To date, little is known about whether central alarin may exert similar effects on insulin sensitivity. In order to investigate this, alarin and its specific antagonist, alarin 6-25Cys, were administered into the cerebral ventricles of type 2 diabetic rats (T2DR) to evaluate the changes in insulin resistance. The results indicated that central treatment with alarin significantly increased the body weight of animals, the 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose uptake, the plasma adiponectin levels, the glucose infusion rates in hyperinsulinemic-euglycemic clamp tests, the vesicle-associated membrane protein 2 as well as glucose transporter 4 (GLUT4 (SLC2A4)) protein and mRNA levels, and the ratios of GLUT4 contents in plasma membranes to total cell membranes in adipocytes, but reduced blood glucose and plasma retinol-binding protein 4 levels. These effects of alarin may be inhibited by pretreatment with alarin 6-25Cys. The above-mentioned results suggest that the central alarin projective system may facilitate insulin sensitivity and glucose uptake via the increase in GLUT4 content and GLUT4 translocation from intracellular pools to plasma membranes in T2DR.

Topics: 4-Chloro-7-nitrobenzofurazan; Adipocytes; Adiponectin; Animals; Blood Glucose; Blotting, Western; Body Weight; Cell Membrane; Deoxyglucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Galanin-Like Peptide; Gene Expression; Glucose Transporter Type 4; Injections, Intraventricular; Insulin Resistance; Male; Peptide Fragments; Protein Transport; Rats, Wistar; Retinol-Binding Proteins, Plasma; Reverse Transcriptase Polymerase Chain Reaction; Vesicle-Associated Membrane Protein 2