Hepatic Glycogen Content Research Articles

Antidiabetic property of ethanol extract of pelargonium graveolens with constituents chemical screening

Objects: The phytochemical screening and the antihyperglycemic impact of Pelargonium gravelens were performed to judge the impact of ethanol extract using alloxan-induced diabetic rats. Methods: Intragastric ethanolic extract amount level of 220 mg/kg body weight were given to alloxan-encouraged diabetic male albino rats for four weeks. Diabetic control rats assumed the equivalent quantity of the vehicle (Dimethylsulfoxide, DMSO) were processed together with the former group. The serum insulin, liver glycogen assay and oral glucose tolerance tests were done. The chemical screening of P. graveolens specified the existence of carbohydrates, glycosides, triterpenes, cardenolides, saponins, sterols, tannins, flavonoids and catechins. Results: The diabetic-treated rats with the ethanolic extract of P. graveolens performed clear improvement of the declined glucose tolerance and hepatic glycogen content without associated excess in serum insulin concentration. Conclusions: ethanol extract of P. Graveolens improved the glucose tolerance of alloxan-treated diabetic rats.

Three weeks of time-restricted eating improves glucose homeostasis in adults with type 2 diabetes but does not improve insulin sensitivity: a randomised crossover trial

Aims/hypothesisTime-restricted eating (TRE) is suggested to improve metabolic health by limiting food intake to a defined time window, thereby prolonging the overnight fast. This prolonged fast is expected to lead to a more pronounced depletion of hepatic glycogen stores overnight and might improve insulin sensitivity due to an increased need to replenish nutrient storage. Previous studies showed beneficial metabolic effects of 6–8 h TRE regimens in healthy, overweight adults under controlled conditions. However, the effects of TRE on glucose homeostasis in individuals with type 2 diabetes are unclear. Here, we extensively investigated the effects of TRE on hepatic glycogen levels and insulin sensitivity in individuals with type 2 diabetes.MethodsFourteen adults with type 2 diabetes (BMI 30.5±4.2 kg/m2, HbA1c 46.1±7.2 mmol/mol [6.4±0.7%]) participated in a 3 week TRE (daily food intake within 10 h) vs control (spreading food intake over ≥14 h) regimen in a randomised, crossover trial design. The study was performed at Maastricht University, the Netherlands. Eligibility criteria included diagnosis of type 2 diabetes, intermediate chronotype and absence of medical conditions that could interfere with the study execution and/or outcome. Randomisation was performed by a study-independent investigator, ensuring that an equal amount of participants started with TRE and CON. Due to the nature of the study, neither volunteers nor investigators were blinded to the study interventions. The quality of the data was checked without knowledge on intervention allocation. Hepatic glycogen levels were assessed with 13C-MRS and insulin sensitivity was assessed using a hyperinsulinaemic–euglycaemic two-step clamp. Furthermore, glucose homeostasis was assessed with 24 h continuous glucose monitoring devices. Secondary outcomes included 24 h energy expenditure and substrate oxidation, hepatic lipid content and skeletal muscle mitochondrial capacity.ResultsResults are depicted as mean ± SEM. Hepatic glycogen content was similar between TRE and control condition (0.15±0.01 vs 0.15±0.01 AU, p=0.88). M value was not significantly affected by TRE (19.6±1.8 vs 17.7±1.8 μmol kg−1 min−1 in TRE vs control, respectively, p=0.10). Hepatic and peripheral insulin sensitivity also remained unaffected by TRE (p=0.67 and p=0.25, respectively). Yet, insulin-induced non-oxidative glucose disposal was increased with TRE (non-oxidative glucose disposal 4.3±1.1 vs 1.5±1.7 μmol kg−1 min−1, p=0.04). TRE increased the time spent in the normoglycaemic range (15.1±0.8 vs 12.2±1.1 h per day, p=0.01), and decreased fasting glucose (7.6±0.4 vs 8.6±0.4 mmol/l, p=0.03) and 24 h glucose levels (6.8±0.2 vs 7.6±0.3 mmol/l, p<0.01). Energy expenditure over 24 h was unaffected; nevertheless, TRE decreased 24 h glucose oxidation (260.2±7.6 vs 277.8±10.7 g/day, p=0.04). No adverse events were reported that were related to the interventions.Conclusions/interpretationWe show that a 10 h TRE regimen is a feasible, safe and effective means to improve 24 h glucose homeostasis in free-living adults with type 2 diabetes. However, these changes were not accompanied by changes in insulin sensitivity or hepatic glycogen.Trial registrationClinicalTrials.gov NCT03992248FundingZonMW, 459001013Graphical abstract

Circulating small extracellular vesicles from patients with periodontitis contribute to development of insulin resistance.

Epidemiological studies have identified the role of periodontitis in the pathogenesis of type 2 diabetes, but the underlying mechanism is poorly understood. It is well-known that small extracellular vesicles are lipid bilayer vesicles derived from cells with a diameter around 30 to 200nm. The purpose of this study was to investigate whether periodontitis induced or exacerbated insulin resistance via circulating small extracellular vesicles. Plasma small extracellular vesicles from control and periodontitis rats were intravenously injected into type 2 diabetic rats. Insulin tolerance tests, glucose tolerance tests, and the activation of the insulin signaling pathway were measured to detect the effect of the plasma small extracellular vesicles on insulin sensitivity. In addition, circulating small extracellular vesicles from patients with periodontitis with or without diabetes were isolated and co-cultured with HepG2 cells. The ability of glucose uptake was assessed using the fluorescence of 2-NBDG via flow cytometry. The activation of insulin signaling pathway was examined via Western blotting. Real time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of enzyme related to glycolysis and gluconeogenesis. Small extracellular vesicles derived from the plasma of periodontitis rats further impaired glucose tolerance and insulin tolerance in diabetic rats and significantly reduced the activation of the insulin signaling pathway in liver tissues, as evidenced by the decreased levels of p-AKT and p-GSK3β and the reduced hepatic glycogen content. For small extracellular vesicles isolated from human plasma, the concentration of small extracellular vesicles in patients with type 2 diabetes combined with periodontitis was higher than that of the healthy control and periodontitis alone. Moreover, circulating small extracellular vesicles from patients with periodontitis significantly inhibited the glucose uptake capacity and inhibited insulin signaling of HepG2 cells. Periodontitis acted as a contributing factor to exacerbate insulin resistance of type 2 diabetic rats. Plasma small extracellular vesicles played a critical role in periodontitis aggravating insulin resistance.

Stbd1-deficient mice display insulin resistance associated with enhanced hepatic ER-mitochondria contact

Starch binding domain-containing protein 1 (STBD1) is an endoplasmic reticulum (ER)-resident, glycogen-binding protein. In addition to glycogen, STBD1 has been shown to interact with several proteins implicated in glycogen synthesis and degradation, yet its function in glycogen metabolism remains largely unknown. In addition to the bulk of the ER, STBD1 has been reported to localize at regions of physical contact between mitochondria and the ER, known as Mitochondria-ER Contact sites (MERCs). Given the emerging correlation between distortions in the integrity of hepatic MERCs and insulin resistance, our study aimed to delineate the role of STBD1 in vivo by addressing potential abnormalities in glucose metabolism and ER-mitochondria communication associated with insulin resistance in mice with targeted inactivation of Stbd1 (Stbd1KO). We show that Stbd1KO mice at the age of 24 weeks displayed reduced hepatic glycogen content and aberrant control of glucose homeostasis, compatible with insulin resistance. In line with the above, Stbd1-deficient mice presented with increased fasting blood glucose and insulin levels, attenuated activation of insulin signaling in the liver and skeletal muscle and elevated liver sphingomyelin content, in the absence of hepatic steatosis. Furthermore, Stbd1KO mice were found to exhibit enhanced ER-mitochondria association and increased mitochondrial fragmentation in the liver. Nevertheless, the enzymatic activity of hepatic respiratory chain complexes and ER stress levels in the liver were not altered. Our findings identify a novel important role for STBD1 in the control of glucose metabolism, associated with the integrity of hepatic MERCs.

High doses of eugenol cause structural and functional damage to the rat liver

Eugenol is a phenolic compound found in clove extract and extensively used in traditional medicine. It is unclear whether its intake can cause positive or negative effects on liver morphology and physiology in healthy individuals. Thus, we aimed to evaluate liver parameters of rats treated with 10, 20, and 40 mg kg−1 eugenol. After 60 days of treatment, liver samples were collected and analyzed by biometric, histological, biochemical, and oxidative analyses. Our results showed that 10, 20, and 40 mg kg−1 eugenol did not alter body and liver weights, serum and hepatic ALT levels and catalase, glutathione-s-transferase, total, Ca2+, and Mg2+ ATPases activities in treated animals. However, 20 and 40 mg kg−1 eugenol reduced Na+/K+ ATPase pump activity and blood glucose levels. They also increased hepatic glycogen content, superoxide dismutase activity, ferric reducing antioxidant power, and nitric oxide and malondialdehyde levels. Still, 20 and 40 mg kg−1 eugenol caused structural and functional damage to the liver tissue of eugenol-treated rats. We concluded that 10 mg kg−1 eugenol is a safe dose for consumption in long-term treatment for rats. Doses higher than 20 mg kg−1 lead to hepatic damage that can impair vital processes of liver functionality.

271-OR: Hepatic Glucagon Resistance in Mice with Nonalcoholic Fatty Liver Disease

Patients with nonalcoholic fatty liver disease (NAFLD) have elevated fasting levels of glucagon (gcg) and amino acids (AA) . Gcg regulates hepatic AA catabolism by augmenting ureagenesis. We hypothesized that hepatic steatosis causes gcg resistance and impaired gcg-induced hepatic ureagenesis. To address this, we developed an isolated liver perfusion model in mice and used it to investigate gcg’s direct effect on hepatic glucose production (HGP) and ureagenesis in 9 male mice with hepatic steatosis (NAFLD mice) (B6.Vlepob/ob/JRj) and healthy controls (CON) (C57bl6/JRj) . NAFLD mice had higher body mass (50 vs. 26 g, P&amp;lt;0.0001) and higher hepatic fat triglycerides (1vs. µmol/g, P&amp;lt;0.0001) compared to CON. Catheters were place in the portal vein and the inferior vena cava and the liver was perfused with Krebs Henseleit buffer with and without 5 mM AA mixture (Vamin) , nM gcg or both. Samples were collected every minute and analyzed for urea and glucose concentrations. Results were normalized to liver tissue protein content. AA administration increased hepatic urea production from baseline in both groups within six minutes (NAFLD mice: 2.4 vs. 5.3 mmol/min × µg protein, P=0.01) , (CON: 3.4 vs. 7.4 mmol/min × µg protein, P=0.02) . Gcg increased the AA-stimulated ureagenesis compared to AA administration alone in CON (7.4 vs. 9.4 mmol/min × µg protein, P&amp;lt;0.0001) but not in NAFLD mice (5.3 vs. 5.1 mmol/min × µg protein, P=0.66) . During the gcg administration (50 minutes) the total HGP was far greater in CON compared to NAFLD mice (309.5 vs. 195.5 µmol/min/µg protein, P=0.03) . The difference in glucose output could not be explained by hepatic glycogen content, as the NAFLD mice showed higher glycogen content than CON (1.7 vs. 0.8 µg/mg liver mass, P=0.02) . Our data support 1) that glucagon acutely increases the substrate-induced ureagenesis and 2) that hepatic steatosis causes resistance to the acute metabolic actions of glucagon on ureagenesis. Disclosure F.R.Ceutz: None. E.E.Christensen: None. M.Winther-soerensen: None. H.Vilstrup: None. J.J.Holst: Advisory Panel; Novo Nordisk, Board Member; Antag Therapeutics, Bainan Biotech. N.J.Wewer albrechtsen: Research Support; Mercodia AB, Novo Nordisk, Regeneron Pharmaceuticals Inc., Speaker's Bureau; Merck &amp; Co., Inc., Mercodia AB. Funding Nicolai J. Wewer Albrechtsen were financed by NNF Excellence Emerging Investigator Grant – Endocrinology and Metabolism (Application No. NNF19OC0055001) , EFSD Future Leader Award (NNF21SA0072746) and DFF Sapere Aude.

237-LB: Weight-Independent Effects of Roux-en-Y Gastric Bypass Surgery on Remission of Nonalcoholic Fatty Liver Disease in Mice

Introduction: Obesity is the primary determinant of nonalcoholic fatty liver disease (NAFLD) . Interventions that decrease body weight, such as bariatric surgery and/or calorie restriction (CR) , may serve as effective therapies for NAFLD. The purpose of this study was to compare the effects of Roux-en-Y gastric bypass surgery (RYGB) to CR on hepatic function in mice with obesity and NAFLD. Methods: 6-week-old male C57BL/6J mice were fed a two-choice chow/high-fat diet (HFD) to promote diet-induced obesity. At 16 weeks of age, mice were randomized to (1) sham surgery (Sham) , (2) RYGB, or (3) sham + weight-matched calorie restriction to RYGB (WM) . Mice were euthanized at 36 weeks for determination of NAFLD/NASH and hepatic function. Body weight/composition and food intake were measured weekly during the treatment period. ANCOVA-adjusted energy expenditure (EE) was determined 3 and 17 weeks after treatment. Hepatic lipid content and NAFLD scores were determined from H&amp;E-stained tissue sections. Hepatic enzymes and glycogen content were determined by ELISA. Results: RYGB &amp; WM achieved a similar reduction in body weight relative to baseline. RYGB decreased adiposity to a greater extent than WM relative to baseline and Sham (-4.4±0.6 vs. -1.3±0.6 Δg, P&amp;lt;0.001) . Decreased body weight was attributable to lower food intake in WM compared to RYGB and Sham (P&amp;lt;0.0001) . WM decreased EE relative to RYGB and Sham (WM:8.6±0.4 vs. RYGB:10.4±0.4 vs. Sham:10.5±0.6 kcals/day, P&amp;lt;0.001) . RYGB decreased hepatic lipid content to a greater extent than WM (92.6 vs. 76.5 % reduction, P=0.02) . RYGB and WM similarly decreased AST and ALT activity relative to Sham. RYGB increased hepatic glycogen relative to both Sham and WM (P&amp;lt;0.001) . Conclusions: RYGB and WM improve hepatic function and decrease the severity of NAFLD through shared and discrete mechanisms of action. RYGB decreases hepatic lipid content to a greater extent than WM independent of food intake, indicating that evading the expected metabolic adaptation in EE after weight loss likely accounts for the additive hepatic benefit of RYGB. Disclosure C. L. Axelrod: None. I. M. Langohr: None. W. S. Dantas: None. R. Townsend: None. V. L. Albaugh: None. J. P. Kirwan: None. H. Berthoud: None. Funding National Institutes of Health (U54GM104940)

Trypanosoma brucei brucei Induced Hypoglycaemia Depletes Hepatic Glycogen and Altered Hepatic Hexokinase and Glucokinase Activities in Infected Mice

Little progress has been made in understanding the effect of Trypanosoma brucei brucei infection that was allowed to run its course without treatment on human and animal carbohydrate metabolism even though most of the symptoms associated with the disease can be clearly linked with interference with host energy generation. The present study therefore assessed the course of untreated Trypanosoma brucei brucei infection on hepatic glycogen, hepatic hexokinase and glucokinase activities. Mice were grouped into two: control and infected group. Trypanosomiasis was induced by intraperitoneal inoculation of 1 × 104 parasites/mice in 0.3ml of phosphate saline glucose. The infection was allowed to run its course until the first mortality was recorded with all the mice showing chronic symptoms of the second stage of the disease before the research was terminated. Blood and liver samples were collected from the mice in each group for the assessment of hepatic glycogen and total protein, hepatic hexokinase and glucokinase activities, liver biomarkers, blood glucose and protein with packed cell volume. The infection resulted in decrease in blood glucose, hepatic glycogen, liver protein, PCV, hepatic hexokinase and glucokinase activities, but increase in serum total protein and liver biomarkers. Trypanosomiasis negatively affects hepatic integrity, resulting in the depletion of hepatic glycogen content and suppression of both hepatic hexokinase and glucokinase activities. The suppression of hepatic hexokinase and glucokinase activities suggested that trypanosomiasis affected the oxidation of glucose and host energy generation via glycolysis. This probably denied the host of the needed energy which is likely the reason for early death in untreated African trypanosomiasis.

Selenoprotein F (SELENOF)-mediated AKT1-FOXO3a-PYGL axis contributes to selenium supranutrition-induced glycogenolysis and lipogenesis

Mounting evidence showed that excess selenium (10.0–15.0-fold of adequate Se) intake caused severe hepatic lipid deposition in the vertebrate. However, the underlying mechanism remains unclear. The study was performed to elucidate the mechanism of Se supranutrition mediated-changes of lipid deposition and metabolism. We found that dietary excessive Se addition increased hepatic TGs and glucose contents, up-regulated lipogenic enzyme activities and reduced hepatic glycogen contents. Transcriptomic and immunoblotting analysis showed that Se supranutrition significantly influenced serine/threonine kinase 1 (AKT1)-forkhead box O3a (FOXO3a)-PYGL signaling and protein levels of SELENOF. Knockdown of SELENOF and PYGL by RNA interference revealed that the AKT1-FOXO3a-PYGL axis was critical for Se supranutrition-induced lipid accumulation. Moreover, Se supranutrition-induced lipid accumulation was via the increased DNA binding capacity of FOXO3a to PYGL promoter, which increased glycogenolysis, and accordingly promoted lipogenesis and lipid accumulation. Our finding provides new insight into the mechanism of Se supranutrition-induced lipid accumulation and suggests that SELENOF may be a therapeutic target for Se supranutrition induced-lipid disorders in the vertebrates.

Dietary protein/carbohydrate ratio and feeding frequency affect feed utilization, intermediary metabolism, and economic efficiency of gilthead seabream (Sparus aurata) juveniles

To evaluate the effects of dietary protein/carbohydrate (P/CHO) ratio and feeding frequency (FF) on growth, intermediary metabolism, and economic efficiency of gilthead seabream (Sparus aurata) juveniles, two practical isolipidic (17%) diets were formulated to include high protein (50%)/ low starch (10%) (diet P50/CHO10) or low protein (40%)/ high starch (20%) (diet P40/CHO20). Triplicate groups of fish with 9.1 ± 0.01 g were fed for 60 days with these diets until visual satiation at three FF: one (9:00), two (9:00 and 17:00), or three (9:00, 13:00, and 17:00) meals per day. Dietary P/CHO ratios did not affect growth performance while feeding 2 or 3 meals per day improved fish growth. Fish fed diet P40/CHO20 had increased feed intake (FI), protein efficiency ratio (PER), and nitrogen retention (NR), and lower feed efficiency (FE), nitrogen intake (NI), and economic conversion ratio (ECR). Feeding 2 or 3 meals per day increased FI, NI, ECR, and economic profit index, and decreased FE, PER, and NR. Fish fed diet P40/CHO20 presented increased hepatic lipid and glycogen content, hepatocyte area covered by lipid vacuoles, and glucokinase (gk) gene expression, and decreased glutamate dehydrogenase expression. Fish fed 3 meals per day had decreased plasma triglycerides and total protein levels, while fish fed 2 or 3 meals per day presented decreased hepatic growth hormone receptor-i (ghr-i), gk, and fatty acid synthase gene expression. Interaction between P/CHO ratio and FF was only observed in plasmatic glucose, cholesterol, and total lipids levels, and insulin-like growth factor-1, and ghr-ii gene expression. Overall, glycogenesis, glycolysis, and economic efficiency seemed to be increased while the amino acid catabolism was reduced in fish fed the P40/CHO20 diet. Higher FF increased growth and economic efficiency, and reduced glycolysis and lipogenesis pathways. In conclusion, a diet with P40/CHO20 ratio fed twice a day appears to be the most adequate strategy regarding feed utilization and economic efficiency for gilthead seabream juveniles in order to achieve optimum sustainable aquaculture.

Inducible Systemic Gcn1 Deletion in Mice Leads to Transient Body Weight Loss upon Tamoxifen Treatment Associated with Decrease of Fat and Liver Glycogen Storage.

GCN1 is an evolutionarily-conserved ribosome-binding protein that mediates the amino acid starvation response as well as the ribotoxic stress response. We previously demonstrated that Gcn1 mutant mice lacking the GCN2-binding domain suffer from growth retardation and postnatal lethality via GCN2-independent mechanisms, while Gcn1-null mice die early in embryonic development. In this study, we explored the role of GCN1 in adult mice by generating tamoxifen-inducible conditional knockout (CKO) mice. Unexpectedly, the Gcn1 CKO mice showed body weight loss during tamoxifen treatment, which gradually recovered following its cessation. They also showed decreases in liver weight, hepatic glycogen and lipid contents, blood glucose and non-esterified fatty acids, and visceral white adipose tissue weight with no changes in food intake and viability. A decrease of serum VLDL suggested that hepatic lipid supply to the peripheral tissues was primarily impaired. Liver proteomic analysis revealed the downregulation of mitochondrial β-oxidation that accompanied increases of peroxisomal β-oxidation and aerobic glucose catabolism that maintain ATP levels. These findings show the involvement of GCN1 in hepatic lipid metabolism during tamoxifen treatment in adult mice.

Polyphenol from Rosaroxburghii Tratt Fruit Ameliorates the Symptoms of Diabetes by Activating the P13K/AKT Insulin Pathway in db/db Mice.

About 4% of the world’s population has type 2 diabetes mellitus (T2DM), and the available hypoglycemic drugs for treating diabetes have some side effects. Therefore, research on the extraction of hypoglycemic components from plants has gradually become popular. This study aimed to investigate the hypoglycemic effects of polyphenol-rich Rosa roxburghii Tratt extract (RP) isolated from Rosa roxburghii Tratt fruit and of four constituents (IRP 1–4 ) isolated from RP on db/db mice. The results indicated that the oral administration of RP and IRP 1–4 could markedly decrease the food intake, water intake, fasting blood glucose (FBG), and serum insulin levels in the db/db mice. Glucose intolerance, insulin resistance, and oxidative stress were ameliorated in the RP and IRP 1–4 groups. Histopathological observation revealed that RP and IRP 1–4 could effectively protect the liver fat against damage and dysfunction. RP and IRP 1–4 also increased the hepatic and muscle glycogen contents by increasing the phosphorylation and reducing the expression of glycogen synthase kinase 3β (GSK3β). The activities of glucokinase (GCK), phosphoenolpyruvate carboxylase (PEPCK), and glucose-6-phosphatase (G6PC) and their respective mRNA expression levels in the liver of db/db mice were simultaneously increased and decreased in the intervention groups. RP and IRP 1–4 significantly increased the expression of phosphatidylinositol 3-kinase (P13K) and the phosphorylation of protein kinase B (AKT). These results indicate that RP and IRP 1–4 exhibit good hypoglycemic effects by activating the P13K/AKT signaling pathway and regulating the expression of FOXO1 and p-GSK3β proteins, controlling hepatic gluconeogenesis and improving hepatic glycogen storage insulin resistance. Therefore, RP and IRP 1–4 could be utilized as the hypoglycemic functional component to alleviate the symptoms of T2DM.

Polysaccharide-Rich Red Algae (Gelidium amansii) Hot-Water Extracts Alleviate Abnormal Hepatic Lipid Metabolism without Suppression of Glucose Intolerance in a Streptozotocin/Nicotinamide-Induced Diabetic Rat Model.

This study was designed to investigate the effects of polysaccharide-rich red algae (Gelidium amansii) hot-water extracts (GHE) on lipid and glucose metabolism in rats with streptozotocin (STZ)/nicotinamide (NA)-induced diabetes. Rats were divided into three groups: NC—normal control group), DM—diabetic group, and DG—diabetic group supplemented with GHE (5%). The experimental diet and drinking water were available ad libitum for 10 weeks. After the 10-week feeding duration, the body weight, liver weight, total adipose tissue weight, and hepatic TBARS and cholesterol levels were significantly increased, and hepatic glycogen content and adipose lipolysis rate were significantly decreased in the DM group, which could be effectively reversed by supplementation of GHE. However, GHE supplementation could not improve the glucose intolerance in DM rats. It was interesting to note that GHE supplementation could decrease the liver glucose-6-phosphotase activity, which was increased in DM rats. Taken together, these results suggested that GHE feeding may ameliorate abnormal hepatic lipid metabolism, but not glucose intolerance, in diabetic rats induced by STZ/NA.

Exogenous Linoleic Acid Intervention Alters Hepatic Glucose Metabolism in an Avian Embryo Model

In the present study, developmental changes of gluconeogenesis and glycolysis in an avian model were measured, and then the intervention effects of in ovo feeding (IOF) linoleic acid (LA) on hepatic glucose metabolism were evaluated. In Experiment 1, thirty fertilized eggs were sampled on embryonic days (E) of 16, 19, 22, 25, 28, 31, and thirty newly-hatched ducklings at hatch (E34 and E35). In Experiment 2, a total of 120 fertilized eggs (60 eggs for each group) were injected into the yolk sac with PBS as the control group and LA as the IOF LA group on E25. Twelve eggs were selected for sample collection on E28 and E31. Serum contents of glucose, pyruvate, and lactate increased ( p < 0.05) linearly or quadratically from E16 to hatch, as well as hepatic glycogen and pyruvate contents. Hepatic mRNA expression related to energy homeostasis, gluconeogenesis, and glycolysis increased ( p < 0.05) in embryogenesis, and the plateau period was presented on E25–E31. IOF LA decreased ( p < 0.05) serum contents of glucose, triacylglycerol, cholesterol, and hepatic oleic acid, unsaturated fatty acids on E28, as well as the gene expression relative to gluconeogenesis. IOF LA increased ( p < 0.05) pyruvate content in serum and liver, and hepatic gene expression relative to glycolysis on E31. In summary, hepatic gluconeogenesis and glycolysis were enhanced to meet the increasing energy demands of embryonic development during E25 – hatch. Exogenous LA intervention on E25 could inhibit hepatic gluconeogenesis and enhance glycolysis during the later developmental period, disrupting glucose embryonic homeostasis and energy status.

Hypoglycemic effects of black brick tea with fungal growth in hyperglycemic mice model

Dark tea (containing Eurotium cristatum) and black tea have hypoglycemic effects. The black brick tea with fungal growth is obtained from black tea by adding E. cristatum, followed by steaming, pressing, fungal growth, and drying. However, the hypoglycemic effects of black brick tea are still unexplored. Here, we used black brick tea with fungal growth and black tea as raw materials to study their hypoglycemic effects in a hyperglycemic mice model. Both these types of black tea could lower the content of blood glucose and increase the content of hepatic glycogen by upregulating the proteins and mRNA expression of phosphatidylinositol-4,5-bisphosphate3-kinase, glycogen synthase, protein kinase B and phosphoinositide-dependent protein kinase-1 and downregulating the protein and mRNA expression of glycogen synthase kinase 3β. These regulatory steps were followed by high activities of glutathione peroxidase and superoxide dismutase and low content of malondialdehyde. These teas can promote blood glucose transport and absorption by upregulating the protein and mRNA expression of insulin receptor substrate-1 and glucose transporter-2 and stimulate glycolysis by upregulating the protein and mRNA expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2. Our study suggests that the black brick tea was more effective than the black tea in terms of hypoglycemic.

Enhancement of Swimming Endurance by Herbal Supplement M3P.

To investigate the effect of M3P (containing Deer antler, Cordyceps sinensis, Rhodiola rosea, and Panax ginseng); an herbal remedy with the function of tonifying Kidney (Shen) and invigorating Spleen (Pi), replenishing qi and nourishing blood; on fatigue alleviation, endurance capacity and toxicity. Swimming with weight-loading of 24 male ICR mice was used to evaluate the endurance capacity, and fatigue-related plasma biomarkers were determined. Mice were randomly assigned to control or M3P treatment groups with 6 mice for each group and were orally administered with M3P everyday for 8 weeks at doses 0, 10, 33 or 100 mg/kg. Swimming time to exhaustion was measured in a specialized water tank. Lliver and kidney functions, body weight, and hematological profile were determined to evaluate the safety and toxicity after long-term M3P administration. M3P supplementation 100 mg/kg significantly increased swimming endurance time up to approximate 2.4 folds of controls (P<0.05). The plasma concentrations of cortisol and hepatic glycogen content were significantly increased in mice received M3P (P<0.05, P<0.01 respectively). The lactic acid level and blood glucose were not changed after M3P treatment (P>0.05). The liver and kidney functions muscle damage biomarker creatine, body weight, and hemograms were not altered in M3P supplementation (P>0.05). M3P supplementation may improve swimming endurance accompanied by increasing hepatic glycogen content and serum cortisol level without major toxicity.

Effects of Aerobic Exercise Combined with D-Ribose Supplementation on Anti-fatigue and Anti-oxidation in Mice

Study the effects of aerobic exercise combined with D-ribose supplementation on the anti-fatigue and antioxidant enzyme activities of mice, the mice were divided into quiet control group, aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group. The aerobic exercise group received aerobic treadmill training for 6 days a week, and the D-ribose group was given 2 mL of ribose (300 mg/100 g) per rat per day. After 12 weeks of regular aerobic treadmill training, an anti-fatigue animal model was established for mice swimming with weight, the time of exhausted swimming was recorded in mice, and hepaticr glycogen (HG), muscle glycogen (MG), and blood glucose in mice, blood urea nitrogen (BUN), blood lactic acid (BLA), malondialdehyde (MDA) content and total antioxidant capacity (T-AOC), glutathione Oxide dismutase (glutathione peroxide dismutase, GSH-Px), superoxide dismutase (SOD), catalase (catalase, CAT) and other activities were measured. The results showed that compared with the quiet control group, the weight-bearing swimming time of mice in the aerobic exercise control group, D-ribose control group, and D-ribose+aerobic exercise group significantly increased (P<0.05), and at the same time the mice's body hepatic glycogen, muscle glycogen and blood sugar content were significantly improved(P<0.05), and the blood urea nitrogen and blood lactic acid content in the body were significantly reduced(P<0.05). In addition, the results of its antioxidant activity showed that compared with the quiet control group, the T-AOC of the aerobic exercise control group, D-ribose control group, D-ribose+aerobic exercise group were all enhanced. The activity of SOD, CAT, GSH-Px also significantly increased (P<0.05), and MDA was significantly reduced (P<0.05). It showed that long-term regular aerobic exercise combined with D-ribose supplementation could significantly increase the liver glycogen, muscle glycogen, blood sugar content and oxidative stress ability in the body, and improve the body's anti-fatigue effect.

Physiological Ecology of Winter Hibernation by the High-Altitude Frog Nanorana parkeri.

AbstractThe Xizang plateau frog, Nanorana parkeri (Anura: Dicroglossidae), enters a dormant state in the winter in response to seasonal cold and lack of food. To investigate the physiological and ecological characteristics of overwintering in this species, we measured habitat conditions (hibernacula temperatures, body temperature, and water quality variables), morphology, metabolite concentrations, total antioxidant capacity (T-AOC), and bacteria-killing ability (BKA) of plasma during summer and winter. We found that N. parkeri hibernates underwater at the bottom of ponds (10-20-cm depth). Dissolved oxygen content in the water decreases significantly (by 12%) in the winter compared with summer, suggesting that overwintering N. parkeri may experience hypoxia. Body mass, body mass index, hepatosomatic index, and hepatic glycogen concentration all increased significantly in winter-collected frogs as compared to summer-collected individuals, indicating that overwintering N. parkeri accumulates high fuel/energy reserves to support prolonged periods of hibernation. A significant reduction in glucose, urea, and lactate concentrations in most organs may be closely related to metabolic depression in overwintering N. parkeri. Liver lactate concentration rose significantly in winter-collected frogs, suggesting that anaerobic metabolism dominates when this species overwinters. The T-AOC of plasma showed a significant reduction in winter, suggesting a reduced need for antioxidant defenses. Oppositely, the BKA of plasma increased significantly in winter versus summer, indicating that innate immunity was enhanced during overwintering. In summary, these behavioral (migrating to caves), physiological, and biochemical adjustments may be key for the successful overwintering of this high-altitude frog.

Yeast culture improved the growth performance, liver function, intestinal barrier and microbiota of juvenile largemouth bass (Micropterus salmoides) fed high-starch diet

The present study was conducted to investigate the effects of yeast culture on the growth, health and microflora of the juvenile largemouth bass fed high-starch diet. The experiment set three isonitrogenous and isolipidic diets, control (high-starch diet), HSY1 (high-starch diet with 1% yeast culture) and HSY3 (high-starch diet with 3% yeast culture). A feeding trial was conducted in largemouth bass juveniles for 8 weeks. The results indicated fish fed with 3% yeast culture not only could improve specific growth rate (SGR), but also significantly decreased hepatic lipid content, hepatic glycogen content, and hepatopancreas somatic index (HSI) compared with the control group (p<0.05). The total superoxide dismutase (T-SOD) and catalase (CAT) activities of HSY3 group significantly increased while malondialdehyde (MDA) content significantly reduced in liver compared with the control group (p<0.05). Meanwhile, the mRNA expression levels of hepatic Sod and Cat were up-regulated (p<0.05), and liver metabolism showed 111 metabolites were significantly changed in HSY3 group, liver lipid metabolism pathway remarkably changed. Besides, the intestinal anti-inflammatory cytokines were significantly up-regulated, and the pro-inflammatory cytokines were significantly down-regulated as the inclusion of yeast culture (p<0.05). Notably, HSY3 group diet up-regulated the expression of Zo-1, Claudin and Occludin in intestine compared with the other groups (p<0.05). Serum d-lactate (D-lac), diamine oxidase (DAO) and lipopolysaccharide (LPS) decreased significantly with the inclusion of yeast culture (p<0.05). Furthermore, the abundance of probiotics (such as Lactobacillus, Bacillus and Bifidobacterium) increased significantly, and the abundance of intestinal potential pathogenic bacteria (Plesiomonas) decreased in HSY3 group (p<0.05). The phenotypic analysis showed that gram-negative bacteria significantly decreased while gram-positive bacteria increased in HSY3 group (p<0.05). All in all, this study revealed that supplementation of 3% yeast culture can improve the growth performance and the health of juvenile largemouth bass, and has the potential to be used as an effective synbiotics for M. salmoides.

Pancreastatin inhibitor PSTi8 prevents free fatty acid-induced oxidative stress and insulin resistance by modulating JNK pathway: In vitro and in vivo findings

AimFree fatty acid-mediated obesity plays a crucial role in the pathogenesis of Type 2 Diabetes. FFA induced JNK activation acts as a central regulator in causing hepatic insulin resistance. Similarly, Pancreastatin, a chromogranin A peptide, serves as a crucial link between FFA-induced insulin resistance. Therefore, in the present work, we sought to test Pancreastatin inhibitor PSTi8 to ameliorate FFA-induced hepatic insulin resistance in in vitro and in vivo models. Material and methodsTo verify our objective, we exposed hepatocytes (HepG2 cells) with palmitate (0.3 mM) or palmitate + PSTi8 (200 nM). Parallelly mice were fed either HFD or HFD + PSTi8 (1 mg/kg). After 21 days animals were scanned for increased fat mass, along with GTT, ITT and PTT experiment to check glucose, and insulin tolerance. Furthermore, ROS generation and hepatic glycogen content was measured in FFA exposed hepatocytes. Gene expression and protein expression studies were further conducted to delineate the action mechanism of PSTi8. Key findingsPSTi8 exposure decreased ROS accumulation, lipid accumulation, and reduced glycogen content in FFA-induced groups. It also enhances glucose uptake and reduces gluconeogenesis to combat the FFA effect. Furthermore, gene expression studies indicate that PSTi8 treatment reduces NADPH oxidase3 (NOX3) expression and inhibits JNK signaling, a predominant source of ROS-induced insulin resistance. SignificanceTo summarize, the protective effect of PSTi8 on FFA-induced insulin resistance is mediated via inhibition of JNK signaling, which leads to decreased ROS generation and enhanced insulin sensitivity. Hence PSTi8 could be a therapeutic molecule to prevent western diet-induced insulin resistance.