Increase In Glucose Concentration Research Articles

Importance of Intracellular Energy Status on High-Hydrostatic-Pressure Inactivation of sake Yeast Saccharomyces cerevisiae.

The HHP inactivation behaviors of Niigata sake yeast Saccharomyces cerevisiae strain S9arg and its aerobic respiratory-deficient mutant strains were investigated after cultivating them in a YPD media containing 2% to 15% glucose, as well as in moromi mash, in a laboratory-scale sake brewing process. The piezotolerance of strain S9arg, shown after cultivation in a YPD medium containing 2% glucose, decreased to become piezosensitive with increasing glucose concentrations in YPD media. In contrast, the piezosensitivity of a mutant strain UV1, shown after cultivation in the YPD medium containing 2% glucose, decreased to become piezotolerant with increasing glucose concentrations in the YPD medium. The intracellular ATP concentrations were analyzed for an S. cerevisiae strain with intact aerobic respiratory ability, as well as for strain UV1. The higher concentration of ATP after cultivation suggested a higher energy status and may be closely related to higher piezotolerance for the yeast strains. The decreased piezotolerance of strain S9arg observed after a laboratory-scale sake brewing test may be due to a lower energy status resulting from a high glucose concentration in moromi mash during the early period of brewing, as well as a lower aeration efficiency during the brewing process, compared with cultivation in a YPD medium containing 2% glucose.

New Insights into the Effects of SARS-CoV-2 on Metabolic Organs: A Narrative Review of COVID-19 Induced Diabetes.

Coronavirus disease 2019 (COVID-19)-induced new-onset diabetes has raised widespread concerns. Increased glucose concentration and insulin resistance levels were observed in the COVID-19 patients. COVID-19 patients with newly diagnosed diabetes may have worse clinical outcomes and can have serious consequences. The types and exact mechanisms of COVID-19-caused diabetes are not well understood. Understanding the direct effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on pancreatic beta cells and insulin target metabolism organs, such as the liver, muscle, and adipose tissues, will provide new ideas for preventing and treating the new-onset diabetes induced by COVID-19.

Organosulfur Compounds in Aged Garlic Extract Ameliorate Glucose Induced Diabetic Cardiomyopathy by Attenuating Oxidative Stress, Cardiac Fibrosis, and Cardiac Apoptosis.

Diabetic cardiomyopathy has emerged as a major cause of cardiac fibrosis, hypertrophy, diastolic dysfunction, and heart failure due to uncontrolled glucose metabolism in patients with diabetes mellitus. However, there is still no consensus on the optimal treatment to prevent or treat the cardiac burden associated with diabetes, which urges the development of dual antidiabetic and cardioprotective cardiac therapy based on natural products. This study investigates the cardiotoxic profile of glucose and the efficacy of AGE against glucose-induced cardiotoxicity in H9c2 cardiomyocytes. The cellular metabolic activity of H9c2 cardiomyocytes under increasing glucose concentration and the therapeutic efficacy of AGE were investigated using the MTT cell cytotoxicity assay. The in vitro model was established in six groups known as 1. control, 2. cells treated with 25 µM glucose, 3. 100 µM glucose, 4. 25 µM glucose +35 µM AGE, 5. 100 µM glucose + 35 µM AGE, and 6. 35 µM AGE. Morphological and nuclear analyses were performed using Giemsa, HE, DAPI, and PI, respectively, whereas cell death was simultaneously assessed using the trypan blue assay. The antioxidant potential of AGE was evaluated by DCFH-DA assay, NO, and H202 scavenging assay. The activities of the antioxidant enzymes catalase and superoxide dismutase were also investigated. The antiglycative potential of AGE was examined by antiglycation assays, amylase zymography, and SDS PAGE. These results were then validated by in silico molecular docking and qRTPCR. Hyperglycemia significantly reduced cellular metabolic activity of H9c2 cardiomyocytes, and AGE was found to preserve cell viability approximately 2-fold by attenuating oxidative, fibrosis, and apoptotic signaling molecules. In silico and qRTPCR studies confirmed that organosulfur compounds target TNF-α, MAPK, TGF-β, MMP-7, and caspase-9 signaling molecules to ameliorate glucose-induced cardiotoxicity. AGE was found to be an antidiabetic and cardioprotective natural product with exceptional therapeutic potential for use as a novel herb-drug therapy in the treatment of diabetic cardiomyopathy in future therapies.

New Selective Inhibitors of α‐Glucosidase for the Treatment of Type 2 Diabetes Mellitus

AbstractType 2 diabetes mellitus is a metabolic dreadful disease caused by an uncontrolled glucose level in the bloodstream, particularly high after a meal. Inhibitors of glucosidases, involved in the digestion of carbohydrates, can regulate this post‐prandial increase in glucose concentration. The traditional drugs act as competitive inhibitors of both pancreatic α‐amylase and α‐glucosidases and this unselective inhibition is behind severe gastrointestinal side effects related to the concomitant inhibition of α‐amylase. We described herein some perglycosylated cyclodextrins as efficient and selective inhibitors of α‐glucosidase with low micromolar IC50 (3.64‐7.98 μM) compared to the acarbose (IC50 212 μM), clinically used for patients suffering from type 2 diabetes. On the other hand, they do not inhibit α‐amylase (IC50>500 μM). Structure/activity relationship rationalization suggests multiple interactions between the described inhibitors and α‐glucosidase, which support the existence of both active site and allosteric interactions.

Effects of Restraint Stress on Circulating Corticosterone and Met Enkephalin in Chickens: Induction of Shifts in Insulin Secretion and Carbohydrate Metabolism.

This study examined the effects of acute restraint stress in the presence or absence of naltrexone on the circulating concentrations of insulin, glucose, Met-enkephalin and corticosterone in 14-week-old chickens [design: 2 sex × 2 stress/non-stress × 2 +/- naltrexone]. In chickens (five male and five females per treatment) subjected to restraint for 30 min, there were increases in the plasma concentrations of corticosterone and Met-enkephalin. The plasma concentrations of insulin and glucose were also increased in the chickens during restraint. Moreover, there were increases in the plasma concentrations of insulin and glucose in the chickens. The patterns of expression of the proenkephalin gene (PENK) in both the anterior pituitary gland and the adrenal gland were very similar to that of plasma Met-enkephalin. There were relationships between the plasma concentrations of corticosterone, Met-enkephalin, insulin and glucose after 30 min of restraint. The effects of naltrexone treatment on both untreated and stressed chickens were also examined, with naltrexone attenuating the stress-induced increases in the plasma concentrations of corticosterone, Met-enkephalin and glucose but not in those of insulin. The present study demonstrates that stress increases insulin secretion in chickens but also induces insulin resistance.

Tear metabolomics for the diagnosis of primary open-angle glaucoma

Primary Open-Angle Glaucoma (POAG) is the most prevalent glaucoma type, and the leading cause of irreversible visual impairment and blindness worldwide. Identification of early POAG biomarkers is of enormous value, as there is not an effective treatment for the glaucomatous optic nerve degeneration (OND). In this pilot study, a metabolomic analysis, by using proton (1H) nuclear magnetic resonance (NMR) spectroscopy was conducted in tears, in order to determine the changes of specific metabolites in the initial glaucoma eyes and to discover potential diagnostic biomarkers. A classification model, based on the metabolomic fingerprint in tears was generated as a non-invasive tool to support the preclinical and clinical POAG diagnosis. 1H NMR spectra were acquired from 30 tear samples corresponding to the POAG group (n = 11) and the control group (n = 19). Data were analysed by multivariate statistics (partial least squares-discriminant analysis: PLS-DA) to determine a model capable of differentiating between groups. The whole data set was split into calibration (65%)/validation (35%), to test the performance and the ability for glaucoma discrimination. The calculated PLS-DA model showed an area under the curve (AUC) of 1, as well as a sensitivity of 100% and a specificity of 83.3% to distinguish POAG group versus control group tear data. This model included 11 metabolites, potential biomarkers of the disease. When comparing the study groups, a decrease in the tear concentration of phenylalanine, phenylacetate, leucine, n-acetylated compounds, formic acid, and uridine, was found in the POAG group. Moreover, an increase in the tear concentration of taurine, glycine, urea, glucose, and unsaturated fatty acids was observed in the POAG group. These results highlight the potential of tear metabolomics by 1H NMR spectroscopy as a non-invasive approach to support early POAG diagnosis and in order to prevent visual loss.

Effects of ingesting beverages containing glycerol and sodium with isomaltulose or sucrose on fluid retention in young adults: a single-blind, randomized crossover trial.

We evaluated changes in hyperhydration and beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) during resting, induced by the consumption of beverages containing glycerol and sodium supplemented with fast-absorbing sucrose or slow-absorbing isomaltulose. In a randomized crossover, single-blinded protocol (clinical trials registry: UMIN000042644), 14 young physically active adults (three women) consumed 1L of beverage containing either 7% glycerol+0.5% sodium (Gly+Na), Gly+Na plus 7% sucrose (Gly+Na+Suc), Gly+Na plus 7% isomaltulose (Gly+Na+Iso), or water (CON) over a 40min period. We assessed the change in plasma volume (ΔPV), BHI (calculated from cumulative urine output following consumption of water relative to that of the beverage), and blood glucose and sodiumfor 180min after initiating ingestion. Total urine volume was reduced in all beverages containing glycerol and sodium compared to CON (all P≤0.002). The addition of isomaltulose increased BHI by ∼45% (3.43±1.0vs. 2.50±0.7 for Gly+Na, P=0.011) whereas sucrose did not (2.6±0.6, P=0.826). The PV expansion was earliest for Gly+Na (30min), slower for Gly+Na+Suc (90min), and slowest for Gly+Na+Iso (120min) with a concomitant lag in the increase of blood glucose and sodium concentrations. Supplementation of beverages containing glycerol and sodium with isomaltulose but not sucrose enhances BHI from those of glycerol and sodium only under a resting state, likely due to the slow absorption of isomaltulose-derived monosaccharides (i.e., glucose and fructose).

Изменение ИК-спектров метаболитов энергетического обмена в крови крыс с гепатоцеллюлярной карциномой при воздействии гипертермии и апитоксина

There is a need to develop and improve conservative treatment methods for malignant liver tumours, since only in a small percentage of cases (10–30 %) radical treatments can be applied. Therefore, of relevance are studies into the effect of hyperthermia on the absorption of antitumour drugs and the effect of bee venom as a physiological therapeutic agent on the energy metabolism of tumour cells. Infrared spectroscopy could potentially be used to study changes in energy metabolism parameters in the blood plasma. The purpose of this article is to assess changes in the concentrations of energy metabolism metabolites in the blood of tumour-bearing animals during hyperthermia under the action of apitoxin using infrared spectroscopy. Materials and methods. The research involved 50 white non-linear female rats, divided into an intact, control and three experimental groups. The control and experimental groups were inoculated with hepatocellular carcinoma. The experimental groups were injected intraperitoneally with honey bee venom followed by hyperthermia sessions at different temperatures (42.5; 43.5 and 44.5 °С). Blood plasma was studied using a spectrophotometer in the wavenumber range of 1170–1025 cm–1. Results. We found a statistically significant increase in adenosine triphosphate concentrations (by 54 %) and a decrease in adenosine monophosphate (by 54 %), adenosine diphosphate (by 18 %) and glucose (by 87 %) levels compared to the control at 42.5 °C hyperthermia under the action of bee venom by the 7th day; however, on the 28th day the opposite effect was observed: an increase in adenosine monophosphate, adenosine diphosphate and glucose concentrations and a decrease in adenosine triphosphate levels. No positive dynamic was detected at other hyperthermia regimens. It is concluded that infrared spectroscopy can be used to assess energy changes in animals with hepatocellular carcinoma at different hyperthermia regimens under the therapeutic effect of bee venom. The optimal conditions for bee venom effects on the body are achieved at 42.5 °C.

Effect of Arterialization on Venous Blood Glucose Concentrations and Implications for Observed Continuous Glucose Monitoring Accuracy.

Background: Heating of the arm and/or hand ("arterialization") is sometimes used in continuous glucose monitoring (CGM) performance studies with the reported aim of reducing differences between venous and capillary glucose concentrations. In this study, the effect of heating on venous glucose concentrations and CGM accuracy was investigated. Methods: A heating pad set to 50°C (122°F) was used with 20 participants to heat either the dominant or nondominant arm and hand. Venous and capillary samples were obtained every 15 min on both arms throughout each of three 6-h glucose challenges. CGM sensors were worn on each upper arm for each of the three visits. Results: Heating of the arm led to a median increase in venous glucose concentrations of +1.4%. No similar effect on capillary concentrations was observed. As a result, the median capillary to venous difference decreased from +5.9% in the nonheated arm to +4.2% in the heated arm. CGM accuracy observed in this study was affected by the selection of heated venous, nonheated venous, or capillary glucose concentrations as comparator data. The heating effect was more pronounced with rapidly decreasing glucose concentrations. Temperatures on the skin did not exceed 40°C (104°F). No adverse events or protocol deviations were associated with the use of the heating pad. Conclusions: Heating of the arm led to a small increase in venous glucose concentrations, but venous concentrations did not reach the level of capillary glucose concentrations. CGM accuracy observed in this study varied depending on the selected comparator data. This study was registered at the German Clinical Trials Register (DRKS00031197).

Glucose volume of distribution affects insulin sensitivity measured by intravenous glucose tolerance test.

To determine whether glucose volume of distribution (VdGLUCOSE ) affects the diagnosis of impaired insulin sensitivity (IS) when using an intravenous glucose tolerance test (IVGTT). Individuals with distinct levels of IS underwent IVGTT after an overnight fast. The prediabetic group (Prediab; n = 33) differed from the healthy group (Healthy; n = 14) in their larger glycosylated hemoglobin (HbA1c of 5.9 ± 0.3 vs. 5.4 ± 0.1%; 41 ± 4 vs. 36 ± 1 mmol/mol; p < 0.001), percent body fat (37 ± 6 vs. 24 ± 3%; p < 0.001) and cardiovascular fitness level (VO2MAX 22 ± 5 vs. 44 ± 5 mL of O2 ·kg-1 ·min-1 ; p < 0.001). Ten minutes after intravenous infusion of the glucose bolus (i.e., 35 g in a 30% solution), VdGLUCOSE was assessed from the increases in plasma glucose concentration. IS was calculated during the next 50 min using the slope of glucose disappearance and the insulin time-response curve. VdGLUCOSE was higher in Healthy than in Prediab (230 ± 49 vs. 185 ± 21 mL·kg-1 ; p < 0.001). VdGLUCOSE was a strong predictor of IS (β standardized coefficient 0.362; p = 0.004). VO2MAX was associated with VdGLUCOSE and IS (Pearson r = 0.582 and 0.704, respectively; p < 0.001). However, body fat was inversely associated with VdGLUCOSE and IS (r = -0.548 and -0.555, respectively; p < 0.001). Since fat mass is inversely related to VdGLUCOSE and in turn, VdGLUCOSE affects the calculations of IS, the IV glucose bolus dose should be calculated based on fat-free mass rather than body weight for a more accurate diagnosis of impaired IS.

Study on the effectiveness of postprandial blood glucose control and glycemic index of acetylated wheat flour in healthy volunteers

Background: The study was conducted to determine the ability to control postprandial blood glucose response and glycemic index of acetylated wheat starch cakes containing 31,2% of resistant starch on 12 healthy volunteers. Material and methods: Research designed using experimental and double-blind methods. During the two days of the clinical trial, after more than 12 hours of overnight fasting, each volunteer consumed a diet consisting of 1 cake containing 50 g of acetylated wheat starch or 50 g of natural wheat starch and 330 ml of filtered water in 15 minutes. Volunteers had determined their capillary blood glucose concentrations at times before meals, 60 and 120 minutes after meals. Results: Blood glucose concentration at 60 minutes after eating acetylated wheat starch cake (G1= 8.6 ± 0.8 mmol/L) was lower than natural wheat starch cake (G1= 11.7 + 1.1 mmol/L) (p &lt; 0.05). Similarly, blood glucose concentration at 120 minutes after eating acetylated wheat starch cake (G2= 7.1 ± 0.7 mmol/L) was lower than natural wheat starch cake (G2= 9.2 ± 1.7 mmol/L) (p &lt; 0.05). The area under the curve of blood glucose concentration after 120 minutes of eating natural wheat starch cake (AUC0-120min= 337.0 min*mmol/L) is doulble times larger than the acetylated wheat starch cake (AUC0-120min= 175.5 min*mmol/L) (p &lt; 0.05). Glycemic index of acetylated wheat starch cake is 52.0. Conclusion: Acetylated wheat starch cake has a low glycemic index, possessing the ability to control postprandial blood glucose effectively, limiting the increase of postprandial blood glucose concentration within the safe range, and it did not cause any digestive disorders in volunteers. This is very meaningful in the application of acetylated wheat starch to process foods not only for diabetic patients but also for pre-diabetic or overweight and obese people to support treatment and improve quality of life. Key words: resistant starch, blood glucose, glycemic index, volunteers.

Micellized conjugated linoleic acid as an immune modifier feed additive for suckling calves

This study was attempted to assess the effects of micellized conjugated linoleic acid (CLA) as a feed additive for suckling calves on their growth performance and blood metabolic, oxidative and immune parameters. Forty-eight Holstein calves were divided among four experimental groups (12 calves/treatment) including: 1) calves with no CLA supplementation (CON), 2) calves supplemented with 1 gr CLA/d as micellized form by dissolving 5 mL/d of a CLA contained emulsion in milk (CLA1), 3) calves supplemented with 2 gr CLA/d as micellized form by dissolving 10 mL/d of a CLA contained emulsion in milk (CLA2) and 4) calves supplemented with 3 gr CLA/d as micellized form by dissolving 15 mL/d of a CLA contained emulsion in milk (CLA3). Calves in the CON group received 10 mL of the emulsion medium with no CLA. Feeding micellized CLA via whole milk resulted in a linear increase in blood concentration of glucose on d 40 (P=0.04), and total protein (P

EFEKTIVITAS BUNGA TELANG (CLITORIA TERNATEA) TERHADAP RESPON GLIKEMIK: SISTEMATIK REVIEW

Background: Diabetes mellitus is a chronic disease that is globally prevalent and has reached a very high prevalence rate. In 2021, more than 422 million people worldwide will suffer from diabetes. Various databases have reported that one of the ornamental plants, namely the butterfly pea flower (Clitoria Ternatea), has quite a hypoglycemic effect. &#x0D; Purpose: The aim of this systematic research is to help in understanding the potential of butterfly pea flowers as an antidiabetic agent.&#x0D; Methods: The research method we used in this systematic review search was the PRISMA method. This article searches literature sources in Pubmed and Google Scholar databases from 2013 to 2023 using appropriate inclusion criteria. Clitoria Ternatea has excellent anti-diabetic properties.&#x0D; Result: In vitro analysis showed that water extract of butterfly pea flower (Clitoria Ternatea), ethanol extract, and protein extract effectively inhibited the α-amylase enzyme, hemoglobin glycosylation, and AGE formation. They also show increased glucose absorption.&#x0D; Conclusion: This explains that CTE can suppress postprandial glucose and insulin responses induced by sucrose through inhibiting intestinal sucrose. It can be concluded that butterfly pea flowers (Clitoria Ternatea) are effective against glycemic responses in the body.

Reflection-fluorescence ratios probe for the stable detection of glucose

Herein, an optical ratios probe with reflection (RE) and fluorescence (FL), named as RE-FL ratios probe, has been developed for the ratiometric detection of glucose (GLU). This probe was prepared through self-assembling monodisperse colloids into opal photonic crystal and immobilizing fluorescence imidazolium ionic liquids as molecular recognition elements. So there was a periodic three-dimensional face-centered cubic arrayed structure and emissions of strong RE and FL in the probe, which allowed dual optical detection of the target analyte. From the results, it was learned that RE and FL emissions of RE-FL ratios probe were decreased when an increase of GLU concentration, and the resulting ratiometric optical changes can be quantitatively correlated to GLU concentration from 1 to 64 mM. The detection of probe was characterized by simple operation, stability, reusability and glucose oxidase independence. Furthermore, the probe successfully used to detect GLU in the real serum sample and showed great stability compared with the only FL pattern. Different types of appropriated recognition elements are expected to be introduced into opal photonic crystals to construct variety ratiometric optical probes in the wide of applications.

Regulatory Role of GgaR (YegW) for Glycogen Accumulation in Escherichia coli K-12.

Glycogen, the stored form of glucose, accumulates upon growth arrest in the presence of an excess carbon source in Escherichia coli and other bacteria. Chromatin immunoprecipitation screening for the binding site of a functionally unknown GntR family transcription factor, YegW, revealed that the yegTUV operon was a single target of the E. coli genome. Although none of the genes in the yegTUV operon have a clear function, a previous study suggested their involvement in the production of ADP-glucose (ADPG), a glycogen precursor. Various validation through in vivo and in vitro experiments showed that YegW is a single-target transcription factor that acts as a repressor of yegTUV, with an intracellular concentration of consistently approximately 10 molecules, and senses ADPG as an effector. Further analysis revealed that YegW repressed glycogen accumulation in response to increased glucose concentration, which was not accompanied by changes in the growth phase. In minimal glucose medium, yegW-deficient E. coli promoted glycogen accumulation, at the expense of poor cell proliferation. We concluded that YegW is a single-target transcription factor that senses ADPG and represses glycogen accumulation in response to the amount of glucose available to the cell. We propose renaming YegW to GgaR (repressor of glycogen accumulation).

Oleic Acid Activates Mitochondrial Energy Metabolism and Reduces Oxidative Stress Resistance in the Pancreatic β-Cell Line INS-1.

Elevated concentration of saturated fatty acids in plasma adversely affects pancreatic β-cells, but the effects of unsaturated fatty acids are controversial. In this study, we examined the effects of oleic acid (OA), a monounsaturated fatty acid, on mitochondrial function, which is important for insulin secretion, using INS-1 cells, a pancreatic β-cell line derived from rats. Observations of mitochondrial membrane potential and intracellular ATP concentration showed that the electron transport chain was enhanced and ATP production increased in cells treated with OA, indicating that the response that occurs from sensing an increase in glucose concentration to the production of ATP was accelerated. Measurements of intracellular reactive oxygen species (ROS) indicated that the rate of increase in ROS after glucose stimulation was significantly higher in OA-treated cells. The mRNA expression levels of superoxide dismutase 1 and 2, which are responsive to ROS and other substances, were significantly increased in OA 1-d treated cells, but decreased in OA 7-d treated cells. It can be inferred that continued exposure to high concentrations of OA reduced ROS processing capacity and increased intracellular ROS levels. The mRNA expression of apoptosis-inducing enzyme Caspase-3 was significantly increased in OA-treated cells, although its activity was not high. However, the apoptosis induction rate after H2O2 stimulation was significantly higher in OA-treated cells. The high OA environment was shown to promote mitochondrial energy metabolism, leading to an increase in glucose sensitivity and a decrease in oxidative stress resistance.

Songbirds avoid the oxidative stress costs of high blood glucose levels: a comparative study.

Chronically high blood glucose levels (hyperglycaemia) can compromise healthy ageing and lifespan at the individual level. Elevated oxidative stress can play a central role in hyperglycaemia-induced pathologies. Nevertheless, the lifespan of birds shows no species-level association with blood glucose. This suggests that the potential pathologies of high blood glucose levels can be avoided by adaptations in oxidative physiology at the macroevolutionary scale. However, this hypothesis remains unexplored. Here, we examined this hypothesis using comparative analyses controlled for phylogeny, allometry and fecundity based on data from 51 songbird species (681 individuals with blood glucose data and 1021 individuals with oxidative state data). We measured blood glucose at baseline and after stress stimulus and computed glucose stress reactivity as the magnitude of change between the two time points. We also measured three parameters of non-enzymatic antioxidants (uric acid, total antioxidants and glutathione) and a marker of oxidative lipid damage (malondialdehyde). We found no clear evidence for blood glucose concentration being correlated with either antioxidant or lipid damage levels at the macroevolutionary scale, as opposed to the hypothesis postulating that high blood glucose levels entail oxidative costs. The only exception was the moderate evidence for species with a stronger stress-induced increase in blood glucose concentration evolving moderately lower investment into antioxidant defence (uric acid and glutathione). Neither baseline nor stress-induced glucose levels were associated with oxidative physiology. Our findings support the hypothesis that birds evolved adaptations preventing the (glyc)oxidative costs of high blood glucose observed at the within-species level. Such adaptations may explain the decoupled evolution of glycaemia and lifespan in birds and possibly the paradoxical combination of long lifespan and high blood glucose levels relative to mammals.

Isolation and identification of yeasts from local fruits in Thua Thien Hue province, Vietnam

In this study, a total of 30 yeast isolates were recovered from local fruits in Thua Thien Hue province. Genetic characterization based on the ITS sequences identified isolates belonging to 3 species including Saccharomyces cerevisiae, Lachancea fermentati, and Clavispora fructus, with high sequence homology (over 99%) compared to published sequences in the GenBank. All identified S. cerevisiae isolates could grow well at 30°C and ferment several sugar including fructose, galactose, sucrose, mannose, maltose, and raffinose with different performances, but were inhibited at temperature higher than 35°C. The strains also grew well in the medium containing 5% ethanol (v/v) and 200 g/L glucose, but their growth ability was decreased gradually with an increase in ethanol and glucose concentrations. Interestingly, D14 strain was able to grow in the medium supplemented with 12% of ethanol, and 500 g/L of glucose at 45°C, while D7 strain could utilize both mannitol and glycerol at a low level. Our results also indicated that some strains have relatively high sedimentation efficiency, which are favorable conditions for beer fermentation and biomass recovery. The isolated yeast strains with good tolerance properties may provide a potential source of valuable raw materials for applications in beverage production and food processing.

Effects of exogenous energy on synthesis of steroid hormones and expression characteristics of the CREB/StAR signaling pathway in theca cells of laying hen

Energy and the cAMP-response element binding protein (CREB)/steroidogenic acute regulatory protein (StAR) signaling pathway play important roles in steroid hormone production and follicular development in hens. This present study aimed to investigate the effects of exogenous energy on the synthesis of steroid hormones and the expression characteristics of the CREB/StAR signaling pathway in theca cells of laying hen. The primary theca cells of small yellow follicles were randomly divided into six treatments and cultured in medium with glucose concentrations of 1, 1.5, 3, 4.5, 6 and 7.5 mg/mL for 48 h. It was found that growth was robust and cell outlines were clear when cells were cultured with 1, 1.5, 3 and 4.5 mg/mL glucose, but cell viability was diminished and cell density decreased after exposure to glucose at 6 and 7.5 mg/mL for 48 h. Cell viability showed an increasing and then decreasing quadratic response to increasing glucose concentration in culture (r2 = 0.688, P < 0.001). The cell viability of theca cells cultured with 4.5 mg/mL glucose was greater than those cultured with 1, 1.5, 6 and 7.5 mg/mL glucose (P < 0.05). The concentration of estradiol in the medium containing 3 mg/mL glucose was higher than in medium containing 1, 1.5 and 6 mg/mL glucose (P < 0.05). There was an increasing and then decreasing quadratic correlation between progesterone concentrations and glucose concentrations (r2 = 0.522, P = 0.002). The concentration of progesterone in medium with 4.5 mg/mL glucose was higher than in medium with 1 and 7.5 mg/mL glucose (P < 0.05). There was an increasing and then decreasing quadratic correlation between the relative expression of CREB1 (r2 = 0.752, P < 0.001), StAR (r2 = 0.456, P = 0.002), CYP1B1 (r2 = 0.568, P < 0.001), and 3β-HSD (r2 = 0.319, P = 0.018) in theca cells of laying hens and glucose concentrations after treatment with different glucose concentrations for 48 h. After treatment with 4.5 mg/mL glucose, the expression of StAR, CYP1B1 and 3β-HSD genes were increased compared to treatment with 1, 1.5, 3, 6 and 7.5 mg/mL glucose (P < 0.001). There was an increasing and then decreasing quadratic correlation between glucose concentrations and protein expression of CREB1 (r2 = 0.819, P < 0.001), StAR (r2 = 0.844, P < 0.001), 3β-HSD (r2 = 0.801, P < 0.001) and CYP11A1 (r2 = 0.800, P < 0.001) in theca cells of laying hens. The protein expression of CREB1, StAR and 3β-HSD in theca cells cultured with 4.5 mg/mL glucose was higher than in other groups (P < 0.001). The results indicate that the appropriate glucose concentration (4.5 mg/mL) can improve the synthesis of steroid hormones in theca cells of laying hens through the upregulation of key genes and proteins in the CREB/StAR signaling pathway.

In Vitro Hypoglycemic and Antioxidant Activities of Dichloromethane Extract of Xerophyta spekei.

Diabetes mellitus is a chronic metabolic disorder which has greatly led to an increase in morbidity and mortality globally. Although Xerophyta spekei is widely used for the management of diabetes among the Embu and Mbeere communities in Kenya, it has never been empirically evaluated for its hypoglycemic activity. This study was carried out to verify the hypoglycemic activity of dichloromethane (DCM) extract of Xerophyta spekei as well as its antioxidant activity using various in vitro techniques. Phytochemicals associated with its antioxidant activity were identified through GC-MS. Data were subjected to descriptive statistics and expressed as mean ± standard error of the mean (X̄ ± SEM). Comparison between various variables was performed by using unpaired Student's t-test and one-way analysis of variance (ANOVA), followed by Tukey's post-hoc test. The confidence interval was set at 95%. The obtained results were presented in tables and graphs. Results showed that there was no difference in α-amylase inhibition activity between the plant extract and the standard (IC50 525.9 ± 12.34 and 475.1 ± 9.115, respectively; p > 0.05). Besides, the glucose adsorption activity of the extract increased with an increase in glucose concentration (from 5.89 to 32.64 mg/dl at 5 mmol and 30 mmol of glucose, respectively; p < 0.05). The extract also limited the diffusion of glucose more than the negative control (7.49 and 17.63 mg/dl, respectively; p < 0.05). It also enhanced glucose uptake by yeast cells. In addition, the studied plant extract showed notable antioxidant activities. The therapeutic effects exhibited by this plant in managing diabetes mellitus and other ailments could be due to its antioxidant as well as its hypoglycemic activity. The study recommends the evaluation of X. spekei for in vivo hypoglycemic and antioxidant activities. Besides, the isolation of bioactive phytochemicals from the plant may lead to the development of new hypoglycaemic agents.