Glucose Uptake Activity Research Articles

The lysosomal LAMTOR / Ragulator complex is essential for nutrient homeostasis in brown adipose tissue

ObjectiveIn brown adipose tissue (iBAT), the balance between lipid/glucose uptake and lipolysis is tightly regulated by insulin signaling. Downstream of the insulin receptor, PDK1 and mTORC2 phosphorylate AKT, which activates glucose uptake and lysosomal mTORC1 signaling. The latter requires the late endosomal/lysosomal adaptor and MAPK and mTOR activator (LAMTOR/Ragulator) complex, which serves to translate the nutrient status of the cell to the respective kinase. However, the role of LAMTOR in metabolically active iBAT has been elusive. MethodsUsing an AdipoqCRE-transgenic mouse line, we deleted LAMTOR2 (and thereby the entire LAMTOR complex) in adipose tissue (LT2 AKO). To examine the metabolic consequences, we performed metabolic and biochemical studies in iBAT isolated from mice housed at different temperatures (30 °C, room temperature and 5 °C), after insulin treatment, or in fasted and refed condition. For mechanistic studies, mouse embryonic fibroblasts (MEFs) lacking LAMTOR 2 were analyzed. ResultsDeletion of the LAMTOR complex in mouse adipocytes resulted in insulin-independent AKT hyperphosphorylation in iBAT, causing increased glucose and fatty acid uptake, which led to massively enlarged lipid droplets. As LAMTOR2 was essential for the upregulation of de novo lipogenesis, LAMTOR2 deficiency triggered exogenous glucose storage as glycogen in iBAT. These effects are cell autonomous, since AKT hyperphosphorylation was abrogated by PI3K inhibition or by deletion of the mTORC2 component Rictor in LAMTOR2-deficient MEFs. ConclusionsWe identified a homeostatic circuit for the maintenance of iBAT metabolism that links the LAMTOR-mTORC1 pathway to PI3K-mTORC2-AKT signaling downstream of the insulin receptor.

Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities of Tectona grandis Methanolic Extracts, Fractions, and Isolated Compounds.

Tectona grandis is a traditional Dai medicine plant belonging to the Lamiaceae family, which can be used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease and as an anti-helminthic. To find more novel therapeutic agents contained in this medicinal plant, the antioxidant, anti-inflammatory and anti-diabetic activities of T. grandis methanolic extract, fractions and compounds were evaluated. In this study, 26 compounds were isolated from the leaves and branches of T. grandis. Their structures were identified based on extensive spectral experiments, including NMR, ESI-MS and comparison with published spectral data. Among them, compounds 1-2, 4-6, 9-14 and 16-22 were reported for the first time for this plant. The antioxidant activity screening results showed that compounds 5, 15 and 23 had potent antioxidant capacities, with SC50 values from 0.32 to 9.92 µmol/L, 0.92 to 1.10 mmol Trolox/L and 1.02 to 1.22 mmol Trolox/L for DPPH, ABTS and FRAP, respectively. In addition, their anti-inflammatory effects were investigated by releasing TNF-α, IL-1β and IL-6 through the use of mouse monocytic macrophages (RAW 264.7). Compounds 1, 13, 18 and 23 had the effects of reducing the expression of inflammatory factors. Compounds 13 and 18 were reported for the first time for their anti-inflammatory activities. Furthermore, the methanolic extract (ME), petroleum ether extract (PEE) and EtOAc extract (EAE) of T. grandis showed significant glucose uptake activities; compounds 21 and 23 significantly promoted glucose uptake of 3T3-L1 adipocytes at 40 µM. Meanwhile, compounds 4, 5 and 7 showed significant inhibitory activities against α-glucosidase, with IC50 values of 14.16 ± 0.34 µmol/L, 19.29 ± 0.26 µmol/L and 3.04 ± 0.08 µmol/L, respectively. Compounds 4 and 5 were reported for the first time for their α-glucosidase inhibitory activities. Our investigation explored the possible therapeutic material basis of T. grandis to prevent oxidative stress and related diseases, especially inflammation and diabetes.

An in vitro Adipogenic Potential and Glucose Uptake Stimulatory Effect of Betulinic acid and Stigmasterol Isolated from Tetracera indica in 3T3-L1 Cell Line

Aerial parts of Tetracera indica Merr. (Dilleniaceae) are rich in betulinic acid and stigmasterol and traditionally used to treat diabetes. This study was aimed to evaluate an in vitro antidiabetic potential of betulinicacid and stigmasterol to ascertain whether they may contribute antidiabetic effect to T. indica. Initially, betulinicacid and stigmasterol were isolated from the most effective subfraction (ethyl acetate) and subjected to an in vitro antidiabetic investigation through adipogenesis and fluorescence glucose (2-NBDG) uptake assays using 3T3-L1 fibroblast. MTT viability assay was performed at 0.78 to 100 µg/mL for 48 h to determine the safe concentration. Both compounds were subjected to 2-NBDG uptake test on the differentiated adipocytes. The cells were treated in safe concentrations (25-100 µg/mL) as well as in different adipogenic cocktails, which were modified by the addition of compounds to be investigated and in the presence or absence of insulin (10 µM). Rosiglitazone (10 µM) was used as standard. Stems ethanol extract and its fractions (hexane and ethyl acetate), betulinic acid and stigmasterol were found safe at their highest concentration (100 µg/mL) by inhibiting cells well below their IC50 values viz. 18.60, 35.27, 21.40, 28.86 and 33.06%, respectively. Both betulinic acid and stigmasterol at the highest safe concentration (100 µg/mL) significantly (p <0.05) induced adipogenesis like insulin, enhanced adipogenesis like rosiglitazone and exhibited glucose uptake activity. The present study demonstrates that both betulinic acid and stigmasterol possess an in vitro antidiabetic potential. However, in vivo antiglycemic study on these compounds and their chemical analogs are still warranted to ensure their therapeutic potential as safe antidiabetic agents.

The standardized Jamu pahitan, an Indonesian antidiabetic formulation, stimulating the glucose uptake and insulin secretion in the in-vitro models

Jamu pahitan is a polyherbal formulation commonly used for the traditional management of diabetes in Indonesia and is mainly prepared from Andrographis paniculata (Burm.f.) Nees. It is widely varied in herbal composition for every region has their own plant component addition to the formulation. A version of the formulation used in the greater Surakarta area contained five plant constituents. This study evaluated the in-vitro glucose uptake and insulin secretion stimulatory activities of Jamu pahitan to provide scientific evidence on its efficacy and safety of use. The water and ethanol extracts of three Jamu pahitan formulations were prepared. The total phenolic content (TPC) of the extracts was evaluated by the standard Folin-Ciocalteau method. Their effects on the viability of L6 skeletal muscle and RIN-m5F pancreatic cells were evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The glucose utilized by L6 myotubes treated with Jamu pahitan was assessed indirectly by the glucose oxidase method. The insulin secreted by RIN-m5F treated with the formulation extracts was analyzed by the enzyme-linked immunosorbent assay (ELISA). The correlation between TPC and the profile of safety and efficacy of the formulation was statistically evaluated. The water extracts of Jamu pahitan were safe and exerted significant glucose uptake and insulin secretion stimulatory activity in L6 and RIN-m5F, respectively. The ethanol extracts showed more potent effects than their water counterpart, albeit they exerted cytotoxic effects on the cells at the higher tested concentrations. The formulations at lower concentrations stimulated the proliferation of RIN-m5F. In addition, the TPC was strongly correlated with the glucose uptake and insulin secretion stimulatory activities and also the IC50 of the cells in positive manner. The present study supported the use of Jamu pahitan for the traditional management of diabetes in Indonesia by stimulating glucose uptake in the muscle cells and improving insulin secretion in β-cells.

MiR 378a/FSCN1 regulatory axis inhibits tumor stemness and increases the cytotoxicity of chemotherapeutic drugs in colorectal cancer cells

Purpose: To evaluate the effect of miR-378a/FSCN1 axis on tumor stemness and aerobic glycolysis in colorectal cancer cells (CRC).
 Methods: Abnormal expressions of miR-378a and FSCN1 in CRC tissues were analyzed through TCGA database. Cell viability and apoptosis were determined using 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay and flow cytometry, respectively, while expression of miR-378a was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Furthermore, Western blotting assay was used to assess protein expressions. The miR-378a target was evaluated using ENCORI and confirmed by luciferase assay. Aerobic glycolysis was evaluated by determining glucose uptake, lactate production and lactate dehydrogenase (LDH) activity.
 Results: Downregulation of miR-378a and upregulation of FSCN1 were observed in both CRC tissues and cell lines (p < 0.05). Overexpression of miR-378a and repression of FSCN1 reduced cell viability and tumor sphere formation, and induced cell apoptosis. Protein expression of SOX2, KLF4, Bmi1 and Oct-4 were downregulated by either the overexpression of miR-378a or repression of FSCN1 (p < 0.01). Glucose uptake, lactate production and LDH activity were inhibited by either overexpression of miR-378a or repression of FSCN1, while cytotoxicity of Dox and 5-Fu was increased by upregulation of miR-378a or downregulation of FSCN1 (p < 0.05). The predictive results of ENCORI demonstrated that FSCN1 was the direct target of miR-378a, and this was confirmed by luciferase assay results (p < 0.005). All the effects of miR-378a in CRC were reversed by overexpression of FSCN1 (p < 0.05).
 Conclusion: This study has shown that miR-378a suppresses tumor stemness and increases the cytotoxicity of chemotherapeutic drugs by directly targeting FSCN1, resulting in the prevention of CRC tumorigenesis. Thus, these findings suggest a new approach to the chemotherapeutic management of CRC.

Selection for Growth Does Not Affect Apparent Energetic Efficiency of Jejunal Glucose Uptake in Mice

Five-wk-old male mice from high growth (M16) and randomly bred control (ICR) lines, plus their reciprocal crosses, ICR × M16 and M16 × ICR, were used to investigate whether whole-body O2 consumption, jejunal respiration, jejunal glucose absorption and the apparent energetic efficiency of jejunal active glucose uptake in mice are altered by genetic selection for growth as well as by heterosis and maternal effects. Whole-body O2 consumption was measured in 12 mice from each line or cross. The mice were later killed for measurement of jejunal O2, using tissue respiration chambers and jejunal glucose transport determined by 3H-3-O-methylglucose accumulation. No heterosis or maternal effects were detected in jejunal glucose active transport and active glucose uptake. Selection for growth (M16 vs. ICR) increased daily gain (1.54 vs. 1.09 g, P < 0.001), small intestinal length and weight, but did not enhance jejunal glucose transport. The apparent energetic efficiency of jejunal active glucose uptake among lines was not different (54.0, 50.4, 51.6 and 47.1 nmol ATP expended/nmol glucose uptake for M16, ICR, M16 × ICR and ICR × M16, respectively, P > 0.63). Selection for growth in mice did not result in more energetically efficient jejunal glucose absorption.

Selection for Body Composition Does Not Affect Energetic Efficiency of Jejunal Glucose Uptake in Mice

Five-wk-old male mice from three lines were used to examine whether the apparent energetic efficiency of active jejunal glucose uptake in mouse jejunum is altered by genetic selection for different body composition. The mice lines were selected as follows: HE, high percentage of body fat with no change in body weight as a constraint; LF, low percentage of body fat; and RS, randomly bred control. Body weight was similar in all lines. Total jejunal O2 consumption and ouabain-sensitive O2 consumption were used to estimate the energy expenditure associated with glucose absorption and Na+/K+-ATPase activity. Tritiated 3-O-methyl-D-glucose was used to determine glucose uptake by mouse jejunum. Line LF, when compared with line HE, had lower body fat as indicated by epididymal fat pad weight (143 vs. 362 mg/mouse, P < 0.001). There were no significant differences in small intestinal weight, length and density (mg/cm) between LF and HE lines. Jejunal villus width was greater in line LF compared with line HE (115 vs. 92 µm, P < 0.002). Jejunal glucose transport and O2 consumption were not different between LF and HE lines. Ouabain-sensitive O2 consumption was not significantly different among the three lines. No differences were noted in the apparent energetic efficiency of active glucose uptake among lines.

Novel Caffeic Acid - Zinc Acetate Complex: Studies on Promising Antidiabetic and Antioxidative Synergism Through Complexation.

The role of Zn(II) in storage, insulin secretion and function has been documented, while plant phenolics have antioxidant and other pharmacological credence. The study aimed at synthesizing a novel medicinal Zn(II) complex. The medicinal properties of zinc(II) and caffeic acid were considered in synthesizing a novel complex with promising and improved antioxidant and anti-hyperglycaemic attributes. Complex synthesis was done using a 1:2 molar ratio of zinc acetate and caffeic acid and structurally characterized using NMR, FT-IR, high resolution-mass spectroscopy and HPLC. Its cellular toxicity was assessed in Chang liver cells and L-myotubes. In vitro, cellular, and isolated tissue models were used to evaluate the antioxidant and anti-hyperglycaemic properties of the complex relative to its precursors. Molecular docking was used to investigate the interaction with insulin signalling target proteins: GLUT-4 and protein kinase B (Akt/PKB). Zinc(II) and caffeic acid interacted via Zn:O4 coordination, with the complex having one moiety of Zn(II) and 2 moieties of caffeic acid. The complex showed in vitro radical scavenging, α- glucosidase and α-amylase inhibitory activity up to 2.6 folds stronger than caffeic acid. The ability to inhibit lipid peroxidation (IC50 = 26.4 μM) and GSH depletion (IC50 = 16.8 μM) in hepatocytes was comparable to that of ascorbic acid (IC50 = 24.5 and 29.2 μM) and about 2 folds stronger than caffeic acid. Complexation improved glucose uptake activity of caffeic acid in L-6 myotubes (EC50 = 23.4 versus 169 μM) and isolated rat muscle tissues (EC50 = 339 versus 603 μM). Molecular docking showed better interaction with insulin signalling target proteins (GLUT-4 and Akt/PKB) than caffeic acid. The complex was not hepatotoxic or myotoxic. Data suggest a synergistic antioxidant and anti-hyperglycaemic potential between zinc and caffeic acid, which could be attributed to the Zn:O4 coordination. Thus, it may be of medicinal relevance.

Circulating Dopamine Is Regulated by Dietary Glucose and Controls Glucagon-like 1 Peptide Action in White Adipose Tissue.

Dopamine directly acts in the liver and white adipose tissue (WAT) to regulate insulin signaling, glucose uptake, and catabolic activity. Given that dopamine is secreted by the gut and regulates insulin secretion in the pancreas, we aimed to determine its regulation by nutritional cues and its role in regulating glucagon-like peptide 1 (GLP-1) action in WAT. Solutions with different nutrients were administered to Wistar rats and postprandial dopamine levels showed elevations following a mixed meal and glucose intake. In high-fat diet-fed diabetic Goto-Kakizaki rats, sleeve gastrectomy upregulated dopaminergic machinery, showing the role of the gut in dopamine signaling in WAT. Bromocriptine treatment in the same model increased GLP-1R in WAT, showing the role of dopamine in regulating GLP-1R. By contrast, treatment with the GLP-1 receptor agonist Liraglutide had no impact on dopamine receptors. GLP-1 and dopamine crosstalk was shown in rat WAT explants, since dopamine upregulated GLP-1-induced AMPK activity in mesenteric WAT in the presence of the D2R and D3R inhibitor Domperidone. In human WAT, dopamine receptor 1 (D1DR) and GLP-1R expression were correlated. Our results point out a dietary and gut regulation of plasma dopamine, acting in the WAT to regulate GLP-1 action. Together with the known dopamine action in the pancreas, such results may identify new therapeutic opportunities to improve metabolic control in metabolic disorders.

The Mechanisms of Neochlorogenic Acid (3-Caffeoylquinic Acid) in Improving glucose and Lipid Metabolism in Rats with Insulin Resistance Induced by A High Fat-High Fructose Diet

This study investigated the effects and the mechanism of actions of neochlorogenic acid (3-caffeoylquinic acid; 3-CQA) on glucose and lipid metabolism in rats fed a high fat-high fructose diet (HFFD). Male rats were fed HFFD (40 % lard and 20 % fructose) for 16 weeks. At the 10th week, the HFFD rats were split into 3 groups: HFFD receiving distilled water (HFFD control group), HFFD receiving 3-CQA 50 mg/kg and HFFD receiving metformin 200 mg/kg once daily for a further 6 weeks. At the end of treatment, fasting blood glucose (FBG), oral glucose-tolerance test (OGTT), lipid profile, insulin, leptin, adiponectin, markers of oxidative stress, and hepatic triglyceride content were measured. Liver, adipose tissue, and skeletal muscle were collected for histological, gene and protein examinations. Compared to the HFFD control group, the 3-CQA group exhibited significantly reduced FBG, insulin and leptin levels, and improved OGTT. Serum adiponectin increased and lipid profiles were normalized. Hepatic triglyceride was reduced with a decrease in lipid droplets in liver histological sections. Levels of serum SOD and CAT activity, and MDA were reversed by 3-CQA treatment. Moreover, 3-CQA significantly reduced the expression of adipocyte pro-inflammatory cytokine genes (MCP-1, TNF-α, and IL-6), hepatic lipogenic genes (SREBP1c, FAS, and GPAT), and hepatic gluconeogenic genes (PEPCK and G6Pase). Additionally, 3-CQA increased expression of muscle GLUT4 gene, and of GLUT4 protein with increased p-AKT and p-AMPK in skeletal muscle. In conclusion, 3-CQA improves glucose and lipid metabolism plausibly by decreasing oxidative stress and inflammation-induced insulin resistance, downregulating the expression of lipogenic and gluconeogenic genes, and enhancing insulin signaling in HFFD-induced insulin-resistant rats. HIGHLIGHTS Neochlorogenic acid (3-CQA) improves glucose and lipid metabolism by decreasing insulin resistance Neochlorogenic acid (3-CQA) deceases insulin resistance due to its activities in ameliorating obesity, oxidative stress, and adipose tissue inflammation The beneficial effects of Neochlorogenic acid (3-CQA) to improve glucose and lipid homeostasis may be mediated via suppression of hepatic glucose production and lipogenesis, and activation of muscle glucose uptake and AKT and AMPK pathways GRAPHICAL ABSTRACT

In Vitro Hypoglycemic Diterpenoids from the Roots of Croton yunnanensis.

Fifteen compounds including nine new diterpenes were isolated from the roots of Croton yunnanensis. By HRESIMS, NMR, ECD data, and X-ray diffraction analysis, the new compounds were characterized as eight neo-clerodane diterpenes (compounds 1-8) and one 15,16-dinor-ent-pimarane diterpene (9). All diterpenes were assayed for their hypoglycemic activities. Compounds 1-4, 6, 7, and 10 promoted glucose uptake activity in insulin-resistant 3T3-L1 adipocytes. Compounds 1 and 6 showed insulin sensitizing activity, potentiating conspicuously their glucose uptake activity at a concentration of 20 μM when treated synergistically with low-concentration insulin at 1 nM.

Sarsasapogenin, a principal active component absorbed into blood of total saponins of Anemarrhena, attenuates proliferation and invasion in rheumatoid arthritis fibroblast-like synoviocytes through downregulating PKM2 inhibited pathological glycolysis.

Increased glycolytic in fibroblast-like synoviocytes (FLS) of rheumatoid arthritis (RA) not only contributes to early-stage disease pathogenesis but leads to sustained proliferation of FLS. Given the importance of PKM2 in glycolysis and apoptosis, PKM2 is considered a potential therapeutic and drug discovery target in RA. Total saponins of anemarrhena (TSA), a class of steroid saponins, originated from Anemarrhena asphodeloides Bge. In this study, we verified that 200 mg/kg TSA could significantly alleviate inflammation and the pathological characteristics of RA and inhibit synovial hyperplasia in AA rats. We confirmed that sarsasapogenin (SA) was the principal active ingredient absorbed into the blood of TSA by the UPLC/Q Exactive MS test. Then we used TNF-α-induced MH7A to get the conclusion that 20 μM SA could effectively inhibit the glycolysis by inhibiting the activity of PKM2 tetramer and glucose uptake. Moreover, 20 μM SA could suppress proliferation, migration, invasion, and cytokine release of FLS, interfere with the growth cycle of FLS, and induce FLS apoptosis by depressing the phosphorylation of PKM2. At last, In-1, a potent inhibitor of the PKM2 was used to reverse verify the above results. Taken together, the key mechanisms of SA on RA treatment through downregulating the activity of PKM2 tetramer and phosphorylation of PKM2 inhibited pathological glycolysis and induced apoptosis to exert inhibition on the proliferation and invasion of RA FLS.

Wnt/BMP Mediated Metabolic Reprogramming Preserves Multipotency of Neural Crest-Like Stem Cells.

Neural crest-like stem cells resembling embryonic neural crest cells (NCs) can be derived from adult human tissues such as the epidermis. However, these cells lose their multipotency rapidly in culture limiting their expansion for clinical use. Here, we show that the multipotency of keratinocyte-derived NCs (KC-NCs) can be preserved by activating the Wnt and BMP signaling axis, promoting expression of key NC-specifier genes and ultimately enhancing their differentiation potential. We also show that transcriptional changes leading to multipotency are linked to metabolic reprogramming of KC-NCs to a highly glycolytic state. Specifically, KC-NCs treated with CHIR and BMP2 rely almost exclusively on glycolysis for their energy needs, as seen by increased lactate production, glucose uptake, and glycolytic enzyme activities. This was accompanied by mitochondrial depolarization and decreased mitochondrial ATP production. Interestingly, the glycolytic end-product lactate stabilized β-catenin and further augmented NC-gene expression. Taken together, our study shows that activation of the Wnt/BMP signaling coordinates the metabolic demands of neural crest-like stem cells governing decisions regarding multipotency and differentiation, with possible implications for regenerative medicine.

Triterpenoid saponins and C21 steroidal glycosides from Gymnema tingens and their glucose uptake activities.

Four new triterpenoid saponins, tigensides A-D (1-4), and one new C21 steroid, tipregnane A(9), together with six known compounds were isolated from the EtOAc fraction of the roots and stems of Gymnema tingens. The chemical structures of the new compounds were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. All compounds were isolated for the first time. Compounds 1-11 promoted glucose uptake in the range of 1.12 to 2.52 fold, respectively. Compound 2 showed the most potent glucose uptake, with 2.52 fold enhancement. Additionally, compound 2 showed a medium effect on the GLUT4 translocation activity in L6 cells in further study.

Glycine Decarboxylase (GLDC) Plays a Crucial Role in Regulating Energy Metabolism, Invasion, Metastasis and Immune Escape for Prostate Cancer.

Glycine decarboxylase (GLDC) is one of the core enzymes for glycine metabolism, and its biological roles in prostate cancer (PCa) are unclear. First, we found that GLDC plays a central role in glycolysis in 540 TCGA PCa patients. Subsequently, a metabolomic microarray showed that GLDC enhanced aerobic glycolysis in PCa cells, and GLDC and its enzyme activity enhanced glucose uptake, lactate production and lactate dehydrogenase (LDH) activity in PCa cells. Next, we found that GLDC was highly expressed in PCa, was directly regulated by hypoxia-inducible factor (HIF1-α) and regulated downstream LDHA expression. In addition, GLDC and its enzyme activity showed a strong ability to promote the migration and invasion of PCa both in vivo and in vitro. Furthermore, we found that the GLDC-high group had a higher TP53 mutation frequency, lower CD8+ T-cell infiltration, higher immune checkpoint expression, and higher immune exclusion scores than the GLDC-low group. Finally, the GLDC-based prognostic risk model by applying LASSO Cox regression also showed good predictive power for the clinical characteristics and survival in PCa patients. This evidence indicates that GLDC plays crucial roles in glycolytic metabolism, invasion and metastasis, and immune escape in PCa, and it is a potential therapeutic target for prostate cancer.

Germinated chickpea protein ficin hydrolysate and its peptides inhibited glucose uptake and affected the bitter receptor signaling pathway in vitro.

The objective of this study was to evaluate germinated chickpea protein hydrolysate (GCPH) in vitro for its effect on markers of type 2 diabetes (T2D) and bitter taste receptor expression in intestinal epithelial cells. Protein hydrolysate was obtained using ficin, and the resulting peptides were sequenced using LC-ESI-MS/MS. Caco-2 cells were used to determine glucose uptake and extra-oral bitter receptor activation. Three peptides, VVFW, GEAGR, and FDLPAL, were identified in legumin. FDLPAL was the most potent peptide in molecular docking studies with a DPP-IV energy of affinity of -9.8 kcal mol-1. GCPH significantly inhibited DPP-IV production by Caco-2 cells (IC50 = 2.1 mM). Glucose uptake was inhibited in a dose-dependent manner (IC25 = 2.0 mM). A negative correlation was found between glucose uptake and PLCβ2 expression in Caco-2 cells (R value, -0.62). Thus, GCPH has the potential to be commercialized as a functional ingredient.

Phytochemical and Biological Investigation of the Leaves of Tridax procumbens

Aims: Because of various traditional uses of Tridax procumbens leaves, the authors choose the plant for investigating the numerous biological activities. The main objective for this study is to search antioxidant activity, hypoglycemic activity and antibacterial activities with initial phytochemical investigations of the leaves of Tridax procumbens.&#x0D; Methodology: The phytochemical purposes were achieved by using two different chromatographic techniques thin layer chromatography (TLC), vacuum liquid chromatography (VLC). DPPH test, glucose uptake activity of yeast cells and agar plate diffusion technique were performed to evaluate the antioxidant capacity, hypoglycemic activity and anti-bacterial properties respectively of different fraction obtained from VLC by using different solvent systems such as dichloromethane, butanol, ethyl acetate and methanol. 31.25 µg/ml, 62.5 µg/ml, 125 µg/ml, 250 µg/ml and 500 µg/ml sample were used from each fraction to investigate antioxidant and hypoglycemic activity where vitamin C tablet and metformin were used as standard respectively. Antibacterial capacity was measured by measuring zone of inhibition resulted by the fractions where ciprofloxacin was taken as reference drug. &#x0D; Results: Some visible spots were identified in the TLC plate which confirms the presence of different compounds in the fractions obtained from the methanolic extract of the leaves of Tridax procumbens. Butanol and ethyl acetate fractions showed the highest antidiabetic activity. In addition to, ethyl acetate, butanol and methanol fractions exerted more than 80% antioxidant capacity in DPPH assay. Furthermore, butanol fraction gives maximum zone of inhibition up to 21 mm against Staphylocuccos aureas which ensure anti-bacterial properties of the leaves of Tridax procumbens especially against Staphylocuccos aureas and its strains.&#x0D; Conclusion: Notwithstanding the all the research, the leaves had anti-inflammatory properties, which may have been generated by their antioxidant activity. As a result, if more therapeutic research is done, the separated compounds in those fractions may be employed as future therapeutic strategies.

Digestion, absorption, and transport properties of soy-fermented douchi hypoglycemic peptides VY and SFLLR under simulated gastrointestinal digestion and Caco-2 cell monolayers

Two novel hypoglycemic peptides VY and SFLLR were identified from douchi as the major peptides responsible for the glucose uptake activity. The present work aimed to elucidate their digestion, absorption and transport properties using simulated digestion and Caco-2 cell monolayers transport models. Besides, the effects of digestion and absorption on the structure and activity were also studied. The results showed that VY was resistant to gastrointestinal tract digestion and could cross Caco-2 cell monolayers intactly via both TJs-mediated passive paracellular pathway and PepT1-mediated active route. In comparison, SFLLR was partially degraded into small fragments of SFLL, SFL, and SF by the digestive system, leading to increased glucose uptake activity. Notably, SFLLR, SFLL, and SFL were partly hydrolyzed by aminopeptidase N or dipeptidyl peptidase IV during transport, but they were transported intact. SFL was transported via both paracellular diffusion and PepT1-mediated routes, while SFLLR and SFLL were via paracellular route only.

Loss of glyoxalase 2 alters the glucose metabolism in zebrafish

Glyoxalase 2 is the second enzyme of the glyoxalase system, catalyzing the detoxification of methylglyoxal to d-lactate via SD-Lactoylglutathione. Recent in vitro studies have suggested Glo2 as a regulator of glycolysis, but if Glo2 regulates glucose homeostasis and related organ specific functions in vivo has not yet been evaluated. Therefore, a CRISPR-Cas9 knockout of glo2 in zebrafish was created and analyzed. Consistent with its function in methylglyoxal detoxification, SD-Lactoylglutathione, but not methylglyoxal accumulated in glo2−/− larvae, without altering the glutathione metabolism or affecting longevity. Adult glo2−/− livers displayed a reduced hexose concentration and a reduced postprandial P70–S6 kinase activation, but upstream postprandial AKT phosphorylation remained unchanged. In contrast, glo2−/− skeletal muscle remained metabolically intact, possibly compensating for the dysfunctional liver through increased glucose uptake and glycolytic activity. glo2−/− zebrafish maintained euglycemia and showed no damage of the retinal vasculature, kidney, liver and skeletal muscle. In conclusion, the data identified Glo2 as a regulator of cellular energy metabolism in liver and skeletal muscle, but the redox state and reactive metabolite accumulation were not affected by the loss of Glo2.

Bioactive compounds from the fruit extract of Clausena excavata Burm. f. (Rutaceae)

• Sixteen compounds were isolated from the EtOAc extract of C. excavata fruits. • Nine compounds ( 1, 3, 5, 6, 8 – 10, 15 , and 16 ) were isolated from C. excavata for the first time. • The absolute configuration of the bioactive limonoids 15 and 16 were confirmed by the X-ray crystallography using Cu Kα radiation. • Compounds 7 (auraptene) and 14 (safrole) showed a moderate glucose uptake with ratios of 1.38-fold and 1.41-fold, respectively. • The cytotoxicity of auraptene 7, 8 , and 10 against lung cancer A549, RAW 264.7 cells, and colorectal cancer SW480 are reported for the first time in this study. Phytochemical investigation of the fruit extract of Clausena excavata Burm. f. resulted in the isolation and identification of 16 compounds, including seven coumarins ( 1 – 7 ), four phenylpropanoids ( 8 – 10 and 14 ), two benzaldehyde derivatives ( 11 and 12 ), one carbazole alkaloid ( 13 ), and two limonoids ( 15 and 16 ). Of these, nine compounds ( 1, 3, 5, 6, 8 – 10, 15 , and 16 ) were isolated from C. excavata for the first time. The absolute configuration of limonoids 15 and 16 was established by X-ray diffraction analysis using Cu Kα radiation. Some isolated compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines, namely lung cancer A549, colorectal cancer SW480, leukemic K562 cells as well as glucose uptake, glucose consumption, and antibacterial activity against Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA). Compounds 7 (auraptene) and 14 (safrole) showed moderate glucose uptake with ratios of 1.38-fold and 1.41-fold compared to the positive control (metformin, 2.25-fold). Compound 7 (auraptene) also exhibited weak cytotoxicity against lung cancer A549, colorectal cancer SW480, and leukemic K562 cells with IC 50 values of 77.2, 157.3, and 105.3 µM, respectively, while compounds 8 (( E )-piperonylprop-2-enal) and 10 (ethyl p -coumarate) exhibited weak cytotoxicity against RAW 264.7 cells and colorectal cancer SW480 cells with IC 50 values of 234.9 and 219.5 μM, respectively. Compounds 1, 3, 7 , and 14 – 16 showed a MIC of >512 µg/mL revealing them to be inactive. :