Glucose Uptake Activity Research Articles

Ectopic expression of the grape hexose transporter VvHT5 restores STP13‐deficiency in Arabidopsis and promotes fungal resistance to Botrytis cinerea

AbstractSugar transporters play a crucial role in plant responses to environmental factors. During plant–pathogen interactions, it is well established that sugar transporters and cell wall invertases are essential for regulating sugar availability at the plant–pathogen interface, impacting both plant resistance and pathogen proliferation. Despite these insights, their role in grapevine defence against pathogens remains underexplored. We examined the expression of sugar transporter and invertase genes in grape leaves infected with the necrotrophic fungus Botrytis cinerea. Our results highlighted significant coordinated upregulation of VvHT5, VvcwINV and defence genes, suggesting a role in enhancing sink strength in infected leaves and implementing host defences. Heterologous expression of GFP‐fused proteins confirmed VvHT5 as a plasma membrane‐localized hexose symporter and phylogenetic analysis indicated its close relation with STP13‐like proteins, which are known to be implicated in host resistance across several plant–pathogen interactions. VvHT5 was heterologously expressed in Arabidopsis thaliana, resulting in high constitutive expression of the VvHT5 protein and increased glucose uptake activity. Phenotypic analysis revealed that VvHT5 enhanced basal resistance to B. cinerea and rescued the wild‐type phenotype in STP13‐deficient plants, indicating that VvHT5 is the grapevine orthologue of AtSTP13. Our findings suggest that VvHT5 may facilitate the reabsorption of extracellular monosaccharides, released from VvcwINV activity or damaged tissues during infection. This activity allows host cells to compete with necrotrophic pathogens for extracellular hexoses, thereby restricting sugar availability to the fungus. It would also support host metabolic demands for defence or serve as a signalling mechanism to orchestrate intracellular processes.

Impaired suppression of fatty acid release by insulin is a strong predictor of reduced whole-body insulin-mediated glucose uptake and skeletal muscle insulin receptor activation.

To examine factors underlying why most, but not all, adults with obesity exhibit impaired insulin-mediated glucose uptake, we compared: (1) adipose tissue fatty acid (FA) release, (2) skeletal muscle lipid droplet (LD) characteristics, and (3) insulin signalling events, in skeletal muscle of adults with obesity with relatively high versus low insulin-mediated glucose uptake. Seventeen adults with obesity (BMI: 36 ± 3 kg/m2) completed a 2 h hyperinsulinemic-euglycemic clamp with stable isotope tracer infusions to measure glucose rate of disappearance (glucose Rd) and FA rate of appearance (FA Ra). Skeletal muscle biopsies were collected at baseline and 30 min into the insulin infusion. Participants were stratified into HIGH (n = 7) and LOW (n = 10) insulin sensitivity cohorts by their glucose Rd during the hyperinsulinemic clamp (LOW< 400; HIGH >550 nmol/kgFFM/min/[μU/mL]). Insulin-mediated suppression of FA Ra was lower in LOW compared with HIGH (p < 0.01). In skeletal muscle, total intramyocellular lipid content did not differ between cohorts. However, the size of LDs in the subsarcolemmal region (SS) of type II muscle fibres was larger in LOW compared with HIGH (p = 0.01). Additionally, insulin receptor-β (IRβ) interactions with regulatory proteins CD36 and Fyn were lower in LOW versus HIGH (p < 0.01), which aligned with attenuated insulin-mediated Tyr phosphorylation of IRβ and downstream insulin-signalling proteins in LOW. Collectively, reduced ability for insulin to suppress FA mobilization, with accompanying modifications in intramyocellular LD size and distribution, and diminished IRβ interaction with key regulatory proteins may be key contributors to impaired insulin-mediated glucose uptake commonly found in adults with obesity.

GLUT1 and cerebral glucose hypometabolism in human focal cortical dysplasia is associated with hypermethylation of key glucose regulatory genes.

Focal cortical dysplasia (FCD) is recognized as a significant etiological factor in pharmacoresistant intractable epilepsy, linked with disturbances in neurovascular metabolism. Our study investigated regulation of glucose-transporter1 (GLUT1) and cerebral hypometabolism within FCD subtypes. Surgically excised human brain specimens underwent histopathological categorization. A subset of samples (paired with matching blood) was assessed for DNA methylation changes of glucose metabolism-related genes. We evaluated GLUT1, VEGFα, MCT2, and mTOR expression by western blot analysis, measured glucose-lactate concentrations, and established correlations with patients' demographic and clinical profiles. Furthermore, we investigated the impact of DNA methylation inhibitor decitabine and hypometabolic condition on the uptake of [ 3 H]-2-deoxyglucose and ATPase in epileptic brain endothelial cells (EPI-EC). We observed hypermethylation of GLUT1 and glucose metabolic genes in FCD brain/blood samples and could distinguish FCDIIa/b from mMCD, MOGHE and non-lesional types in brain. Low GLUT1 and glucose-lactate ratios corresponded to elevated VEGFα and MCT2 in FCDIIa/b vs non-lesional tissues, independent of age, gender, seizure-onset, or duration of epilepsy. Increased mTOR signaling in FCDIIa/b tissues was evident. Decitabine stimulation increased GLUT1, decreased VEGFα expression, restored glucose uptake and ATPase activity in EPI-ECs and reduced mTOR and MCT2 levels in HEK cells. We demonstrated: 1) hypermethylation of glucose regulatory genes distinguish FCDIIa/b from mMCD, MOGHE and non-lesional types, 2) glucose uptake reduction is due to GLUT1 suppression mediated possibly by a GLUT1-mTOR mechanism; and 3) DNA methylation regulates cellular glucose update and metabolism. Together, these studies may lead to GLUT1-mediated biomarkers, glucose metabolism and identify early intervention strategies in FCD.

Targeting osteoblastic 11β-HSD1 to combat high-fat diet-induced bone loss and obesity

Excessive glucocorticoid (GC) action is linked to various metabolic disorders. Recent findings suggest that disrupting skeletal GC signaling prevents bone loss and alleviates metabolic disorders in high-fat diet (HFD)-fed obese mice, underpinning the neglected contribution of skeletal GC action to obesity and related bone loss. Here, we show that the elevated expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), the enzyme driving local GC activation, and GC signaling in osteoblasts, are associated with bone loss and obesity in HFD-fed male mice. Osteoblast-specific 11β-HSD1 knockout male mice exhibit resistance to HFD-induced bone loss and metabolic disorders. Mechanistically, elevated 11β-HSD1 restrains glucose uptake and osteogenic activity in osteoblast. Pharmacologically inhibiting osteoblastic 11β-HSD1 by using bone-targeted 11β-HSD1 inhibitor markedly promotes bone formation, ameliorates glucose handling and mitigated obesity in HFD-fed male mice. Taken together, our study demonstrates that osteoblastic 11β-HSD1 directly contributes to HFD-induced bone loss, glucose handling impairment and obesity.

TRIM27 revealing by tumor educated platelet RNA-sequencing, as a potential biomarker for malignant ground-glass opacities diagnosis mediates glycolysis of non-small cell lung cancer cells partially through HOXM1.

Efficient ground-glass opacities (GGOs) diagnosis is challenging. A diagnostic method distinguishing malignant from benign GGOs is warranted. In this study, we sought to construct a noninvasive method based on tumor educated platelet (TEP) RNA profiles for malignant GGOs diagnosis and explore the molecular mechanism of the potential biomarker for the first time. Based on TEP RNA-sequencing (TEP RNA-seq) in benign and malignant GGOs, a classification model was constructed using differentially expressed genes (DEGs) and was used to evaluate diagnostic performance. High-throughput quantitative polymerase chain reaction (HT-qPCR) verified 23 genes selected from the top 60 DEGs between benign and malignant GGOs. The correlation between 17 verified DEGs and 22 key glycolytic genes was analyzed. Tripartite motif-containing 27 (TRIM27) overexpressing and knockdown (KD) cell models were constructed using A549 and PC-9 cells, respectively in which cell growth, apoptosis, migration and invasion were evaluated. The protein levels of HK-1/2, PKM1/2, LDHA and GLUT1 were evaluated by western blot. Glycolysis was evaluated through adenosine triphosphate (ATP), reactive oxygen species (ROS), lactate acid (LD) production, glucose uptake, and lactate dehydrogenase (LDH) activity assays. RNA-seq was performed in loss-of TRIM27-KD PC-9 cells to clarify the downstream factors of TRIM27 which was verified using western blot and immunofluorescence double staining. In 81 samples, the 1,647-DEG-based classification model exhibited area under the curve (AUC), sensitivity, and specificity values of 0.99 [95% confidence interval (CI): 0.972-1.000], 100%, and 91%, respectively, while the top 60-DEG-based classification model exhibited AUC, sensitivity, and specificity values of 0.986 (95% CI: 0.962-1.000), 98%, and 91%, respectively. TRIM27 achieved AUC of 0.87 in the diagnosis of malignant GGOs, with 83.93% sensitivity, 78.79% specificity, 81.15% accuracy, 77.05% positive predictive value (PPV) and 85.25% negative predictive value (NPV). TRIM27 was highly expressed in non-small cell lung cancer (NSCLC) cells, and accelerated cell migration and invasion. In addition, TRIM27 was found to promote glycolysis in NSCLC cells partially through HMOX1 which was negatively correlated with TRIM27. We constructed a novel TEP RNA-seq based classifier for malignant GGOs diagnosis. TRIM27, an important target discovered, could accelerate migration, invasion and regulate glycolysis partially through HMOX1 in NSCLC cells, thus providing scientific support for TRIM27 as a diagnostic biomarker for malignant GGO diagnosis.

Targeting insulin resistance: myricetin and isorhamnetin from Hardwickia binata, and luteolin from Hedysarum alpinum enhance glucose uptake and AMPK signaling in HepG2 cells

This study examined five plants (Xylopia aethiopica, Agave sisalana, Hardwickia binata, Hedysarum alpinum, and Toxicodendron vernicifluum) for their potential to address insulin resistance in type 2 diabetes. In-vitro assays showed that H. binata leaves and H. alpinum flowers inhibited α-glucosidase and α-amylase while enhancing glucose uptake in normal and insulin-resistant HepG2 cells. Phytochemical screening and SPE purification identified the key constituents responsible for the effects. The chromatographic and spectral analysis confirmed flavonoids in H. binata (myricetin, isorhamnetin, quercetin, kaempferol, and catechin) and H. alpinum (luteolin, quercetin, kaempferol, and apigenin). Myricetin, isorhamnetin, and luteolin significantly increased glucose uptake, enhanced hexokinase and pyruvate kinase activities, and promoted IRec and IRS-1 phosphorylation, modulating insulin signalling. They activated AMPK and Akt, with molecular docking confirming strong AMPK binding. These findings suggest that H. binata, H. alpinum, and their flavonoids are promising candidates for managing insulin resistance and type 2 diabetes, warranting further research.

Effects of Supplementation with NAD + Precursors on Metabolic Syndrome Parameters: A Systematic Review and Meta-Analysis.

Intracellular levels of NAD + regulate metabolism, among other ways, through enzymes that use NAD + as a substrate, capable of inducing catabolic processes, such as lipid oxidation, glucose uptake, and mitochondrial activity. In several model organisms, administering precursor compounds for NAD + synthesis increases its levels, improves lipid and glucose homeostasis, and reduces weight gain. However, evidence of the effects of these precursors on human patients needs to be better evaluated. Therefore, we carried out a systematic review and meta-analysis of randomized clinical trials that assessed the effects of NAD + precursors on Metabolic Syndrome parameters in humans. We based our methods on PRISMA 2020. Our search retrieved 429 articles, and 19 randomized controlled trials were included in the meta-analysis. We assessed the risk of bias with the Rob 2 algorithm and summarized the quality of evidence with the GRADE algorithm. Supplementation with NAD + precursors reduced plasma levels of total cholesterol and triglycerides in volunteers, but the intervention did not significantly affect the other outcomes analyzed. Three of the included articles presented a high risk of bias. The quality of evidence varied between very low and low due to the risk of bias, imprecision, and indirectness. The number of participants in outcomes other than lipidemia is still generally tiny; therefore, more clinical trials evaluating these parameters will increase the quality of the evidence. On the other hand, quality randomized studies are essential to assess better the effects of NAD + precursors on lipidemia.

Structural characterization, physicochemical properties and hypoglycemic activity of soluble dietary fibers from salt stressed mung bean sprouts

Low-salt stress germination is an effective way to improve the nutritional composition of food crops. A novel soluble dietary fiber (MS-SDF) was isolated from low-salt stress mung bean sprouts that were exposed to low-salt stress using anion exchange and gel permeation techniques. Structural analysis revealed that MS-SDF was a homogeneous heteropolysaccharide with an average molecular weight of 164.997 KDa. It featured a loose structure and contained the characteristic functional groups typical of polysaccharides. MS-SDF was composed of arabinose, galactose, glucose, and mannose with a molar ratio of 3.95:3.86:82.69:9.02. The structure was mainly composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,6)-α-D-Glcp-(1→ as the main chain. Branched at O-3 position with single β-D-Manp-(1→ as major the side chain. Furthermore, in vitro hypoglycemic assays indicate that MS-SDF exhibits α-glucosidase inhibitory activity, significantly enhancing glucose uptake, glycogen synthesis, and pyruvate kinase activity in insulin-resistant HepG2 cells. Overall, MS-SDF could be used as a promising source of functional hypoglycemic foods.

Extraction, characterization, antioxidant, and antidiabetic activities of ethanolic extracts from the split gill mushroom (Schizophyllum commune)

Split gill mushroom (Schizophyllum commune) is among the known functional foods for the antitumor and immunomodulatory activities. However, its antidiabetic activity has not been well characterized. Thus, this study aims to characterize ethanolic extracts and investigate the antidiabetic mechanism of the extracts from the split gill mushroom. We utilized both dried and fresh split gill mushrooms as sources for ethanol extractions. We find that the extracts have differential carbohydrate, protein, total phenolic, and total flavonoid compositions, and antioxidant activities. The fresh mushroom extract 1 (FME1) is the best stimulator of glucose uptake in the C2C12 myotubes. Furthermore, FME1 dose-dependently activates glucose uptake in 3T3-L1 adipocytes, possibly by promoting the phosphorylation of the α-subunit of the AMP-activated protein kinase (AMPK) complex. This sample also enhance lipid accumulation in 3T3-L1 adipocytes. Additionally, the ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHLC-ESI-QTOF/MS) reveals many potential antidiabetic compounds in the sample. In conclusion, we illustrated the antioxidant and antidiabetic mechanism of an ethanolic extract from fresh split gill mushrooms and identified potential antidiabetic components in the extract, demonstrating the antidiabetic potential of S. commune.

A COMPREHENSIVE STUDY OF MURRAYA KOENIGII (LINN.) ON RESTORATION OF CONSCIOUSNESS BY AUGMENTING GLUCOSE UPTAKE IN THE NEURONS: A REVIEW

Fainting, also known as syncope or passing out, is caused by decreased cerebral blood flow leading to loss of consciousness and muscle strength. It is caused by lack of blood supply to the brain leading to decrease blood sugar supply to the neurons. Symptoms like dizziness, sweating, pale complexion, blurred vision, nausea, vomiting or a warm feeling precede the loss of consciousness[1]. For the brain, glucose serves as its main energy source. In order for glucose to be transported from the blood into the brain, it must pass through the endothelial cells that line the blood-brain barrier and enter the neurons and glia. These processes are mediated by facilitative Glucose transporter protein. Kaidarya is an Ayurvedic drug from the ancient samhitas, commonly known as curry leaves. Due to its grahi properties it increases the glucose uptake activity. When glucose uptake activity increases in the brain, it supplies sufficient glucose to the brain cells, which helps in management of fainting or syncope.

Design and synthesis of novel thiazolidinone hybrid as α-amylase inhibitor, glucose uptake and antioxidant activity

A design and synthesis of novel series of substituted thiazolidinone has been synthesised from 2-amino-thiazole and pyrazole-2-aldehyde using DCC under mild condition. These compounds were first examined for α-amylase inhibition, glucose uptake activity and antioxidant activities. The α-amylase inhibition profile was found to be competitive for compound 3b. Including, compounds 3h exhibited significant glucose update activity with IC50 values of 10.21 μM. Additionally, the free-radical scavenging activity of 3a-n was assessed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay.

Synthesis and characterization of Pyrus communis fruit extract synthesized ZnO NPs and assessed their anti-diabetic and anti-microbial potential

The fruit Pyrus communis, owing to its presence of phenolics and flavonoids, was chosen for its nanoparticle's reducing and stabilizing properties. Furthermore, the zinc metal may be nano-absorbed by the human body. As a result, the study involves synthesizing zinc oxide nanoparticles (ZnO NPs) from P. communis fruit extract using the green method. The synthesized nanoparticle was examined with a UV–visible spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS). When absorption studies were performed with a UV–visible spectrophotometer, the nanoparticle exhibited a blue shift. The FTIR spectrum revealed the molecular groups present in both the fruit extract and metal. In the SEM analysis, the ZnO NPs appeared as spherical particles, agglomerated together, and of nano-size. The larger size of the ZnO NPs in DLS can be attributed to their ability to absorb water. After characterization, nanoparticles were tested for anti-diabetic (α-amylase and yeast glucose uptake activity) and anti-microbial properties. The α-amylase inhibition percentage was 46.46 ± 0.15% for 100 μg/mL, which was comparable to the acarbose inhibition percentage of 50.58 ± 0.67% at the same concentration. The yeast glucose uptake activity was 64.24 ± 0.80% at 20 mM glucose concentration, which was comparable to the standard of 78.03 ± 0.80. The nanoparticle was more effective against Gram-negative bacteria Shigella sp. and Salmonella typhi than against Gram-positive bacteria Bacillus cereus and Streptococcus pneumoniae.

Phytochemical Screening and Antidiabetic Efficacy of Balanites aegyptiaca Seed Extract and Their Silver Nanoparticles on Muscle and Pancreatic Cell Lines.

Balanites aegyptiaca (L.) Delile, a member of the Zygophyllaceae family, is commonly known as the desert date. This tree is famous for yielding edible fruits and is esteemed for its nutritional richness and diverse health advantages. The primary aim of this research was to assess the potential antidiabetic and cytotoxic effects of seed extracts from B. aegyptiaca and its AgNPs for the first time on C2C12 and MIN6 cells, focusing on glucose uptake and insulin secretion, respectively. Additionally, the seed extracts underwent column chromatography through different solvent systems, resulting in the isolation of five distinct fractions with a mixture of methanol and water as an eluting solvent in different ratios. Comprehensive characterization of the aqueous seed extract was carried out using GC-MS and UPLC-MS. The study determined that the aqueous seed extract exhibited no toxicity at any tested concentration (6.25-100 μg/mL) on both cell types. The calculated IC50 values were 206.00 and 140.44 μg/mL for C2C12 and MIN6 cells, respectively, for seeds of AgNPs. Additionally, the aqueous seed extract and their AgNPs significantly increased glucose uptake by 150.45% and 156.00% of the control in C2C12 cells at a concentration of 100 μg/mL. Insulin secretion was also notably enhanced by 3.47- and 3.92-fold of the control after administering seed extracts and AgNPs, respectively, at 100 μg/mL. GC-MS and UPLC-MS analyses identified various compounds across different categories. Notably, the F2 fraction (methanol and water in ratio of 80:20 as eluting solvent) exhibited the highest glucose uptake activity (156.81% of control), while the F3 fraction (methanol and water in ratio of 70:30 as eluting solvent) fraction demonstrated the highest insulin secretion activity (3.70 folds of the control) among all fractions at 100 μg/mL. GC-MS analysis was employed to characterize both fractions, aiming to identify the compounds contributing to their antidiabetic potential. The study's findings concluded that both seed extracts and their AgNPs possess significant antidiabetic properties, with elevated activity observed in the case of AgNPs in both assays. Various compounds, including diosgenin, oleic acid, linoleic acid and palmitic acid esters were detected in the seed extracts, known for their reported antidiabetic and hypoglycemic effects.

Is Methylglyoxal a Potential Biomarker for the Warburg Effect Induced by the Lipopolysaccharide Neuroinflammation Model?

Methylglyoxal (MG) is considered a classical biomarker of diabetes mellitus and its comorbidities. However, a role for this compound in exacerbated immune responses, such as septicemia, is being increasingly observed and requires clarification, particularly in the context of neuroinflammatory responses. Herein, we used two different approaches (in vivo and acute hippocampal slice models) to investigate MG as a biomarker of neuroinflammation and the neuroimmunometabolic shift to glycolysis in lipopolysaccharide (LPS) inflammation models. Our data reinforce the hypothesis that LPS-induced neuroinflammation stimulates the cerebral innate immune response by increasing IL-1β, a classical pro-inflammatory cytokine, and the astrocyte reactive response, via elevating S100B secretion and GFAP levels. Acute neuroinflammation promotes an early neuroimmunometabolic shift to glycolysis by elevating glucose uptake, lactate release, PFK1, and PK activities. We observed high serum and cerebral MG levels, in association with a reduction in glyoxalase 1 detoxification activity, and a close correlation between serum and hippocampus MG levels with the systemic and neuroinflammatory responses to LPS. Findings strongly suggest a role for MG in immune responses.

Type II Interleukin-4 Receptor Activation in Basal Breast Cancer Cells Promotes Tumor Progression via Metabolic and Epigenetic Modulation.

Interleukin-4 (IL4) is a Th2 cytokine that can signal through two different receptors, one of which-the type II receptor-is overexpressed by various cancer cells. Previously, we have shown that type II IL4 receptor signaling increases proliferation and metastasis in mouse models of breast cancer, as well as increasing glucose and glutamine metabolism. Here, we expand on those findings to determine mechanistically how IL4 signaling links glucose metabolism and histone acetylation to drive proliferation in the context of triple-negative breast cancer (TNBC). We used a combination of cellular, biochemical, and genomics approaches to interrogate TNBC cell lines, which represent a cancer type where high expression of the type II IL4 receptor is linked to reduced survival. Our results indicate that type II IL4 receptor activation leads to increased glucose uptake, Akt and ACLY activation, and histone acetylation in TNBC cell lines. Inhibition of glucose uptake through the deletion of Glut1 ablates IL4-induced proliferation. Additionally, pharmacological inhibition of histone acetyltransferase P300 attenuates IL4-mediated gene expression and proliferation in vitro. Our work elucidates a role for type II IL4 receptor signaling in promoting TNBC progression, and highlights type II IL4 signaling, as well as histone acetylation, as possible targets for therapy.

Quercetin Impairs the Growth of Uveal Melanoma Cells by Interfering with Glucose Uptake and Metabolism.

Monosomy 3 in uveal melanoma (UM) increases the risk of lethal metastases, mainly in the liver, which serves as the major site for the storage of excessive glucose and the metabolization of the dietary flavonoid quercetin. Although primary UMs with monosomy 3 exhibit a higher potential for basal glucose uptake, it remains unknown as to whether glycolytic capacity is altered in such tumors. Herein, we initially analyzed the expression of n = 151 genes involved in glycolysis and its interconnected branch, the "pentose phosphate pathway (PPP)", in the UM cohort of The Cancer Genome Atlas Study and validated the differentially expressed genes in two independent cohorts. We also evaluated the effects of quercetin on the growth, survival, and glucose metabolism of the UM cell line 92.1. The rate-limiting glycolytic enzyme PFKP was overexpressed whereas the ZBTB20 gene (locus: 3q13.31) was downregulated in the patients with metastases in all cohorts. Quercetin was able to impair proliferation, viability, glucose uptake, glycolysis, ATP synthesis, and PPP rate-limiting enzyme activity while increasing oxidative stress. UMs with monosomy 3 display a stronger potential to utilize glucose for the generation of energy and biomass. Quercetin can prevent the growth of UM cells by interfering with glucose metabolism.

Metabolites from Aerial Parts of Glycyrrhiza foetida as Modulators of Targets Related to Metabolic Syndrome.

A detailed phytochemical investigation has been carried out on the aerial parts of G. foetida leading to the isolation of 29 pure compounds, mainly belonging to the amorfrutin and polyphenol classes. Among them, the new amorfrutin N (5) and exiguaflavone L (21) were isolated and their structures elucidated by means of HR-ESIMS and NMR. All the isolated compounds were investigated for modulation of mitochondrial activity and stimulation of glucose uptake via GLUT transporters, two metabolic processes involved in intracellular glucose homeostasis, which, therefore, correlate with the incidence of metabolic syndrome. These experiments revealed that amorfrutins were active on both targets, with amorfrutin M (17) and decarboxyamorfrutin A (2) emerging as mitochondrial stimulators, and amorfrutin 2 (12) as a glucose uptake promoter. However, members of the rich chalcone/flavonoid fraction also proved to contribute to this activity.

Glucoregulatory Properties of a Protein Hydrolysate from Atlantic Salmon (Salmo salar): Preliminary Characterization and Evaluation of DPP-IV Inhibition and Direct Glucose Uptake In Vitro.

Metabolic disorders are increasingly prevalent conditions that manifest pathophysiologically along a continuum. Among reported metabolic risk factors, elevated fasting serum glucose (FSG) levels have shown the most substantial increase in risk exposure. Ultimately leading to insulin resistance (IR), this condition is associated with notable deteriorations in the prognostic outlook for major diseases, including neurodegenerative diseases, cancer risk, and mortality related to cardiovascular disease. Tackling metabolic dysfunction, with a focus on prevention, is a critically important aspect for human health. In this study, an investigation into the potential antidiabetic properties of a salmon protein hydrolysate (SPH) was conducted, focusing on its potential dipeptidyl peptidase-IV (DPP-IV) inhibition and direct glucose uptake in vitro. Characterization of the SPH utilized a bioassay-guided fractionation approach to identify potent glucoregulatory peptide fractions. Low-molecular-weight (MW) fractions prepared by membrane filtration (MWCO = 3 kDa) showed significant DPP-IV inhibition (IC50 = 1.01 ± 0.12 mg/mL) and glucose uptake in vitro (p ≤ 0.0001 at 1 mg/mL). Further fractionation of the lowest MW fractions (<3 kDa) derived from the permeate resulted in three peptide subfractions. The subfraction with the lowest molecular weight demonstrated the most significant glucose uptake activity (p ≤ 0.0001), maintaining its potency even at a dilution of 1:500 (p ≤ 0.01).

Evaluation of Anti-Obesity and Antidiabetic Activities of Orostachys japonicus in Cell and Animal Models.

Orostachys japonicus is a popular traditional medicinal herb used in Asian countries. This study is focused on evaluating its role in lipid and glucose metabolism in cell and animal models to establish the plant as an anti-obesity and antidiabetic herb. A butanol fraction of O. japonicus was used in the study. The lipid production was evaluated by the Oil Red O technique while the expression of adipogenic markers by Western blotting and RT-PCR using 3T3-L1 preadipocyte. The effect on glucose uptake activity was evaluated in C2C12 myoblast cells. The animal study was carried out in C57BL mice to evaluate anti-obesity activity using the high-fat diet model. The evaluation of serum lipid, blood glucose, adipogenic and fibrosis markers in the liver, and fat deposition in the liver and adipose tissue (by histology) of mice was conducted. Butanol fraction of O. japonicus significantly inhibited the lipid production in the 3T3-L1 cells and reduced the expression of PPARγ, C/EBPα, SREBP-1c and aP2. It enhanced glucose uptake in insulin-resistant C2C12 myoblast cells. It reduced body weight, triglycerides, and blood glucose in the obese mice. It significantly inhibited lipid accumulation in the liver and adipose tissue of obese mice along with suppression of expression of adipogenic and fibrosis markers in the liver. In summary, supporting the previous results, this study helped to establish the potent anti-obesity, antidiabetic, and liver-protecting effect of the butanol fraction of O. japonicus.

Glycolipids Derived from the Korean Endemic Plant Aruncus aethusifolius Inducing Glucose Uptake in Mouse Skeletal Muscle C2C12 Cells.

Aruncus spp. has been used as a traditional folk medicine worldwide for its anti-inflammatory, hemostatic, and detoxifying properties. The well-known species A. dioicus var. kamtschaticus has long been used for multifunctional purposes in Eastern Asia. Recently, it was reported that its extract has antioxidant and anti-diabetic effects. In this respect, it is likely that other Aruncus spp. possess various biological activities; however, little research has been conducted thus far. The present study aims to biologically identify active compounds against diabetes in the Korean endemic plant A. aethusifolius and evaluate the underlying mechanisms. A. aethusifolius extract enhanced glucose uptake without toxicity to C2C12 cells. A bioassay-guided isolation of A. aethusifolius yielded two pure compounds, and their structures were characterized as glycolipid derivatives, gingerglycolipid A, and (2S)-3-linolenoylglycerol-O-β-d-galactopyranoside by an interpretation of nuclear magnetic resonance and high-resolution mass spectrometric data. Both compounds showed glucose uptake activity, and both compounds increased the phosphorylation levels of insulin receptor substrate 1 (IRS-1) and 5'-AMP-activated protein kinase (AMPK) and protein expression of peroxisome proliferator-activated receptor γ (PPARγ). Gingerglycolipid A docked computationally into the active site of IRS-1, AMPK1, AMPK2, and PPARγ (-5.8, -6.9, -6.8, and -6.8 kcal/mol).