Sodium-dependent Glucose Transporter Research Articles

Profiling of Antidiabetic Bioactive Flavonoid Compounds from an Edible Plant Kudzu (Pueraria lobata).

Pueraria lobata (Willd.) Ohwi, known as kudzu and used as a "longevity powder" in China, is an edible plant which is rich in flavonoids and believed to be useful for regulating blood sugar and treating diabetes, although the modes of action are unknown. Here, a total of 53 flavonoids including 6 novel compounds were isolated from kudzu using multidimensional preparative liquid chromatography. The flavonoid components were found to lower blood sugar levels, promote urine sugar levels in mice, and reduce the urine volume. Molecular docking and in vitro assays suggested that the antidiabetic effect of kudzu was attributed to at least three targets: sodium-dependent glucose transporter 2 (SGLT2), protein tyrosine phosphatase-1B (PTP1B), and alpha-glucosidase (AG). This study suggests a possible mechanism for the antidiabetic effect that may involve the synergistic action of multiple active compounds from kudzu.

A comprehensive in-vitro/in-vivo screening toolbox for the elucidation of glucose homeostasis modulating properties of plant extracts (from roots) and its bioactives.

Plant extracts are increasingly recognized for their potential in modulating (postprandial) blood glucose levels. In this context, root extracts are of particular interest due to their high concentrations and often unique spectrum of plant bioactives. To identify new plant species with potential glucose-lowering activity, simple and robust methodologies are often required. For this narrative review, literature was sourced from scientific databases (primarily PubMed) in the period from June 2022 to January 2024. The regulatory targets of glucose homeostasis that could be modulated by bioactive plant compounds were used as search terms, either alone or in combination with the keyword "root extract". As a result, we present a comprehensive methodological toolbox for studying the glucose homeostasis modulating properties of plant extracts and its constituents. The described assays encompass in-vitro investigations involving enzyme inhibition (α-amylase, α-glucosidase, dipeptidyl peptidase 4), assessment of sodium-dependent glucose transporter 1 activity, and evaluation of glucose transporter 4 translocation. Furthermore, we describe a patch-clamp technique to assess the impact of extracts on KATP channels. While validating in-vitro findings in living organisms is imperative, we introduce two screenable in-vivo models (the hen's egg test and Drosophila melanogaster). Given that evaluation of the bioactivity of plant extracts in rodents and humans represents the current gold standard, we include approaches addressing this aspect. In summary, this review offers a systematic guide for screening plant extracts regarding their influence on key regulatory elements of glucose homeostasis, culminating in the assessment of their potential efficacy in-vivo. Moreover, application of the presented toolbox might contribute to further close the knowledge gap on the precise mechanisms of action of plant-derived compounds.

Effects of Three Kinds of Carbohydrate Pharmaceutical Excipients-Fructose, Lactose and Arabic Gum on Intestinal Absorption of Gastrodin through Glucose Transport Pathway in Rats.

Some glucoside drugs can be transported via intestinal glucose transporters (IGTs), and the presence of carbohydrate excipients in pharmaceutical formulations may influence the absorption of them. This study, using gastrodin as probe drug, aimed to explore the effects of fructose, lactose, and arabic gum on intestinal drug absorption mediated by the glucose transport pathway. The influence of fructose, lactose, and arabic gum on gastrodin absorption was assessed via pharmacokinetic experiments and single-pass intestinal perfusion. The expression of sodium-dependent glucose transporter 1 (SGLT1) and sodium-independent glucose transporter 2 (GLUT2) was quantified via RT‒qPCR and western blotting. Alterations in rat intestinal permeability were evaluated through H&E staining, RT‒qPCR, and immunohistochemistry. Fructose reduced the area under the curve (AUC) and peak concentration (Cmax) of gastrodin by 42.7% and 63.71%, respectively (P < 0.05), and decreased the effective permeability coefficient (Peff) in the duodenum and jejunum by 58.1% and 49.2%, respectively (P < 0.05). SGLT1 and GLUT2 expression and intestinal permeability remained unchanged. Lactose enhanced the AUC and Cmax of gastrodin by 31.5% and 65.8%, respectively (P < 0.05), and increased the Peff in the duodenum and jejunum by 33.7% and 26.1%, respectively (P < 0.05). SGLT1 and GLUT2 levels did not significantly differ, intestinal permeability increased. Arabic gum had no notable effect on pharmacokinetic parameters, SGLT1 or GLUT2 expression, or intestinal permeability. Fructose, lactose, and arabic gum differentially affect intestinal drug absorption through the glucose transport pathway. Fructose competitively inhibited drug absorption, while lactose may enhance absorption by increasing intestinal permeability. Arabic gum had no significant influence.

SGLT2i Alleviates Atherosclerosis by Inhibiting NHE1 Activation to Protect against Macrophage Senescence Induced by Angiotensin II.

Sodium-dependent glucose transporter (SGLT2) inhibitors (SGLT2i) have been found to have anti-atherosclerotic effects in clinical treatment. The aim of this study was to explore whether angiotensin II (Ang II) induces changes in the expression of Na+/H+ exchanger of cytoplasmic membrane channel proteins (NHE1) and SGLT2 in macrophages and whether dapagliflozin (DAPA), an SGLT2i, protects against Ang II induced macrophage senescence by inhibiting NHE1 activation to alleviate Atherosclerosis (AS). After intervention with DAPA plus gavage or feeding them a high-fat diet, the mice's aortas were dissected, and oil red O staining was performed. Cell proliferation and toxicity detection, western blot, immunofluorescence, and β-galactosidase staining methods were adopted to detect cell activity, expressions of senescence-related genes, and number of senescent cells after different concentrations of Ang II or DAPA or plasmid NHE1 were treated with RAW264.7 cells. (1) The formation of AS plaques in ApoE -/- mice showed a downward trend under DAPA. (2) After the intervention of Ang II, the cell activity of RAW264.7 decreased, and the expression of senescent cells and related genes increased. (3) Under the Ang II condition, the expression of SGLT2 and NHE1 increased, and SGLT2, NHE1, and senescence-related genes decreased with the addition of DAPA. (4) The expression of NHE1, senescent cells and related genes decreased in RAW264.7 cells after DAPA treatment with plasmid NHE1 intervention. SGLT2i alleviates atherosclerosis by inhibiting NHE1 activation to protect against macrophage senescence induced by Ang II.

The Effect of Antihyperglycemic Medications on COVID-19: A Meta-analysis and Systematic Review from Observational Studies.

Diabetes, a chronic disease worldwide, may be associated with a poorer prognosis in patients with coronavirus disease 2019 (COVID-19). While some antihyperglycemic medications may be beneficial, others may increase the risk of adverse clinical outcomes of COVID-19. We aimed to analyze the effect of antihyperglycemic medications on COVID-19. We searched the Web of Science, Cochrane Library, EMBASE, PubMed, and Scopus databases from December 2019 to June 2022 to identify literature related to patients with COVID-19 and type 2 diabetes mellitus (T2DM) treated with antihyperglycemic medications. 56 studies were included in the analysis. Metformin (OR 0.66; 95% CI 0.58-0.74; p < 0.05), Glucagon-like peptide-1 receptor agonist (GLP-1ra) (OR 0.73; 95% CI 0.59-0.91; p < 0.05), and sodium-dependent glucose transporters 2 inhibitor (SGLT 2i) (OR 0.77; 95% CI 0.69-0.87; p < 0.05) were associated with lower mortality risk, while insulin was associated with increased mortality risk (OR 1.40; 95% CI 1.26-1.55; p < 0.05). Meanwhile, metformin (OR 0.65; 95% CI 0.50-0.85; p < 0.05) and GLP-1ra (OR 0.84; 95% CI 0.76-0.94; p < 0.05) were significantly associated with decreased severe manifestation risk. What's more, metformin (OR 0.77; 95% CI 0.62-0.96; p < 0.05), GLP-1ra (OR 0.86; 95% CI 0.81-0.92; p < 0.05), and SGLT 2i (OR 0.87; 95% CI 0.79-0.97; p < 0.05) were also associated with a decreased risk of hospitalization, but insulin were associated with an increased risk of hospitalization (OR 1.31; 95% CI 1.12-1.52; p < 0.05). Nevertheless, the results of the subgroup analyses showed that the effects of different glucose-lowering agents on COVID-19 may be related to in-hospital use or out-hospital use, elderly or non-elderly patients use, and different geography. Metformin, GLP-1ra, and SGLT 2i have shown a positive effect on clinical outcomes in COVID-19, particularly in non-elderly individuals. However, insulin use may pose a higher risk, especially in elderly patients, so need with caution. Meanwhile, DPP-4i, TZD, α-GLUi, and sulfonylureas appeared to have a neutral effect. These results need to be validated in future clinical studies.

Electrogenic transport of amino acids and glucose differs between jejunum and ileum of female and castrated male finishing pigs

It has been shown that the jejunum represents the most important site for the nutrient’s absorption in several species. However, in pigs, this information seems to be controversial and limited information are available about differences in intestinal physiology between female and castrated male pigs. The trans-epithelial electrical resistance (TEER) and the active uptake of L-glutamate (L-Glu), L-arginine (L-Arg), L-methionine (L-Met) and D-glucose (D-Glu) in the jejunum and ileum of female (n = 5) and castrated male (n = 7) pigs fed a protein-restricted grower and finisher diet (128 and 112 g of crude protein/kg dry matter) were investigated. The intestine segments were collected at slaughter and mounted in Ussing chambers. Results were further investigated by protein expression analysis of the D-Glu transporter Sodium-dependent Glucose Transporter 1 (SGLT1) and using serum creatinine, non-esterified fatty acids (NEFAs) and serum glucose concentrations measurements as indicators of muscle mass deposition and metabolic status of the animals. A linear mixed-effects regression (Lme4) model was used for data analysis. Independent of sex, the uptake of both L-Met and D-Glu was higher (p < 0.001) in the ileum than in the jejunum (2.1- and 3.6-fold increases, respectively). The L-Arg uptake was higher (p = 0.001) in females compared to castrates (1.9-fold increase). No significant differences were observed between the segments in the SGLT1 protein expression, regardless of sex. Serum measurements were also not significantly different between the female and castrates. This study suggests that the ileum has an important role in the active uptake of amino acids and D-Glu uptake and differences exist between female and castrated finishing pigs.

Comparing the effects of empagliflozin and liraglutide on lipid metabolism and intestinal microflora in diabetic mice.

Recent studies have shown that the imbalance of intestinal flora is related to the occurrence and progression of diabetic nephropathy (DN) and can affect lipid metabolism. Sodium-dependent glucose transporters 2 (SGLT2) inhibitor and glucagon-like peptide-1 (GLP-1) receptor agonist are commonly used hypoglycemic drugs and have excellent renal safety. The purpose of this study was to compare the protective effects of empagliflozin and liraglutide on kidneys, lipid metabolism, and intestinal microbiota in diabetic mice. We established a mouse model of type two diabetes by feeding rats a high-fat diet (HFD) followed by an intraperitoneal injection of STZ. The mice were randomly divided into groups: normal control (NC), diabetic model (DM), liraglutide treatment (LirT), empagliflozin treatment (EmpT), and liraglutide combined with empagliflozin treatment (Emp&LirT) groups. Blood glucose, lipids, creatinine, and uric acid, as well as urinary nitrogen and albumin levels were measured. The renal tissues were subjected to HE, PAS and Masson's staining. These parameters were used to evaluate renal function and histopathological changes in mice. Mice feces were also collected for 16sRNA sequencing to analyze the composition of the intestinal flora. All the indexes related to renal function were significantly improved after treatment with drugs. With respect to lipid metabolism, both drugs significantly decreased the serum triglyceride levels in diabetic mice, but the effect of liraglutide on reducing serum cholesterol was better than that of empagliflozin. However, empagliflozin had a better effect on the reduction of low-density lipoproteins (LDL). The two drugs had different effects on intestinal flora. At the phylum level, empagliflozin significantly reduced the ratio of Firmicutes to Bacteroidota, but no effect was seen with liraglutide. At the genus level, both of them decreased the number of Helicobacter and increased the number of Lactobacillus. Empagliflozin also significantly increased the abundance of Muribaculaceae, Muribaculum, Olsenella, and Odoribacter, while liraglutide significantly increased that of Ruminococcus. Liraglutide and empagliflozin were both able to improve diabetes-related renal injury. However, the ability of empagliflozin to reduce LDL was better compared to liraglutide. In addition, their effects on the intestine bacterial flora were significantly different.

SGLT2i improves kidney senescence by down-regulating the expression of LTBP2 in SAMP8 mice.

Senescent kidney can lead to the maladaptive repairment and predispose age-related kidney diseases. Here, we explore the renal anti-senescence effect of a known kind of drug, sodium-dependent glucose transporters 2 inhibitor (SGLT2i). After 4 months intragastrically administration with dapagliflozin on senescence-accelerated mouse prone 8 (SAMP8) strain mice, the physiologically effects (lowering urine protein, enhancing glomerular blood perfusion, inhibiting expression of senescence-related biomarkers) and structural changes (improving kidney atrophy, alleviating fibrosis, decreasing glomerular mesangial proliferation) indicate the potential value of delaying kidney senescence of SGLT2i. Senescent human proximal tubular epithelial (HK-2) cells induced by H2 O2 also exhibit lower senescent markers after dapagliflozin treatment. Further mechanism exploration suggests LTBP2 have the great possibility to be the target for SGLT2i to exert its renal anti-senescence role. Dapagliflozin down-regulate the LTBP2 expression in kidney tissues and HK-2 cells with senescent phenotypes. Immunofluorescence staining show SGLT2 and LTBP2 exist colocalization, and protein-docking analysis implies there is salt-bridge formation between them; these all indicate the possibility of weak-interaction between the two proteins. Apart from reducing LTBP2 expression in intracellular area induced by H2 O2 , dapagliflozin also decrease the concentration of LTBP2 in cell culture medium. Together, these results reveal dapagliflozin can delay natural kidney senescence in non-diabetes environment; the mechanism may be through regulating the role of LTBP2.

Ocular and Plasma Pharmacokinetics of Enavogliflozin Ophthalmic Solution in Preclinical Species.

An enavogliflozin ophthalmic solution (DWRX2008) is being developed to treat diabetic retinopathy and macular edema. This study evaluated the ocular distribution and plasma pharmacokinetics (PKs) of enavogliflozin in animal species. A sample of [14C] enavogliflozin was ocularly administered to two rabbits per time point at single doses of 600 μg/eye to evaluate ocular PK, which was evaluated using autoradiography until 48 h post-dose. Plasma concentrations after ocular administration in six rabbits, three rats, and three beagle dogs with single doses of 400 μg, 25 μg, and 100 μg, respectively, were investigated for 24 h. The retinal concentration of [14C] enavogliflozin reached Cmax at 2.0 h with an elimination half-life of 32.5 h, which remained above the IC50 value of sodium-dependent glucose transporter 2 until 24 h post-dose. In the plasma of rabbits, the fastest Tmax of 0.5 h and a 3.6 h half-life were observed among animal species. The relative bioavailability in rabbits after ocular administration was 3.4 compared to oral administration. Ocular administration of enavogliflozin could be a potential therapeutic route for diabetic retinal complications, based on relative bioavailability and effective delivery to the posterior ocular segment. DWRX2008 would be applicable to humans with favorable PK profiles and minimal systemic adverse effect.

The inflammatory injury of porcine small intestinal epithelial cells induced by deoxynivalenol is related to the decrease in glucose transport.

The present study aimed to investigate the effects of deoxynivalenol (DON) stimulation on inflammatory injury and the expression of the glucose transporters sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter protein 2 (GLU2) in porcine small intestinal epithelial cells (IPEC-J2). Additionally, the study aimed to provide initial insights into the connection between the expression of glucose transporters and the inflammatory injury of IPEC-J2 cells. DON concentration and DON treatment time were determined using the CCK‑8 assay. Accordingly, 1.0 µg/mL DON and treatment for 24h were chosen for subsequent experiments. Then IPEC-J2 cells were treated without DON (CON, N = 6) or with 1 μg/mL DON (DON, N = 6). Lactate dehydrogenase (LDH) content, apoptosis rate, and proinflammatory cytokines including interleukin (IL)-1β, Il-6, and tumor necrosis factor α (TNF-α) were measured. Additionally, the expression of AMP-activated protein kinase α1 (AMPK-α1), the content of glucose, intestinal alkaline phosphatase (AKP), and sodium/potassium-transporting adenosine triphosphatase (Na+/K+-ATPase) activity, and the expression of SGLT1 and GLU2 of IPEC-J2 cells were also analyzed. The results showed that DON exposure significantly increased LDH release and apoptosis rate of IPEC-J2 cells. Stimulation with DON resulted in significant cellular inflammatory damage, as evidenced by a significant increase in proinflammatory cytokines (IL-1β, IL-6, and TNF-α). Additionally, DON caused damage to the glucose absorption capacity of IPEC-J2 cells, indicated by decreased levels of glucose content, AKP activity, Na+/K+-ATPase activity, AMPK-α1 protein expression, and SGLT1 expression. Correlation analysis revealed that glucose absorption capacity was negatively correlated with cell inflammatory cytokines. Based on the findings of this study, it can be preliminarily concluded that the cell inflammatory damage caused by DON may be associated with decreased glucose absorption.

The New Challenge of Obesity - Obesity-Associated Nephropathy.

In recent years, obesity has become one of the major diseases that affect human health and consume human health resources, especially when it causes comorbidities such as hypertension, diabetes, cardiovascular disease and kidney disease. Many studies have demonstrated that obesity is associated with the development of chronic kidney disease and can exacerbate the progression of end-stage renal disease. This review described the mechanisms associated with the development of obesity-associated nephropathy and the current relevant therapeutic modalities, with the aim of finding new therapeutic targets for obesity-associated nephropathy. The mechanisms of obesity-induced renal injury include, in addition to the traditional alterations in renal hemodynamics, the involvement of various mechanisms such as macrophage infiltration in adipose tissue, alterations in adipokines (leptin and adiponectin), and ectopic deposition of lipids. At present, there is no "point-to-point" treatment for obesity-induced kidney injury. The renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-dependent glucose transporter 2 (SGLT-2) inhibitors and bariatric surgery described in this review can reduce urinary protein to varying degrees and delay the progression of kidney disease. In addition, recent studies on the therapeutic effects of intestinal flora on obesity may reduce the incidence of obesity-related kidney disease from the perspective of primary prevention. Both of these interventions have their own advantages and disadvantages, so the continuous search for the mechanism of obesity-induced related kidney disease will be extremely helpful for the future treatment of obesity-related kidney disease.

Pharmacological Research Progress of Novel Antihypertensive Drugs.

Cardiovascular disease stands as the leading cause of death globally, with hypertension emerging as an independent risk factor for its development. The worldwide prevalence of hypertension hovers around 30%, encompassing a staggering 1.2 billion patients, and continues to escalate annually. Medication plays a pivotal role in managing hypertension, not only effectively regulating blood pressure (BP) but also substantially mitigating the occurrence of cardiovascular and cerebrovascular diseases. This review comprehensively outlines the categories, mechanisms, clinical applications, and drawbacks of conventional antihypertensive drugs. It delves into the five primary pharmacological classifications, namely β-receptor blockers, calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and diuretics. The emphasis is placed on elucidating the mechanisms, advantages, and research progress of novel antihypertensive drugs targeting emerging areas. These include mineralocorticoid receptor antagonists (MRAs), atrial natriuretic peptides (ANPs), neutral endopeptidase inhibitors (NEPIs), sodium-dependent glucose transporter 2 inhibitors (SGLT-2Is), glucagon-like peptide-1 receptor agonists (GLP-1RAs), endothelin receptor antagonists (ERAs), soluble guanylate cyclase (sGC) agonists, brain aminopeptidase A inhibitors (APAIs), and small interfering ribonucleic acids (siRNAs) targeting hepatic angiotensinogen. Compared to conventional antihypertensive drugs, these novel alternatives exhibit favorable antihypertensive effects with minimal adverse reactions. This review serves as a valuable reference for future research and the clinical application of antihypertensive drugs.

Superiority of Intestinal Adaptation by Hepatocyte Growth Factor in the Jejunum: An Experimental Study in a Short-Bowel Rat Model

BackgroundWe evaluated the effect of recombinant human hepatocyte growth factor (rh-HGF) on intestinal adaptation in a rat model of short-bowel syndrome (SBS). MethodsSprague–Dawley rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90 % small bowel resection. The animals were divided into 3 groups: TPN/SBS (control group, n = 7), TPN/SBS/intravenous recombinant human hepatocyte growth factor (HGF) (0.3 mg/kg/day) (HGF group, n = 7), and TPN/SBS/intravenous c-Met inhibitor (0.3 mg/kg/day) (anti-HGF group, n = 5). On day 7, rats were euthanized and histologically evaluated. Serum diamine oxidase (S-DAO) levels were evaluated using an enzyme-linked immunosorbent assay. The nutrient transporter and glucagon-like peptide-2 (GLP-2) receptor expression were evaluated using real-time polymerase chain reaction. ResultsThe jejunal and ileal villus heights were higher and the S-DAO concentrations significantly higher (p = 0.04) in the HGF group than in the control and anti-HGF groups. The sodium-dependent glucose transporter 1 expression in the HGF group was significantly higher than in the control group and significantly suppressed in the anti-HGF group (p < 0.01). The peptide transporter 1 expression in the jejunum was higher in the HGF group than in the other groups and significantly suppressed in the anti-HGF group (p < 0.01). The GLP-2 receptor expression in the jejunum was higher in the HGF group than the other groups, and it was significantly suppressed in the anti-HGF group (p < 0.01). These jejunal results regarding nutrient transporter an GLP-2 receptor were not found in the ileum. ConclusionsThe administration of rh-HGF appears to be more effective in the jejunum than in the ileum. Type of StudyExperimental Research. Level of EvidenceN/A.

Sodium-dependent glucose transporter 2 inhibitor alleviates renal lipid deposition and improves renal oxygenation levels in newly diagnosed type 2 diabetes mellitus patients: a randomized controlled trial

BackgroundSodium-dependent glucose transporter 2 inhibitor (SGLT2i) has the advantages of effectively lowering blood glucose levels and improving renal outcomes in diabetic patients. This study evaluated the effect of canagliflozin on intrarenal lipid content and oxygenation in newly diagnosed type 2 diabetes mellitus (T2DM) patients.MethodsA total of 64 newly diagnosed T2DM patients with normal renal function were randomly divided into canagliflozin (n = 33) and glimepiride control (n = 31) groups. All patients underwent functional magnetic resonance imaging (fMRI) scanning to assay patients' intrarenal lipid content and oxygenation level before and after 24 weeks of treatment. Furthermore, the relationship between body mass index and intrarenal lipid content in T2DM patients was analyzed and the correlation between changes in intrarenal lipid content and improvements in renal hypoxia was further assessed.ResultsThe canagliflozin group had a greater decrease in body weight and blood uric acid level than the glimepiride group (all P < 0.05). The intrarenal lipid content could be significantly reduced after canagliflozin treatment for 24 weeks. The R2* values, a parameter for quantifying the oxygen content in tissues and is inversely related to the oxygen content, of the renal cortex and medulla in the canagliflozin group decreased from the baseline by 6.40% (P < 0.01) and 12.09% (P = 0.000007), respectively. In addition, the degree of reduction of fat fraction (ΔFF) in the kidneys of the canagliflozin group was correlated with the degree of improvement of oxygenation level (ΔR2*) in the renal cortex (r = 0.422, P = 0.014).ConclusionsThe early renal protective effect of SGLT2i in newly diagnosed T2DM patients may be partly attributed to the amelioration of renal hypoxia via the alleviation of ectopic lipid deposition in the kidneys.Trial Registration: Chu Hsien-I Memorial Hospital of Tianjin Medical University (ChiCTR2000037951).

Membrane potential accelerates sugar uptake by stabilizing the outward facing conformation of the Na/glucose symporter vSGLT

Sodium-dependent glucose transporters (SGLTs) couple a downhill Na+ ion gradient to actively transport sugars. Here, we investigate the impact of the membrane potential on vSGLT structure and function using sugar uptake assays, double electron-electron resonance (DEER), electrostatic calculations, and kinetic modeling. Negative membrane potentials, as present in all cell types, shift the conformational equilibrium of vSGLT towards an outward-facing conformation, leading to increased sugar transport rates. Electrostatic calculations identify gating charge residues responsible for this conformational shift that when mutated reduce galactose transport and eliminate the response of vSGLT to potential. Based on these findings, we propose a comprehensive framework for sugar transport via vSGLT, where the cellular membrane potential facilitates resetting of the transporter after cargo release. This framework holds significance not only for SGLTs but also for other transporters and channels.

Metabolomic analysis of serum samples from a clinical study on ipragliflozin and metformin treatment in Japanese patients with type 2 diabetes: Exploring human metabolites associated with visceral fat reduction.

The effects of the sodium-dependent glucose transporter-2 inhibitor ipragliflozin were compared with metformin in a previous study, which revealed that ipragliflozin reduced visceral fat content by 12%; however, the underlying mechanism was unclear. Therefore, this sub-analysis aimed to compare metabolomic changes associated with ipragliflozin and metformin that may contribute to their biological effects. In the previous study, 103 patients with type 2 diabetes were randomly assigned to receive ipragliflozin 50 mg or metformin 1000 mg daily. Of the 103 patients, 15 patients in the ipragliflozin group with the highest reduction in visceral fat areas and 15 patients in the metformin group with matching characteristics, such as age, sex, baseline A1C, baseline visceral fat area, smoking status, and concomitant medication, were selected. The clinical data were reanalyzed, and metabolomic analysis of serum samples collected before and 24 weeks after drug administration was performed using capillary electrophoresis time-of-flight mass spectrometry. The reduction in the mean visceral fat area after 24 weeks of treatment was significantly larger (P=0.002) in the ipragliflozin group (-19.8%) than in the metformin group (-2.5%), as were the subcutaneous fat area and body weight. The A1C and blood glucose levels decreased in both groups. Glutamic pyruvic oxaloacetic transaminase, γ-glutamyl transferase, uric acid, and triglyceride levels decreased in the ipragliflozin group. Low-density lipoprotein cholesterol level decreased in the metformin group. After ipragliflozin administration, N2 -phenylacetylglutamine, inosine, guanosine, and 1-methyladenosine levels increased, whereas galactosamine, glucosamine, 11-aminoundecanoic acid, morpholine, and choline levels decreased. After metformin administration, metformin, hypotaurine, methionine, methyl-2-oxovaleric acid, 3-nitrotyrosine, and cyclohexylamine levels increased, whereas citrulline, octanoic acid, indole-3-acetaldehyde, and hexanoic acid levels decreased. Metabolites that may affect visceral fat reduction were detected in the ipragliflozin group. Studies are required to further elucidate the underlying mechanisms.

The SGLT2 inhibitor empagliflozin attenuates atherosclerosis progression by inducing autophagy.

Cardiovascular disease due to atherosclerosis is one of the leading causes of death worldwide; however, the underlying mechanism has yet to be defined. The sodium-dependent glucose transporter 2 inhibitor (SGLT2i) empagliflozin is a new type of hypoglycemic drug. Recent studies have shown that empagliflozin not only reduces high glucose levels but also exerts cardiovascular-protective effects and slows the process of atherosclerosis. The purpose of this study was to elucidate the mechanism by which empagliflozin ameliorates atherosclerosis. Male apolipoprotein E-deficient (ApoE-/-) mice were fed a high-fat Western diet to establish an atherosclerosis model. The area and size of atherosclerotic lesions in ApoE-/- mice were then assessed by performing hematoxylin-eosin (HE) staining after empagliflozin treatment. Concurrently, oxidized low-density lipoprotein (oxLDL) was used to mimic atherosclerosis in three different types of cells. Then, following empagliflozin treatment of macrophage cells (RAW264.7), human aortic smooth muscle cells (HASMCs), and human umbilical vein endothelial cells (HUVECs), western blotting was applied to measure the levels of autophagy-related proteins and proinflammatory cytokines, and green fluorescent protein (GFP)-light chain 3 (LC3) puncta were detected using confocal microscopy to confirm autophagosome formation. Oil Red O staining was performed to detect the foaming of macrophages and HASMCs, and flow cytometry was used for the cell cycle analysis. 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8), and scratch assays were also performed to examine the proliferation and migration of HASMCs. Empagliflozin suppressed the progression of atherosclerotic lesions in ApoE-/- mice. Empagliflozin also induced autophagy in RAW246.7 cells, HASMCs, and HUVECs via the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, and it significantly increased the levels of the Beclin1 protein, the LC3B-II/I ratio, and p-AMPK protein. In addition, empagliflozin decreased the expression of P62 and the protein levels of inflammatory cytokines, and it inhibited the foaming of RAW246.7 cells and HASMCs, as well as the expression of inflammatory factors by inducing autophagy. Empagliflozin activated autophagy through the AMPK signaling pathway to delay the progression of atherosclerosis. Furthermore, the results of flow cytometry, EdU assays, CCK-8 cell viability assays, and scratch assays indicated that empagliflozin blocked HASMCs proliferation and migration. Empagliflozin activates autophagy through the AMPK signaling pathway to delay the evolution of atherosclerosis, indicating that it may represent a new and effective drug for the clinical treatment of atherosclerosis.

A multi-enzymatic cascade reaction for the synthesis of bioactive C-oligosaccharides

C-Oligosaccharides are rare in nature and possess diverse bioactivities. However, their chemical synthesis faces many challenges. In this work, enzymatic introduction of C-linked sugar chains to target aglycones was successfully achieved by multi-enzymatic cascade reactions. A C-glycosyltransferase from Aloe barbadensis was employed to introduce the first C-linked glucose and then a cyclomaltodextrin glucanotransferase from Bacillus licheniformis was used to extend the sugar chain. A total of twenty C-oligosaccharides with 2–6 sugars were synthesized from scale-up reactions and exhibited good water solubility and sodium-dependent glucose transporter 2 (SGLT2) inhibitory activity. Furthermore, a glucoamylase was used to control the length of the sugar chain and the C-maltosides were efficiently synthesized. These findings not only expanded the structural diversity of C-oligosaccharides, but also provided a strategy for the modification of C-glycoside drugs to improve the druggability.

Could flavonoid aglycones prevent the absorption of flavonoid glycosides by inhibiting sodium-dependent glucose transporter-1 in the small intestine?

Flavonoids present a large group of natural polyphenols with numerous important health benefits for preventing and treating a diverse variety of pathological conditions. However, the actual therapeutic use of these phytochemicals is impeded by their low oral bioavailability. In this commentary article, an interesting paradox is presented: while the ingested flavonoid glycosides can be absorbed by means of sodium-dependent glucose transporters (SGLTs; SGLT1) located in the brush border membrane facing the lumen of the small intestine, certain flavonoid aglycones are able to inhibit these shuttle proteins. It is expected that avoiding the co-intake of such SGLT1 inhibitors concomitantly with flavonoid-rich foods might provide a new option for enhancing the oral bioavailability of flavonoids, thereby preventing the transport of unabsorbed compounds to the large intestine and conversion into catabolites by the colonic microbiota. Altogether, the administration of flavonoids in appropriate combinations is highlighted for getting the maximal health benefits from consuming these bioactive compounds.

Effect of mannan-rich fractions and a mixture of sodium butyrate and zinc proteinate on performance, intestinal morphometry, and gene expression in broilers

This study evaluated the effects of isolated or combined prebiotics blended with sodium butyrate and zinc proteinate on performance, intestinal morphometry, and expression of genes associated with nutrient transport and immune response in broilers. 1,400 birds were randomly assigned to 5 treatments (Negative control (NC) without antibiotic; Positive control (PC) with antibiotic; Prebiotic (Prebio) composed of mannan fractions; Blend, composed of sodium butyrate, hydrolysed yeast cell wall and zinc proteinate; and the combination Prebio + Blend), with eight replications and 35 birds per experimental unit. The PC led to higher weight gain (WG) and lowered feed conversion (FCR) from 1 to 7 days of life than the other treatments. The use of prebio and blend resulted in high WG from 22 to 42 days (1773; 1768.9 g, respectively). However, the combination of prebio + blend was similar to PC and NC treatments. The additives resulted in longer duodenal villi when administered alone and in ileal villi (p = 0.001) combined, with no effect on jejunal villi. Crypt depth and duodenal villus: crypt ratio was higher for both additives types. A significant difference among treatments in the expression of the sodium-dependent glucose transporter gene (SGLT1) was noted, with greater expression in birds that received NC. There was higher expression of the neutral and cationic amino acid transporter gene (y + LAT-2) with the prebio and blend, either alone or in combination. The prebio blend with sodium butyrate and zinc proteinate additives used separately in broiler diets supported beneficial changes in intestinal morphometry, nutrient absorption, and performance, indicating their value in antibiotic-free broiler production systems.