Human Sodium Glucose Cotransporter Research Articles

In-silico screening and identification of glycomimetic as potential human sodium-glucose co-transporter 2 inhibitor

Sodium-glucose co-transporter 2 (SGLT2) is one of the important targets against type II diabetes mellitus. A typical SGLT2 inhibitor acts by inhibiting glucose reabsorption, thus lowering the blood glucose level. Unlike SGLT1, SGLT2 is responsible for almost 90% glucose reabsorption from glomerular filtrate. The current SGLT2 inhibitors include gliflozins, often prescribed as second or third-line agents in diabetes mellitus. The SGLT2 inhibitors also benefit patients with heart and kidney disease. Due to instability issues with the natural O-aryl glycoside analogues C-glycoside analogues were developed and showed improved stability. Despite enhanced bioavailability and selectivity of newer derivatives, some serious side effects are associated with gliflozin analogues. At the present study, we applied in-silico approaches to find new glycomimetic compounds as potent SGLT2 inhibitors that could show improvement in side effects associated with current analogues. This work applied both ligand-based and structure-based drug approaches to find potential compounds. We developed a 3D-QSAR method to screen potential inhibitors from a library of ten thousand compounds and performed docking studies. The compounds were ranked based on predicted pIC50 and docking score. An initial screening of five thousand compounds was conducted, and the subsequently selected top 12 compounds were based on binding free energy calculations. These selected compounds were subjected to molecular dynamics (MD) simulations. Remarkably, our simulations identified nine compounds that exhibited significant and sustained binding affinity compared to the co-crystallized Empagliflozin. Collectively, considering the anticipated pharmacokinetic profiles and toxicity assessments, several of these compounds emerged as promising candidates for further in-depth evaluation.

Metabolic Communication by SGLT2 Inhibition.

SGLT2 (sodium-glucose cotransporter 2) inhibitors (SGLT2i) can protect the kidneys and heart, but the underlying mechanism remains poorly understood. To gain insights on primary effects of SGLT2i that are not confounded by pathophysiologic processes or are secondary to improvement by SGLT2i, we performed an in-depth proteomics, phosphoproteomics, and metabolomics analysis by integrating signatures from multiple metabolic organs and body fluids after 1 week of SGLT2i treatment of nondiabetic as well as diabetic mice with early and uncomplicated hyperglycemia. Kidneys of nondiabetic mice reacted most strongly to SGLT2i in terms of proteomic reconfiguration, including evidence for less early proximal tubule glucotoxicity and a broad downregulation of the apical uptake transport machinery (including sodium, glucose, urate, purine bases, and amino acids), supported by mouse and human SGLT2 interactome studies. SGLT2i affected heart and liver signaling, but more reactive organs included the white adipose tissue, showing more lipolysis, and, particularly, the gut microbiome, with a lower relative abundance of bacteria taxa capable of fermenting phenylalanine and tryptophan to cardiovascular uremic toxins, resulting in lower plasma levels of these compounds (including p-cresol sulfate). SGLT2i was detectable in murine stool samples and its addition to human stool microbiota fermentation recapitulated some murine microbiome findings, suggesting direct inhibition of fermentation of aromatic amino acids and tryptophan. In mice lacking SGLT2 and in patients with decompensated heart failure or diabetes, the SGLT2i likewise reduced circulating p-cresol sulfate, and p-cresol impaired contractility and rhythm in human induced pluripotent stem cell-derived engineered heart tissue. SGLT2i reduced microbiome formation of uremic toxins such as p-cresol sulfate and thereby their body exposure and need for renal detoxification, which, combined with direct kidney effects of SGLT2i, including less proximal tubule glucotoxicity and a broad downregulation of apical transporters (including sodium, amino acid, and urate uptake), provides a metabolic foundation for kidney and cardiovascular protection.

Collective Domain Motion Facilitates Water Transport in SGLT1.

The human sodium-glucose cotransporter protein (SGLT1) is an important representative of the sodium solute symporters belonging to the secondary active transporters that are critical to the homeostasis of sugar, sodium, and water in the cell. The underlying transport mechanism of SGLT1 is based on switching between inward- and outward-facing conformations, known as the alternating access model, which is crucial for substrate transport, and has also been postulated for water permeation. However, the nature of water transport remains unclear and is disputed along the passive and active transport, with the latter postulating the presence of the pumping effect. To better examine the water transport in SGLT1, we performed a series of equilibrium all-atom molecular dynamics simulations, totaling over 6 μs of sample representative conformational states of SGLT1 and its complexes, with the natural substrates, ions, and inhibitors. In addition to elucidating the basic physical factors influencing water permeation, such as channel openings and energetics, we focus on dynamic flexibility and its relationship with domain motion. Our results clearly demonstrate a dependence of instantaneous water flux on the channel opening and local water diffusion in the channel, strongly supporting the existence of a passive water transport in SGLT1. In addition, a strong correlation found between the local water diffusion and protein domain motion, resembling the "rocking-bundle" motion, reveals its facilitating role in the water transport.

Chemical and Biological Review of Endophytic Fungi Associated with Morus sp. (Moraceae) and In Silico Study of Their Antidiabetic Potential

The chronic nature of diabetes mellitus motivates the quest for novel agents to improve its management. The scarcity and prior uncontrolled utilization of medicinal plants have encouraged researchers to seek new sources of promising compounds. Recently, endophytes have presented as eco-friendly leading sources for bioactive metabolites. This article reviewed the endophytic fungi associated with Morus species and their isolated compounds, in addition to the biological activities tested on their extracts and chemical constituents. The relevant literature was collected from the years 2008-2022 from PubMed and Web of Science databases. Notably, no antidiabetic activity was reported for any of the Morus-associated endophytic fungal extracts or their twenty-one previously isolated compounds. This encouraged us to perform an in silico study on the previously isolated compounds to explore their possible antidiabetic potential. Furthermore, pharmacokinetic and dynamic stability studies were performed on these compounds. Upon molecular docking, Colletotrichalactone A (14) showed a promising antidiabetic activity due to the inhibition of the α-amylase local target and the human sodium-glucose cotransporter 2 (hSGT2) systemic target with safe pharmacokinetic features. These results provide an in silico interpretation of the possible anti-diabetic potential of Morus endophytic metabolites, yet further study is required.

Structural basis of inhibition of the human SGLT2-MAP17 glucose transporter.

Human sodium-glucose cotransporter 2 (hSGLT2) mediates the reabsorption of the majority of filtrated glucose in the kidney1. Pharmacological inhibition of hSGLT2 by oral small-molecule inhibitors, such as empagliflozin, leads to enhanced excretion of glucose and is widely used in the clinic to manage blood glucose levels for the treatment of type 2 diabetes1. Here we determined the cryogenic electron microscopy structure of the hSGLT2-MAP17 complex in the empagliflozin-bound state to an overall resolution of 2.95 Å. Our structure shows eukaryotic SGLT-specific structural features. MAP17 interacts with transmembrane helix 13 of hSGLT2. Empagliflozin occupies both the sugar-substrate-binding site and the external vestibule to lock hSGLT2 in an outward-open conformation, thus inhibiting the transport cycle. Our work provides a framework for understanding the mechanism of SLC5A family glucose transporters and also develops a foundation for the future rational design and optimization of new inhibitors targeting these transporters.

In silico Screening and Identification of Natural Compound Sophoraflavanone G as Potential Human Sodium-Glucose Cotransporter 2 Inhibitor

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance, and it is hitherto incurable. Among different therapeutic modalities, glucose co-transporter (SGLT) inhibitors have gained prominence. In the current study, we have screened natural compounds as potential SGLT inhibitor and compared with conventional gliflozin drugs. We have selected human SGLT 1 and 2 sequences modeled by homology modeling using SWISS-MODEL server, stability analysis was performed in silico. We used CDOCKER to dock the selected gliflozin drugs and natural compounds with SGLT 1 and 2. We further checked adsorption, distribution, metabolism, excretion, and toxicity using ADMETSAR tools and identified Sophoraflavonone G as a potential natural compound with good binding energy and drug-like characteristics. The molecular dynamic simulation revealed sophoraflavonone G binds with SGLT2 and forms a stable complex.

Dapagliflozin Does Not Directly Affect Human α or β Cells.

Selective inhibitors of sodium glucose cotransporter-2 (SGLT2) are widely used for the treatment of type 2 diabetes and act primarily to lower blood glucose by preventing glucose reabsorption in the kidney. However, it is controversial whether these agents also act on the pancreatic islet, specifically the α cell, to increase glucagon secretion. To determine the effects of SGLT2 on human islets, we analyzed SGLT2 expression and hormone secretion by human islets treated with the SGLT2 inhibitor dapagliflozin (DAPA) in vitro and in vivo. Compared to the human kidney, SLC5A2 transcript expression was 1600-fold lower in human islets and SGLT2 protein was not detected. In vitro, DAPA treatment had no effect on glucagon or insulin secretion by human islets at either high or low glucose concentrations. In mice bearing transplanted human islets, 1 and 4 weeks of DAPA treatment did not alter fasting blood glucose, human insulin, and total glucagon levels. Upon glucose stimulation, DAPA treatment led to lower blood glucose levels and proportionally lower human insulin levels, irrespective of treatment duration. In contrast, after glucose stimulation, total glucagon was increased after 1 week of DAPA treatment but normalized after 4 weeks of treatment. Furthermore, the human islet grafts showed no effects of DAPA treatment on hormone content, endocrine cell proliferation or apoptosis, or amyloid deposition. These data indicate that DAPA does not directly affect the human pancreatic islet, but rather suggest an indirect effect where lower blood glucose leads to reduced insulin secretion and a transient increase in glucagon secretion.

Discovery of Novel N-Glycoside and Non-Glycoside hSGLT2 Inhibitors for the Treatment of Type 2 Diabetes Mellitus

Human sodium-glucose cotransporter 2 (hSGLT2) is a membrane protein responsible for glucose reabsorption from the glomerular filtrate in the proximal tubule. Inhibition of hSGLT2 has been regarded as a brand new therapeutic approach for the treatment of type 2 diabetes mellitus (T2DM) due to its non-insulin related characteristics with less side effects. Current commercially available hSGLT2 inhibitors are all C-glycoside inhibitors. Previous studies have reported that N-glycoside inhibitors have better potential to serve as new drugs due to their good metabolic stability. In addition, non-glycoside inhibitors have been shown to exhibit the capability to overcome the existing problems of current glycoside inhibitors, including low tissue permeability, poor stability and short serum half-time. Here, we aimed to discover novel N-glycoside and non-glycoside hSGLT2 inhibitors by a combination of several computational approaches. A ligand-based pharmacophore model was generated, well validated and subsequently utilized as a 3D query to identify novel hSGLT2 inhibitors from National Cancer Institute (NCI) and Traditional Chinese Medicine (TCM) databases. Finally, one N-glycoside (NSC679207) and one non-glycoside (TCM_Piperenol_A) hSGLT2 inhibitors were successfully identified, which were proven to exhibit excellent binding affinities, pharmacokinetic properties and less toxicity than the commercially available hSGLT2 inhibitor, canagliflozin, via molecular docking, ADMET prediction, molecular dynamics (MD) simulations and binding free energy calculations. All together, our results strongly suggest that these two compounds have great potential to serve as novel hSGLT2 inhibitors for the treatment of T2DM and their efficacies may be further examined by a series of in vitro and/or in vivo bioassays.

Active site voltage clamp fluorometry of the sodium glucose cotransporter hSGLT1

In the human sodium glucose cotransporter (hSGLT1) cycle, the protein undergoes conformational changes where the sugar-binding site alternatively faces the external and internal surfaces. Functional site-directed fluorometry was used to probe the conformational changes at the sugar-binding site. Residues (Y290, T287, H83, and N78) were mutated to cysteines. The mutants were expressed in Xenopus laevis oocytes and tagged with environmentally sensitive fluorescent rhodamines [e.g., tetramethylrhodamine (TMR)-thiols]. The fluorescence intensity was recorded as the mutants were driven into different conformations using voltage jumps. Sugar binding and transport by the fluorophore-tagged mutants were blocked, but Na+ binding and the voltage-dependent conformational transitions were unaffected. Structural models indicated that external Na+ binding opened a large aqueous vestibule (600 Å3) leading to the sugar-binding site. The fluorescence of TMR covalently linked to Y290C, T287C, and H83C decreased as the mutant proteins were driven from the inward to the outward open Na+-bound conformation. The time courses of fluorescence changes (milliseconds) were close to the SGLT1 capacitive charge movements. The quench in rhodamine fluorescence indicated that the environment of the chromophores became more polar with opening of the external gates as the protein transitioned from the inward to outward facing state. Structural analyses showed an increase in polar side chains and a decrease in hydrophobic side chains lining the vestibule, and this was reflected in solvation of the chromophore. The results demonstrate the opening and closing of external gates in real time, with the accompanying changes of polarity of the sugar vestibule.

Early drug use of dapagliflozin prescribed by general practitioners and diabetologists in Germany.

Dapagliflozin is an inhibitor of the human sodium-glucose co-transporter 2 (SGLT2) that has been shown to improve glycaemic control in patients with type 2 diabetes mellitus (T2DM). This study aimed to evaluate the characteristics and treatment patterns of dapagliflozin users in comparison to users of other anti-diabetic (AD) treatments in Germany. Data from patients with T2DM initiating at least one prescription for dapagliflozin or other AD therapy between November 2012 and April 2014 were collected from the IMS German Disease Analyzer database. The use of dapagliflozin combination therapy (n=1034; 74%) was more common than monotherapy (n=371; 26%). In comparison with other AD therapy users, a higher percentage of dapagliflozin users were ⩽64years of age (62.3% vs. 36.4%), and a higher proportion were male (59.1% vs. 53.6%). The average duration of diabetes was comparable between dapagliflozin patients and other AD therapy users (5.7yearsvs. 5.5years), however higher levels of HbA1c were found in dapagliflozin users (8.2% (66mmol/mol) vs. 7.5% (58mmol/mol). For the vast majority (71.5% of 10mg dapagliflozin users and 88.9% of 5mg users), dapagliflozin was prescribed in combination with other AD therapy. Patients starting on dapagliflozin differed in several demographic and health-related respects to patients starting another AD therapy during the same period. Dapagliflozin was predominantly used as a component of combination therapy, adding on to existing therapy. After initiation, switching to other AD treatments or adding to therapy was comparatively rare during the first year.

Recent Developments of C-Aryl Glucoside SGLT2 Inhibitors.

Sodium-glucose cotransporter 2 (SGLT2) is almost exclusively expressed in the proximal renal tubules. It is responsible for about 90% of the glucose reabsorption from tubular fluid. Selective inhibition of SGLT2 is expected to favor in the normalization of plasma glucose levels in T2DM patients through the prevention of renal glucose reabsorption and the promotion of glucose excretion from urine. Selective SGLT2 inhibitors have the merits to minimize the gastrointestinal side effects associated with SGLT1 inhibition, and selective SGLT2 inhibition may have a low risk of hypoglycemia. Since the C-aryl glucosides are metabolically more stable than the O-glucosides, numerous efforts have been made in the development of potent and selective C-aryl glucoside SGLT2 inhibitors, and a number of them are now used as anti-diabetes drugs in clinic or at various stages of clinical developments. Based on their structural features, in this review, these SGLT2 inhibitors are classified as three types: the phenyl/arylmethylphenyl C-glucosides, with an emphasis on the modifications on the proximal and/or the distal phenyl ring, and the spacer; the heteroarylmethylphenyl Cglucosides, with a replacement of the distal phenyl ring by a heterocycle like pyridazine, pyrimidine, thiophene and benzothiophene, thiazole, 1,3,4-thiadiazole, and triazolopyridinone; and the glucose-modified Caryl glucosides, including the glucose C-1 derived O-spiroketals, C-4 gem-difluoro analogues, C-5 and C-6 modified derivatives, dioxa-bicyclo[3.2.1]octane bridged ketals, the thioglucosides, and carbasugars. The structure-activity relationships (SARs) of each type along with their inhibitory potency against human SGLT2 and selectivity over human SGLT1 are discussed.

Binding interaction of SGLT with sugar and thiosugar by the molecular dynamics simulation

The human sodium–glucose co-transporter 2 (hSGLT2) is a transporter responsible for reabsorption of glucose in the proximal convoluted tubule of the kidney. hSGLT2 inhibitors, including luseogliflozin, have been developed as drugs for type 2 diabetes mellitus. Only luseogliflozin contains a thiosugar ring in its chemical structure, while other hSGLT2 inhibitors contain glucose rings. Consequently, we focused on the binding interactions of hSGLT2 with sugars and thiosugars. We first revealed that the binding affinities of thiosugars are stronger than those of sugars through molecular dynamics simulations of Vibrio parahaemolyticus, sodium–galactose co-transporter, and human hSGLT2. We then demonstrated that Na+ dissociates from the protein to the cytoplasmic solution more slowly in the thiosugar system than in the sugar system. These differences between sugars and thiosugars are discussed on the basis of the different binding modes due to the atom at the 5-position of the sugar and thiosugar rings. Finally, as a result of Na+ dissociation, we suggest that the dissociation of thiosugars is slower than that of sugars.

In vitro characterization of luseogliflozin, a potent and competitive sodium glucose co-transporter 2 inhibitor: Inhibition kinetics and binding studies

In this study, we evaluated an inhibition model of luseogliflozin on sodium glucose co-transporter 2 (SGLT2). We also analyzed the binding kinetics of the drug to SGLT2 protein using [3H]-luseogliflozin. Luseogliflozin competitively inhibited human SGLT2 (hSGLT2)-mediated glucose uptake with a Ki value of 1.10 nM. In the absence of glucose, [3H]-luseogliflozin exhibited a high affinity for hSGLT2 with a Kd value of 1.3 nM. The dissociation half-time was 7 h, suggesting that luseogliflozin dissociates rather slowly from hSGLT2. These profiles of luseogliflozin might contribute to the long duration of action of this drug.

Analysis of the effect of canagliflozin on renal glucose reabsorption and progression of hyperglycemia in zucker diabetic Fatty rats.

Sodium-glucose cotransporter 2 (SGLT2) plays a major role in renal glucose reabsorption. To analyze the potential of insulin-independent blood glucose control, the effects of the novel SGLT2 inhibitor canagliflozin on renal glucose reabsorption and the progression of hyperglycemia were analyzed in Zucker diabetic fatty (ZDF) rats. The transporter activity of recombinant human and rat SGLT2 was inhibited by canagliflozin, with 150- to 12,000-fold selectivity over other glucose transporters. Moreover, in vivo treatment with canagliflozin induced glucosuria in mice, rats, and dogs in a dose-dependent manner. It inhibited apparent glucose reabsorption by 55% in normoglycemic rats and by 94% in hyperglycemic rats. The inhibition of glucose reabsorption markedly reduced hyperglycemia in ZDF rats but did not induce hypoglycemia in normoglycemic animals. The change in urinary glucose excretion should not be used as a marker to predict the glycemic effects of this SGLT2 inhibitor. In ZDF rats, plasma glucose and HbA1c levels progressively increased with age, and pancreatic β-cell failure developed at 13 weeks of age. Treatment with canagliflozin for 8 weeks from the prediabetic stage suppressed the progression of hyperglycemia, prevented the decrease in plasma insulin levels, increased pancreatic insulin contents, and minimized the deterioration of islet structure. These results indicate that selective inhibition of SGLT2 with canagliflozin controls the progression of hyperglycemia by inhibiting renal glucose reabsorption in ZDF rats. In addition, the preservation of β-cell function suggests that canagliflozin treatment reduces glucose toxicity via an insulin-independent mechanism.

SHR3824, a novel selective inhibitor of renal sodium glucose cotransporter 2, exhibits antidiabetic efficacy in rodent models.

The sodium glucose cotransporter 2 (SGLT2) plays an important role in renal glucose reabsorption, thus serves as a new target for the treatment of diabetes. The purpose of this study was to evaluate SHR3824 as a novel selective SGLT2 inhibitor and to characterize its in vivo effects on glucose homeostasis. The effects of chronic administration of SHR3824 on peripheral insulin sensitivity and pancreatic β-cell function were also investigated. The in vitro potency and selectivity of SHR3824 were assessed in HEK293 cells transfected with human SGLT2 or SGLT1. Acute and multi-dose studies were performed on ICR mice, GK rats and db/db mice to assess the ability of SHR3824 to enhance urinary glucose excretion and improve blood glucose levels. 2-Deoxyglucose uptake and insulin immunohistochemical staining were performed in the soleus muscle and pancreas, respectively, of db/db mice. A selective SGLT2 inhibitor BMS512148 (dapagliflozin) was taken as positive control. SHR3824 potently inhibited human SGLT2 in vitro, but exerted much weak inhibition on human SGLT1 (the IC50 values of SHR3824 against human SGLT2 and SGLT1 were 2.38 and 4324 nmol/L, respectively). Acute oral administration of SHR3824 (0.3, 1.0, 3.0 mg/kg) dose-dependently improved glucose tolerance in ICR mice, and reduced hyperglycemia by increasing urinary glucose excretion in GK rats and db/db mice. Chronic oral administration of SHR3824 (0.3, 1.0, 3.0 mg·kg(-1)·d(-1)) dose-dependently reduced blood glucose and HbA1c levels in GK rats and db/db mice, and significantly increased insulin-stimulated glucose uptake in the soleus muscles and enhanced insulin staining in the islet cells of db/db mice. SHR3824 is a potent and selective SGLT2 inhibitor and exhibits antidiabetic efficacy in several rodent models, suggesting its potential as a new therapeutic agent for the treatment of type 2 diabetes.

A cell-based fluorescent glucose transporter assay for SGLT2 inhibitor discovery

The sodium/glucose cotransporter 2 (SGLT2) is responsible for the majority of glucose reabsorption in the kidney, and currently, SGLT2 inhibitors are considered as promising hypoglycemic agents for the treatment of type 2 diabetes mellitus. By constructing CHO cell lines that stably express the human SGLT2 transmembrane protein, along with a fluorescent glucose transporter assay that uses 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]2-deoxyglucose (2-NBDG) as a glucose analog, we have developed a nonradioactive, cell-based assay for the discovery and characterization of SGLT2 inhibitors.

Pharmacodynamics and Subchronic Toxicity in Mice and Monkeys of ISIS 388626, a Second-Generation Antisense Oligonucleotide That Targets Human Sodium Glucose Cotransporter 2

ISIS 388626, a 2'-methoxyethyl (MOE)-modified antisense oligonucleotide (ASO) that targets human sodium glucose cotransporter 2 (SGLT2) mRNA, is in clinical trials for the management of diabetes. SGLT2 plays a pivotal role in renal glucose reabsorption, and inhibition of SGLT2 is anticipated to reduce hyperglycemia in diabetic subjects by increasing urinary glucose elimination. To selectively inhibit SGLT2 in the kidney, ISIS 388626 was designed as a "shortmer" ASO, consisting of only 12 nucleotides with two 2'-MOE-modified nucleotides at the termini. Mice and monkeys received up to 30 mg/kg/week ISIS 388626 via subcutaneous injection for 6 or 13 weeks. Dose-dependent decreases in renal SGLT2 mRNA expression were observed, which correlated with dose-related increases in glucosuria without concomitant hypoglycemia. There were no histologic changes in the kidney attributed to SGLT2 inhibition after 6 or 13 weeks of treatment. The remaining changes observed in these studies were typical of those produced in these species by the administration of oligonucleotides, correlated with high doses of ISIS 388626, and were unrelated to the inhibition of SGLT2 expression. The kidney contained the highest concentration of ISIS 388626, and dose-dependent basophilic granule accumulation in tubular epithelial cells of the kidney, which is evidence of oligonucleotide accumulation in these cells, was the only histologic change identified. No changes in kidney function were observed. These results revealed only readily reversible changes after the administration of ISIS 388626 and support the continued investigation of the safety and efficacy of ISIS 388626 in human trials.

Tofogliflozin, a Potent and Highly Specific Sodium/Glucose Cotransporter 2 Inhibitor, Improves Glycemic Control in Diabetic Rats and Mice

Sodium/glucose cotransporter 2 (SGLT2) is the predominant mediator of renal glucose reabsorption and is an emerging molecular target for the treatment of diabetes. We identified a novel potent and selective SGLT2 inhibitor, tofogliflozin (CSG452), and examined its efficacy and pharmacological properties as an antidiabetic drug. Tofogliflozin competitively inhibited SGLT2 in cells overexpressing SGLT2, and K(i) values for human, rat, and mouse SGLT2 inhibition were 2.9, 14.9, and 6.4 nM, respectively. The selectivity of tofogliflozin toward human SGLT2 versus human SGLT1, SGLT6, and sodium/myo-inositol transporter 1 was the highest among the tested SGLT2 inhibitors under clinical development. Furthermore, no interaction with tofogliflozin was observed in any of a battery of tests examining glucose-related physiological processes, such as glucose uptake, glucose oxidation, glycogen synthesis, hepatic glucose production, glucose-stimulated insulin secretion, and glucosidase reactions. A single oral gavage of tofogliflozin increased renal glucose clearance and lowered the blood glucose level in Zucker diabetic fatty rats. Tofogliflozin also improved postprandial glucose excursion in a meal tolerance test with GK rats. In db/db mice, 4-week tofogliflozin treatment reduced glycated hemoglobin and improved glucose tolerance in the oral glucose tolerance test 4 days after the final administration. No blood glucose reduction was observed in normoglycemic SD rats treated with tofogliflozin. These findings demonstrate that tofogliflozin inhibits SGLT2 in a specific manner, lowers blood glucose levels by increasing renal glucose clearance, and improves pathological conditions of type 2 diabetes with a low hypoglycemic potential.

TS-071 is a novel, potent and selective renal sodium-glucose cotransporter 2 (SGLT2) inhibitor with anti-hyperglycaemic activity

The renal sodium-glucose cotransporter 2 (SGLT2) plays an important role in the reuptake of filtered glucose in the proximal tubule and therefore may be an attractive target for the treatment of diabetes mellitus. This study characterizes the pharmacological profile of TS-071 ((1S)-1,5-anhydro-1-[5-(4-ethoxybenzyl)-2-methoxy-4-methylphenyl]-1-thio-D-glucitol hydrate), a novel SGLT2 inhibitor in vitro and in vivo. Inhibition of glucose uptake by TS-071 was studied in CHO-K1 cells stably expressing either human SGLT1 or SGLT2. Single oral dosing studies were performed in rats, mice and dogs to assess the abilities of TS-071 to increase urinary glucose excretion and to lower plasma glucose levels. TS-071 inhibited SGLT2 activity in a concentration-dependent manner and was a potent and highly selective inhibitor of SGLT2. Orally administered TS-071 increased urinary glucose excretion in Zucker fatty rats and beagle dogs at doses of 0.3 and 0.03 mg·kg(-1) respectively. TS-071 improved glucose tolerance in Zucker fatty rats without stimulating insulin secretion and reduced hyperglycaemia in streptozotocin (STZ)-induced diabetic rats and db/db mice at a dose of 0.3 mg·kg(-1). These data indicate that TS-071 is a potent and selective SGLT2 inhibitor that improves glucose levels in rodent models of type 1 and 2 diabetes and may be useful for the treatment for diabetes mellitus.

EGT1442, a potent and selective SGLT2 inhibitor, attenuates blood glucose and HbA 1c levels in db/db mice and prolongs the survival of stroke-prone rats

Sodium glucose co-transporter 2 (SGLT2) is a renal type III integral membrane protein that co-transports sodium and glucose from filtrate to epithelium in the proximal tubule. Human subjects with homozygous or compound heterozygous mutations in SLC5A2 exhibit glucosuria without hypoglycemia or other obvious morbidity, suggesting that blockade of SGLT2 has the potential to promote normalization of blood glucose without hypoglycemia in the setting of type 2 diabetes. This report presents the in vitro and in vivo pharmacological activities of EGT1442, a recently discovered SGLT2 inhibitor in the C-aryl glucoside class. The inhibitory effects of EGT1442 for human SGLT1 and SGLT2 were evaluated in an AMG uptake assay and the in vivo efficacy of treatment with EGT1442 was investigated in rats and dogs after a single dose and in db/db mice after chronic administration. The effect of EGT1442 on median survival of SHRSP rats was also evaluated. The IC 50 values for EGT1442 against human SGLT1 and SGLT2 are 5.6 μM and 2 nM, respectively. In normal rats and dogs a saturable urinary glucose excretion was produced with an ED 50 of 0.38 and 0.09 mg/kg, respectively. Following chronic administration to db/db mice, EGT1442 dose-dependently reduced HbA 1c and blood glucose concentration without affecting body mass or insulin level. Additionally, EGT1442 significantly prolonged the median survival of SHRSP rats. EGT1442 showed favorable properties both in vitro and in vivo and could be beneficial to the management of type 2 diabetic patients.