The Role of SGLT2 Inhibitor Ipragliflozin on Cardiac Hypertrophy and microRNA Expression Profiles in a Non-diabetic Rat Model of Cardiomyopathy.

Evidence from clinical trials suggests that the cardioprotective effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors may arise through non-glycemic control-related mechanisms. Further, the cardiovascular advantages of SGLT2 inhibitors are likely present among non-diabetic patients with known cardiovascular diseases (CVDs). Here, we studied the impact of ipragliflozin, a selective SGLT2 inhibitor, on cardiac histopathology and microRNA (miRNA) expression profiles in a non-diabetic rat model of cardiomyopathy. Ipragliflozin was added to chow (0.01% (w/w)) and given to male DahlS.Z-Leprfa/Leprfa (DS/obese) rats for 6 weeks. Similarly aged male DahlS.Z-Lepr+/Lepr+ (DS/lean) rats were treated as controls. Measurements of systolic blood pressure (SBP) and heart rate (HR) were taken every other week. Following ipragliflozin treatment for 6 weeks, we conducted echocardiography, histopathological examination, and miRNA expression analysis (microarray). The impact of ipragliflozin on blood parameters was additionally examined. In DS/obese rats, ipragliflozin reduced SBP without affecting HR, reduced interventricular septal thickness in echocardiography and left ventricular (LV) organ weight, and improved hypertrophy of cardiomyocytes according to histopathological experiments. Further, ipragliflozin reduced plasma inflammatory cytokine levels in DS/obese rats. Additionally, ipragliflozin treatment altered the expression profile of miRNAs related to cardiac hypertrophy and heart failure in the LV compared to DS/obese control rats. Ipragliflozin prevented LV hypertrophy and altered related miRNA expression profiles in non-diabetic DS/obese rats. These findings suggest that miRNAs may play a partial role in regulating the structure of the heart and that SGLT2 inhibitors may exert cardio-protective effects by changing miRNA expression profiles in non-diabetic patients with CVDs.

Therapeutic Effects of SGLT2 Inhibitor Ipragliflozin and Metformin on NASH in Type 2 Diabetic Mice.

Background and aim: Sodium-glucose cotransporter (SGLT) 2 is responsible for most of the glucose reabsorption in the kidneys and has been proposed as a novel therapeutic target for the treatment of type 2 diabetes. In recent years, nonalcoholic steatohepatitis (NASH), the pathogenesis of which is strongly associated with insulin resistance, obesity, and type 2 diabetes, has become a considerable healthcare burden worldwide. However, there is currently no established pharmacotherapy for NASH. Here, we investigated the therapeutic effects of the SGLT2 selective inhibitor ipragliflozin alone and in combination with metformin on NASH in high fat and cholesterol diet-fed KK/Ay type 2 diabetic mice.Results: This diabetic model had hyperglycemia, insulin resistance, and obesity, and also exhibited steatosis, inflammation, and fibrosis in the liver, pathological features resembling those in human NASH. Four-week repeated administration of ipragliflozin significantly improved not only hyperglycemia, insulin resistance, and obesity but also hyperlipidemia and NASH-associated symptoms including hepatic steatosis and fibrosis. In addition, ipragliflozin attenuated inflammation and oxidative stress in the liver. Repeated administration of metformin also significantly improved symptoms of type 2 diabetes with NASH to a comparable degree to that by ipragliflozin. In addition, combination treatment with ipragliflozin and metformin additively improved these symptoms.Conclusions: These results demonstrate that the SGLT2 selective inhibitor ipragliflozin improves not only hyperglycemia but also NASH in type 2 diabetic mice, suggesting that treatment with ipragliflozin alone and in combination with metformin may be effective for treating type 2 diabetes with NASH.

Acute and Direct Effects of Sodium-Glucose Cotransporter 2 Inhibition on Glomerular Filtration Rate in Spontaneously Diabetic Torii Fatty Rats.

Recent clinical studies indicate that sodium-glucose cotransporter 2 (SGLT2) inhibitors exhibit a renoprotective effect. While studies at the single nephron level suggest that direct effects of SGLT2 inhibitors on renal hemodynamics may be a possible mechanism underlying their renoprotective effect, few studies have focused on such direct effects at the whole-kidney level. In the present study, we investigated the acute and direct effect of SGLT2 inhibition on creatinine clearance, an index of whole-kidney glomerular filtration rate (GFR), in a rat model of type 2 diabetes. Twelve to fifteen-week-old male Spontaneously Diabetic Torii (SDT) fatty rats and Sprague-Dawley rats were used as diabetic animals and non-diabetic controls, respectively. Under general anesthesia, baseline urine samples were collected from the left and right ureters for 1 h. The selective SGLT2 inhibitor ipragliflozin or vehicle was subsequently administered intravenously and post-drug urine was collected for 1 h. Baseline and post-drug blood samples were collected immediately before baseline urine collection and immediately after post-drug urine collection, respectively. Plasma glucose, urine volume, urinary glucose and albumin excretion were measured, and creatinine clearance was calculated. Blood pressure and heart rate were monitored continuously throughout the experiment. A single intravenous injection of ipragliflozin increased both urine output and glucose excretion, but reduced creatinine clearance without affecting systemic blood pressure. These results suggest that SGLT2 inhibition directly reduced whole-kidney GFR, most likely due to a reduction in intraglomerular pressure, by altering local renal hemodynamics, which may contribute to the renoprotective effects demonstrated in clinical studies.

In Vitro Pharmacological Profile of Ipragliflozin, a Sodium Glucose Co-transporter 2 Inhibitor.

Ipragliflozin, a selective sodium glucose cotransporter 2 (SGLT2) inhibitor, is used for the treatment of type 2 diabetes mellitus. To date, the only known in vitro pharmacological characteristic of ipragliflozin is its selectivity for SGLT2 over SGLT1, which was previously reported by our group. Therefore, in this study, we investigated other in vitro pharmacological characteristics of ipragliflozin and compared them with those of phlorizin, a naturally occurring SGLT inhibitor. Selectivity of ipragliflozin and phlorizin for human (h) SGLT2 over hSGLT3, hSGLT4, hSGLT5, hSGLT6 and hSodium/myo-inositol (MI) cotransporter 1 (hSMIT1) was examined in Chinese hamster ovary (CHO) cells overexpressing each transporter using specific radio-ligands. Ipragliflozin had higher selectivity for hSGLT2 than other hSGLTs. Phlorizin showed lower selectivity for hSGLT2 compared to ipragliflozin. Studies using CHO cells overexpressing hSGLT2 demonstrated that both ipragliflozin and phlorizin competitively inhibited SGLT2-mediated methyl-α-D-glucopyranoside (AMG) uptake with an inhibitory constant (Ki) of 2.28 and 20.2 nM, respectively. Ipragliflozin, but not phlorizin, inhibited hSGLT2 in a wash-resistant manner, suggesting that binding of ipragliflozin to hSGLT2 was persistent. These data demonstrate that ipragliflozin is a competitive inhibitor of SGLT2, has high selectivity for SGLT2 over not only SGLT1 but also other SGLT family members, and binds persistently to hSGLT2.

First-dose effect of the SGLT2 inhibitor ipragliflozin on cardiovascular activity in spontaneously diabetic Torii fatty rats.

The first dose of a sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor induces osmotic diuresis and can thereby affect cardiovascular activity in hyperglycemic patients. We aimed to determine whether the first dose of the selective SGLT2 inhibitor ipragliflozin affects cardiovascular activity in non-diabetic Sprague-Dawley (SD) rats and Spontaneously Diabetic Torii (SDT) fatty rats in two studies, a urine collection study and a telemetry study. In the former study, urine was collected for 24 hours after a single oral dose of ipragliflozin. In the latter study, systolic blood pressure (SBP) and heart rate (HR) were continuously monitored for 24 hours under conscious and unrestrained conditions from immediately before the administration of ipragliflozin. The telemetry study was conducted in a crossover design at successive 1 week intervals. Cardiovascular autonomic nerve activity was calculated from the SBP and HR. SDT fatty rats exhibited polyuria, glucosuria and hyperglycemia. In addition, the mean and standard deviation of SBP were higher, while the coefficient of variance of HR was lower than the respective parameters in SD rats. Ipragliflozin increased both urine output and urinary glucose excretion, and the increases were more pronounced in SDT fatty rats than in SD rats. In contrast, ipragliflozin had no effect on SBP, the standard deviation of SBP, HR, and the coefficient of variance of HR, or on autonomic nerve activity in either rat strain. These results suggest that the first dose of the SGLT2 inhibitor ipragliflozin has little impact on cardiovascular activity despite causing glucosuria with osmotic diuresis.

Protective Effect of Ipragliflozin on Pancreatic Islet Cells in Obese Type 2 Diabetic db/db Mice.

Ipragliflozin is a selective sodium glucose cotransporter 2 (SGLT2) inhibitor that increases urinary glucose excretion and subsequently improves hyperglycemia in patients with type 2 diabetes mellitus (T2DM). To assess the beneficial effect of ipragliflozin on the mass and function of pancreatic ß-cells under diabetic conditions, obese T2DM db/db mice were treated with ipragliflozin for 5 weeks. Glucose and lipid metabolism parameters, pathological changes in pancreatic islet cells and insulin content were evaluated. Pathological examination of pancreatic islet cells comprised measuring the ratios of insulin- and glucagon-positive cells and levels of oxidative stress markers. Hemoglobin A1c, plasma glucose, non-esterified fatty acid and triglyceride levels in ipragliflozin-treated groups were reduced compared to the diabetic control (DM-control) group. Histopathological examination of pancreatic islet cells revealed strong insulin staining and reduced glucagon staining in the ipragliflozin 10 mg/kg-treated group compared with the DM-control group. The ratio of α- to ß-cell mass was lower in the ipragliflozin 10 mg/kg-treated group than the DM-control group and was similar to that of the non-diabetic control group. The density of immunostaining for 4-hydroxy-2-nonenal, an oxidative stress marker, in pancreatic islets was significantly lower in the ipragliflozin 10 mg/kg-treated group than the DM-control group. Pancreatic insulin content tended to be higher in the ipragliflozin-treated groups than the DM-control group. Our findings demonstrate the benefit of ipragliflozin treatment in improving glucolipotoxicity and reducing oxidative stress in pancreatic islet cells. Treatment with ipragliflozin may protect against the progressive loss of islet ß-cells in patients with T2DM.

The Sodium Glucose Cotransporter 2 Inhibitor Ipragliflozin Promotes Preferential Loss of Fat Mass in Non-obese Diabetic Goto-Kakizaki Rats.

Sodium glucose cotransporter 2 (SGLT2) inhibitors improve hyperglycemia in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion. In addition to their antihyperglycemic effect, SGLT2 inhibitors also reduce body weight and fat mass in obese and overweight patients with T2DM. However, whether or not SGLT2 inhibitors similarly affect body composition of non-obese patients with T2DM remains unclear. In this study, we investigated the effect of the SGLT2 inhibitor ipragliflozin on body composition in a Goto-Kakizaki (GK) rat model of non-obese T2DM. GK rats were treated with ipragliflozin once daily for 9 weeks, starting at 23 weeks of age. Body composition was then analyzed using dual-energy X-ray absorptiometry. Treatment with ipragliflozin increased urinary glucose excretion, reduced hemoglobin A1c (HbA1c) levels and suppressed body weight gain as the dose increased. Body composition analysis revealed that body fat mass was lower in the ipragliflozin-treated groups than in the control group, while lean body mass and bone mineral contents were comparable between groups. Thus, an SGLT2 inhibitor ipragliflozin was found to promote preferential loss of fat mass in a rat model of non-obese T2DM. Ipragliflozin might also promote preferential loss of fat in non-obese patients with T2DM.

Characterization and comparison of sodium-glucose cotransporter 2 inhibitors: Part 2. Antidiabetic effects in type 2 diabetic mice.

Previously we investigated the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six sodium-glucose cotransporter (SGLT) 2 inhibitors commercially available in Japan using normal and diabetic mice. We classified the SGLT2 inhibitors with respect to duration of action as either long-acting (ipragliflozin and dapagliflozin) or intermediate-acting (tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin). In the present study, antidiabetic effects of repeated administration of these SGLT2 inhibitors in type 2 diabetic mice were investigated. When repeatedly administered for 4 weeks, all SGLT2 inhibitors significantly exhibited antihyperglycemic, antihyperinsulinemic, and pancreas-protective effects, as well as insulin resistance-improving effects. When compared at doses producing comparable reduction in hyperglycemia across all drugs, the antidiabetic effects of ipragliflozin and dapagliflozin were more potent than those of the other four drugs, but these differences among the six drugs were not statistically significant. Further, an oral glucose tolerance test performed after repeated administration demonstrated significant improvement in glucose tolerance only with ipragliflozin and dapagliflozin, implying improved insulin resistance and secretion. Taken together, these findings demonstrate that, although all SGLT2 inhibitors exert antidiabetic effects in type 2 diabetic mice, these pharmacologic effects might be slightly superior with the long-acting drugs, which are able to provide favorable blood glucose control throughout the day.

Characterization and comparison of sodium-glucose cotransporter 2 inhibitors in pharmacokinetics, pharmacodynamics, and pharmacologic effects.

The sodium-glucose cotransporter (SGLT) 2 offer a novel approach to treating type 2 diabetes by reducing hyperglycaemia via increased urinary glucose excretion. In the present study, the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six SGLT2 inhibitors commercially available in Japan were investigated and compared. Based on findings in normal and diabetic mice, the six drugs were classified into two categories, long-acting: ipragliflozin and dapagliflozin, and intermediate-acting: tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin. Long-acting SGLT2 inhibitors exerted an antihyperglycemic effect with lower variability of blood glucose level via a long-lasting increase in urinary glucose excretion. In addition, ipragliflozin and luseogliflozin exhibited superiority over the others with respect to fast onset of pharmacological effect. Duration and onset of the pharmacologic effects seemed to be closely correlated with the pharmacokinetic properties of each SGLT2 inhibitor, particularly with respect to high distribution and long retention in the target organ, the kidney. While all six SGLT2 inhibitors were significantly effective in increasing urinary glucose excretion and reducing hyperglycemia, our findings suggest that variation in the quality of daily blood glucose control associated with duration and onset of pharmacologic effects of each SGLT2 inhibitor might cause slight differences in rates of improvement in type 2 diabetes.

Antihyperglycemic effect of ipragliflozin, a sodium-glucose co-transporter 2 inhibitor, in combination with oral antidiabetic drugs in mice.

Inhibition of sodium-glucose cotransporter 2 is a novel strategy for glycemic control in type 2 diabetes mellitus patients. As the mechanism of action of sodium-glucose cotransporter 2 inhibitors on plasma glucose levels is distinct from that of existing oral antidiabetic drugs, a combination of the two might provide a therapeutic benefit. Here, we investigated the antihyperglycemic effect of ipragliflozin, a selective sodium-glucose cotransporter 2 inhibitor, alone or in combination with oral antidiabetic drugs in a range of relevant mouse models to analyse the blood glucose-lowering properties of different drug types based on their mechanism of action. Oral glucose tolerance tests in ICR mice were used to evaluate the effect of ipragliflozin in combination with the insulin secretagogues, glibenclamide or nateglinide. Liquid meal tests in ICR mice and diabetic KK-A(y) mice were used to investigate the combined effect of ipragliflozin with the dipeptidyl peptidase-4 inhibitor, sitagliptin, and α-glucosidase inhibitor, voglibose, respectively. Four-week repeated administration tests in KK-A(y) mice were used to examine the combined effect of ipragliflozin with the insulin sensitizers, pioglitazone and metformin. In all mouse models tested, the combination of ipragliflozin and existing oral antidiabetic drugs lowered blood glucose or glycated hemoglobin levels more than either monotherapy. In conclusion, inhibition of sodium-glucose cotransporter 2 by ipragliflozin, alone or in combination with existing oral antidiabetic drugs, has a robust effect on blood glucose levels in a range of mouse models of hyperglycemia.

Antidiabetic effects of SGLT2-selective inhibitor ipragliflozin in streptozotocin-nicotinamide-induced mildly diabetic mice.

Sodium-glucose cotransporter (SGLT) 2 plays an important role in renal glucose reabsorption, and inhibition of renal SGLT2 activity represents an innovative strategy for the treatment of hyperglycemia in diabetic patients. The present study investigated the antidiabetic effects of ipragliflozin, a SGLT2-selective inhibitor, in streptozotocin-nicotinamide-induced mildly diabetic mice, which exhibited a mild decline in glucose tolerance associated with the loss of early-phase insulin secretion. Oral administration of ipragliflozin increased urinary glucose excretion in a dose-dependent manner, an effect which was significant at doses of 0.3 mg/kg or higher and lasted over 12 h. In addition, ipragliflozin dose-dependently improved hyperglycemia and glucose intolerance with concomitant decreases in plasma insulin levels without causing hypoglycemia. Once-daily dosing of ipragliflozin (0.1 - 3 mg/kg) for 4 weeks attenuated hyperglycemia, glucose intolerance, and impaired insulin secretion. These results suggest that the SGLT2-selective inhibitor ipragliflozin increases urinary glucose excretion by inhibiting renal glucose reabsorption, improves hyperglycemia in streptozotocin-nicotinamide-induced mildly diabetic mice, and may be useful for treating type 2 diabetes.

Synthesis and evaluation of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety as selective ß3-adrenergic receptor agonists.

In the search for potent and selective human ß3-adrenergic receptor (AR) agonists as potential drugs for use in treating obesity and non-insulin dependent (type 2) diabetes, a series of N-phenyl-(2-aminothiazol-4-yl)acetamides with phenoxypropanolamine moiety were prepared and their biological activities against human ß3-, ß2-, and ß1-ARs were evaluated. Among these compounds, N-phenyl-(2-phenylaminothiazol-4-yl)acetamide (4 g), N-phenyl-(2-benzylaminothiazol-4-yl)acetamide (4j), and N-phenyl-[2-(3-methoxyphenyl)aminothiazol-4-yl]acetamide (6g) derivatives showed potent agonistic activity against the ß3-AR with functional selectivity over the ß1- and ß2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent model of diabetes.

Synthesis and evaluation of novel phenylethanolamine derivatives containing acetanilides as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential pharmacotherapies for the treatment of obesity and non-insulin dependent (type II) diabetes, we prepared a novel series of phenylethanolamine derivatives containing acetanilides and evaluated their biological activities at the human beta3-, beta2-, and beta1-ARs. Among these compounds, the 6-amino-2-pyridylacetanilide (36b), 2-amino-5-methylthiazol-4-ylacetanilide (36g), and 5-amino-1,2,4-thiadiazol-3-ylacetanilide (36h) derivatives showed potent agonistic activity at the beta3-AR with functional selectivity over the beta1- and beta2-ARs. In addition, these compounds exhibited significant hypoglycemic activity in a rodent diabetic model.

Discovery of novel thiourea derivatives as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, we prepared a novel series of phenoxypropanolamine derivatives containing the thiourea moiety and evaluated their biological activities at human beta3-, beta2-, and beta1-ARs. Among these compounds, 4-nitrophenylthiourea (18i) and 3-methoxyphenylthiourea (18k) derivatives were found to exhibit potent agonistic activity at the beta3-AR, with EC(50) values of 0.10 and 0.16 microM, respectively, and no agonistic activity for either the beta1- or beta2-AR. In addition, they showed significant hypoglycemic activity in a rodent diabetic model.

Synthesis and evaluation of novel phenoxypropanolamine derivatives containing acetanilides as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, a novel series of phenoxypropanolamine derivatives containing acetanilides were prepared and their biological activities were evaluated at the human beta3-, beta2-, and beta1-ARs. Several of the analogues (21a, 21b, and 27a) exhibited potent agonistic activity at the beta3-AR. Among the compounds described herein, the N-methyl-1-benzylimidazol-2-ylacetanilide derivative (21b) was found to be the most potent and selective beta3-AR agonist, with an EC(50) value of 0.28 microM and no agonistic activity for either the beta1- or beta2-AR. In addition, 21b showed significant hypoglycemic activity in a rodent diabetic model.

SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone prevents progression of nonalcoholic steatohepatitis in a type 2 diabetes rodent model.

Nonalcoholic steatohepatitis (NASH) has become the most common cause of chronic liver disease worldwide in recent years. The pathogenesis of NASH is closely linked to metabolic diseases such as insulin resistance, obesity, dyslipidemia, and type 2 diabetes. However, there is currently no pharmacological agent for preventing the progression of NASH. Sodium-glucose cotransporter (SGLT) 2 inhibitors increase urinary glucose excretion by inhibiting renal glucose reabsorption, and improve various pathological conditions of type 2 diabetes, including insulin resistance. In the present study, we examined the effects of ipragliflozin, a SGLT2-selective inhibitor, alone and in combination with pioglitazone on NASH in high-fat diet-fed KK/Ay type 2 diabetic mice. Type 2 diabetic mice with NASH exhibited steatosis, inflammation, and fibrosis in the liver as well as hyperglycemia, insulin resistance, and obesity, features that are observed in human NASH. Four-week repeated administration of ipragliflozin (0.1-3 mg/kg) led to significant improvements in hyperglycemia, insulin resistance, and obesity in addition to hyperlipidemia and liver injury including hepatic steatosis and fibrosis. Moreover, ipragliflozin reduced inflammation and oxidative stress in the liver. Repeated administration of pioglitazone (3-30 mg/kg) also significantly improved various parameters of diabetes and NASH, excluding obesity. Furthermore, combined treatment comprising ipragliflozin (1 mg/kg) and pioglitazone (10 mg/kg) additively improved these parameters. These findings indicate that the SGLT2-selective inhibitor ipragliflozin improves hyperglycemia as well as NASH in type 2 diabetic mice. Therefore, treatment with ipragliflozin monotherapy or coadministered with pioglitazone is expected to be a potential therapeutic option for the treatment of type 2 diabetes with NASH.

Effect of ipragliflozin, an SGLT2 inhibitor, on cardiac histopathological changes in a non-diabetic rat model of cardiomyopathy.

AIMS: We investigated the effect of the selective sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin on cardiac dysfunction and histopathology in a non-diabetic rat model of cardiomyopathy. MAIN METHODS: Ipragliflozin was mixed with chow (0.01%, w/w) and administered to male DahlS.Z-Leprfa/Leprfa (DS/obese) rats for 8 weeks. Male DahlS.Z-Lepr+/Lepr+ (DS/lean) rats of the same age were used as controls. Systolic blood pressure (SBP) and heart rate (HR) were measured every 4 weeks. After 8 weeks of treatment, echocardiography and histopathological examinations were performed. Further, the effect of ipragliflozin on blood and urine parameters were investigated. KEY FINDINGS: In the DS/obese rats, ipragliflozin delayed the age-related increase in SBP without affecting HR, reduced left ventricular (LV) mass and intraventricular septal thickness in echocardiography, and ameliorated hypertrophy of cardiomyocytes and LV fibrosis in histopathological examination. Although ipragliflozin significantly increased both urine volume and urinary glucose excretion in DS/obese rats, it did not alter plasma glucose levels. SIGNIFICANCE: Ipragliflozin prevented LV hypertrophy and fibrosis in non-diabetic DS/obese rats without affecting plasma glucose levels. These findings suggest that SGLT2 inhibitors have a cardio-protective effect in non-diabetic patients with cardiomyopathy.

Pharmacological profile of ASP8497, a novel, selective, and competitive dipeptidyl peptidase-IV inhibitor, in vitro and in vivo.

Dipeptidyl peptidase (DPP)-IV is involved in the inactivation of glucagon-like peptide-1 (GLP-1), a potent insulinotropic peptide. Thus, DPP-IV inhibitors are expected to become a useful new class of antidiabetic agent. This report describes the pharmacological profile of the novel DPP-IV inhibitor, ASP8497 [(2S,4S)-4-fluoro-1-({[4-methyl-1-(methylsulfonyl)piperidin-4-yl]amino}acetyl)pyrrolidine-2-carbonitrile monofumarate], both in vitro and in vivo. ASP8497 inhibited DPP-IV in plasma from mice, dogs, and humans with median inhibition concentration (IC(50)) values of 2.6 nM, 7.3 nM, and 6.2 nM, respectively. In contrast, ASP8497 did not potently inhibit human DPP8 or DPP9 activity (IC(50)=1,700 nM and 100 nM, respectively) and exhibited selectivity against several proteases, including proline-specific proteases (IC(50)>10 microM). Kinetic analysis indicated that ASP8497 is a competitive DPP-IV inhibitor. In normal mice, ASP8497 inhibited plasma DPP-IV activity even 12 h after administration. ASP8497 significantly inhibited increases in the blood glucose level during the oral glucose tolerance test (OGTT) conducted 0.5 h after administration. This was accompanied by increases in the plasma active GLP-1 and insulin levels. In addition, ASP8497 significantly inhibited increases in the blood glucose level during the OGTT conducted 8 h after administration. Furthermore, in Zucker fatty rats, ASP8497 dose dependently improved glucose tolerance with significance at doses of 1 mg/kg or higher. In contrast, ASP8497 did not cause hypoglycemia in fasted normal mice. These results indicate that ASP8497 is a potent, competitive, and selective DPP-IV inhibitor with antihyperglycemic activity.

Antidiabetic effects of SGLT2 inhibitor ipragliflozin in type 2 diabetic mice fed diets containing different carbohydrate contents.

AIMS: Daily intake of carbohydrates differs among individual patients with type 2 diabetes. Here, we investigated whether or not dietary carbohydrate content affects the efficacy of the sodium-glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin in type 2 diabetic mice. MAIN METHODS: Diabetic mice were fed a regular (50% kcal), high (75% kcal)-, or low (25% kcal)-carbohydrate diet. Ipragliflozin was orally administered once a day for 4 weeks. KEY FINDINGS: In all groups, mice exhibited characteristics of type 2 diabetes, including hyperglycemia, hyperinsulinemia, and obesity. Hyperglycemia was more severe in the high-carbohydrate diet group and milder in the low-carbohydrate diet group than in the regular diet group. In all diabetic mice, ipragliflozin significantly increased urinary glucose excretion and improved hyperglycemia, hyperinsulinemia, glucose tolerance, insulin resistance, obesity, and nephropathy. Although these antidiabetic effects of ipragliflozin were more marked in the high-carbohydrate diet group (which showed more severe hyperglycemia) than in the other two groups, no significant differences in effective dose or degree of response were observed among the three groups. SIGNIFICANCE: The antidiabetic effects of ipragliflozin were not greatly affected by dietary carbohydrate content, suggesting that ipragliflozin may have similar efficacy for patients with type 2 diabetes regardless of carbohydrate intake.

Effects of the SGLT2 inhibitor ipragliflozin on various diabetic symptoms and progression of overt nephropathy in type 2 diabetic mice.

Diabetic nephropathy is the leading cause of end-stage renal disease and is associated with high-cardiovascular risk and significant morbidity and mortality. The recent development of sodium-glucose cotransporter (SGLT) 2 inhibitors offers a new antidiabetic therapy via enhanced glucose excretion; however, the beneficial effect of these drugs on the development of type 2 diabetic overt nephropathy is still largely unclear. We examined the therapeutic effects of the SGLT2 inhibitor ipragliflozin on various diabetic symptoms and the progression of nephropathy in uninephrectomized type 2 diabetic mice, which exhibit not only typical diabetic symptoms, such as impaired insulin secretion, glucose intolerance, hyperglycemia, and obesity, but also overt nephropathy with decline in renal function. Diabetes was induced by intraperitoneal administration of nicotinamide (1000 mg/kg) and streptozotocin (150 mg/kg) to uninephrectomized high-fat diet-fed mice. Ipragliflozin (0.1-3 mg/kg) was orally administered to diabetic mice once daily for 4 weeks. Repeated administration of ipragliflozin improved diabetic symptoms, such as hyperglycemia and insulin resistance, via an increase in urinary glucose excretion. In addition, ipragliflozin attenuated albuminuria/proteinuria and the decline in renal function, and improved renal injury, including glomerulosclerosis and interstitial fibrosis. Our results demonstrate that ipragliflozin improves various diabetic symptoms and delays development of diabetic nephropathy. Therefore, SGLT2 inhibitors could constitute a novel therapeutic target for the treatment of type 2 diabetes with overt nephropathy.