SGLT2 inhibitor ipragliflozin exerts antihyperglycemic effects via the blood glucose-dependent increase in urinary glucose excretion in type 2 diabetic mice.

This study investigated the antihyperglycemic effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin via the blood glucose-dependent increase in urinary glucose excretion in KK/Ay type 2 diabetic mice. In oral glucose tolerance tests (glucose load: 1, 2, or 4 g/kg) in 24-h-fasted mice, blood glucose levels increased in a glucose-loading dose-dependent manner. Oral administration of ipragliflozin (1 mg/kg) significantly inhibited the increase in blood glucose concomitant with urinary glucose excretion. To investigate the effects of ipragliflozin under low blood glucose conditions, blood glucose level and urinary glucose excretion were examined under fasting conditions in diabetic mice that had prefasted for 0, 6, 12, 18, or 24 h. Ipragliflozin significantly lowered blood glucose levels in mice that had prefasted for 0, 6, or 12 h, but not 18 h or more. Blood glucose level was well correlated with ipragliflozin-induced antihyperglycemic and urinary glucose excretion effects, suggesting that these effects occur in a blood glucose-dependent manner. Thus, in a hyperglycemic state, ipragliflozin exerts a potent antihyperglycemic effect and marked increases in urinary glucose excretion; however, in a non-hyperglycemic or hypoglycemic state, the hypoglycemic effect is weak. Ipragliflozin may therefore be a useful antidiabetic agent for normalizing daily blood glucose fluctuations in type 2 diabetes.

Effects of neurokinin 3 receptor antagonist fezolinetant on hot flash-like symptoms in ovariectomized rats.

The majority of women experience vasomotor symptoms (VMS), such as hot flashes and night sweats, during the menopausal transition. Recent evidence strongly suggests a connection between neurokinin 3 (NK3) receptor signaling and VMS associated with menopause. The NK3 receptor antagonist fezolinetant is currently in phase 3 development for treatment of moderate to severe VMS associated with menopause. We investigated the pharmacological effects of repeated administration of fezolinetant on levels of sex hormones and gonadotropins, neuronal activity in the hypothalamus, and skin temperature as an index of hot flash-like symptoms in ovariectomized rats as a model of menopause. Ovariectomized rats exhibited several typical menopausal symptoms: hyperphagia, increased body weight, significantly decreased plasma estradiol levels, increased luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, and significantly increased skin temperature. Increased c-Fos expression (an indirect marker of neuronal activity) in median preoptic nucleus (MnPO) hypothalamic neurons was also observed in ovariectomized rats. Repeated oral administration of fezolinetant (1-10 mg/kg, twice daily) for 1 week dose-dependently reduced plasma LH levels without affecting estradiol or FSH levels, inhibited the activation of MnPO neurons, and attenuated hot flash-like symptoms. In addition, fezolinetant dose-dependently reduced hyperphagia and weight gain in ovariectomized rats. These preclinical findings suggest that fezolinetant attenuates hot flash-like symptoms via inhibition of neuronal activity in the MnPO of ovariectomized rats and provides further support for the ongoing clinical development of fezolinetant for the treatment of VMS associated with menopause.

Effects of SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone on fluid retention in type 2 diabetic mice with NASH.

Several antidiabetic agents, including thiazolidinediones and sodium-glucose cotransporter (SGLT) 2 inhibitors, attenuate the symptoms of nonalcoholic steatohepatitis (NASH). However, thiazolidinediones have serious side effects such as fluid retention and increased risk of congestive heart failure. We examined the effects of SGLT2 inhibitor ipragliflozin, pioglitazone, and ipragliflozin + pioglitazone on fluid retention in type 2 diabetic mice with NASH. Four-week repeated administration of pioglitazone caused significant increases in heart weight (31% increase in 30 mg/kg pioglitazone-treated group compared to vehicle-treated group) concomitant with fluid retention, as estimated by a decrease in plasma osmolality and increase in water intake/urine volume ratio. In addition, pioglitazone significantly increased (by 1.5 to 2-fold) mRNA expression of α, ß, and γ subtypes of ENaC and AQP2 and 3 subtypes in the renal medulla. Thus, pioglitazone-induced fluid retention may arise from enhanced reabsorption of sodium and water associated with increased expression of these channels in the kidney. In contrast, ipragliflozin alone did not induce these symptoms and did not affect ENaC or AQP expression. Combination treatment with ipragliflozin + pioglitazone attenuated these symptoms by ipragliflozin-induced osmotic diuresis. These findings demonstrate that treatment with ipragliflozin monotherapy or coadministered with pioglitazone may be a potential therapeutic option for the treatment of type 2 diabetes with NASH without fluid retention as a side effect.

Therapeutic effects of interleukin-1 receptor-associated kinase 4 inhibitor AS2444697 on diabetic nephropathy in type 2 diabetic mice.

Renal inflammation is a final common pathway of chronic kidney disease including diabetic nephropathy, which is the leading cause of end-stage renal disease and is associated with high cardiovascular risk and significant morbidity and mortality. Interleukin-1 (IL-1) receptor-associated kinase 4 (IRAK-4) is a pivotal molecule for IL-1 receptor- and Toll-like receptor-induced activation of proinflammatory mediators. In this study, we investigated the renoprotective properties of IRAK-4 inhibitor AS2444697 in KK/Ay type 2 diabetic mice. Four-week repeated administration of AS2444697 dose-dependently and significantly improved albuminuria; hyperfiltration, as measured by creatinine clearance; renal injury, including glomerulosclerosis; tubular injury markers, including urinary N-acetyl-ß-D-glucosaminidase activity; and glomerular podocyte injury markers, including urinary nephrin excretion. In addition, AS2444697 attenuated plasma levels of proinflammatory cytokines, including IL-6; plasma levels of endothelial dysfunction markers, including intercellular adhesion molecule-1; and plasma levels and renal contents of oxidative stress markers. In contrast, AS2444697 did not significantly affect food intake or blood glucose levels. These results suggest that AS2444697 attenuates the progression of diabetic nephropathy mainly via anti-inflammatory mechanisms through inhibition of IRAK-4 activity under diabetic conditions and may represent a promising therapeutic option for the treatment of type 2 diabetic nephropathy.

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.

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.

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.

Effects of the SGLT2 inhibitor ipragliflozin on food intake, appetite-regulating hormones, and arteriovenous differences in postprandial glucose levels in type 2 diabetic rats.

AIMS: The sodium-glucose cotransporter (SGLT) 2 inhibitor, ipragliflozin, improves not only hyperglycemia but also obesity in type 2 diabetic animals and patients; however, there have been concerns that it may also cause an increase in compensatory food intake. Appetite is regulated by complex mechanisms involving the central nervous system, part of which involves appetite-related hormones and arteriovenous differences in postprandial glucose levels. We evaluated the effect of ipragliflozin in type 2 diabetic rats on food intake, appetite-related hormones and arteriovenous differences in postprandial glucose levels, and their correlation with food intake. MAIN METHODS: Ipragliflozin and several antidiabetic drugs were administered to type 2 diabetic rats and various parameters concerning food intake were measured. KEY FINDINGS: Ipragliflozin significantly increased urinary glucose excretion and reduced postprandial hyperglycemia. Compared to normal rats, diabetic rats exhibited hyperphagia and elevated plasma levels of the appetite-stimulating hormones neuropeptide Y and ghrelin. Ipragliflozin induced significant weight loss and reduced plasma levels of appetite-stimulating hormones without affecting food intake. Diabetic rats exhibited a significantly reduced arteriovenous difference in postprandial glucose levels due to insulin insufficiency; this was improved by ipragliflozin, which increased renal arteriovenous differences in glucose levels by increasing urinary glucose excretion. SIGNIFICANCE: These results indicate that the SGLT2 inhibitor, ipragliflozin, exerts antihyperglycemic actions by increasing urinary glucose excretion, and induces weight loss without a compensatory increase in food intake in type 2 diabetic mice. The mechanisms underlying these effects can be attributed, in part, to an increased arteriovenous difference in postprandial glucose levels and improved regulation of appetite-related hormones in the diabetic animal model. While this study was conducted in rodents and the results may be distinct from those in humans, it is possible that some of the pharmacological mechanisms, including the regulation of appetite-related hormones, can be extrapolated to clinical settings and may be valuable for further studies including clinical investigations.

Prevention of progression of diabetic nephropathy by the SGLT2 inhibitor ipragliflozin in uninephrectomized type 2 diabetic mice.

Diabetic nephropathy is the leading cause of end-stage renal disease in the world. Although recent development of sodium-glucose cotransporter (SGLT) 2 inhibitors offers a new antidiabetic therapeutic strategy, it remains unclear whether such treatments are beneficial for limiting the progression of type 2 diabetic overt nephropathy. This study examined the effect of the SGLT2 inhibitor ipragliflozin on the progression of nephropathy in uninephrectomized KK/Ay type 2 diabetic mice, which exhibit not only typical diabetic symptoms such as hyperglycemia, hyperinsuemia, glucose intolerance, insulin resistance, hyperlipidemia, inflammation, and obesity, but also moderate hypertension and overt nephropathy with decline in renal function. Four-week repeated administration of ipragliflozin improved various diabetic symptoms, including hyperglycemia, insulin resistance, and inflammation by increasing urinary glucose excretion. In addition, ipragliflozin ameliorated albuminuria/proteinuria; decline in renal function, as measured by creatinine clearance; hypertension; and renal injury, including glomerulosclerosis and interstitial fibrosis. These effects were significant at doses of 1 mg/kg or higher and were similar to those observed following administration of losartan (30 mg/kg). These results suggest that the SGLT2 inhibitor ipragliflozin prevents progression to diabetic overt nephropathy in uninephrectomized type 2 diabetic mice. SGLT2 inhibitors may therefore represent a promising therapeutic option for the management of type 2 diabetes to slow the progression of diabetic nephropathy.

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.

Antidiabetic and antiobesity effects of SGLT2 inhibitor ipragliflozin in type 2 diabetic mice fed sugar solution.

Obesity due to excessive calorie intake is a known aggravating factor contributing to the development and progression of type 2 diabetes. Recently, excessive intake of sugar-sweetened beverages has presented challenges in stemming the tide of obesity. Here, we investigated the possible effects of sugar solution intake on the antidiabetic effects of sodium-glucose cotransporter 2 (SGLT2) inhibitor ipragliflozin in type 2 diabetic mice that were fed ordinary drinking water, water + glucose solution, or water + sucrose solution. Under all feeding conditions, all mice exhibited type 2 diabetic symptoms, including hyperglycemia, hyperinsulinemia, and obesity; ipragliflozin subsequently improved these symptoms through increases in urinary glucose excretion. Effective dose of and response to ipragliflozin for diabetes improvement did not significantly differ by feeding condition. Further, under all feeding conditions, ipragliflozin administration resulted in significantly increased intake of both water and sugar solutions in association with increased urine volume resulting from increased urinary glucose excretion. In sugar solution-fed diabetic mice, ipragliflozin administration tended to slightly increase the proportion of sugar solution intake in total drinking volume, although not significantly so. In addition, ipragliflozin significantly decreased calorie balance, as calculated using calorie intake from food and sugar solution and calorie excretion via urinary glucose excretion. Our observation that the antidiabetic and antiobesity effects of the SGLT2 inhibitor ipragliflozin were not greatly affected by sugar solution intake in type 2 diabetic mice suggests that, in a clinical setting, ipragliflozin will remain an effective treatment for type 2 diabetic patients with excessive intake of carbohydrates.

Characterization and comparison of SGLT2 inhibitors: Part 3. Effects on diabetic complications in type 2 diabetic mice.

In this study, we investigated and compared the effects of all six sodium-glucose cotransporter (SGLT) 2 inhibitors commercially available in Japan on diabetes-related diseases and complications in type 2 diabetic mice. Following 4-week repeated administration to diabetic mice, all SGLT2 inhibitors showed significant improvement in diabetes-related diseases and complications, including obesity; abnormal lipid metabolism; steatohepatitis; inflammation; endothelial dysfunction; and nephropathy. While all SGLT2 inhibitors exerted comparable effects in reducing hyperglycemia, improvement of these diabetes-related diseases and complications was more potent with the two long-acting drugs (ipragliflozin and dapagliflozin) than with the four intermediate-acting four drugs (tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin), albeit without statistical significance. These findings demonstrate that SGLT2 inhibitors alleviate various diabetic pathological conditions in type 2 diabetic mice, and suggest that SGLT2 inhibitors, particularly long-acting drugs, might be useful not only for hyperglycemia but also in diabetes-related diseases and complications, including nephropathy in type 2 diabetes.

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.

Effects of the combination of SGLT2 selective inhibitor ipragliflozin and various antidiabetic drugs in type 2 diabetic mice.

The sodium-glucose cotransporter 2 (SGLT2) is responsible for most glucose reabsorption in the kidney and has been proposed as a novel therapeutic target for the treatment of type 2 diabetes. In the present study, the combinatory effects of SGLT2 selective inhibitor ipragliflozin and various antidiabetic drugs in high-fat diet and streptozotocin-nicotinamide-induced type 2 diabetic mice were investigated. Ipragliflozin dose-dependently increased urinary glucose excretion and improved glucose tolerance. In addition, each antidiabetic drug (mitiglinide, glibenclamide, sitagliptin, insulin, metformin, voglibose, or rosiglitazone) also significantly improved glucose tolerance without affecting urinary glucose excretion. Combination treatment of ipragliflozin with each antidiabetic drug additively improved glucose tolerance. In these experiments, ipragliflozin-induced increases in urinary glucose excretion were not influenced by combination treatment with antidiabetic drugs. Further, ipragliflozin did not affect antidiabetic drug-induced insulinotropic action (mitiglinide and glibenclamide), increases in plasma glucagon-like peptide-1 and insulin levels via inhibition of dipeptidyl peptidase 4 activity (sitagliptin), increases in plasma insulin level (insulin), decreases in hepatic phosphoenolpyruvate carboxykinase activity (metformin), inhibition of small intestinal disaccharidase activity (voglibose), or improvement of impaired insulin secretion (rosiglitazone). These results suggest that combination treatment of ipragliflozin with various antidiabetic drugs additively enhances the improvement in glucose tolerance without affecting each drug's unique pharmacological effects. Ipragliflozin may therefore be expected to be effective when administered as part of a combination regimen in the treatment of 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.

Renoprotective effects of novel interleukin-1 receptor-associated kinase 4 inhibitor AS2444697 through anti-inflammatory action in 5/6 nephrectomized rats.

Renal inflammation is a final common pathway of chronic kidney disease (CKD), and its progression can be used to effectively gauge the degree of renal dysfunction. Interleukin-1 (IL-1) receptor-associated kinase 4 (IRAK-4) has been reported to be a pivotal molecule for IL-1 receptor- and Toll-like receptor-induced signaling and activation of proinflammatory mediators. In this study, we hypothesized that if inflammation plays a key role in renal failure, then the anti-inflammatory effect of IRAK-4 inhibitor should be effective in improving CKD. To determine its pharmacological potency, we investigated the renoprotective properties of the novel IRAK-4 inhibitor AS2444697 (N-[3-carbamoyl-1-(tetrahydro-2H-pyran-4-yl)-1H-pyrazol-4-yl]-2-(2-methylpyridin-4-yl)-1,3-oxazole-4-carboxamide hydrochloride (1:1)) in 5/6 nephrectomized (Nx) rats, a model of CKD. Six weeks' repeated administration of AS2444697 (0.3-3 mg/kg, twice daily) dose-dependently and significantly reduced urinary protein excretion and prevented the development of glomerulosclerosis and interstitial fibrosis without affecting the blood pressure. In addition, AS2444697 showed beneficial effects on renal function as demonstrated by the decrease in levels of plasma creatinine and blood urea nitrogen and attenuation of decline in creatinine clearance. 5/6 Nx rats exhibited low-grade inflammation as evidenced by increased renal mRNA expression and plasma levels of proinflammatory cytokines (IL-1ß, IL-6, TNF-α, and MCP-1) and C-reactive protein as a marker of systemic inflammation. AS2444697 significantly reduced or showed a decreasing trend in expression and levels of these inflammatory parameters. These results suggest that AS2444697 suppresses the progression of chronic renal failure via anti-inflammatory action and may therefore be potentially useful in treating CKD patients.

Effects of sodium-glucose cotransporter 2 selective inhibitor ipragliflozin on hyperglycaemia, oxidative stress, inflammation and liver injury in streptozotocin-induced type 1 diabetic rats.

OBJECTIVE: Sodium-glucose cotransporter (SGLT) 2 plays an important role in renal glucose reabsorption and has been highlighted as a therapeutic target for the treatment of diabetes. Here, we investigated the therapeutic effects of SGLT2 selective inhibitor ipragliflozin in type 1 diabetic rats. METHODS: Type 1 diabetic rats were prepared by intravenous administration of streptozotocin (STZ). Ipragliflozin was acutely or chronically administered, and therapeutic effects were investigated. KEY FINDINGS: Single administration of ipragliflozin significantly increased urinary glucose excretion, and its effect lasted over 12 h. In addition, ipragliflozin improved glucose tolerance and sustainably reduced hyperglycaemia. Repeated administration of ipragliflozin to diabetic rats for 4 weeks significantly improved not only hyperglycaemia, but also hyperlipidaemia and hepatic steatosis with concomitant increases in urinary glucose excretion. In addition, ipragliflozin ameliorates renal glomerular hyperfiltration and albuminuria. Further, ipragliflozin reduced liver levels of oxidative stress biomarkers and plasma levels of inflammatory markers, and improved liver injury as assessed by plasma levels of aminotransferases. CONCLUSION: These results suggest that SGLT2 selective inhibitor ipragliflozin exerts a beneficial effect on glycaemic control and ameliorates diabetes-associated metabolic abnormalities and complications in STZ-induced diabetic rats, and would be a potential agent for the treatment of type 1 diabetes.

SGLT2 selective inhibitor ipragliflozin reduces body fat mass by increasing fatty acid oxidation in high-fat diet-induced obese rats.

Ipragliflozin is a novel and selective sodium-glucose cotransporter 2 (SGLT2) inhibitor that induces sustained increases in urinary glucose excretion by inhibiting renal glucose reabsorption and thereby exerting a subsequent antihyperglycemic effect. Here, we examined the effect of ipragliflozin on body weight in high-fat diet-induced (HFD) obese rats. Treatment of ipragliflozin (10mg/kg once daily) reduced body weight despite a slight increase in food intake. Dual-energy X-ray absorptiometry and computed tomography demonstrated that the reduction in body weight was accompanied by reduced visceral and subcutaneous fat masses but not lean mass or bone mineral content. Analysis of plasma and urinary parameters suggested the possibility that ipragliflozin enhanced lipolysis and fatty acid oxidation, and indirect calorimetry showed that ipragliflozin decreased the heat production rate from glucose but increased the rate from fat and lowered the respiratory exchange ratio. In conclusion, these data demonstrate that ipragliflozin-induced urinary glucose excretion specifically reduces fat mass with steady calorie loss by promoting the use of fatty acids instead of glucose as an energy source in HFD rats. By improving hyperglycemia and promoting weight reduction, ipragliflozin may prove useful in treating type 2 diabetes in obese individuals.