Combined antidiabetic benefits of exenatide and dapagliflozin in diabetic mice

Dapagliflozin mitigates oxidative stress, inflammatory, and histopathological markers of aging in mice

Aging, a complex physiological process affecting all living things, is a major area of research, particularly focused on interventions to slow its progression. This study assessed the antiaging efficacy of dapagliflozin (DAPA) on various aging-related parameters in a mouse model artificially induced to age. Forty male Swiss albino mice were randomly divided into four groups of ten animals each. The control group (Group I) received normal saline. The aging model group (Group II) was administered D-galactose orally at 500mg/kg to induce aging. Following the aging induction, the positive control group received Vitamin C supplementation (Group III), while the DAPA group (Group IV) was treated with dapagliflozin. The inflammatory mediators (TNF-α and IL-1β) showed similar patterns of change. No statistically significant difference was observed between groups III and IV. Both groups had significantly lower values compared to GII, while it was significantly higher compared to GI. Glutathione peroxidase (GSH-Px) showed no statistically significant difference between groups GIII and GIV, but it was higher in GIII compared to GII and significantly lower in GIII compared to GI. The study demonstrated that dapagliflozin exerts a beneficial impact on many indicators of aging in mice. The intervention resulted in a reduction in hypertrophy in cardiomyocytes, an enhancement in skin vitality, a decrease in the presence of inflammatory mediators, and an improvement in the efficacy of antioxidants.

Blockade of sodium-glucose co-transporters improves peritoneal ultrafiltration in uraemic rodent models

BACKGROUND

The most used PD fluids contain glucose as a primary osmotic agent. Glucose peritoneal absorption during dwell decreases the osmotic gradient of peritoneal fluids and causes undesirable metabolic consequences. Inhibitors of sodium-glucose co-transporter (SGLT) type 2 are wildly used for the treatment of diabetes, heart and kidney failure. Previous attempts to use SGLT2 blockers in experimental peritoneal dialysis yielded contrasting results. We studied whether peritoneal SGLTs blockade may improve ultrafiltration (UF) via partial inhibition of glucose uptake from dialysis fluids.

METHODS

Kidney failure was induced in mice and rats by bilateral ureteral ligation, and dwell was performed by injection of glucose-containing dialysis fluids. The effect of SGLT inhibitors on glucose absorption during fluid dwell and UF was measured in vivo.

RESULTS

Diffusion of glucose from dialysis fluid into the blood appeared to be sodium-dependent, and blockade of SGLTs by phlorizin and sotagliflozin attenuated blood glucose increment thereby decreasing fluid absorption. Specific SGLT2 inhibitors failed to reduce glucose and fluid absorption from the peritoneal cavity in a rodent kidney failure model.

CONCLUSIONS

Our study suggests that peritoneal non-type 2 SGLTs facilitate glucose diffusion from dialysis solutions, and we propose that limiting glucose reabsorption by specific SGLT inhibitors may emerge as a novel strategy in PD treatment to enhance UF and mitigate the deleterious effects of hyperglycaemia.

Sodium-glucose co-transporter 2 inhibitors and Sarcopenia: A controversy that must be solved

Diabetes mellitus is a risk factor for muscle loss and sarcopenia. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) or "gliflozins" are one of the newest anti-hyperglycemic drugs. They reduce blood glucose levels by inhibiting renal glucose reabsorption in the early proximal convoluted tubule. Various randomized trials showed that SGLT2i have cardio-protective and reno-protective action. SGLT2i also affect body composition. They usually decrease body fat percentage, visceral and subcutaneous adipose tissue. However, regarding the muscle mass, there are conflicting findings some studies showing detrimental effects and others showed neutral or beneficial effects. This issue is extremely important not only because of the wide use of SGLT2i around globe; but also skeletal muscle mass consumes large amounts of calories during exercise and is an important determinant of resting metabolic rate and skeletal muscle loss hinders energy consumption leading to obesity. In this systematic review, we extensively reviewed the experimental and clinical studies regarding the impact of SGLT2i on muscle mass and related metabolic alterations. Importantly, studies are heterogeneous and there is unmet need to highlight the alterations in muscle during SGLT2i use.

Empagliflozin ameliorates symptoms of diabetes and renal tubular dysfunction in a rat model of diabetes with enlarged kidney (DEK)

Background

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are widely used to reduce hyperglycemia. The present study investigated the effects of a SGLT2 inhibitor, empagliflozin, on hyperglycemia in a novel rat model of non-obesity type 2 diabetes with enlarged kidney (DEK).

Methods

Male DEK rats with non-fasting blood glucose concentrations ≤300 mg/dl and >300 mg/dl were classified as nondiabetic and diabetic, respectively. Groups of nondiabetic (control) and diabetic (DM-cont) rats were fed standard chow for 12 weeks, whereas another group of diabetic (DM-empa) rats was fed standard chow containing empagliflozin (300 mg/kg/day) for 12 weeks. Blood glucose, body weight, glucose tolerance, food and water intake, urinary volume, plasma and urinary biochemical parameters, and bone mineral density were measured, and their kidneys and pancreas histologically analyzed.

Results

Treatment with empagliflozin reduced blood glucose concentration and food intake in diabetic rats, but inhibited loss of adeps renis and led to body weight gain. Empagliflozin attenuated polyuria and polydipsia but increased plasma concentrations of total cholesterol, sodium and total protein toward normal level. Empagliflozin also significantly reduced urinary excretion of proteins and electrolytes and restored bone mineral density and plasma concentrations of valine and isoleucine to normal levels. Moreover, dilation of renal tubules and kidney enlargement were not attenuated in the DM-empa group.

Conclusion

The response of DEK rats to empagliflozin differed from that of other diabetic animal models, suggesting that DEK rats have unique characters for studying and evaluating the multiple biological effects of SGLT2 inhibitors. These findings also indicted that empagliflozin could ameliorate systemic metabolism and improve renal tubule function in diabetic condition.

Synthesis and Evaluation of Dapagliflozin Ester Prodrugs with Improved Hygroscopicity and Thermal Stability

Background:

Dapagliflozin, developed as an SGLT-2 inhibitor, has a low melting point and high hygroscopicity, which needs extreme care during pharmaceutical production to keep the active pharmacological property. Various attempts have been made to overcome these problematic properties.

Objectives:

To develop dapagliflozin prodrugs that have similar pharmacological effects with improved hygroscopicity and thermal stability.

Methods:

The novel dapagliflozin ester prodrugs containing pharmaceutically acceptable moieties were synthesized and their pharmacokinetics (PK) and physical properties were compared with dapagliflozin propanediol hydrate (DPD, Farxiga®). The PK in dog and rat, in vitro stability, hygroscopicity, and physical property studies in accelerated conditions (40°C, 75% RH) were performed with prodrugs.

Results and Discussion:

Among the eight synthesized prodrugs, Cmax and AUC0-48h values of prodrug 8b (1.35 μg/ml and 14.78 μg·h/ml, respectively) were similar to those of DPD (1.67 μg/ml and 14.27 μg·h/ml, respectively). However, the rest of the prodrugs 8a, 8c, 8d, 8e, 8f, 8g and 8h showed significantly lower Cmax and AUC0-48h values than DPD. Prodrug 8b completely converted into parent drug in the body.

Conclusion:

The novel prodrug 8b exhibited comparative PK profile to that of DPD, but with low hygroscopic property and better thermal stability than DPD.

Combined effect of canagliflozin and exercise training on high-fat diet-fed mice

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been reported to improve obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in addition to exercise training, whereas the combined effects remain to be elucidated fully. We investigated the effect of the combination of the SGLT2i canagliflozin (CAN) and exercise training in high-fat diet-induced obese mice. High-fat diet-fed mice were housed in normal cages (sedentary; Sed) or wheel cages (WCR) with or without CAN (0.03% of diet) for 4 wk. The effects on obesity, glucose metabolism, and hepatic steatosis were evaluated in four groups (Control/Sed, Control/WCR, CAN/Sed, and CAN/WCR). Numerically additive improvements were found in body weight, body fat mass, blood glucose, glucose intolerance, insulin resistance, and the fatty liver of the CAN/WCR group, whereas CAN increased food intake and reduced running distance. Exercise training alone, CAN alone, or both did not change the weight of skeletal muscle, but microarray analysis showed that each resulted in a characteristic change of gene expression in gastrocnemius muscle. In particular, in the CAN/WCR group, there was acceleration of the angiogenesis pathway and suppression of the adipogenesis pathway compared with the CAN/Sed group. In conclusion, the combination of an SGLT2i and exercise training improves obesity, insulin resistance, and NAFLD in an additive manner. Changes of gene expression in skeletal muscle may contribute, at least in part, to the improvement of obesity and insulin sensitivity.

Lansoprazole enhances the antidiabetic effect of dapagliflozin in fortified diet-fed streptozotocin-treated diabetic rats

Dapagliflozin (DAPA) is used for treating type 2 diabetes, whereas lansoprazole (LPZ) is used as a traditional antiulcer drug. The present study investigated the possible antidiabetic effects of LPZ on fortified diet-fed streptozotocin (FDF/STZ)-induced insulin-resistant diabetic rats. On the basis of the current results, it can be concluded that LPZ could be used as an add-on drug along with the conventional treatment for T2D as it showed beneficial effects in the current experimental model of insulin resistance.

Effects of sodium-glucose cotransporter 2 inhibitor (dapagliflozin) on food intake and plasma fibroblast growth factor 21 levels in type 2 diabetes patients

The objective of this study was to investigate whether sodium-glucose cotransporter 2 inhibitors (SGLT2i) treatment in patients with type 2 diabetes induced compensatory hyperphagia by reducing fibroblast growth factor 21 (FGF21) secretion. This prospective study was performed in 26 type 2 diabetes patients treated with dapagliflozin (5 mg/day). Hormonal factors associated with glucose metabolism, dietary intakes estimated by brief self-administered diet-history questionnaire (BDHQ), body weight (BW), and body composition were measured at baseline, and 4 and 12 weeks after dapagliflozin. At 12 weeks, HbA1c levels and BW decreased significantly (both p < 0.0001). BMI at baseline was predictive to baseline log₁₀ (FGF21) (p = 0.037). This study showed no change in FGF21, but insulin and glucagon levels decreased significantly (both p < 0.05). Although hyperphagia was found in 10 patients (38.5%), defining hyperphagia as >20% increase in carbohydrate intake, dapagliflozin treatment induced no hyperphagia, when analyzed by all subjects, and there was no significant association between changes in FGF21 levels and carbohydrate intake. On the other hand, a positive correlation between changes in FGF21 levels or carbohydrate intake and BW was observed (both p < 0.005). Taken together, this study demonstrates that the intervention to maintain the reduced levels in FGF21 is beneficial for BW reduction in type 2 diabetes patients treated with SGLT2i.

Assessment of Dapagliflozin Effectiveness as Add-on Therapy for the Treatment of Type 2 Diabetes Mellitus in a Qatari Population

The effectiveness of dapagliflozin in the management of type-2 diabetes mellitus (T2-DM) is an essential issue for establishing a basis for prescribing dapagliflozin. This study aimed to assess the effectiveness of dapagliflozin in combination with other hypoglycemic agents (OHAs) in reducing glycated hemoglobin (HbA1c) and fasting blood glucose (FBG) at 3, 6, 9 and 12 months. This retrospective observational study included all patients who visited the endocrine clinics at Hamad Medical Corporation (HMC) and were treated with dapagliflozin. Demographics and laboratory data were obtained retrospectively from computerized patient medical profiles (eMR-viewer). The main outcome measures were the differences in HbA1c and FBG from baseline at different months. Eighty-one Qatari patients were found to have received dapagliflozin during the study period; 72% of them (n = 58) were males, with a mean age of 57.0 ± 9.0 years and a mean baseline HbA1c of 9.0 ± 1.4%. Administration of dapagliflozin as an add-on therapy was found to decrease HbA1c significantly by 0.8 percentage point after 6 months (P = 0.006) and by 1.5 percentage point after 12 months (P = 0.062). FBG was significantly reduced at 6 months and 9 months (P = 0.001 and P = 0.03, respectively). Dapagliflozin effectively reduced the HbA1c level and FBG when used in combination with other OHAs or insulin within 6 to 12 months.

Molecular Mechanisms Underlying the Cardiovascular Benefits of SGLT2i and GLP-1RA

PURPOSE OF REVIEW

In addition to their effects on glycemic control, two specific classes of relatively new anti-diabetic drugs, namely the sodium glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have demonstrated reduced rates of major adverse cardiovascular events (MACE) in subjects with type 2 diabetes (T2D) at high risk for cardiovascular disease (CVD). This review summarizes recent experimental results that inform putative molecular mechanisms underlying these benefits.

RECENT FINDINGS

SGLT2i and GLP-1RA exert cardiovascular effects by targeting in both common and distinctive ways (A) several mediators of macro- and microvascular pathophysiology: namely (A1) inflammation and atherogenesis, (A2) oxidative stress-induced endothelial dysfunction, (A3) vascular smooth muscle cell reactive oxygen species (ROS) production and proliferation, and (A4) thrombosis. These agents also exhibit (B) hemodynamic effects through modulation of (B1) natriuresis/diuresis and (B2) the renin-angiotensin-aldosterone system. This review highlights that while GLP-1RA exert direct effects on vascular (endothelial and smooth muscle) cells, the effects of SGLT2i appear to include the activation of signaling pathways that prevent adverse vascular remodeling. Both SGLT2i and GLP-1RA confer hemodynamic effects that counter adverse cardiac remodeling.

Increased sugar intake as a form of compensatory hyperphagia in patients with type 2 diabetes under dapagliflozin treatment

AIMS

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) cause substantially less weight loss than would be expected based on their caloric deficits, probably due to enhanced appetite regulation known as "compensatory hyperphagia," which occurs to offset the negative energy balance caused by increased glycosuria. We examined whether any specific nutrients contributed to the compensatory hyperphagia in diabetic patients taking SGLT2i.

METHODS

Sixteen patients with type 2 diabetes were newly administered dapagliflozin 5 mg daily as the experimental SGLT2i group. Sixteen age-, sex- and BMI-matched type 2 diabetes patients not receiving dapagliflozin served as controls. A brief-type self-administered diet history questionnaire (BDHQ) was undertaken just before and 3 months after study initiation to evaluate changes of energy and nutrient intakes in each group.

RESULTS

At 3 months, daily intakes of total calories and the proportions of the three major nutrients were not significantly increased in either group. However, daily sucrose intake was significantly increased after treatment versus the baseline value in the SGLT2i group (p = .003), but not in controls. The calculated intakes of all other nutrients were not significantly changed in either group.

CONCLUSIONS

Dapagliflozin treatment specifically increased sucrose intake, which might be an ideal target for nutritional approaches to attenuate compensatory hyperphagia.

Real-world effectiveness and safety of dapagliflozin therapy added to a GLP1 receptor agonist in patients with type 2 diabetes

BACKGROUND AND AIM

To evaluate the effectiveness and safety of a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, dapagliflozin, in patients with type 2 diabetes mellitus (T2DM) and background glucagon-like peptide-1 receptor agonist (GLP1-RA) therapy.

METHODS AND RESULTS

This is a 12-month, real-world observational study, which assessed the effectiveness and safety of dapagliflozin in patients with T2DM and background GLP1-RA therapy. The main outcome measures were changes in A1C and weight at 6 and 12 months from baseline. Secondary outcomes were differences in A1C and weight reduction between this cohort and another group of patients with T2DM treated with dapagliflozin but without background GLP1-RA therapy. In total, 109 patients with GLP1-RA and 104 patients without GLP1-RA were included. Baseline mean A1C and weight in the GLP1-RA and non-GLP1-RA groups were 7.4% vs. 7.3% and 96.2 kg vs. 95.1 kg, respectively. A significant reduction in A1C was seen with dapagliflozin in both cohorts at 6 and 12 months (GLP1-RA: -0.51% and -0.34%, non-GLP1-RA: -0.69% and -0.62%, respectively, p < 0.0001 in all analyses). Weight was significantly reduced in both groups at 6 and 12 months (GLP1-RA: -2.3 kg and -2.4 kg, non-GLP1-RA: -3.9 kg and -4.8 kg, respectively, p < 0.0001 in all analyses). A1C reduction and weight loss were significantly lower in patients with GLP1-RA than in patients without GLP1-RAs. Drug discontinuation rates were similar in both cohorts.

CONCLUSIONS

Dapagliflozin, when added in real life to patients with T2DM treated with GLP1-RAs, induced a further significant, albeit modest improvement in A1C and a further weight loss.

Combination therapy of SGLT2 inhibitors with incretin-based therapies for the treatment of type 2 diabetes mellitus: Effects and mechanisms of action

Type 2 diabetes mellitus (T2DM) is a growing health problem worldwide; its pathogenesis is multifactorial and its progressive nature often necessitates a combination therapy with multiple antihyperglycemic agents. Sodium glucose cotransporter 2 (SGLT2) inhibitors and the incretin-based therapies - dipeptidyl peptidase 4(DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) receptor agonists - were introduced for the treatment of T2DM within the last decade. Evidence of the beneficial effects of these antihyperglycemic agents on micro- and macrovascular complications have started to emerge, which will become important in individualizing different combinations of antihyperglycemic agents to different patient populations. We review here the mechanisms of action, glycemic and cardiovascular effects of SGLT2 inhibitors and incretin-based therapies and their combination in the treatment of T2DM.

SGLT inhibitors attenuate NO-dependent vascular relaxation in the pulmonary artery but not in the coronary artery

Inhibitors of sodium-glucose cotransporter (SGLT)2 are a new class of oral drugs for type 2 diabetic patients that reduce plasma glucose levels by inhibiting renal glucose reabsorption. There is increasing evidence showing the beneficial effect of SGLT2 inhibitors on glucose control; however, less information is available regarding the impact of SGLT2 inhibitors on cardiovascular outcomes. The present study was designed to determine whether SGLT inhibitors regulate vascular relaxation in mouse pulmonary and coronary arteries. Phlorizin (a nonspecific SGLT inhibitor) and canagliflozin (a SGLT2-specific inhibitor) relaxed pulmonary arteries in a dose-dependent manner, but they had little or no effect on coronary arteries. Pretreatment with phlorizin or canagliflozin significantly inhibited sodium nitroprusside (SNP; a nitric oxide donor)-induced vascular relaxation in pulmonary arteries but not in coronary arteries. Phlorizin had no effect on cGMP-dependent relaxation in pulmonary arteries. SNP induced membrane hyperpolarization in human pulmonary artery smooth muscle cells, and pretreatment of cells with phlorizin and canagliflozin attenuated SNP-induced membrane hyperpolarization by decreasing K(+) activities induced by SNP. Contrary to the result observed in ex vivo experiments with SGLT inhibitors, SNP-dependent relaxation in pulmonary arteries was not altered by chronic administration of canagliflozin. On the other hand, canagliflozin administration significantly enhanced SNP-dependent relaxation in coronary arteries in diabetic mice. These data suggest that SGLT inhibitors differentially regulate vascular relaxation depending on the type of arteries, duration of the treatment, and health condition, such as diabetes.

Dapagliflozin for the treatment of type 2 diabetes: a review of the literature

OBJECTIVE

Dapagliflozin was the first drug in a class of therapies that took a new approach to glycemic control in adults with type 2 diabetes (T2D). It is an inhibitor of the sodium glucose cotransporter, resident in the proximal nephron, which is responsible for the recovery of filtered glucose back into circulation. Inhibiting this cotransporter reduces glucose recovery, increases glucose excretion, and reduces hyperglycemia. Here, we review some of the literature relating to the action, efficacy, and clinical use of dapagliflozin.

MATERIALS AND METHODS

A Medline search was conducted within date, animal, and language limits, and relevant papers were selected for review. Conference proceedings were reviewed to obtain up-to-date literature on this drug. Clinical trial websites were reviewed for ongoing studies.

RESULTS

On average, treatment with dapagliflozin results in improvement in glycated hemoglobin by 0.50%, fasting plasma glucose by 1 mmol/L, weight by 2 kg, body mass index by 1.1%, and systolic/diastolic blood pressure by 4/2 mmHg over 24-52 weeks. The weight benefit is greater when used in association with sulfonylureas. It is generally well tolerated, but comes with an increased risk of genitourinary and urinary tract infections. In addition, it is associated with reversible changes to renal function that need to be explored. Early reports of an association with cancer also need to be carefully monitored.

CONCLUSION

Dapagliflozin is a useful therapy for adult patients with T2D. It also holds potential for a broader range of patients with T2D (such as the elderly and pediatric populations), as well as those with other forms of diabetes, such as type 1 diabetes. While longer-term outcome studies of safety and efficacy are awaited, dapagliflozin forms a very useful and welcome addition to our armamentarium for managing patients with T2D.

Divergent effects of liraglutide, exendin-4, and sitagliptin on beta-cell mass and indicators of pancreatitis in a mouse model of hyperglycaemia

AIMS

Glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP4) inhibitors improve glucose tolerance by still incompletely understood mechanisms. Each class of antihyperglycemic drugs has also been proposed to increase pancreatitis risk. Here, we compare systematically the effects of two widely-used GLP-1 analogues, liraglutide and exendin-4, and the DPP4 inhibitor, sitagliptin, in the mouse.

METHODS

C57BL6 mice were maintained for 131 days on a normal diet (ND) or a diet comprising 60% fat (HFD) before measurements of fasting blood glucose and insulin, and intraperitoneal glucose tolerance. Beta- and alpha- cell volume, and Reg3b immunoreactivity, were measured by immunohistochemical analysis of pancreatic slices.

RESULTS

Whereas liraglutide (200 µg/kg) and exendin-4 (10 µg/kg) treatment reduced body weight and/or improved glucose tolerance, sitagliptin (10 mg/kg) was without effect on either parameter. Liraglutide caused a sharp reduction in beta-cell mass in both ND and HFD mice, whereas exendin-4 exerted no effect. By contrast, sitagliptin unmasked an action of high fat diet to increase beta-cell mass. Reg3B positive area was augmented by all three agents in normal chow-fed mice, whilst sitagliptin and exendin-4, but not liraglutide, affected this parameter in HFD animals. Correspondingly sitagliptin, but not the GLP-1 analogues, increased circulating amylase levels in ND and HFD mice.

CONCLUSIONS

Liraglutide improves glucose tolerance in the mouse whilst exerting relatively modest effects on pancreatitis risk. Conversely, exendin-4 and sitagliptin, at doses which exert, respectively, minor or no effects on metabolic parameters, lead to signs of pancreatitis.