Combination of the sodium-glucose cotransporter-2 inhibitor empagliflozin with orlistat or sibutramine further improves the body-weight reduction and glucose homeostasis of obese rats fed a cafeteria diet.

The present study assessed the potential of the sodium glucose-linked transporter (SGLT)-2 inhibitor empagliflozin to decrease body weight when administered alone or in combination with the clinically effective weight-loss agents orlistat and sibutramine in obese rats fed a cafeteria diet. Female Wistar rats were exposed to a cafeteria diet to induce obesity. Empagliflozin was dosed once daily (10, 30, and 60 mg/kg) for 28 days. Combination studies were subsequently performed using a submaximal empagliflozin dose (10 mg/kg) with either sibutramine or orlistat. Body weight, food, and water intake were recorded daily. The effect of drug treatment on glucose tolerance, relevant plasma parameters, and carcass composition was determined. Empagliflozin dose-dependently reduced body weight, plasma leptin, and body fat though increased urinary glucose excretion. The combination of empagliflozin and orlistat significantly reduced body weight compared to animals treated with either drug alone, and significantly improved glucose tolerance, plasma insulin, and leptin compared to vehicle-treated controls. The effect of sibutramine to improve glycemic control in an oral glucose-tolerance test was also significantly increased, with empagliflozin and combination treatment leading to a reduction in carcass fat greater than that observed with either drug alone. These data demonstrate that empagliflozin reduces body weight in cafeteria-fed obese rats. In combination studies, empagliflozin further improved the body-weight or body-fat loss of animals in comparison to orlistat or sibutramine alone. Such studies may indicate improved strategies for the treatment of obese patients with prediabetes or type 2 diabetes.

Effect of linagliptin, alone and in combination with voglibose or exendin-4, on glucose control in male ZDF rats.

The effects of the dipeptidyl peptidase-4 (DPP-4) inhibitor, linagliptin, alone and in combination with voglibose or exendin-4, on glycaemic control and body weight were assessed in an animal model of type 2 diabetes. Voglibose is an α-glucosidase inhibitor but also increases glucagon-like peptide 1 (GLP-1). Exendin-4 is a GLP-1 receptor agonist. Male Zucker Diabetic Fatty (ZDF) rats were dosed for 3 days, fasted overnight and a sucrose/glucose tolerance test was performed. Linagliptin (1mg/kg po) improved glucose tolerance by increasing plasma GLP-1 (active) and insulin secretion, whilst having no effect on body weight. Voglibose (1 and 10mg/kg po) reduced body weight, improved glycaemic control, reduced plasma insulin and increased total but not active GLP-1. The combination of linagliptin and voglibose significantly reduced body weight, improved glycaemic control and reduced plasma insulin compared to linagliptin alone. Furthermore, linagliptin plus voglibose produced a marked increase in GLP-1 (active) at 5min post-sucrose, compared to linagliptin, possibly because linagliptin prevented the degradation of GLP-1 secreted in response to voglibose. Exendin-4 (10µg/kg sc) significantly reduced body weight, improved glucose tolerance but reduced GLP-1 (active). The combination of linagliptin and exendin-4 significantly reduced body weight and improved glycaemic control but had no effect on plasma GLP-1. Overall it did not markedly improve glycaemic control compared to the individual drugs. The improved glucose control, reduced body weight and markedly increased plasma GLP-1 levels in animals given linagliptin with voglibose, suggests that this combination may be particularly beneficial in the treatment of type 2 diabetes.

Effects of the DPP-4 inhibitor, linagliptin, in diet-induced obese rats: a comparison in naive and exenatide-treated animals.

BACKGROUND: To assess the chronic effect of the DPP-4 inhibitor, linagliptin, alone, in combination with exenatide, and during exenatide withdrawal, in diet-induced obese (DIO) rats. METHODS: Female Wistar rats were exposed to a cafeteria diet to induce obesity. Animals were then dosed with vehicle or linagliptin (3 mg/kg PO) orally once-daily for a 28 day period. In a subsequent study, rats received exenatide (either 3 or 30 microg/kg/day) or vehicle by osmotic mini-pump for 28 days. In addition, groups of animals were dosed orally with linagliptin either alone or in combination with a 3 microg/kg/day exenatide dose for the study duration. In a final study, rats were administered exenatide (30 microg/kg/day) or vehicle by osmotic mini-pump for eleven days. Subsequently, exenatide-treated animals were transferred to vehicle or continued exenatide infusion for a further ten days. Animals transferred from exenatide to vehicle were also dosed orally with either vehicle or linagliptin. In all studies, body weight, food and water intake were recorded daily and relevant plasma parameters and carcass composition were determined. RESULTS: In contrast to exenatide, linagliptin did not significantly reduce body weight or carcass fat in DIO rats versus controls. Linagliptin augmented the effect of exenatide to reduce body fat when given in combination but did not affect the body weight response. In rats withdrawn from exenatide, weight regain was observed such that body weight was not significantly different to controls. Linagliptin reduced weight regain after withdrawal of exenatide such that a significant difference from controls was evident. CONCLUSIONS: These data demonstrate that linagliptin does not significantly alter body weight in either untreated or exenatide-treated DIO rats, although it delays weight gain after exenatide withdrawal. This finding may suggest the utility of DPP-4 inhibitors in reducing body weight during periods of weight gain.