G protein-coupled receptor 119 (GPR119) is a
G protein-coupled receptor expressed predominantly in pancreatic β-cells and gastrointestinal enteroendocrine cells.
Metformin is a first-line treatment of
type 2 diabetes, with minimal
weight loss in humans. In this study, we investigated the effects of
GSK2041706 [2-([(1S)-1-(1-[3-(1-methylethyl)-1,2,4-oxadiazol-5-yl]-4-piperidinyl)ethyl]oxy)-5-[4-(methylsulfonyl)phenyl]
pyrazine], a GPR119 agonist, and
metformin as monotherapy or in combination on
body weight in a diet-induced obese (DIO) mouse model. Relative to vehicle controls, 14-day treatment with
GSK2041706 (30 mg/kg b.i.d.) or
metformin at 30 and 100 mg/kg b.i.d. alone caused a 7.4%, 3.5%, and 4.4% (all P < 0.05)
weight loss, respectively. The combination of
GSK2041706 with
metformin at 30 or 100 mg/kg resulted in a 9.5% and 16.7%
weight loss, respectively. The combination of
GSK2041706 and
metformin at 100 mg/kg caused a significantly greater
weight loss than the projected additive
weight loss of 11.8%. This
body weight effect was predominantly due to a loss of fat. Cumulative food intake was reduced by 17.1% with
GSK2041706 alone and 6.6% and 8.7% with
metformin at 30 and 100 mg/kg, respectively. The combination of
GSK2041706 with
metformin caused greater reductions in cumulative food intake (22.2% at 30 mg/kg and 37.5% at 100 mg/kg) and higher fed plasma
glucagon-like peptide 1 and
peptide tyrosine tyrosine levels and decreased plasma
insulin and
glucose-dependent insulinotropic
polypeptide levels compared with their monotherapy groups. In addition, we characterized the effect of
GSK2041706 and
metformin as monotherapy or in combination on neuronal activation in the appetite regulating centers in fasted DIO mice. In conclusion, our data demonstrate the beneficial effects of combining a GPR119 agonist with
metformin in the regulation of
body weight in DIO mice.