To assess the impact of concomitant inhibition of sodium-glucose cotransporter (SGLT) 2 and dipeptidyl
peptidase IV (DPP4) for the treatment of type 2 diabetes mellitus (T2DM), the effect of combined treatment
with canagliflozin, a novel SGLT2 inhibitor, and teneligliptin, a DPP4 inhibitor, on glucose intolerance was
investigated in Zucker diabetic fatty (ZDF) rats. Canagliflozin potently inhibited human and rat SGLT2 and
moderately inhibited human and rat SGLT1 activities but did not affect DPP4 activity. In contrast, teneligliptin
inhibited human and rat DPP4 activities but not SGLT activities. A single oral treatment of canagliflozin
and teneligliptin suppressed plasma glucose elevation in an oral glucose tolerance test in 13
week-old ZDF rats. This combination of agents elevated plasma active GLP-1 levels in a synergistic
manner, probably mediated by intestinal SGLT1 inhibition, and further improved glucose intolerance. In
the combination-treated animals, there was no pharmacokinetic interaction of the drugs and no further
inhibition of plasma DPP4 activity compared with that in the teneligliptin-treated animals. These results
suggest that the inhibition of SGLT2 and DPP4 improves glucose intolerance and that combined treatment
with canagliflozin and teneligliptin is a novel therapeutic option for glycemic control in T2DM.