Alogliptin is a novel, highly selective and potent inhibitor of serine protease dipeptidylpeptidase-4 (DPP-4) with IC50 value of less than 10 nM [1].

Alogliptin has been reported to significantly reduce plasma DPP-4 activity and increase active GLP-1 levels in a dose-dependent manner in ob/ob mice. Besides, alogliptin after 4 weeks administration remarkably reduced non-fasting glycosylated hemoglobin, non-fasting plasma glucose and triglyceride levels, as well as siginificantly increased non-fasting plasma insulin and fasting pancreatic insulin content in ob/ob mice. Moreover, alogliptin treated ob/ob mice have shown the increase of early-phase insulin secretion and the decrease of plasma glucose AUC [2]

References:
[1] Feng J, Zhang Z, Wallace MB, Stafford JA, Kaldor SW, Kassel DB, Navre M, Shi L, Skene RJ, Asakawa T, Takeuchi K, Xu R, Webb DR, Gwaltney SL 2nd. Discovery of alogliptin: a potent, selective, bioavailable, and efficacious inhibitor of dipeptidyl peptidase IV. J Med Chem. 2007 May 17;50(10):2297-300.
[2] Moritoh Y1, Takeuchi K, Asakawa T, Kataoka O, Odaka H. Chronic administration of alogliptin, a novel, potent, and highly selective dipeptidyl peptidase-4 inhibitor, improves glycemic control and beta-cell function in obese diabetic ob/ob mice. Eur J Pharmacol. 2008 Jul 7;588(2-3):325-32.