Preparation and Pharmaceutical Characterizations of Lipidated Dimeric Xenopus Glucagon-Like Peptide-1 Conjugates

Abstract

A pair of glucagon-like peptide-1 (GLP-1) analogs (1 and 2) were synthesized by hybridizing the key sequences of GLP-1, exendin-4, lixisenatide, and xenGLP-1B (Xenopus GLP-1 analog). To achieve long-acting hypoglycemic effects and to further improve their anti-diabetic potencies, lipidization and dimerization strategies were used to afford two lipidated dimeric conjugates (9 and 11). Conjugates 9 and 11 showed stronger receptor activation potency than GLP-1 and exendin-4 in vitro. Moreover, 9 and 11 exhibited superior hypoglycemic and insulinotropic activities to liraglutide in type 2 diabetic C57BL/6J-m Lepr (db/db) mice. Pharmacokinetic studies revealed that the circulating half-lives (t) of 9 and 11 were 2.3- and 1.7-fold longer than that of liraglutide. The improved pharmacokinetic profiles led to significantly protracted in vivo anti-diabetic effects as confirmed by multiple oral glucose tolerance tests and hypoglycemic duration tests. Most importantly, chronic treatment studies found that once daily administration of 9 or 11 in db/db mice achieved more beneficial effects on HbA1c reduction and glucose tolerance normalization than liraglutide. Our research demonstrated lipidization and dimerization as useful tools for the development of novel GLP-1 receptor agonists. The preclinical studies suggested the potential of 9 and 11 to be developed as novel anti-diabetic agents.

Lithocholic Acid-Based Peptide Delivery System for an Enhanced Pharmacological and Pharmacokinetic Profile of Xenopus GLP-1 Analogs

“…Blood samples were collected and HbA1c levels were measured using a chemistry analyzer based on the immunoagglutination inhibition method (DCA 2000+, Bayer Diagnostics, USA), and then mice were divided based on matching HbA1c. 33 Saline and liraglutide (25 nmol•kg −1 ) were twice daily s.c. injected at 8 a.m. and 8 p.m., and 5b (25 nmol• kg −1 ) was once daily s.c. injected at 8 a.m. for 35 days. HbA1c and plasma insulin concentrations were measured weekly using a DCA 2000+ chemistry analyzer and a mouse insulin ELISA kit, respectively.…”

“…Mice were acclimatized for 1 week. Blood samples were collected and HbA1c levels were measured using a chemistry analyzer based on the immunoagglutination inhibition method (DCA 2000+, Bayer Diagnostics, USA), and then mice were divided based on matching HbA1c . Saline and liraglutide (25 nmol·kg –1 ) were twice daily s.c. injected at 8 a.m. and 8 p.m., and 5b (25 nmol·kg –1 ) was once daily s.c. injected at 8 a.m. for 35 days.…”

Discovery of lixisenatide analogues as long-acting hypoglycemic agents using novel peptide half-life extension technology based on mycophenolic acid

“…In the second experiment, the hypoglycemic activities of lixisenatide, semaglutide and 2c were measured in db/db mice (n ¼ 6) under non-fasted condition. 40 The mice were allowed to free access to food. On the experiment day, mice were s.c. injected with saline (control), lixisenatide, semaglutide, and 2c (25 nmol kg À1 ) at t ¼ 0 h. The blood was obtained and the blood glucose levels were measured using the same above described method at 0, 2, 4, 6, 12, 24 and 48 h.…”

The chronic administration of two novel long‐acting Xenopus glucagon‐like peptide‐1 analogs xGLP159 and XGLP296 potently improved systemic metabolism and glycemic control in rodent models

“…The obtained supernatants were analyzed via liquid chromatography-tandem mass spectrometry, and the multiple reaction monitoring signals of liraglutide, xGLP159, and xGLP296 were transferred to concentrations using the standard curve plotted previously. PK parameters were calculated using Bioavailability Program Package software 2.2 (27).…”