title: Combination of dipeptidylpeptidase IV inhibitor and low dose thiazolidinedione: preclinical efficacy and safety in db/db mice.
abstract: Thiazolidinediones (TZDs) are currently the most efficacious class of oral antidiabetics. However, they carry the burden of weight gain and haemodilution, which may lead to cardiovascular complications. The present study was designed to ascertain whether a combination of dipeptidyl peptidase IV (DPP IV) inhibitor with low dose of a thiazolidinedione absolves TZD associated weight gain and oedema without compromising its efficacy. In this study, we examined the efficacy and safety of lower dose (1 mg/kg/day) of rosiglitazone, a thiazolidinedione, in combination with 5 mg/kg/day dose of LAF-237 (vildagliptin), a known DPP IV inhibitor, in aged db/db mice after 14 days of treatment and compared the combination with therapeutic dose (10 mg/kg) of rosiglitazone. The combination therapy showed similar efficacy as that of 10 mg/kg/day rosiglitazone in lowering random blood glucose (53.8%, p<0.001 and 54.3%, p<0.001 respectively), AUC ((0-120) min) during oral glucose tolerance test (OGTT) (38.6 %, p<0.01; 38.3%, p<0.01 respectively) and triglyceride levels (63.9% and 61% respectively; p<0.01). Plasma active glucagon like peptide-1 (GLP-1) and insulin levels were found to be elevated significantly (p<0.01 and p<0.05 respectively) in both LAF-237 and combination treated groups following oral glucose load. LAF-237 alone had no effect on random glucose and glucose excursion during OGTT in severely diabetic db/db mice. Interestingly, the combination treatment showed no significant increase in body weight as compared to the robust weight gain by therapeutic dose of rosiglitazone. Rosiglitazone at 10 mg/kg/day showed significant reduction (p<0.05) in haematocrit, RBC count, haemoglobin pointing towards haemodilution associated with increased mRNA expression of Na(+), K(+)-ATPase-alpha and epithelial sodium channel gamma (ENaCgamma) in kidney. The combination therapy escaped these adverse effects. The results suggest that combination of DPP IV inhibitor with low dose of thiazolidinedione can interact synergistically to represent a therapeutic advantage for the clinical treatment of type 2 diabetes without the adverse effects of haemodilution and weight gain associated with thiazolidinediones.
authors.affiliation: Ranbaxy Research Laboratories, New Drug Discovery Research, Gurgaon-122001, Haryana, India. subhasis.roy@ranbaxy.com
authors.forename: Subhasis
authors.initials: S
authors.lastname: Roy
authors.forename: Vivek
authors.initials: V
authors.lastname: Khanna
authors.forename: Shivani
authors.initials: S
authors.lastname: Mittra
authors.forename: Arti
authors.initials: A
authors.lastname: Dhar
authors.forename: Shuchita
authors.initials: S
authors.lastname: Singh
authors.forename: Dipak C
authors.initials: DC
authors.lastname: Mahajan
authors.forename: Priyanka
authors.initials: P
authors.lastname: Priyadarsiny
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Davis
authors.forename: Jitendra
authors.initials: J
authors.lastname: Sattigeri
authors.forename: Kulvinder S
authors.initials: KS
authors.lastname: Saini
authors.forename: Vinay S
authors.initials: VS
authors.lastname: Bansal
mesh_terms: D000218:Adamantane / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology; D054873:Dipeptidyl-Peptidase IV Inhibitors; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011759:Pyrrolidines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D014280:Triglycerides / Q000097:blood
chemical_list: C475520:1-(((3-hydroxy-1-adamantyl)amino)acetyl)-2-cyanopyrrolidine; D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D007004:Hypoglycemic Agents; D011759:Pyrrolidines; D045162:Thiazolidinediones; D014280:Triglycerides; D000077154:Rosiglitazone; D000218:Adamantane