ROLE OF THE INCRETINS IN HYPOGLYCEMIC EFFECT OF PHLOGACANTHUS THYRSIFLORUS NEES IN CHEMICALLY INDUCED DIABETIC MICE

Objective: This study was aimed to evaluate the role of GLP-1, GIP in the hypoglycemic activity of Phlogacanthus thyrsiflorus Nees. Materials and Methods: We have evaluated the influence of Phlogacanthus thyrsiflorus Nees, a traditionally used antidiabetic medicinal plant on some metabolic parameters, glucose homeostasis, insulin production, glucagon like peptide 1 (GLP1) and gastric Inhibitory Polypeptide (GIP) in high fat diet fed (HFD) obese mice and High fat diet + streptozotocin (HFD + STZ) induced diabetic mice. Oral glucose tolerance test (OGTT) was done to study the glucose homeostasis in both HFD fed obese mice and HFD + STZ induced diabetic mice. Effect of P. thyrsiflorus on pancreatic beta cells was assessed using histological studies. Results: Phlogacanthus thyrsiflorus aqueous extract (PTAE) treatment lowered the blood glucose levels in HFD fed obese mice and HFD + STZ induced diabetic mice significantly. PTAE treatment reduced the weight gain in HFD fed obese mice and prevented the constant weight loss in HFD+STZ induced diabetic mice. PTAE treatment decreased the food intake significantly in HFD fed obese mice. PTAE treatment improved the glucose tolerance and the lipid profile in HFD fed obese mice. PTAE treatment decreased the insulin level in HFD fed obese mice and increased the insulin level in HFD + STZ induced diabetic mice. PTAE treatment increased the GLP –1 level and decreased the GIP level significantly in both HFD fed obese mice and HFD + STZ induced diabetic mice. Histological studies of pancreas showed that P.thyrsiflorus helps normalizing the pancreatic histoarchitecture. Conclusion: This study states that the hyperglycaemic activity of the P.thyrsiflorus is due to the modulation of the entero-insular axis in the Hypoglycemic mice. However the study also revealed the doubtful role of GIP as incretins and its role in diabetes treatment