Cacao extract enriched in polyphenols prevents endocrine-metabolic disturbances in a rat model of prediabetes triggered by a sucrose rich diet.

Ethnopharmacological Relevance: Cocoa extracts rich in polyphenols are used as potential agent for treating diabetes. Cocoa polyphenols have been proved to ameliorate important hallmarks of type-2 diabetes (T2D). They can regulate glucose levels by increasing insulin secretion, promoting β-cell proliferation and a reduction of insulin resistance.

Effects of islet neogenesis associated protein depend on vascular endothelial growth factor gene expression modulated by hypoxia-inducible factor 1-alpha.

Background: Pharmacology has provided efficient tools to improve insulin effect/secretion but the decrease in β-cell mass remains elusive. INGAP-PP could provide a therapeutic alternative to meet that challenge.

Aim: To further understand the mechanism that links INGAP-PP effects upon β-cell mass and function with islet angiogenesis.

INGAP-PP effects on β-cell mass and function are related to its positive effect on islet angiogenesis and VEGFA production.

Our aim was to determine whether islet angiogenesis and VEGFA production/release participate in the mechanism by which INGAP-PP enhances β-cell function and mass. We used two models: a) in vivo (normal rats injected with INGAP-PP for 10 days) and b) in vitro (normal islets cultured for 4 days with INGAP-PP, VEGFA, Rapamycin, and the specific VEGF-Receptor inhibitor, SU5416). INGAP-PP administration enhanced insulin secretion, β-cell mass, islet vascularization, and angiogenesis without affecting glucose homeostasis.

VMP1-related autophagy induced by a fructose-rich diet in β-cells: its prevention by incretins.

The aim of the present study was to demonstrate the role of autophagy and incretins in the fructose-induced alteration of β-cell mass and function. Normal Wistar rats were fed (3 weeks) with a commercial diet without (C) or with 10% fructose in drinking water (F) alone or plus sitagliptin (CS and FS) or exendin-4 (CE and FE). Serum levels of metabolic/endocrine parameters, β-cell mass, morphology/ultrastructure and apoptosis, vacuole membrane protein 1 (VMP1) expression and glucose-stimulated insulin secretion (GSIS) were studied.

Islet NADPH oxidase activity modulates β-cell mass and endocrine function in rats with fructose-induced oxidative stress.

Background: Islet NADPH oxidase activity is modulated by glucose and other insulin secretagogues and it might be part of the regulatory mechanism of insulin secretion. We studied its modulatory role of islet NADPH oxidase upon β-cell function in rats with fructose-induced oxidative stress.

Methods: Normal rats were fed for 3weeks with a standard diet, a fructose-rich diet or both diets plus apocynin.