Increase of glucagon-like peptide-1 by yacon fos and its effects on diabetic rats

HABIB N.; HONORÉ S.M.; GENTA S.B.; SANCHEZ S.S.

Puerto Madryn, Chubut, Argentina

Congreso; XLVI Reunion Anual de la Sociedad Argentina de Bioquimica y Biologia Molecular (SAIB); 2010

SAIB

Smallanthus sonchifolius [Poepp. & Ende] H. Robinson (yacon) is a plant originating from South America. Its roots contain low polymerization degree oligosaccharides (FOS) as the main storage saccharides. We have evaluated the influence of yacon roots on glucose homeostasis, insulin production, intestinal and plasmatic glucagon-like peptide-1 (GLP-1) content in streptozotocin (STZ)-induced diabetic rats. Male Wistar rats received either i.p. STZ (45mg/kg) or vehicle (CT); one week later, they were fed for 8 weeks with either the standard diet (STZ-CT), or with a diet containing yacon roots in a dose equivalent to 340 mg FOS/Kg/day (STZ-Y340). Yacon roots improve glucose tolerance in the post-prandial state and reduced slightly food intake as compared with STZ-CT rats. After 8 weeks, plasmatic insulin levels were doubled in STZ-Y340 rats. We have shown that yacon treatment increased GLP-1 levels in blood and caecum. This result is accompanied with higher levels of GLP-1 receptor mRNA in pancreatic tissue. We propose that yacon FOS, through its fermentation in the colon, promoted the secretion of colonic GLP-1, with beneficial consequences on post-prandial glycaemia and insulin secretion in diabetic rats.