Chicory inulin ameliorates type 2 diabetes mellitus and suppresses JNK and MAPK pathways in vivo and in vitro.

Abstract

Chicory inulin is a naturally occurring fructan that is conducive to glucose and lipid metabolism in patients with diabetes mellitus. This study aims to investigate the mechanism by which chicory inulin improves glucolipid metabolism in diabetic conditions. Rats were injected with streptozotocin and fed with high fat diet to induce diabetes, and then administrated with different doses of chicory inulin for 8 weeks. The glycometabolism and lipid metabolism parameters were determined, the activity of insulin receptor substrate (IRS) and mitogen-activated protein kinase (MAPK) pathways were examined by western blot. The effect of chicory inulin on glucose uptake of myoblast and hepatocyte were also measured in vitro. Data were analyzed by student's t-test or one-way analysis of variance followed by the Bonferroni post-hoc testing. The results showed that chicory inulin improved glucolipid metabolism, and it activated IRS but suppressed the MAPK pathways in vivo and in vitro. Our study demonstrates that chicory inulin, as a nutritional supplement, may be beneficial for the patients with type 2 diabetes mellitus, and the metabolism-modulatory effect seems to be related with the inhibition of JNK and P38 MAPK pathways.