Inulin Increases Glucose Transport in C2C12 Myotubes and HepG2 Cells via Activation of AMP-Activated Protein Kinase and Phosphatidylinositol 3-Kinase Pathways

Abstract

Inulin, a naturally occurring, functional food ingredient found in various edible plants, has been reported to exert potential health benefits, including decreased risk of colonic diseases, non-insulin-dependent diabetes, obesity, osteoporosis, and cancer. However, the mechanism of the antidiabetic activity of inulin has not yet been elucidated. In this study, we showed that inulin increased the uptake of glucose in C2C12 myotubes, which was associated with both AMP-activated protein kinase (AMPK) and phosphatidylinositol 3-kinase (PI3-K) signaling pathways, but both of these pathways appeared to transmit their signals in an independent manner. Moreover, we found that inulin was able to increase the uptake of glucose in C2C12 myotubes in which insulin resistance was induced by exposing cells to high glucose concentrations. The identical effects of inulin were also observed in HepG2 hepatoma cells. Collectively, we report the antidiabetic activity of inulin and further demonstrate for the first time that such activity is associated with AMPK and PI3-K activation.

Myricetin attenuates hyperinsulinemia-induced insulin resistance in skeletal muscle cells

“…In fact, the similar activity of several beneficial components of plants has been reported and is therefore not a novel finding. For example, in a previous study of inulin, a naturally functional food ingredient found in various edible plants, the similar effects and mechanisms about glucose uptake in C2C12 myotubes were observed [26]. However, quite different to our results, a similar plant flavonol, resveratrol, had been shown to stimulate glucose uptake under normal condition by activating AMPK in C2C12 myotubes, but not PI3K/Akt pathway [27].…”

Antihyperglycemic effect of rice husk derived xylooligosaccharides in high‐fat diet and low‐dose streptozotocin‐induced type 2 diabetic rat model

“…As expected, the present study demonstrated that the phosphorylation of AMPK Thr172 was markedly reduced in T2DM rats, and these alterations were restored after RH-XOS, metformin, and the combination of RH-XOS and metformin treatments. Although there are a few reports on the relationship between XOS and their AMPK activation, supplementation with inulin, a well-known prebiotic, demonstrated the activation of AMPK phosphorylation in C2C12 myotubes (Yun et al, 2009). Although there are a few reports on the relationship between XOS and their AMPK activation, supplementation with inulin, a well-known prebiotic, demonstrated the activation of AMPK phosphorylation in C2C12 myotubes (Yun et al, 2009).…”

“…To date, metformin is known as an antidiabetic medication for T2DM patients, and its mechanism to control blood sugar is mainly activated by GLUT4 translocation via AMPK pathway (Lee et al, 2012). Although there are a few reports on the relationship between XOS and their AMPK activation, supplementation with inulin, a well-known prebiotic, demonstrated the activation of AMPK phosphorylation in C2C12 myotubes (Yun et al, 2009). These data suggest that either insulin-stimulated Akt phosphorylation or AMPK activation by RH-XOS treatment leads to increase in GLUT4 translocation and enhanced glucose transport into skeletal muscle, which lessens hyperglycemia in T2DM rats.…”

Prebiotics to Fight Diseases: Reality or Fiction?

“…It can be speculated that these compounds act as direct ROS scavengers (Bolouri-Moghaddam et al, 2010;Van den Ende et al, 2011). Alternatively, and perhaps more likely, they can interfere with the uptake mechanisms of glucose or other metabolites and/or with AMPK signaling pathways (De Gara et al, 2003;Yun et al, 2009;Stoyanova et al, 2011). In particular, the antioxidant effect of levan-type fructans under oxidative stress conditions was examined on pancreatic INS-1E cells.…”