11 research outputs found

    Naringenin and falcarinol stimulate glucose uptake and TBC1D1 phosphorylation in porcine myotube cultures

    Get PDF
    Abstract: Insulin resistance in muscles is a major problem associated with Type 2 diabetes. Bioactive compounds of plant origin have long been known for possessing anti-diabetic properties. We have studied the effect of the bioactive compounds naringenin (dihydroflavonol) and falcarinol (polyacetylene) on glucose uptake (GU) in normal and insulin resistant primary porcine myotubes, in the presence and absence of insulin to identify signaling pathways mediating their effects on GU. The dependence on glucose transporter type 4 (Glut4) activity, insulin signaling and AMP-activated protein kinase (AMPK)-signaling was studied by using the Glut4 inhibitor indinavir, the phosphatidyl inositol-3 kinase (PI3K) and p38 mitogen activated protein kinase (MAPK) inhibitor wortmannin, and the AMPK inhibitor dorsomorphin (DM), respectively. Naringenin and falcarinol stimulated GU was attenuated in the presence of indinavir and wortmannin, indicating a dependence on Glut4 activity as well as PI3K and/or p38MAPK activity. By contrast, DM diminished GU induced by naringenin only, indicating that falcarinol-stimulated GU was independent of AMPK activity. Finally, we show that naringenin and falcarinol enhance phosphorylation of TBC1D1 suggesting that these compounds enhance translocation of Glut4 containing vesicles and thereby GU via a TBC1D1-dependent mechanism

    Naringenin and falcarinol stimulate glucose uptake and TBC1D1 phosphorylation in porcine myotube cultures

    No full text
    Abstract: Insulin resistance in muscles is a major problem associated with Type 2 diabetes. Bioactive compounds of plant origin have long been known for possessing anti-diabetic properties. We have studied the effect of the bioactive compounds naringenin (dihydroflavonol) and falcarinol (polyacetylene) on glucose uptake (GU) in normal and insulin resistant primary porcine myotubes, in the presence and absence of insulin to identify signaling pathways mediating their effects on GU. The dependence on glucose transporter type 4 (Glut4) activity, insulin signaling and AMP-activated protein kinase (AMPK)-signaling was studied by using the Glut4 inhibitor indinavir, the phosphatidyl inositol-3 kinase (PI3K) and p38 mitogen activated protein kinase (MAPK) inhibitor wortmannin, and the AMPK inhibitor dorsomorphin (DM), respectively. Naringenin and falcarinol stimulated GU was attenuated in the presence of indinavir and wortmannin, indicating a dependence on Glut4 activity as well as PI3K and/or p38MAPK activity. By contrast, DM diminished GU induced by naringenin only, indicating that falcarinol-stimulated GU was independent of AMPK activity. Finally, we show that naringenin and falcarinol enhance phosphorylation of TBC1D1 suggesting that these compounds enhance translocation of Glut4 containing vesicles and thereby GU via a TBC1D1-dependent mechanism

    Screening for bioactive metabolites in plant extracts modulating glucose uptake and fat accumulation

    Get PDF
    Dichloromethane and methanol extracts of seven different food and medicinal plants were tested in a screening platform for identification of extracts with potential bioactivity related to insulin-dependent glucose uptake and fat accumulation. The screening platform included a series of in vitro bioassays, peroxisome proliferator-activated receptor (PPAR) γ-mediated transactivation, adipocyte differentiation of 3T3-L1 cell cultures, and glucose uptake in both 3T3-L1 adipocytes and primary porcine myotubes, as well as one in vivo bioassay, fat accumulation in the nematode Caenorhabditis elegans. We found that dichloromethane extracts of aerial parts of golden root (Rhodiola rosea) and common elder (Sambucus nigra) as well as the dichloromethane extracts of thyme (Thymus vulgaris) and carrot (Daucus carota) were able to stimulate insulin-dependent glucose uptake in both adipocytes and myotubes while weekly activating PPARγ without promoting adipocyte differentiation. In addition, these extracts were able to decrease fat accumulation in C. elegans. Methanol extracts of summer savory (Satureja hortensis), common elder, and broccoli (Brassica oleracea) enhanced glucose uptake in myotubes but were not able to activate PPARγ, indicating a PPARγ-independent effect on glucose uptake
    corecore