FIG. 4.

Inulin increases glucose uptake and overcomes insulin resistance in HepG2 hepatoma cells. HepG2 cells were incubated with the indicated concentrations of inulin for 1 hour. (A) Protein extracts were prepared and subjected to western blot assay using anti-phosphospecific ACC-Ser⁷⁹ (p-ACC), total ACC (ACC), anti-phosphospecific AMPK-Thr¹⁷² (p-AMPK), total AMPK (AMPK-α), anti-phosphospecific Akt-Ser⁴⁷³ (p-Akt), and total Akt (AKT) antibodies. Experiments were repeated three times with similar results, and a representative result is shown. (B) Glucose uptake was measured as described in Materials and Methods. Data are mean ± SD values for two independent assays performed in triplicate. (C) HepG2 cells were incubated in serum-free medium overnight and incubated in serum-free medium containing either normal (5.5 mM) or high (30 mM) concentrations of d-glucose for an additional 24 hours. Before harvesting, the cells were stimulated with 1 mg/mL inulin or 100 nM insulin for 1 hour. The phosphorylation of AKT, and AMPK was analyzed with anti-phospho-Ser⁴⁷³ Akt and anti-phospho-Thr¹⁷² AMPK antibodies, respectively. Experiments were repeated three times with similar results, and a representative result is shown. (D) Glucose uptake was measured as described in Materials and Methods. Data are mean ± SD values for two independent assays performed in triplicate. *P < .05 versus normal glucose; ^#P < .05 versus high glucose alone.