Quantification of glycogen and glucose production in HepG2 hepatocytes. (a). Enhancement of glycogen content in inhibitor-pretreated HepG2 hepatocytes in the presence of TNF-α. Human HepG2 hepatocytes were plated in serum-free DMEM media for 24 h prior to testing. Inhibitors were added 30 min before stimulation with 10 ng/ml TNF-α. After 5 h, the cells were treated with 100 nM insulin for 10 min, and further steps were carried out according to the manufacturer’s instructions (Biovision, Milpitas, CA, USA). All values are mean ± SD, n = 3. (b). The effect of MAP kinase inhibitors on glucose production. All values are mean ± SD, n = 3.