Berberine reverses free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ

Figure 1 Insulin-induced 2-deoxy-[³H]-D-Glucose uptake in 3T3-L1 adipocytes . 3T3-L1 preadipocytes (5 × 10⁵/well) were differentiated to adipocytes in a 24-well plate. After serum-starvation in 0.2% BSA DMEM overnight, the cells were incubated in 0.2% BSA DMEM containing 0.5 mmol/L PA or (and) 1 &mgr;mol/L, 10 &mgr;mol/L Ber or 5 mmol/L Aspirin for 24 h or 48 h. Then, the cells were incubated in 1 mL KRP-HEPES without or with 100 nmol/L insulin for 30 min at 37°C after washed three times in KRP-HEPES buffer. Next, the cells were incubated in 1 mL KRP-HEPES containing 0.5 &mgr;Ci/mL 2-deoxy-D-[³H] glucose for 10 min at 37°C. Finally, the cells were washed three times in ice-cold PBS and solubilized in 1ml of 0.1 mol/L NaOH for 2 h. Radioactivity was determined by liquid scintillation spectrometry. Nonspecific deoxyglucose uptake was measured in the presence of 20 &mgr;mol/L cytochalasin B and specific glucose uptake was detected from the subtracted total uptake. Three replicate wells were set up and each experiment was repeated three times. ^bP < 0.01, vs Mod group.