Naringenin Inhibits Adipogenesis and Reduces Insulin Sensitivity and Adiponectin Expression in Adipocytes
Figure 2
Naringenin inhibits insulin-sensitive glucose uptake from 1.5 to 24 hours and in a dose-dependent manner. Fully differentiated 3T3-L1 adipocytes were serum-deprived for 24 hours prior to performing glucose uptake assays. Cells were stimulated with 5 nM insulin for 7 minutes. Glucose uptake was initiated by the addition of 2-[3H] deoxyglucose. The glucose uptake values shown represent the mean ± SEM of triplicate determinations from three independent experiments. Cells were pretreated with vehicle (DMSO) or the indicated dose of naringenin overnight (a). Prior to insulin administration, the serum-deprivation medium was refreshed and the cells were retreated with the vehicle and indicated dose of naringenin. Cells were treated with vehicle (0 time point) for 24 hours or 50 μg/mL of naringenin for the indicated length of time prior to insulin administration (b). White bars: minus insulin; black bars: plus insulin. Glucose uptake was significantly greater with insulin (relative to basal uptake): *, **, and ***. Statistically significant relationships among insulin-stimulated glucose uptake values are indicated in (a) for all combinations of naringenin doses. #Represents statistical significance () for each naringenin versus 0 time point. All other comparisons were not statistically significant.
