Magnolia officinalis Extract Contains Potent Inhibitors against PTP1B and Attenuates Hyperglycemia in db/db Mice

Figure 4

Effects of ME on insulin signaling pathway. Differentiated 3T3-L1 adipocytes (a and c) and C2C12 myotubes (b and d) were starved for 4 h before stimulation. The cells were incubated with vehicle or ME at various concentrations for 30 min and then stimulated with vehicle or 10 nM insulin for 5 min. Tyrosine phosphorylations of IR and ERK were determined by Western blotting with anti-phospho-IRβ and anti-phospho-ERK1/2 antibodies and were normalized with IR and ERK protein, respectively, which were then calculated as fold changes of insulin alone. Data are presented as mean ± SEM (). , , versus insulin alone.

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