Berberine Attenuates Hyperglycemia by Inhibiting the Hepatic Glucagon Pathway in Diabetic Mice

Figure 4

Effects of BBR on cAMP levels and CREB phosphorylation induced by various agonists. (a) cAMP in hepatocytes after glucagon treatment with and without BBR pretreatment. ^##, compared with the none group; , compared with the glucagon group (). (b) cAMP in the liver with and without intravenous glucagon treatment. ^##, compared with the none group; , compared with the glucagon group (). (c–e) Primary hepatocytes were preincubated with BBR for 15 min, then stimulated with 1 mM 8-bromo-cAMP (c), 10 μM forskolin (d), or 1 mM IBMX (e) for another 30 min, and protein was analyzed by western blot with the total CREB antibodies and the phospho- (p-) CREB antibody. CREB phosphorylation was normalized to total CREB levels. The data are expressed as the ^#, compared with the untreated group; , compared with the agonist group ().

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