Inhibitory effect of ERK1/2 and AP-1 by hyperoside isolated from Acanthopanax sessiliflorus

Consumption of fruits and vegetables is correlated with a lower incidence of cancer. Here, we identified hyperoside as an active compound from Acanthopanax sessiliflorus, and investigated the effect of hyperoside on UVB-induced transactivation of activator protein 1 (AP-1) and on the mitogen-activated protein kinase signalling pathway in JB6 P + cells. Hyperoside inhibited UVB-induced AP-1 transactivation. It inhibited the UVB-induced phosphorylation of p90^RSK. Kinase assays revealed that hyperoside significantly inhibited ERK1/2 activity. Furthermore, hyperoside bound to ERK1/2 to suppress its activity. In addition, phosphorylation of cAMP response element binding protein (CREB) and signal transducers and activators of transcription (STAT) 3 were suppressed by hyperoside. Overall, these results indicate that hyperoside may be a promising chemopreventive agent that acts by suppressing the transactivation of AP-1 and the phosphorylation of p90^RSK, CREB, and STAT3 through the binding and inhibition of ERK1/2.