Inhibitory effect of panduratin A on UV-induced activation of mitogen-activated protein kinases (MAPKs) in dermal fibroblast cells.

Exposure of the skin to ultraviolet (UV) induces photoaging associated with up-regulated matrix metalloproteinases (MMPs) activities and decreased collagen synthesis. We previously reported that panduratin A, a chalcone compound isolated from KAEMPFERIA PANDURATA Roxb ., decreased MMP-1 expression in UV-irradiated human skin fibroblasts. Here, we have investigated the effect of panduratin A on UV-induced activation of mitogen-activated protein kinases (MAPKs) signaling modules such as extracellular-regulated protein kinase (ERK), Jun-N-terminal kinase (JNK) and p38 kinase. Treatment with panduratin A in the range of 0.001 - 0.1 microM significantly inhibited UV-induced ERK, JNK and p38 activation. Moreover, inhibition of ERK, JNK and p38 by panduratin A resulted in decreased c-Fos expression and c-Jun phosphorylation induced by UV, which led to inhibition of activator protein-1 (AP-1) DNA binding activity. Panduratin A showed stronger activity than epigallocatechin 3- O-gallate (EGCG) known as a natural anti-aging agent. The results suggest that panduratin A can down-regulate UV-induced MMP-1 expression by inhibiting the MAPKs pathways and AP-1 activation. AP-1:activator protein-1 EGCG:epigallocatechin 3- O-gallate ERK:extracellular-regulated protein kinase JNK:c-Jun N-terminal kinase MAPK:mitogen-activated protein kinase MMP:matrix metalloproteinase UV:ultraviolet.