Brown pine leaf extract and its active component trans-communic acid inhibit ultraviolet B induced matrix metalloproteinase-1 expression in 2D and 3D skin cell culture system

Abstract

Pine (Pinus densiflora), Korean national tree, has grown in all parts of Korea peninsula. Every two year, Pine leaf changes its color to brown and falls. Even though this brown pine leaf is widely spread, we have not paid much attention to its value. In this study, brown pine leaf is suggested as an anti-photoaging agent to our skin. Brown pine leaf extract (BPLE) inhibits UVB-induced matrix metalloproteinase-1 (MMP-1) expression more than pine leaf extract (PLE) in human keratinocyte and human skin equivalent model. HPLC analysis shows that the quantity of trans-communic acid (TCA) and dehydroabietic acid (DAA) increased by the pine leaf color change from green to brown. BPLE and TCA are able to reduce UVB-induced MMP-1 mRNA expression and activator protein-1 (AP-1) transactivation. However, UVB-induced mitogen activated protein kinase (MAPK), which is known to regulate AP-1 transactivation, was not affected by BPLE and TCA. Compared to UVB only treated group, BPLE and TCA treated groups attenuate collagen degradation and the MMP-1 protein level. In sum, both BPLE and its active component TCA exhibit possible chemopreventive activity against UVB-induced skin aging.