Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression

International Journal of Molecular Sciences

Jong-Eun Kim¹  Ki Won Lee¹ 

[1] WCU Biomodulation Major, Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Korea; E-Mail:

关键词: silkworm thorn;    cyclooxygenase-2;    ultraviolet;    RSK2;   

DOI  :  10.3390/ijms161025096

来源: mdpi

【 摘 要 】

Excessive exposure to solar UV (sUV) is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW) is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark) is consumable as a functional food or tea. In this study, we found that SW extract (SWE) inhibited the elevated expression of sUV-induced cyclooxygenase (COX)-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.