Photoprotection against UVAR: effective triterpenoids require a lipid raft stabilizing chemical structure.

Abstract

UVA(Ultraviolet A)-induced gene expression is supposed to be a hallmark for inflammation, for immunosuppression and in long-term cancer formation. In previous studies, we have shown for keratinocytes that physiological doses of UVA radiation result in the upregulation of gene expression mediated by ceramide formation from sphingolipids/cholesterol-rich microdomains (rafts), which can be blocked by preloading keratinocytes with cholesterol or plant sterols. Here, we show that besides stigmasterol and ß-sitosterol, also sterols like 14-dehydroergosterol, ergosterol-peroxide and 29-norcycloartenol inhibit the UVA response. Moreover, we present evidence that natural material-derived triterpenoids such as oleanolic acid can abrogate UVA-induced gene expression by raft stabilization. This effect depends on the structure of the molecule, because its isomer ursolic acid also integrates within the rafts without inhibiting ceramide formation and upregulation of gene expression.

DOI: 10.1111/j.1600-0625.2011.01350.x

Cite this paper

@article{Bayer2011PhotoprotectionAU, title={Photoprotection against UVAR: effective triterpenoids require a lipid raft stabilizing chemical structure.}, author={Mirko Bayer and Peter Proksch and Ingo Felsner and Heidi Brenden and Zippora Kohne and Rehab Walli and Tu Ngoc Duong and Christine Goetz and Jean Krutmann and Susanne Grether-Beck}, journal={Experimental dermatology}, year={2011}, volume={20 11}, pages={955-8} }