Isolation and identification of four antioxidants from Rhodiola crenulata and evaluation of their UV photoprotection capacity in vitro

Rhodiola crenulata has recently been reported to be able to attenuate radiation induced oxidative injury and improve skin homeostasis. The purpose of this research is to identify and evaluate the active constituents responsible for its anti-photoaging effects. Four ingredients, Salidroside, Arbutin, Kaempferol and Rhodiolinin were purified form R. crenulata and their antioxidant effects were tested. Further, the protective effects of the four compounds against UVB irradiation on HSF and HaCaT cells were determined and the proinflammatory cytokines IL-6 and TNF-α were analyzed by the ELISA kits. Results showed that the four compounds could effectively improve UVB irradiation-induced cell apoptosis and regulate the production of inflammatory cytokines IL-6 and TNF-α. Kaempferol and arbutin exerted more powerful repairing capacities and played more significant role in reversing the abnormity of cytokines secretion in cell supernatant, indicating that the two compounds may be the more effective ingredients from R. crenulata to exert anti-photoaging function.