Effects of phenylethanol glycosides from Orobanche cernua Loefling on UVB-Induced skin photodamage: a comparative study.

Previous study has found that Orobanche cernua Loefling(OC) and its main ingredient, acteoside, possess excellently anti-photo-aging effect. In addition to acteoside, crenatoside, isoacteoside and 2'-acetylacteoside were also identified as the main phenylethanol glycosides (PhGs) in OC. To screen optimum effective substance and further clarify the photoprotective ingredients of OC, the effects of four major PhGs in OC were compared using UVB-irradiated HaCaT cells. Results indicated that acteoside, isoacteoside and 2'-acetylacteoside effectively decreased UVB-induced MMP-1 expression and stimulated type I procollagen synthesis through inhibition of MAPK/AP-1 and activation of TGF-β/Smad pathway. Moreover, acteoside and 2'-acetylacteoside significantly reduced UVB-induced ROS and TARC secretion, which is involved in the inhibition of NF-κβ/Iκβα and stimulation of Nrf2 antioxidant defense system. However, crenatoside did not show any effect on the regulation of signal cascades mentioned above. Together, our results suggested that 2'-acetylacteoside and isoacteoside also served as efficient agents against UV radiation-induced skin damage. Among them, acteoside and 2'-acetylacteoside showed a higher efficiency than that of isoacteoside, which possessed great potential in treating skin photo-damage.