Tyrosol prevents apoptosis in irradiated keratinocytes

Background: Phenolic compounds, the biggest group of natural antioxidants, have attracted much attention due to their known and wide-ranging biological activities, as well as to their health effects. In particular, regardless their antioxidant activity, they play a key role in the control of several inflammation-associated processes as well as in improving antioxidant defense system. In an our previous work we have demonstrated the ability of Hydroxytyrosol, an ortho-diphenolic compound, essential component of oleuropein, in preventing apoptotic cell death induced by UVB radiation in HaCaT cell lines in vitro. In olive oil, besides Hydroxytyrosol, there are appreciable amounts of Tyrosol and its secoiridoid derivatives. Objective: It has been well established that Tyrosol has a significantly lower antioxidant activity than Hydroxytyrosol, but despite this, recent studies suggest that Tyrosol exerts a powerful protective effect against oxidative injuries in cell systems and that it is able to improve the intracellular antioxidant defenses. Materials and methods: Here, Tyrosol effect has been evaluated in HaCaT cells exposed to UVB radiation by means of morphological and molecular analyses. Results: Our study revealed the polyphenol ability in reducing apoptotic markers and in protecting HaCaT cells from damage. Conclusion: These findings suggest an important role of Tyrosol in protecting cells from apoptotic cell death and encourage the use of this phytochemical as biological ingredient in topical preparations as possible tool to prevent skin damage. (C) 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.