Kinetics of Sulforaphane Supplementation in an Immortalizedhuman Keratinocyte (HaCaT) Cell Line Exposed to UVB Irradiation

Abstract

Introduction: Exposure of skin to UVB irradiation leads to adverse effects on health including skin aging, cancer, etc. Sulforaphane is an antioxidant compound derived naturally from cruciferous vegetables and also known for its chemo-preventive properties. This research project aims to investigate the effect of sulforaphane supplementation in human keratinocyte (HaCaT) cells exposed to UVB irradiation. Methods and Results: Briefly, exposure to UVB has a negative impact in HaCaT cell viability in a manner where the higher the intensity of the exposure the greater the reduction in cell viability. In addition, it was observed that the greatest degree of sulforaphane-induced protection was when the cells were pre-treated (for 24 hrs) and 48 hrs after exposure to the highest dose of UVB irradiation (200mJ/cm2). In fact, at this time point (48 hrs), sulforaphane was found to cause an increased rate of cell proliferation observed at every concentration tested: 0.5μM (122.0%), 1.0μM (130.0%), 2.5μM (136.0%), 5.0μM (141.0%) and 10.0μM (111.0%). Conclusion: Our data suggest that sulforaphane significantly protected HaCaT cells from exposure to UVB. In addition, we have also demonstrated that when added post-exposure, sulforaphane was less effective in providing protection against UVB irradiation, in HaCaT cells, and was even cytotoxic at concentrations of 10.0μM and higher.