Cytoprotective Effect of 3,4-Dihydroxybenzoic Acid Isolated from Cladophora wrightiana Harvey Against Ultraviolet B Radiation-Mediated Oxidative Damage in HaCaT Keratinocytes

Abstract

The purpose of the present study was to elucidate the protective effect of 3,4-dihydroxybenzoic acid (DBA) isolated from Cladophora wrightiana Harvey (a green algae) against ultraviolet B (UVB)-induced damage on HaCaT cells. DBA exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), the superoxide anion and the hydroxyl radical. Furthermore, DBA diminished the levels of intracellular reactive oxygen species (ROS) generated by hydrogen peroxide or UVB treatment of the cells. DBA also decreased the UVB-augmented levels of phospho-histone H2A.X and the extent of comet tail formation, which are both indications of damaged DNA. In addition, the compound prevented keratinocytes from UVB-induced injury by reversing the production of apoptotic bodies, overturning the disruption of mitochondrial membrane potential, increasing the expression of the anti-apoptotic protein, B-cell lymphoma 2 (Bcl-2) and decreasing the expression of the pro-apoptotic proteins, Bcl-2-associated X (Bax) and cleaved caspase-3. Taken together, these results demonstrate that DBA isolated from a green algae protects human keratinocytes against UVB-mediated oxidative stress and apoptosis.