Characterization and cytoprotective properties of Sargassum natans fucoidan against urban aerosol-induced keratinocyte damage.

The escalation of fine particulate matter (PM) air pollution has recently become a global concern. Evidence is fast accumulating on PM exposure-related skin damage. The present study explored the therapeutic potentials of fucoidan purified from Sargassum natans against damaging effects of PM exposure on human HaCaT keratinocytes. Fucoidan (SNF7) was purified from S. natans by an enzyme-assisted extraction and purified by anion exchange chromatography. SNF7 (≈50 kDa) was identified as a fucoidan containing 70.97% fucose and 36.41 ± 0.59% of sulfate. Treatment of fine dust from Beijing, China (CFD) increased intracellular ROS levels in HaCaT cells triggering DNA damage and apoptosis. Treatment of SNF7 dose-dependently attenuated CFD-induced surge of intracellular ROS levels in keratinocytes by increasing antioxidant defense enzymes. Moreover, SNF7 chelated metal ions Pb2+, Ba2+, Sr2+, Cu2+, Fe2+, and Ca2+ coming from CFD. The results substantiated the potential therapeutic effects of SNF7 against CFD-induced oxidative stress. Further studies could promote SNF7's use as an active ingredient in cosmetics.