Fucoidan refined by Sargassum confusum indicate protective effects suppressing photo-oxidative stress and skin barrier perturbation in UVB-induced human keratinocytes

Int J Biol Macromol. 2020 Dec 1;164:149-161. doi: 10.1016/j.ijbiomac.2020.07.136. Epub 2020 Jul 16.


Damage from ultraviolet (UV)B exposure is cumulative and proceeds via augmenting cellular oxidative stress. The present study investigates UVB-protective effects of Sargassum confusum derived fucoidans in human keratinocytes. Algae was extracted using Celluclast, and fucoidan fractions were recovered by step gradient ethanol precipitation. Refined fucoidan fractions were treated to human HaCaT keratinocytes and exposed to UVB (50 mJ cm-2). Among fucoidan fractions, SCFC4, the lowest molecular weight (MW) fraction indicated better UVB-protective effects with dose-dependent reduction of intracellular ROS levels, while recovering the cell viability. SCFC4 suppressed UVB-induced apoptotic body formation, sub-G1 cell content, and DNA damage by hindering the mitochondria-mediated apoptotic pathway. Also, SCFC4 repressed upstream mediators of UVB-induced inflammatory responses, which would impair stratum corneum hydration. The above therapeutic effects of SCFC4 could be attributed to suppression of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) pathways while activating nuclear factor erythroid 2-related factor 2 (Nrf2) mediated production of antioxidant enzymes. SCFC4 was identified as a fucoidan (MW ≈ 20 kDa) with a 64.64% fucose and 23.62% sulfate contents. Further analysis of shelf life, safety, and efficacy could promote SCFC4's use as a cosmetic ingredient.

Keywords: Fucoidan; Sargassum confusum; Skin hydration.

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Apoptosis / radiation effects
  • Benzimidazoles
  • Carbocyanines
  • Cell Cycle / drug effects
  • Chemical Precipitation
  • DNA Damage
  • Dose-Response Relationship, Radiation
  • Electrophoresis, Agar Gel
  • Ethanol
  • Humans
  • Keratinocytes / drug effects*
  • Keratinocytes / radiation effects
  • MAP Kinase Signaling System / drug effects
  • Mitochondria / drug effects
  • Mitochondria / radiation effects
  • Molecular Weight
  • NF-E2-Related Factor 2 / physiology
  • NF-kappa B / metabolism
  • Nuclear Magnetic Resonance, Biomolecular
  • Oxidative Stress / drug effects
  • Photochemistry
  • Polysaccharides / chemistry
  • Polysaccharides / isolation & purification*
  • Polysaccharides / pharmacology
  • Sargassum / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Ultraviolet Rays


  • Benzimidazoles
  • Carbocyanines
  • NF-E2-Related Factor 2
  • NF-kappa B
  • NFE2L2 protein, human
  • Polysaccharides
  • 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine
  • Ethanol
  • fucoidan