Photoprotective Effect of a Polyopes affinis (Harvey) Kawaguchi and Wang (Halymeniaceae)-Derived Ethanol Extract on Human Keratinocytes

  • YJ Hyun
  • MJ Piao
  • KC Kim
  • J Zheng
  • CW Yao
  • JW Cha
  • HK Kang
  • ES Yoo
  • YS Koh
  • NH Lee
  • MH Ko
  • JW Hyun
Keywords: Human keratinocytes, Polyopes affinis, Reactive oxygen species, Red algae, Ultraviolet B, Apoptosis, DNA fragmentation

Abstract

Purpose: To investigate the photoprotective effect of the ethanol extract of the red marine alga, Polyopes affinis (PAE) against ultraviolet B (UVB) radiation on cultured human keratinocytes.
Methods: The 2',7'-dichlorodihydrofluorescein diacetate method was used to detect intracellular reactive oxygen species (ROS) generated by H2O2 treatment or UVB radiation. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT ) assay. Superoxide anion or hydroxyl radical was detected using an electron spin resonance spectrometer after reaction with the nitrone spin trap. Lipid peroxidation was assayed by determining the level of 8-isoprostane. Protein carbonyl formation was determined using a protein carbonyl ELISA kit. The degree of oxidative DNA damage was determined using an alkaline comet assay. Apoptosis was assessed by apoptotic bodies and DNA fragmentation.
Results: PAE significantly scavenged the free radical 1,1-diphenyl-2-picrylhydrazyl, as well as hydrogen peroxide- and UVB-induced intracellular ROS. Furthermore, PAE showed 23 % scavenging effect of the superoxide anion and 33 % of the hydroxyl radical. PAE also absorbed UVB rays in the 280 – 320 nm range. PAE significantly decreased cellular damage resulting from UVB-induced oxidative stress to lipids, proteins, and DNA. Furthermore, PAE-treated keratinocytes showed significant reduction in UVB-induced apoptosis, as exemplified by fewer apoptotic bodies and reduced DNA fragmentation.
Conclusion: These results suggest that PAE protects keratinocytes against UVB-induced oxidative stress by absorbing UVB rays and scavenging ROS, thereby reducing injury to cellular constituents.

Keywords: Human keratinocytes, Polyopes affinis, Reactive oxygen species, Red algae, Ultraviolet B, Apoptosis, DNA fragmentation

Published
2014-09-12
Section
Articles

Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996