1. Photoprotective Effect of a Polyopes affinis (Harvey) Kawaguchi and Wang (Halymeniaceae)-Derived Ethanol Extract on Human Keratinocytes
- Author
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Hyun, YJ, Piao, MJ, Kim, KC, Zheng, J, Yao, CW, Cha, JW, Kang, HK, Yoo, ES, Koh, YS, Lee, NH, Ko, MH, and Hyun, JW
- Subjects
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