Phloroglucinol protects human keratinocytes from ultraviolet B radiation by attenuating oxidative stress.
Ultraviolet B generates reactive oxygen species by interacting with water in irradiated skin tissues and cells in turn causes lipid peroxidation, protein modification and further DNA damage. This study examined the cytoprotective effects of phloroglucinol (1,3,5-trihydroxybenzene) on ultraviolet B-irradiated cultured human keratinocytes. The human keratinocyte cell line HaCaT cells were treated with 10 μM of phloroglucinol. After 1 h, the cells were irradiated with ultraviolet B light at 30 mJ/cm(2) and incubated at 37°C. Phloroglucinol scavenged both the superoxide anion and hydroxyl radical in a cell-free system and ultraviolet B-induced intracellular reactive oxygen species. Phloroglucinol reduced ultraviolet B-generated lipid peroxidation, protein modification and DNA strand breaks. The enzymatic effects of phloroglucinol restored cellular glutathione levels, superoxide dismutase and catalase activities, which were impaired by ultraviolet B radiation. Phloroglucinol provides the protective effects in human keratinocyte cell line exposed to ultraviolet B radiation, suggesting that phloroglucinol can be used as a photoprotective agent.