Purpose: We aimed to find active substances to help relieve the symptoms caused by increased photosensitivity after alpha hydroxy acid (AHA) peeling.
Methods: A questionnaire survey was provided to 66 patients who received AHA peeling therapy to understand if increased photosensitivity existed and its specific symptoms. We verified increased photosensitivity after AHA peeling by monitoring cell viability to detect the combined toxicity of glycolic acid (GA) and UVB in HaCaT cells. The ELISA method was used to determine the expression of KLK7, FLG, IL-1β, and IL-8 to correlate damage to the skin barrier and inflammation induced by GA and UVB and the relieving effects of Portulaca oleracea extract.
Results: Our survey results showed that 6.06% of people were more sensitive to sunlight after AHA peeling than before. Experiments at the cellular level showed that UVB induced cytotoxicity on HaCaT cells pre-treated with GA. Combined exposure of GA and UVB induced up-regulation of KLK7 and down-regulation of FLG and increased inflammatory cytokines of IL-1β and IL-8. P. oleracea extract inhibited the reduction of FLG and increased KLK7, IL-1β, and IL-8 expression caused by combined exposure.
Conclusions: Our study found that combined exposure to GA and UV disrupted the skin barrier and induced significant inflammation. These results provided a theoretical basis for increased photosensitivity after chemical peeling. P. oleracea extract ameliorated GA and UVB-induced impaired skin barrier function and inflammation in HaCaT cells and may have the potential to relieve photosensitivity after AHA peeling.
Keywords: Alpha hydroxy acids peeling; Portulaca oleracea; photosensitivity; skin barrier.