Platelet-rich plasma (PRP) has seen wide clinical use owing to its regenerative and repair abilities. Objective: To investigate the anti-photoaging effects of pre-and post-treatment of PRP on UVB-damaged HaCaT cells. Methods: HaCaT cells were irradiated with 80 mJ/cm 2 UVB, before or after PRP treatment (1000 × 10 7 /L), and following measurements were taken: survival rate of UVB-irradiated HaCaT cells, malondialdehyde (MDA) content and activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT). Western blot was used to determine the effect of different PRP intervention on the expression of PI3K, AKT, ERK, MMP-1, MMP-9, TIMP-1 and γ-H2AX in the UVB-irradiated HaCaT cells. Results: pre-and post-PRP treatment reduced MDA content and increased the activities of GSH-Px, SOD and CAT in photoaged HaCaT cells. These changes resulted in reduced cytotoxic effects. Besides, different PRP intervention promoted cell proliferation via PI3K/AKT pathway. Furthermore, PRP application suppressed the expression of γ-H2AX. Also, PRP intervention alleviated photoaging effects by upregulating the expression level of tissue inhibitor of metalloproteinases-1 (TIMP-1) while downregulating matrix metalloproteinase (MMP) expression level in photoaged HaCaT cells. Conclusion: pre-and post-PRP treatment play anti-photoaging role through strengthening cellular oxidative defense capacity, mitigating MMP expression, alleviating DNA damages and promoting proliferation of UVB-irradiated HaCaT cells.Abbreviations: APB-PRP, adult peripheral blood-derived PRP; HaCaT, human keratinocyte cells; PRP, platelet-rich plasma; UCB-PRP, umbilical cord blood-derived PRP.

To investigate the role of Platelet-rich plasma(PRP) from different sources in alleviating oxidative stress and ameliorating melanogenesis in UVB-irradiated PIG1 cells. PIG1 cells were irradiated with 80 mJ/cm2 UVB prior to 1% PRP application and the following experiments were taken: The viability of UVB-irradiated PIG1 cells, cellular malondialdehyde (MDA) and reactive oxygen species (ROS)content, and activities of anti-oxidant enzymes. Western blotting was utilized to detect the expression level of proteins associated with melanin synthesis, apoptosis and DNA lesions. We found that PRP intervention promoted cell proliferation, reduced MDA and ROS content, increased the activities of series of anti-oxidant enzymes and alleviated DNA damages in UVB-damaged PIG1 cells. Of notes, PRP treatment inhibited UVB-induced melanogenesis via PI3K/Akt/GSK3β signal pathway. Therefore, we suppose PRP treatment exerts protective role through their anti-oxidation effect on UVB-damaged PIG1 cells and hinders melanogenesis induced by UVB irradiation.