BACKGROUND: Ultraviolet B (UVB) irradiation induces photoaging and apoptosis in various cell types. Inhibition of UVB-induced apoptotic pathways has been explored in different apoptotic cascades. Conditioned media from human umbilical cord blood mesenchymal stem cells (CM-hUCB-MSC) contain important substances for cell regeneration. However, the potential of CM-hUCB-MSC in preventing UVB-induced apoptosis has not been clearly elucidated. Therefore, the current research was conducted to investigate the potential of CM-hUCB-MSC in inhibiting UVB-induced apoptosis and its role in the antiapoptotic signaling pathway. METHODS: An experimental RESULTS: CM-hUCB-MSC significantly inhibited UVB-induced apoptosis in NIH3T3 cells (P=0.002, Dunn-Bonferroni test). CM-hUCB-MSC significantly induced Akt phosphorylation at Ser 473 in UVB-irradiated NIH3T3 cells (P<
0.001, Tukey's HSD test). The CM-hUCB-MSC-induced phosphorylation of Akt was significantly inhibited by LY294002 (P<
0.001, Tukey's HSD test). CONCLUSION: Taken together, it can be concluded that CM-hUCB-MSC inhibits UVB-induced NIH3T3 cell apoptosis via the activation of phosphatidylinositol-3-kinase (PI3K)/Akt signaling cascades.