Abstract: Objective: To determine the protective effect of dihydroartemisinin (DHA) on HaCaT cells apoptosis induced by UVB. Methods: HaCaT cells cultured in vitro were divided into blank control group, UVB group and UVB+DHA (20, 40, 60, 80 μmol/L) group. The proliferation of HaCaT cells, cell apoptosis, mRNA levels of anti-apoptotic gene survivin and pro-apoptotic gene caspease-3 and corresponding protein levels were detected by MTT, flow cytometric analysis, qRT-PCR and Western blotting. Results: After the HaCaT cells was irradiated for 24 hs, the proliferation of the cells in the UVB group and UVB+DHA (20, 40, 60, 80 μmol/L) groups was (50.13±2.42)%, (60.23±2.30)%, (69.24±3.19)%, (79.37±2.47)% and (70.41±2.24)% of the blank control group. The apoptosis rate in the UVB group and UVB+60 μmol/L DHA group was (46.7±3.2)% and (23.71±1.2)%. Compared with the UVB group, the mRNA and protein levels of pro-apoptotic gene caspease-3 in the UVB+60 μmol/L DHA group was decreased and the levels of anti-apoptotic gene survivin was increased. Conclusion: DHA inhibits the apoptosis of HaCaT cells induced by UVB, which may be related with caspase-3 and survivin.

Key words: dihydroartemisinin, HaCaT cells, caspase-3, UVB