Objective: To investigate the effects of IPL and IPL plus 5-ALA on the proliferation, melanogenesis and tyrosinase activity of cultured B16 murine melanoma cells.
Methods: B16 cells were pretreated with or without ALA and irradiated with IPL (20, 30, 40 J/cm2), also the negative control group and the positive control UVA irradiation group (3, 4, 5 J/cm2) were designed. The proliferation of the treated B16 cells were evaluated with MTT method, the melanogenesis of the cells was tested with NaOH assay as well as tyrosinase activity was detected at 1 d, 2 d, 3 d, 4 d, and 5 d after irradiation.
Results: 5 mmol/L 5-ALA did not affect the proliferation, melanogenesis and tyrosinase activity in B16 melanoma cell. The cell yielding in UVA group increased significantly (P < 0.05) compared with that of negative control group after UVA irradiation (3, 4 J/cm2), but the proliferation of the treated B16 cells were suppressed after UVA irradiation (5 J/cm2). IPL (20, 30, 40 J/cm2) or IPL plus ALA did not have any significant effects on cell proliferation. IPL or IPL plus ALA have inhibitory effects on melanogenesis without any influence on cell tyrosinase activity in B16 cells. ALA, as the photosensitizer, combined with IPL could have stronger effect than IPL alone.
Conclusions: We demonstrated that UVA could stimulate the proliferation of B16 cells, increase the melanogenesis and tyrosinase activity of the cells. IPL or IPL plus ALA have inhibitory effects on melanogenesis without any influence on cell proliferation and tyrosinase activity in B16 cells. IPL plus ALA had stronger effect than IPL alone.