Abstract: OBJECTIVE To explore the protective effect of astaxanthin on blue light induced oxidative damage in mouse cone cells(661W).METHODS 661W cells were divided into three groups: normal group, blue light group and astaxanthin intervention group. Cells in astaxanthin intervention group were pretreated with 15 μmol·L^-1 astaxanthin solution for 24 h, and the other two groups did not give the drug intervention. After 24 h, cells in astaxanthin intervention group and blue light group were exposed to 450 nm short-wave blue light for 6 h, while cells in normal group were cultured routinely. After 12 h, cells were collected. The optimal astaxanthian concentration were screened by CCK-8 detection kit. Reactive oxygen species(ROS) detection kit was used to detect the intracellular ROS generation. The relative expressions of nuclear factor E2-related factor 2(Nrf2) and heme oxygenase-1(HO-1) in cone cells were detected by Real-time PCR and immunofluorescence assay.RESULTS CCK-8 assay showed that the optimal concentration of astaxanthin was 15 μmol·L^-1. Compared with control group, the generation of ROS was increased after blue light irradiation(P < 0.01). The enhancement of oxidative stress led to a significant decrease in cell proliferation activity. The mRNA relative expressions level of Nrf2 and HO-1 were increased. Immunofluorescence assay showed that the level of Nrf2 was decreased, while the level of HO-1 was increased. All the differences were statistically significant(P < 0.01). Compared with blue light group, astaxanthin pretreatment significantly reduced ROS content while increased cell proliferation activity(P < 0.01). The mRNA relative expressions levels of Nrf2 and HO-1 were decreased(P < 0.01), and the protein expression level of Nrf2 and HO-1 were increased(P < 0.05).CONCLUSION Astaxanthin can inhibit oxidative stress injury and the over-activation of the Nrf2/HO-1 pathway induced by short-wave blue light, and maintain the Nrf2/HO-1 pathway homeostasis, which is expected to provide a new protective strategy for blue light-induced retinal injury.