ROS production by blue, white and green LED light exposure.
(A–C) Blue LED light and white LED light exposure increased each 1.4-fold and 1.2-fold ROS production and green LED light did not increase ROS level. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA). (D) Representative images show JC-1 stained cells. The healthy cells with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells. Scale bar represents 50 μm. (E) The number of cells with red or yellow color were counted. The ratio of merged cells to red color cells was increased by blue LED light exposure for 12 h or 24 h. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA).