Determination of intracellular ROS production. (A) Image of green fluorescence in NHDF cells. After DCF-DA treatment, green fluorescence in cells was observed under a fluorescent microscope (Eclipse TX100, Nikon, Tokyo, Japan). NHDF cells were also examined under an optical microscope (left column) and a florescence microscope (right column) at 200× magnification. (B) Level of green fluorescence in NHDF cells. Signal intensities were quantified using ImageJ software [17]. Data are reported as the means ± SD. * p < 0.05 compared to the No group. # p < 0.05 compared to the UV + Vehicle group. Abbreviations: LCPO, low concentration CPO; MCPO, medium concentration CPO; HCPO, high concentration CPO; GEGR, gallotannin-enriched extract of Galla Rhois.