Intracellular ROS amounts in HaCaT cells as quantified by NBT assay. Figures 10-a, -b: The retained cell morphology and the diminished ROS were shown in HW-prepared culture medium for comparing with RW. Yellow dashed lines indicate abundant dark-blue dyes that were the reaction products where ROS such as superoxide anion radical was found to react with NBT-stain. Figures 10-c, -d: The expressions of surface plotter by ImageJ. Figure 10-e: The mean gray values obtained from ImageJ used to express the increase or decrease in superoxide anion radicals within normal human epidermis-derived keratinocytes HaCaT according to NBT-stain. In detail, the vertical axis shows the brightness presented as a mean gray value, which is considered as an index to show the cellular stained intensity and use to indicate ROS amounts. The cell morphologies of RW and HW were divided into the eight regions and then compared with their mean gray values by Student’s t-test (** p < 0.01). Magnification: ×200; scale bars = 100 μm.