Fig. 3
Free radical scavenging activity analysis and intracellular reactive oxygen species (ROS) production in Quercus acuta Thunb. fruit (QAF)-treated HaCaT cells. (A) Effects of QAF on ROS production following ultraviolet B (UVB) irradiation. HaCaT cells were pretreated with a range of concentrations of QAF (5, 10, 20, and 50 μg/mL) or vitamin C (ascorbic acid) at 200 μM for 24 h, H2O2 (100 μM) for 2 h, followed by exposure to 30 mJ/cm2 UVB. After incubation, cells were stained with DCFH-DA (20 μM) for 30 min. Fluorescence was then measured using a fluorescence spectrophotometer. (B) 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and (C) 2,20-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities. DPPH was examined with different concentrations of QAF, and ascorbic acid was used as a standard. Data are expressed as the mean ± SD. #p < 0.05, ##p < 0.01, ###p < 0.001 versus control group; *p < 0.05, **p < 0.01, ***p < 0.001 versus UVB-treated group