Panax ginseng Fraction F3 Extracted by Supercritical Carbon Dioxide Protects against Oxidative Stress in ARPE-19 Cells

In our previous work, the ethanolic extract of Panax ginseng C. A. Meyer was successively partitioned using supercritical carbon dioxide at pressures in series to yield residue (R), F1, F2, and F3 fractions. Among them, F3 contained the highest deglycosylated ginsenosides and exerted the strongest antioxidant and anti-inflammatory activities. The aim of this study was to investigate the protective effects of P. ginseng fractions against cellular oxidative stress induced by hydrogen peroxide (H2O2). Viability of adult retinal pigment epithelium-19 (ARPE-19) cells was examined after treatments of different concentrations of fractions followed by exposure to H2O2. Oxidative levels (malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and reactive oxygen species (ROS)) and levels of activity of antioxidant enzymes were assessed. Results showed that F3 could dose-dependently protected ARPE-19 cells against oxidative injury induced by H2O2. F3 at a level of 1 mg/mL could restore the cell death induced by H2O2 of up to 60% and could alleviate the increase in cellular oxidation (MDA, 8-OHdG, and ROS) induced by H2O2. Moreover, F3 could restore the activities of antioxidant enzymes suppressed by H2O2. In conclusion, F3 obtained using supercritical carbon dioxide fractionation could significantly increase the antioxidant capacity of P. ginseng extract. The antioxidant capacity was highly correlated with the concentration of F3.