Figure 1.

Effects of ginsenoside Rd (GSRd) on viability of 1-methyl-4-phenylpyridinium (MPP⁺) treated SH-SY5Y cells. (A,B) After incubation in 150 μM MPP⁺ with or without GSRd for 72 h, cell death and cell viability were assessed by lactate dehydrogenase (LDH) leakage and methylthiazolyldiphenyl-tetrazolium bromide (MTT) assays. Control group was treated with MPP⁺ alone, and GSRd 0 μM group was treated with MPP⁺ and vehicle; (C) Representative photomicrographs showing Hoechst 33342 and propidium iodide (PI) double stained SH-SY5Y cells of normal, control and GSRd 10 μM group; (D) The percentages of surviving cells in different groups based on Hoechst 33342/PI double staining. Scale bar: 50 μm (200×); and (E) The protective effect of GSRd at different concentrations of MPP⁺. * p < 0.05; ** p < 0.01; and *** p < 0.001 vs. control group.