Figure 4.

Rhodamine detection of ROS in neuronal PC12 cells after MPP⁺ and/or CuE treatment. Nonfluorescent DHR is converted to fluorescent rhodamine in the presence of several free radicals (OH^•, NO₂ ^•, CO₃ ^•−, H₂O₂, HOCl, and ONOO⁻). (a) Fluorescent microscopy. A significant signal is marked in neuronal cells treated with MPP⁺ but not in those exposed to CuE or the vehicle (Ctrl). Administration of CuE + MPP⁺ does not reduce fluorescence significantly compared to MPP⁺ alone. Scale bar = 10 μm. (b) Histogram. Semiquantitative analysis of rhodamine fluorescence. Data are expressed as relative fluorescence units and are means ± S.E.M. n = 4. ^*** P < 0.001 versus Ctrl and n.s. = nonsignificant.