Carnosic acid (CA) accumulates both in neurons and in non-neuronal cells. (a, c, and e) Cortical cultures (E17, DIV21) treated with various concentrations of CAB for 20 h were stained with anti-MAP2 monoclonal antibody to identify neurons (green) and rhodamine-conjugated streptavidin antibody to detect intracellular CAB (red). Hoechst dye 33,258 was used to label nuclei (blue). (b, d, and f) Anti-S100 monoclonal antibody was used to identify non-neuronal cells (green). Yellow and white arrows indicate accumulation of CAB in non-neuronal cells and neurons, respectively. Scale bar: 25 μm.