Figure 5.

Fluorescence photomicrograph of effects of zeaxanthin on mitochondrial transmembrane potential (MTP) of uveal melanoma cells after JC-1 staining. Melanoma cells (C918) were treated by zeaxanthin at 0 (upper row) and 30 μM (lower row) for 24 h, and the MTP was determined by JC-1 staining (see Section 2). Cells were observed by fluorescence microscopy using dual band-pass filters (at 490 nm excitation and 530 and 590 nm emission). In normal mitochondria, the aggregated dye appears as red fluorescence located in the mitochondria (upper), whereas in cells with damaged MTP, the dye remains as monomers in the cytoplasm with diffuse green fluorescence (lower). The MTP in melanoma cells was observed at 530 nm (left) and 590 mm (right).