Study of Solanine on Mitochondrion in HepG2 Cell

Objective: To observe the effect of solanine on the membrane potential of mitochondria in HepG

2

cells and [Ca

2+

]

i

in the cells, and to uncover the mechanism by which solanine induces apoptosis.Methods: HepG

2

cells are double stained with AO/EB, and morphological changes of the cells are observed using laser confocal scanning microscopy (LCSM). HepG

2

cells are stained with TMRE, and change in the membrane potential of mitochondria in the cells are observed using LCSM. HepG

2

cells are double stained with Fluo-3/AM, and change of [Ca

2+

]

i

in the cells are observed using LCSM. HepG

2

cells are double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca

2+

]

i

in the cells are observed using LCSM.Results: Cells in treated groups show typical signs of apoptosis. The results of staining with TMRE show that solanine can lower membrane potential; those of staining with Fluo-3/AM show that solanine can increase the concentration of Ca

2+

in tumor cells; and those of double staining with TMRE and Fluo-3/AM show that solanine can lower membrane potential; those of staining with TMRE show that solanine can increase the concentration of Ca

2+

in the cells at the same time as it lowers the membrane potential of mitochondria. Conclusions: Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca

2+

being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca

2+

in the cell, turning on the mechanism for apoptosis.