Effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca2+]i in the cells.
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 were double stained with AO/EB, and morphological changes of the cells were observed using laser confocal scanning microscopy (LCSM). HepG(2) cells were stained with TMRE, and change in the membrane potential of mitochondria in the cells were observed using LCSM. HepG(2) cells were double stained with Fluo-3/AM, and change of [Ca(2+)](i) in the cells were observed using LCSM. HepG(2) cells were 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 were observed using LCSM.


RESULTS
Cells in treated groups showed typical signs of apoptosis. Staining with TMRE showed that solanine could lower membrane potential; staining with Fluo-3/AM showed that solanine could increase the concentration of Ca(2+) in tumor cells; and those of double staining with TMRE and Fluo-3/AM showed that solanine could increase the concentration of Ca(2+) in the cells at the same time as it lowered the membrane potential of mitochondria.


CONCLUSIONS
Solanine opens up the PT channels in the membrane by lowering the membrane po-tential, 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.
Gao
Shi-Yong
SY
Department of Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu Province.
Wang
Qiu-Juan
QJ
Ji
Yu-Bin
YB
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000032:analysis* / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology*; D045744:Cell Line, Tumor; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D008113:Liver Neoplasms / Q000737:chemistry* / Q000473:pathology / Q000503:physiopathology*; D008564:Membrane Potentials / Q000187:drug effects* / Q000502:physiology; D018613:Microscopy, Confocal; D051336:Mitochondrial Membranes / Q000187:drug effects* / Q000502:physiology; D012992:Solanine / Q000494:pharmacology*
D012992:Solanine; D002118:Calcium