Alanine and glutamic acid induced apoptosis of gastric cancer cell line. (A-B). Induction of apoptosis was detected by flow cytometry with Annexin V-PI staining. Representative flow cytometry plots demonstrating an increase in apoptosis of gastric cancer cell lines after treatment with 10 mM Ala or Glu for 48 h (A). From parallel experiments, apoptosis was quantified (B). (C-D). Induction of apoptosis in SGC-7901 cells through dysregulation of the mitochondrial membrane potential. SGC-7901 cells were treated with 10 mM Ala, 10 mM Glu or negative control (NC) for 24 h, respectively. Then the mitochondrial membrane depolarization of cells was examined by JC-1 dye staining with confocal microscopy. Left and middle images showed green JC-1 monomer and red JC-1 aggregate, respectively. The right images showed the overlay of two images. Green fluorescence indicates the presence of depolarized mitochondria (apoptotic cells). Red fluorescence indicates normally functional and polarized mitochondria (healthy cells) (C). From parallel experiments, quantitative assessment of mitochondrial membrane depolarization in SGC-7901 cells was presented as ratio of JC-1 aggregates/monomers (D). Data were represented as mean ± SD of three independent experiments. *P < 0.05 versus NC.