Gamma irradiation of aloe-emodin induced structural modification and apoptosis through a ROS- and caspase-dependent mitochondrial pathway in stomach tumor cells

AbstractPurpose: The changes in molecular structure and the physiological properties of a gamma-irradiated aloe-emodin were examined.Materials and methods: Aloe-emodin was gamma-irradiated at doses ranging from 0 to 150 kGy, and the molecular structure was then analyzed using high-performance liquid chromatography (HPLC). AGS cells were cultured in RPMI medium and treated gamma irradiated aloe-emodin. Cell viability was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis efficiency was investigated by cell cycle arrest, cell morphology, and signaling pathway. The structure of new radiolytic peak was identified by the hydrogen-nuclear magnetic resonance (1H NMR).Results: HPLC results showed that gamma irradiation induced new radiolytic peaks that were distinguishable from the aloe-emodin standard, and the area of new peaks was increased as the radiation dose increased. Gamma-irradiated aloe-emodin treatment significantly increased the cytotoxicity in AGS tum...