Objective To observe the outcomes of using different concentrations of arsenic trioxide at varying phases on the breast cancer cell line MCF-7 and to study the mechanism of this effect. Methods The effect of arsenic trioxide on the growth of breast cancer cell line MCF-7 was observed after applying arsenic trioxide of different concentrations （0.5-16 μmol/Ｌ）. The inhibitory effect of arsenic trioxide on the cell proliferation was investigated with 3-(4，5-dimethyl-thizazol-2-yl)-2， 5-diphenyl tetrazolium bromide (MTT) and the induction of arsenic trioxide on cell apoptosis was detected by DNA ladder and terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results The effect of arsenic trioxide on breast cancer cell line MCF-7 depended on the phase and the dose. The number of cell decreased significantly and there were conspicuously typical morphological changes of apoptosis after the use of arsenic trioxide， including membrane blebbing， chromatin pyknosis, nuclear fragmentation and the formation of apoptotic body. The typical DNA ladders were observed in the MCF-7 cells after 48 h administration of arsenic trioxide at concentrations 1-8 μmol/Ｌ. Significant elevations of apoptosis index at 24 h, 48 h and 72 h were all detected by TUNEL after incubating with 4 μmol/L arsenic trioxide. Conclusion Arsenic trioxide may inhibit the growth of breast cancer cell line MCF-7 significantly by inducing the apoptosis of breast cancer cell.
Objective To explore the effect of artemisinin on the apoptosis of pancreas acinar cells in acute pancreatitis (AP), and to study whether artemisinin can relieve the severity of AP. Methods ① In vivo experiment: twenty one Wistar rats were divided into the following 3 groups randomly: the normal control group, the AP group and the artemisinin group. The model of AP was established by injecting cerulein into the peritoneal cavity of rat. After establishment of AP in the artemisinin group, artemisinin was injected into the peritoneal cavity. Meanwhile normal saline was injected into the peritoneal cavity of rats of the normal control group and the AP group. The apoptosis of pancreas acinar cell was detected by terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The activity of myeloperoxidase was detected by absorption spectrometry. ② In vitro experiment: the pancreas acinar cells of normal rats were isolated through twostep enzyme digestion, and cultured. These acinar cells were divided into 3 groups: the normal control group, the AP group and the artemisinin group. Then, the cells of AP group were cocultured with cerulein, and those of the artemisinin group were cocultured with cerulein and artemisinin. The apoptosis of pancreas acinar cells were detected by AO dyeing and the measurement of the activity of caspase3. And the activity of LDH and AMS in the culture medium of each group were measured. Results ① In vivo: the apoptosis index of the artemisinin group was sigificantly increased and the activity of myeloperoxidase was obviously decreased compared with the AP group (P＜0.05). ② In vitro: the apoptosis index and the activity of caspase3 of the artemisinin group were significantly increased compared with the AP group (P＜0.05); the activities of LDH and AMS of the artemisinin group were more decreased than those of the AP group (P＜0.05). Conclusion Artemisinin could contribute to the apoptosis of rat pancreas acinar cells, decrease the releasing of trypsogen, alleviate the activation of neutrophil and relieve the severity of AP.