Relation of apoptosis of K562 cells induced by naringenin in vitro to enzyme activity changes of caspase-3 and caspase-8 and expression of FAS/FASL proteins / 中国实验血液学杂志

The objective of this study was to investigate the apoptosis-inducing effect and underlying mechanism of naringenin (NGEN) on K562 cells in vitro. The inhibition of NGEN on K562 cells was evaluated by means of MTT assay so as to observe the cytotoxicity of NGEN; The morphological changes of the cells treated by NGEN were observed by transmission electron microscope; cell apoptosis rate influenced by NGEN was assessed by flow cytometry; the enzyme activity changes of caspase-3 and caspase-8 in the process of NGEN-induced K562 apoptosis were detected by Caspase Colorimetric Assay Kit; immunohistochemistry technique was used to detect FAS, FASL protein expression in K562 cells. The results showed that the growth of cells was inhibited by NGEN in dose-and time-dependent manners (p<0.05); NGEN-induced K562 cells apoptosis and sub-G1 peak was observed; some typically early and final phase changes of cell apoptosis were revealed under transmission electron microscope; the enzyme activity of caspase-3 and caspase-8 and the expression of FAS remarkably increased, meanwhile the expression of FASL was down-regulated (p<0.05). It is concluded that NGEN exerts anti-cancer effect by inducing K562 cell apoptosis, and the regulation of the expression of FAS and FASL. The caspase-3 and caspase-8 co-pathway brings about one of the mechanisms.

Protection against doxorubicin-induced oxidative damage in normal blood cells by naringenin / 中国实验血液学杂志

The objective of this study was to investigate the protection by naringenin against doxorubicin-induced oxidative damage in normal blood cells. Inhibiting effects of naringenin, doxorubicin and naringenin combined with doxorubicind on K562 cells and polymorphonuclear leukocytes were detected with MTT method, the level of reactive oxygen species (ROS) and lipid peroxidation (MDA), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were examined with spectrophotometric method in the K562 cells and polymorphonuclear leukocytes. The results indicated that the proliferation of K562 cells was not inhibited by the cytotoxicity of doxorubicin in combination of naringenin with doxorubicin. As compared with the doxorubicin, the addition of naringenin after doxorubicin for 1 hour, the levels of reactive oxygen species (ROS) and lipid peroxidation (MDA) obviously decreased, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) obviously increased in the polymorphonuclear leukocytes, but these were not changed obviously in K562 cells. It is concluded naringenin can protect against doxorubicin-induced oxidative damage in normal blood cells. The mechanism of naringenin may be elevating activities of antioxidant enzyme and degrading oxidative production level in normal blood cells, and meanswhile decreasing level of oxidative products.