AIMClinical studies stated that low molecular weight compounds (< 1.0 kd) extracted from the new born calf liver could effectively inhibit the proliferation of tumor cells. In this report, we observed inhibition effects and their regulative mechanisms of taurine, ornithine, carnosine on the proliferation of HL-60 cells.

METHODSThree active ingredients, i.e., taurine, ornithine and carnosine were separated by ion-exchange chromatographic column and identified from the low molecular weight filtrate of new born calf liver. MTT assay was used to test the survival rate of HL-60 cells and normal lymphocytes treated by the three ingredients. The various effects of the three compounds on HL-60 cells were respectively evaluated by agarose gel electrophoresis, ESR and immunohistochemical methods.

RESULTSThese compounds effectively inhibited the proliferation of HL-60 cells and induced apoptosis which was determined by apoptotic changes in morphology and nuclear DNA degradation. Whereas no inhibition effects on normal lymphocytes were observed. In addition, the results of ESR showed that the activity of oxygen radical within HL-60 cells treated with there compounds decreased to trace level. Furthermore, in the immunohistochemical experiments, we found that the level of p45/skp2 in HL-60 cells decreased while the level of p27/kip increased.

CONCLUSIONThe taurine, ornithine and carnosine compounds can selectively suppress tumor cells proliferation by regulating the level of cell cycle proteins.