Effects of the main extracts of Astragalus membranaceus on inducing the erythroid differentiation of K562 cells / 解放军医学杂志

ABSTRACT

Objective To investigate the effects of different astragalosides(AST) and hydro-soluble astragali polysaccharide(APS) of Astragalus membranaceus on inducing erythroid differentiation of human leukaemic K562 cells.Methods APS and AST were extracted by alcohol or water from Astragalus membranaceus.K562 cells were treated with APS,AST and sodium butyrate(BA) respectively.The proportion of benzidine-positive cells was examined after 1-4 days culture.MTT assay was performed for evaluating the proliferation effects of APS,AST and BA on K562 cells.Results The percentages of benzidine-positive cells induced by APS,AST and BA were 13.2%,2.9% and 17.5%,respectively.The kinetic characteristics of K562 cells induced by different levels of APS(1,2,4,8mg/ml) indicated that 4 mg/ml APS was sufficient to induce K562 cells to turn to be benzidine-positive.The results suggested that APS,other than AST,could induce the K562 cells towards erythroid differentiation.Compared with BA,the percentage of benzidine-positive cells induced by APS was lower at 24h,48h and 72h(F=237.44,P=0.00),while the total number of benzidine-positive cells was higher at 96h(F=322.25,P=0.00).The results of MTT assay for Absorbance(A) showed that APS and AST had no inhibitory effects on growth of K562 cells(P=0.28,P=0.11),while BA showed an obvious inhibitory effect on K562 cells(P=0.00).Conclusion Astragalus membranaceus has pharmacological effects to induce the K562 cells towards erythroid differentiation,and its valuable constituents are contained in hydro-soluble astragali polysaccharide(APS).The induction of differentiation is most evident with a dosage of 4 mg/ml APS.The cell growth curve reveals that APS has no inhibitory effect on K562 cells.