黄芪不同提取物对K562细胞向红系分化的诱导作用研究

Effects of the main extracts of Astragalus membranaceus on inducing the erythroid differentiation of K562 cells

目的探讨黄芪不同提取物对K562细胞向红系分化的影响。方法用超声醇提水提法从黄芪根中获取富含黄芪总苷(AST)的醇溶部分和富含黄芪多糖(APS)的水溶部分并分别作用于K562细胞,联苯胺染色法观察K562细胞向红系分化的情况,MTT法测定细胞活性。以丁酸钠(BA)处理的K562细胞作为阳性对照。结果以不同浓度(1、2、4、8mg/ml)APS作用于K562细胞后显示其有诱导后者向红系分化的作用,以4mg/ml为最适浓度,而AST诱导作用不明显。4mg/ml APS、AST及0.5mmol/L BA作用后K562细胞的联苯胺染色阳性率(BZ%)峰值分别为13.2%、2.9%及17.5%。以4mg/ml APS作用于K562细胞24、48、72h后,其BZ%显著低于同时点BA组(P<0.01),但72、96h的联苯胺染色阳性细胞总数明显高于BA组(P<0.01)。MTT测定结果显示,APS、AST对K562细胞的生长无明显抑制作用,而BA对细胞生长有明显抑制作用(P<0.01)。结论黄芪可诱导K562细胞向红系分化,其有效成分在富含多糖的水溶部分(APS),以4mg/ml浓度的诱导作用最强。黄芪提取物对K562细胞的生长无明显抑制作用。

Objective To investigate the effects of different astragalosides （AST） and hydro-soluble astragali polysaceharide （APS） of Astragalus membranaceus on inducing erythroid differentiation of human leukaemie 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 polysaceharide （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.