Effect of Huaier Aqueous Extract Combined with Routine Chemo-therapeutic Drugs on Human Acute Lymphoblastic Leukemia Cells Nalm-6 and Sup-B15

Abstract

To investigate the proliferation inhibition and pro-apoptotic effect of Huaier aqueous extract combined with routine chemotherapeutic drugs including Vincristine (VCR), Daunorubicin (DNR), L-aspartase (L-Asp) on human acute lymphoblastic leukemia cell lines Nalm-6 and Sup-B15. Nalm-6 and Sup-B15 cell lines were treated with different concentrations of Huaier aqueous extract and chemotherapeutics including VCR, DNR, L-Asp alone or in combination for 48 h, and the growth inhibitory effect and IC50 values (the half maximal inhibitory concentration) were detected by CCK-8. Jin's formula was used to estimated the synergistic effect of these combinations. Apoptosis rates of Nalm-6 and Sup-B15 cells and expression of apoptosis-related proteins BAX, BCL-2, cleaved Caspase-3 were determined by flow cytometry and Western blot respectivcly. Huaier aqueous extract, VCR, DNR and L-Asp had inhibition effect on Nalm-6 and Sup-B15 cell lines. The inhibition rate of Huaier aqueous extract combined with VCR, DNR and L-Asp were all higher than those of each dug alone (P＜0.05) and the combination index (q) was between 0.85 and 1.15 or greater than 1.15. The two kinds of drugs showed had additive or synergistic effects. The results of flow cytometry showed that the cell apoptosis rates in combined treatment group were higher than those of each drug alone (P＜0.05). The results of Western blot revealed that Huaier aqueous extract and VCR all decreased protein expression of BCL-2 (P＜0.05) and increase protein expression of BAX (P＜0.05) and cleaved Caspase-3 (P＜0.05) in Nalm-6 and Sup-B15 cells. Compared with Huaier aqueous extract or VCR alone, the effect of two drug combination were more significant. DNR down-regulated protein expression of BCL-2 (P＜0.05) and up-regulated cleaved Caspase-3 (P＜0.05). However, it had no effect on the expression of BAX in Nalm-6 and Sup-B15 cells. When it was combined with Huaier aqueous extract, the expression of cleaved Caspase-3 and BCL-2 showed more significant changes. The expression of BAX in combined treated group did not show significant difference, compared with group treated with Huaier aqueous extract in Nalm-6 and Sup-B15 cells. L-Asp did not show significant effect on the three apoptosis-related proteins and there was no significant difference between the combination group and the Huaier aqueous extract group. the combination of Huaier aqueous extract and VCR, DNR, L-Asp shows additive or synergistic effects on human acute lymphoblastic leukemia cell lines Nalm-6 and Sup-B15.