After irradiation by 8. 0 Gy γ-ray, each mouse was stomach-fed by 4 mg ligustrazine injection twice a day. On the 7th day after irradiation, CD49d expression in ligustrazine-treated group was significantly higher than that in control group (P<0. 01), and showed no difference from that in normal group (P> 0. 05). On the 14th day after irradiation. CD49d expression was increased in control group, but decreased significantly in ligustrazine-treated group (P<0. 01). The expression of Cyclin D2 in spleen mononuclear cells (MNC) in ligustrazinetreated group was significantly higher than that in control group, but the ratio of G0+G1 phase cells was significantly lower in ligustrazine-treated group (P<0. 01). This finding indicated that ligustrazine could increase the expression of adherent molecule on bone marrow hematopoietic cells and Cyclin D2 in spleen MNC, thereby promoting the growth of hematopoietic cells.
To understand the effect of rh-IFN-γ on the ability of curcumin to kill HL-60 cellsin vitro, the myeloid leukemic cell line HL-60 was studied by using cell culture. BrdU incorporation rate was examined by SABC, DNA content was determined by flow cytometry and apoptotic cell percentage was determined by TUNEL method. The results showed that curcumin inhibited proliferation of leukemic cells in a dose-dependent manner. When HL-60 cells were treated with 25 μmol curcumin for 24 h, the proliferative inhibitory rate was 43. 75±2. 00 %. This effect could be enhanced obviously by IFN-γ, the combined proliferative inhibitory rate increased to over 80 %. The 5-BrdU incorportion rate and the distribution of DNA content indicated that curcumin could arrest cells in the G1,/G0 and G2/M phase of cell cycle. At the same time, the sub-G1 peak (apoptotic peak) appeared. After IFN-γ combined with curcumin DNA synthesis rate decreased further. It showed a significant difference when compared with single drug group (P < 0. 05). Meanwhile, sub-Gi peak also increased. The percentage of TUNEL positive cells was aslo increased. It is concluded that IFN-γ can enhance the antiproliferative ability of curcumin against HL-60 cells.