ABSTRACT
The study was purposed to investigate the effects of the panaxadiol saponin (PDS) from Ginseng on proliferation and differentiation of human CD34(+) cells from human bone marrow. Highly purified CD34(+) cells were isolated from human bone marrow by using the Dynal CD34 Cell Selection System (Dynal, Norway). The cells were exposed to PDS at various concentrations in both agar semi-solid culture of CFU-Mix and suspension culture of myeloid and erythroid cells in order to observe the effects of PDS on proliferation of CD34(+) cells. The cells were marked with 4 kinds of monoclonal antibody in related with their differentiation toward to myeloid and erythroid lineages, then examined by flow cytometry (FACS) after being incubated with PDS for 14 days. The results showed that the number of CD34(+) cells was 1.0 +/- 0.15% out of marrow nuclear cells after being purified by Dynal beads system. The enrichment of CD34(+) cells reached to 86.8 +/- 2.8%. The best efficiency in promoting proliferation of CD34(+) cells in vitro was obtained when the concentration of PDS was 25 mg/L, the formation of CFU-Mix colonies significantly increased by 56.3 +/- 3.5% over those of no-PDS control (p < 0.01). The results from suspension culture revealed that myeloid cells elevated in a dose-dependent manner with a peak increasing rate of 35.6 +/- 3.2%, and erythroid cells significantly increased by 22.3 +/- 2.1% over those of no-PDS control (all p < 0.01). After incubation with PDS for 14 days, number of CD33(+) cells increased in a dose-dependent manner with a peak increasing rate at 50 mg/L. CD71(+) cells reaching the peak were at 25 mg/L, while G-A(+) cells were increased by 7.2 +/- 1.3% (p < 0.01) at 10 mg/L, but the number of CD15(+) cells was not found to be changed before and after treating with PDS. It is concluded that PDS not only enhance the proliferation of CD34(+) cells, but also induce differentiation of CD34(+) cells toward to myeloid and erythroid lineages. PDS may play the roles as like hematopoietic growth factor, or provide synergistic effects on growth factor in the regulation of hematopoiesis.