Changes of telomere and telomerase in effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence

OBJECTIVE: To investigate the roles of telomere(definition) and telomerase in the effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence(definition). METHOD: Sca-1(+) HSC was isolated by magnetic cell sorting(MACS) and divided into five groups: the control group, the aged model group, the Rg1 group, the Rg1 treated aged group and the Rg1 delayed aged group. The changes of cells were observed by senescence-associated beta-Galactosidase (SA-beta-Gal) staining. Cell cycle assay and culture of mixed hematopoietic progenitor cell were used to investigate the effect of ginsenoside Rg1 to delay Sca-1(+) HSC senescence. Telomere length and telomerase activity were detected by southern blotting and TRAP-PCR-SYBR Green staining. RESULT: Compared with aged model group, the percentage of positive cells expressed SA-beta-Gal and the number of cells entered G1 phase were decreased and the number of colony of mixed hematopoietic progenitor was increased. It showed markedly decreased in the shortening of telomere length and reinforcing in the telomerase activity to Rg1 treated aged group and Rg1 delayed aged group. The change of Rg1 delayed aged group was significantly higher than Rg1 treated aged group. CONCLUSION: Activation of telomerase and prolonging of telomere length might be involved in the process of ginsenoside Rg1 to delay and treat the senescence of Sca-1(+) HSC.