ABSTRACT
<p><b>OBJECTIVE</b>The effect of angelica sinensis polysaccharides (ASP) on the production of reactive oxygen specie (ROS), the capability of total anti-oxidant (T-AOC), and the expression of p16 in mRNA level in mice hematopoietic stem cells (HSCs) were observed to explore the underlying mechanism that ASP delay aging of HSCs in vivo.</p><p><b>METHOD</b>C57BL/6J mice were randomly divided into normal group, aging group, and the above groups treated with ASP. Mice were uniformly explored in X-ray (3.0 Gy/8 F) to erect model of aging. Normal and aging ASP intervention groups mice were treated with ASP by intragastric administration, while normal and aging groups were treated with equal-volume NS during X-ray irradiation. Mice HSCs were isolated by magnetic cell sorting and cultured in vitro. Senescence-associated beta-galactosidase (SA-beta-Gal) staining was used to detect aging HSCs. Cell cycles analysis and CFU-Mix cultivation were used to evaluate the capability of self-renewing and colony forming in HSCs. The production of ROS in HSCs was evaluated by flow cytometry analysis and immunofluorescence assess, respectively. T-AOC was detected by chemical colorimetric method. The expression of p16 was determined by real-time quantitative PCR (qRT-PCR).</p><p><b>RESULT</b>Exogenous X-ray irradiation induced HSCs aging was compared with normal group without irradiation. Biological feature of HSCs in aging group with X-ray irradiation as follows: The percentage of SA-beta-Gal positive cells, the ratio of G1 stages and the production of ROS were significantly increased , the expression of p16 in mRNA level was also upregulated. The capacility of colony forming and T-AOC in HSCs were decreased. ASP could significantly decrease the percentage of SA-beta-Gal positive cells, the ratio of G1 stages and the production of ROS in HSCs, and downregulate the expression of p16 in mRNA level in HSCs contrast to aging group without ASP treatment. In addition, ASP could remarkably increase T-AOC and the capacility of colony forming in HSCs compared with aging group without ASP treatment.</p><p><b>CONCLUSION</b>X-ray (3.0 Gy/8 F) could induce mice HSCs aging. ASP could delay senescence HSCs aging which maybe partly ascribed to the inhibition of oxidative damage and the downregulation of p16 mRNA expression.</p>