Effects of combined injection of Angelica sinensis polysaccharide and cytarabine on bone marrow mononuclear cells of transplanted human leukemia mice Angelica sinensis polysaccharides delay aging of hematopoietic stem cells through inhibitting oxidative damge Effect of Angelica sinensis polysaccharide on expression of telomere, telomerase and P53 in mice aging hematopoietic stem cells