Effects of total saponins from Sanguisorba officinalis on promoting hematopoietic cell proliferation Effects of total saponins from Sanguisorba officinalis on promoting hematopoietic cell proliferation Effect of angelica polysaccharides co-erythropoietin on JAK2/STAT5 signal transduction pathway in hematopoietic stem/ progenitor cells Effect of angelica polysaccharides co-erythropoietin on JAK2/STAT5 signal transduction pathway in hematopoietic stem/ progenitor cells