OBJECTIVETo investigate the effects of HS 6101 and recombinant human granulocyte colony stimulating factor (rhG-CSF) on hematopoiesis recovery of ICR mice injured by cyclophosphamide (CTX).

METHODSA total of 103 ICR mice were divided into 4 groups, including CTX control (46 mice), HS 6101 (21 mice), rhG-CSF (18 mice) and HS 6101+rhG-CSF (18 mice), respectively. The mouse model of chemotherapy-induced haematopoietic injury was established by CTX intraperitoneal injection at a dose of 100 mg/kg once a day for 3 consecutive days. Single dose of HS 6101 (27 µg/mouse) was injected subcutaneously at 1 hour before the first administration of CTX. One day after the last CTX treatment, 2 µg/mouse of rhG-CSF was injected subcutaneously once a day for 5 consecutive days. The peripheral blood cell counts of the mice were observed once every 2 days. Hematopoietic progenitor cell colony counting and histopathological assessment of bone marrow cells were evaluated in the mice at days 4 and 9 after the first administration of CTX.

RESULTSBoth HS 6101 and rhG-CSF alone or in combination, significantly elevated the nadirs of peripheral blood leukocytes and neutrophils, increased the number of bone marrow hematopoietic progenitor cells, and stimulated the hematopoietic cell hyperplasia of bone marrow in the mice treated with CTX. The effect of HS 6101 combined with rhG-CSF was better than that of the drugs used alone.

CONCLUSIONThe HS 6101 at 27 µg/mouse can significantly promote the recovery of hematopoiesis in ICR mice treated with CTX chemotherapy, and its combination with rhG-CSF shows synergistic effects.