OBJECTIVE  To observe the protective effects of alcohol-sedated aqueous extract(CⅡ-3) and ethanol extract(PA-B) of the Periplaneta americana on cyclophosphamide(CTX)-induced myelosuppression in mice.

METHODS  CTX 40 mg·kg⁻¹ intraperitoneal injection to establish myelosuppression model. A total of 126 SPF Kunming mice were randomly divided into Con group, Mol group, ginsenoside Rg1 group, CⅡ-3 dose group(L-CⅡ-3, M-CⅡ-3, H-CⅡ-3), and PA-B dose group(L-PA-B, M-PA-B, H-PA-B) and treated for 14 d. Blood samples were collected from the tail vein on the 7th and 14th day to measure peripheral blood cells. Spleen and thymus were taken to calculate organ index; bone marrow nucleated cell were counted; ELLSA was used to detect expression levels erythropoietin(EPO), interleukin-3(IL-3), interleukin-6(IL-6), superoxide dismutase(SOD) and malondialdehyde(MDA); HE staining of femur; flow cytometry was used to determine the bone marrow cell cycle and hematopoietic stem cells(HSCs) content.

RESULTS  The peripheral blood cell counts were significantly lower at 14th days than at 7th days. Treatment with CII-3 and PA-B resulted in a significant increase in white blood cell counts(P<0.01), it was increased in splenic index and thymic index, increased in the number of BMNC(P<0.01), increased in levels of EPO, IL-3, IL-6 and SOD, decreased in the level of MDA(P<0.01). It increased the ratio of S and G2/M phase, increased the PI index and the content of HSCs in bone marrow(P<0.01).

CONCLUSION  Periplaneta americana extract promotes the activation, differentiation and migration of HSCs, regulates the entry of cells into S and G2/M phases, slows down bone marrow cell senescence, and repairs bone marrow damage caused by CTX.