Guilu Erxian Glue () Inhibits Chemotherapy-Induced Bone Marrow Hematopoietic Stem Cell Senescence in Mice May via p16INK4a-Rb Signaling Pathway.

OBJECTIVE

To evaluate the effect of Guilu Erxian Glue (, GEG) on cyclophosphamide (CTX)-induced bone marrow hematopoietic stem cells (HSCs) senescence in mice and explore the underlying mechanism.

METHODS

The H22 liver cancer ascites lump model was established in male Kunming mice by injecting intraperitoneally (i.p.) with 5 × 106/mL H22 cells per mouse. Fifty tumor-bearing mice were divided into the control, model, pifithrin-α, GEG, and GEG+pifithrin-α groups using a random number table, 10 mice in each group. CTX (100 mg/kg i.p.) was administrated to mice from day 1 to day 3 (d1-d3) continuously except for the control group. The mice in the pifithrin-α, GEG and GEG+pifithrin-α groups were treated with pifithrin-α (2.2 mg/(kg·d) i.p.) for 6 consecutive days (d4-d9), GEG (9.5 g/(kg·d) i.p.) for 9 consecutive days (d1-d9), and GEG plus pifithrin-α, respectively. HSCs were collected after 9-d drug treatment. The anti-aging effect of GEG was studied by cell viability, cell cycle, and β -galactosidase (β -gal) assays. The mRNA and protein expressions of cyclin-dependent kinase 2 (CDK2), CDK4, inhibitor of cyclin-dependent kinase 4a encoding the tumor suppressor protein p16 (p16INK4a), p21Cip1/Waf1, p53, and phosphorylated retinoblastoma (pRb) were evaluated by quantitative real-time reverse transcription-polymerase chain reaction and semi-quantitative Western blot, respectively.

RESULTS

Compared with the model group, GEG increased cell viability as well as proliferation (P<0.05 or P<0.01) and reduced β -gal expression. Furthermore, GEG significantly decreased the expressions of p16INK4a, p53 and p21Cip1/Waf1 proteins, and increased the expressions of CDK2, CDK4 and pRb proteins compared with the model group (P<0.05 or P<0.01).

CONCLUSION

GEG can alleviate CTX-induced HSCs senescence in mice, and the p16INK4a-Rb signaling pathway might be the underlying mechanism.