Guilu Erxian Glue(龟鹿二仙胶)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(龟鹿二仙胶,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 5×10^6/mL H22 cells per mouse.Fifty tumor-bearing mice were divided into the control,model,pifithrin-α,GEG,and GEG+pifithrin-αgroups 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-αgroups 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,andβ-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^(p16^INK4a),p21^Cip1/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 reducedβ-gal expression.Furthermore,GEG significantly decreased the expressions of p16^INK4a,p53 and p21^Cip1/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 p16^INK4a-Rb signaling pathway might be the underlying mechanism.