Total Saponins Of Panax Ginseng Ameliorates Irradiation-induced Bone Marrow Hematopoietic Cell Injury And Senescence

After chemotherapy or irradiation （IR） in many patients will besecondary to acute or long-term （permanent） of bone marrow injury，thus tolimit cancer treatment success and influence the quality of life. Acute bonemarrow suppression caused by hematopoietic progenitor cells （HPCs）apoptosis, while the stationary state of hematopoietic stem cells （HSCs） lesseffect, clinical through application of hematopoietic growth factors can besuccessfully treated; Instead, long-term bone marrow injury is mainlyattributed to the HSC internal damage to the HSC self-renewal capacity loss.Therefore, protection, improvement of HSC self-renewal ability is thedevelopment of novel anti drugs core. At present, most of chemical synthesisof bone marrow suppression protection agent due to its inherent toxicity andlimit the clinical application, from natural herb plants such as ginseng extractthe active ingredients, because of their obvious protective effect has lowtoxicity and has attracted much attention, become the screening of drugs isan important source. Ginseng has been extensively used in traditional Chinese medicine,Total Saponins of Panax Ginseng are the major active components inginseng. TSPG play a duplexing role, Our previous study suggested thatTSPG may not only improve the proliferation and differentiation ofhaematopoietic stem/progenitor cell, but also inhibit the proliferation ofleukemia cells, and induce them apoptosis and differentiation toward themature cells. At present Effects of Total Saponins of panaxGinsenginhibition of irradiation-induced bone marrow injury and senescence andtheir mechanisms remain to be studied.There are two parts in the research:1.Establishment of mouse model of irradiation-induced bone marrowinjury and senescence2.Effects of Total Saponins of panaxGinseng inhibition of irradiation-induced bone marrow injury and senescenceOur research aims to research effects of Total Saponins of panaxGinsenginhibition of irradiation-induced bone marrow injury and senescence,andto provide theoretical and experimental evidence for clinic treatment ofhaematologic disease.Part1：Establishment of mouse model of irradiation-inducedbone marrow injury and senescenceObjective: to establish mouse model of irradiation-induced bone marrow injuryand senescence for further screening anti-irradiation drugs.Method:1.50mice were randomly divided into control and radiation groupsincluding different dosages of4Gy,6.5Gy,8.5Gy and10.5Gy. The survivalrate within30days was dynamically observed.2. On day1,3,7,30after20mice were irradiated with6.5Gy, routineblood test, bone marrow mononuclear cell （BM-MNC） counting,hematopoietic cell colony forming unit （CFU） counting were performed.Apoptosis was determined by flow cytometry. Mononuclear cell senescencewas evaluated by senescence-associated β-galactosidase （SA-β-gal） stainingand expression of p16Ink4aprotein.Result：1. The survival rate of30days was100%in both control and4Gygroups,80%in6.5Gy,0%in8.5Gy and10.5Gy groups.2. The numbers of white blood cell, platelet, mononuclear cell and CFUdecreased on day1after6.5Gy administration and decreased maximally onday3, and then began to increase on day7and significantly increased on day30, though they were still below the control levels.3. Irradiation in6.5Gy significantly induced apoptosis in BM-MNCswhich was35.71±0.30%on day3（control group7.32±1.87%）, graduallydecreased on day7and30. 4. In addition, MNCs from irradiated mice exhibited an increasedexpression of the2commonly used biomarkers of cellular senescence,p16Ink4aand SA-β-gal with the positive cell rate to the highest on day3,gradually decreased from day7.Conclusion:Irradiation by the dosage of6.5Gy may successfully induce bonemarrow suppression in C57BL/6mice, which builds up the foundation forfurther screening anti-irradiation drugs.Part2：Effects of Total Saponins of panaxGinseng inhibition ofirradiation-induced bone marrow injury and senescenceObjective:To investigate the Effects of Total Saponins of panaxGinseng inhibitionof irradiation-induced bone marrow injury and senescenceMethod:1.Experimental groups and dispose of methods: experimental groupscontrolgroup;IRgroup;T50group;T200group. Provide of drugs3days， then irradiation （IR），and continue to Provide of drugs7days， detect of each indicator.2.After each group of mouse were conducted, detect of routine bloodtes; Bone marrow mononuclear cell （BM-MNC） counting, hematopoieticcell colony forming unit （CFU） counting were performed; Cell cycle was determined by flow cytometry; Mononuclear cell senescence was evaluatedby senescence-associated β-galactosidase （SA-β-gal） staining andexpression of p16^Ink4aprotein.Result：1. Compared with IR group，The number of WBC from T50grouphave no change,but T200group was increased,RBC and Plt from each grouphave no different changes.2.Bone marrow mononuclear cell （BM-MNC） counting andhematopoietic cell colony forming unit （CFU） counting from T50grouphave a little of change,but T200group was increased.3.Add to TSPG50mg/kg,200mg/kg, G1period cells in cell cycle withdrug concentration increases the proportion of the decrease of the trend.4.In addition, MNCs from irradiated mice exhibited an increasedexpression of the2commonly used biomarkers of cellular senescence,p16^Ink4aand SA-β-gal from T200group with the passive cell rate.Conclusion:TSPG（200mg/kg） may delay or threat from inhibition of irradiation-induced bone marrow injury and senescence.