Protective Effects And Possible Mechanism Of 12-Otetradecanoylo-Phorbol-13-Decanoate(TPD) Against Acute Intestinal Irradiation Injury Of Mice

ObjectiveTo investigate the effect of TPD on protect acute irradiation injury of mice in the intestine and possibly mechanism.MethodsAnimal experiments:Acute intestinal irradiation-damaged model of BALB/c mice were establishedTwelve female BALB/c mice aged 6-8 weeks were randomly divided into 4groups:control group,irradiation group?6Gy,8Gy,10Gy?,3 mice in each group.Control mice were not irradiated,irradiated mice were evenly irradiated with different doses of each group.Observed and recorded the general condition of mice,such as mental status,activity,diet.3.5 days after irradiation,the mice were sacrificed by cervical dislocation,and the jejunum tissues were removed.The number of small intestine crypts in mice was counted by microscope after HE staining.To investigate the effects of TPD on the survival cycle and activities of the whole body irradiated mice.Twenty female BALB/c mice aged 6-8 weeks were divided by random number table method into control group,and TPD group?25?g/Kg,50?g/Kg,100?g/Kg?.the TPD group was administrated TPD before irradiation with caudal vein injection for 3 days.and the control group was injected Physiological saline.observe and record the survival cycle,mental status and activities of irradiated mice lasted for 20 days.To investigate the effect of TPD on the amounts of small intestinal crypt cells with 3.5 days of whole body irradiation in mice.Twenty female BALB/c mice aged 6-8 weeks were divided by random number table method into control group,and TPD group?25?g/Kg,50?g/Kg,100?g/Kg?.the TPD group was administrated TPD before irradiation with caudal vein injection for 3 days.and the control group was injected Physiological saline.after 3.5 days,the mice was sacrificed.immunochemistry were used to observe the amounts of small intestinal crypt cells with 3.5 days of whole body irradiation in mice.Cell experiments:To investigate the effect of TPD on the proliferation of irradiated IEC-6 cells.IEC-6 cells in logarithmic growth phase were divided by random number table method into control group,and TPD group.Rat intestinal epithelial cells?IEC-6?were pretreated with 1nM TPD for 12h before irradiation,CCK-8analysis was used to detect the capability of cell proliferation at different time.ResultsAnimal experiments:The BALB/c mice irradiated with ⁶⁰Co?-rays at a dose of 10Gy in the irradiation group,the average number of crypts in the small intestine counted by microscope was 9 on average.Mice showed significant decreased activity,apathetic,hair loss,diet,diarrhea and other clinical manifestations,all of the typical symptoms is consistent with acute intestinal injury.The TPD group?100ug/Kg?in the average survival time was 10 days,the control groupin the average survival time was 4.2 days.The TPD group?100ug/Kg?slightly decreased the hair loss,increase the diet and mice activity than the control group.the most important is The TPD group?100ug/Kg?prolong the average survival time than control group.The TPD group?100ug/Kg?at 3.5 day the average amounts of small intestinal crypt is 35,and the control group is 11.The TPD group?100ug/Kg?slightly increased the average amounts of small intestinal crypt than the control group.Cell experiments:TPD promote enterocyte proliferation in IEC-6 following ⁶⁰Co?irradiation.The proliferation ability of the TPD group IEC-6 cells were increased gradually in initial 4 days.The proliferation ability of the control group IEC-6 cells was increased slightly less than TPD group.ConclusionsAnimal and Cell experiments confirmed,TPD has protective effect on acute intestinal irradiation injury in mice and its protective mechanism maybeachieved by promoting intestinal crypt cell proliferation and increasing the number of crypts in the intestine.