| With the rapid development of ionizing radiation technology and nuclear science,human beings are more and more inseparable from these two technologies,however,ionizing radiation pollution accompanied by these two technologies is becoming more and more serious,ionizing radiation pollution will lead to leukemia,cancer and other malignant diseases,it is urgent to develop more efficient materials against ionizing radiation.Persimmon tannin is a natural polyphenol compound in persimmon,which has anti-tumor,anti-bacterial and anti-radiation effects.Aloe vera is a kind of natural plant with anti-tumor,healing human wounds,anti-oxidation and other effects,in recent years,the application prospect of these two materials in the field of anti-ionizing radiation has attracted more and more attention.In this paper,the radiation resistance was studied of persimmon tannin modifying by aloe vera freeze-dried powder towards human normal cells(human hepatocytes(L02),human immortalized epidermal cells(HaCat))and tumor cells(Human liver cancer cell(HepG2)).(1)In the study of anti-ionizing radiation of L02 cells by persimmon tannin composites,the results of the CCK-8 test show the best experimental conditions were X-radiation dose was 8Gy,the cells were cultured for 12 h after the radiation test.Moreover,when the compound weight ratio of persimmon tannin in persimmon powder and the o-acetyl group in aloe vera freeze-dried powder was 2:1,the composite material had the best resistance to ionizing radiation,therefore,the composite material with this mass ratio was selected as the best experimental ratio.In the Hoechst33258 fluorescence staining experiment,when the concentration of the composite was 200?g/mL,the fluorescence intensity of the L02 was the lowest,which demonstrated that L02 pretreated with this concentration had the least apoptosis.In the experiment of L02 apoptosis detection by flow cytometry,the apoptotic rate of the composite concentration group of 200?g/mL was 5.7% and 4.32%,which was the lowest in all experimental groups.In the experiment of removing the active oxygen in L02 by persimmon tannin composite,the DCF fluorescence intensity of the experimental group with the concentration of 200?g/mL was 47% compared with the experimental group without the composite pretreatment,which is the lowest value in all experimental group.The results of these experiments show that the persimmon tannin composite has significant anti-ionizing radiation ionizing radiation protection effect on L02,and the optimal anti-ionizing radiation concentration of the composite to L02 is 200?g/mL.In addition,the composite material contains a large number of reducing phenolic hydroxyl groups,so the ROS removal experiment can also be concluded that the anti-ionizing radiation principle of the composite material is to remove the excess ROS that generated by the irradiation,avoid ROS causing malignant diseases.(2)Persimmon tannin composite material was used to protect HepG2 cells from ionizing radiation.the results of the CCK-8 test show the best experimental conditions were X-radiation dose was 8Gy,the cells were cultured for 12 h after the radiation test.Moreover,when the compound weight ratio of persimmon tannin in persimmon powder and the o-acetyl group in aloe vera freeze-dried powder was 2:1,the composite material had the best resistance to ionizing radiation,therefore,the composite material with this mass ratio was selected as the best experimental ratio.In all Hoechst 33258 fluorescent staining experiments,the experimental group with a composite concentration of 100?g/mL had the lowest fluorescence intensity.The apoptosis rate of cells in each experimental group detected by flow cytometry showed that the apoptosis rate of cells in the experimental group with the composite material concentration of 100ug/mL was 9.8%,which was the lowest among all groups.In the ROS removal experiment,the DCF fluorescence intensity of the experimental group with a composite concentration of 100?g/mL was 56% of that of the experimental group without the material pretreatment.Summarizing the experimental results,it is can be seen that the best anti-ionizing radiation concentration of persimmon tannin composite for HepG2 cells is 100?g/mL.The anti-ionizing radiation mechanism of the composite material removes excess ROS from the cells by the highly reductive phenolic hydroxyl groups of the material itself,and avoids subsequent damage caused by ROS peroxidation.(3)In the study of anti-ionizing radiation of HaCat cells by persimmon tannin composites,the results of the CCK-8 test show the best experimental conditions were X-radiation dose was 8Gy,the cells were cultured for 12 h after the radiation test.Moreover,when the compound weight ratio of persimmon tannin in persimmon powder and the o-acetyl group in aloe vera freeze-dried powder was 2:1,the composite material had the best resistance to ionizing radiation,therefore,the composite material with this mass ratio was selected as the best experimental ratio.Secondly,in the Hoechst 33258 fluorescence staining experiment,the experimental group with a concentration of 200?g/mL had the lowest fluorescence intensity.Flow cytometry showed that the apoptosis rate of each experimental group showed that the apoptosis rate of the experimental group with the concentration of 200?g/mL was the lowest,only 4.32%.In the experiment of removing intracellular ROS with composite materials,the apoptosis rate in the 200ug/mL concentration group was the lowest(36%)compared with the experimental group without composite materials.The results of the above experiments showed that 200?g/mL was the best concentration of persimmon tannin to protect HaCat cells from ionizing radiation,which was the same as that of L02 cells.In addition,through ROS removal experiments,the ionizing radiation protection mechanism of the composite material on HaCat cells was the same as that of L02 cells and HepG2 cells.The anti-ionizing radiation experiment of persimmon tannin composites on three kinds of cells showed that the radiation protection of the composites to normal cells(200?g/mL)was higher than that of cancer cells(100?g/mL),and the concentration of the composites to protect the normal cells from the best ionizing radiation was greater than that of the cancer cells,at this time,the activity of cancer cells has been inhibited.In addition,the ROS clearance rate of the composite material in cancer cells was lower than that in normal cells,the optimal ROS removal concentration(200ug/mL)of the composite material for normal cells had a low ROS removal rate for cancer cells.As mentioned above,the composite material can protect normal cells from ionizing radiation without providing strong conditions for the growth of cancer cells.Therefore,persimmon tannin composite can be regarded as a kind of natural and harmless material with broad prospects of practical application. |
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