Anti-Radiation Drug Screening From Chinese Traditional Medicines And Its Effective Components And Mechanism Research

Radioprotectors are needed to protect cancer patient with radiotherapy and other potentially exposed populations, such as workers in the nuclear-power industry, space travelers or operators on radioactive devices. Great efforts are put into searching for ideal radioprotectors considering its importance. A cell model is built to quick screen anti-radiation drugs in vitro from lots of natural medicines or compounds in this experiment. Some researches focus on the molecular mechanisms of irradiation induced thymocyte damages and protective effects of paeoniflorin andβ-sitosteral by means of cellular and molecular technologies. The radioprotective effect of paeoniflorin in vivo is also evaluated. The conclusions are below:1. Carries on the preliminary screening of anti-radiation activeness drugs from 500 nauture extracting samples and effective components through the cell model, 16 of them show radioprotective activies.2. Apoptosis is the main form of irradiation-induced thymocyte early death (2-8Gy, 23.12%, 29.83%, 37.65%, 38.74%) with radiation does-dependent manners. Along with the increase of radiation time or dose, the necrosis cells gradually increase. Deceasing of cell viabilities (2-8Gy, 81.92%, 62.65%, 48.98%, 31.68%) and increasing DNA damage (2-8Gy TailDNA, 18.92%, 23.17%, 27.39%, 34.12%) show radiation does-dependent manners. Cell damages are related to free radicals production induced by irradiation (r=-0.9874 and 0.9259). DNA damage, translocation of mitochondrial intermembrane proteins and activation of MAPKinases are important reason to induce apoptosis in irradiated thymocyte. Paeoniflorin andβ-sitosteral may protect thymocyte against irradiation-induce cell damage by scavenging free radicals and blocking cellular apoptotic pathways.3. Paeoniflorin increases both survival rate (30%) and survival time (4.3 days) of the irradiated mouse, while its anti-oxidation and immuno-regulative actions are detected. Therefore, it radioprotective function is confirmed.In brief, 16 agents with anti-radiation activities in vitro are found from natural medicines or compounds in this experiment. Protective effects of paeoniflorin andβ-sitosteral are involved in its antioxidant actions and inhibitory effect on cell apoptosis. The radioprotective effect of paeoniflorin in vivo is also confirmed.