| Tumor is one of the most familiar diseases which threaten life and damage health of human and it is a major cause for man to death. Because lacking the effective method to cure this disease, many of the patients with tumor get bad results. Radiotherapy is one of the routine methods. The mechanism of radiotherapy is its ionization action, which can kill the tumor cell directly or indirectly by generation of free radicals, reactive oxygen species to cure the disease. But, at the same time, the side effects caused by irradiation limit the therapy going on.According to the characteristics of free radicals (FR) and reactive oxygen species (ROS), our laboratory has studied the mechanism of the side effect caused by irradiation. Results revealed that it had differences between the location and the whole body in effects, and instant and delayed in time damaged by radiotherapy on the tumor. The irradiation can increase the contents of MDA, NO and NOS, decrease the activities of T-SOD, Mn-SOD, CAT, GSH and total antioxidative capacity in tissues. The antioxidant supplementation can inhibite these changes caused by the irradiation. This results demonstrated that the local irradiation can cause the oxidative injury on the whole body which was induced by FR and ROS.These FR and ROSgenerated by local irradiation play a key role in the action of killing tumor cells and also in the side effect on the whole body, but at the different time and location. These phenomena could be named "differential concentric round".In this study, the tumor bearing animal model was made to be the object of this experiment. The tumor was irradiated by 60Co-y-ray to simulate the patients with tumor who was treated in process of radiotherapy. Bone marrow is sensitive to radiation. So we used tumor-bearing rat model to observe oxidative injury of bone marrow caused by 60Co-y-ray local radiation and the protection of multi-antioxidants.This experiment was divided into 3 parts. In the first part, microsomal lipid peroxidation (LPO) models were applied to select effective antioxidants. Firstly, Sprague-Dawley rats were killed and then the livers were removed to isolate the microsome which generated the reactive oxygen species in the presence of Vcand Fe2+, cumene hydroperoxite (CHP) or carbon tetrachloride (CCL4). In these LPO models, different dosages of tea-poll solution were added. Then the contents of MDA were determined for analyzing the antioxidative action of tea-poll. Results showed the content of MDA in 50mg/ml, 25mg/ml, 12.5mg/ml and 6.25mg/ml groups of tea-poll decreased significantly compared with that of control group (P< 0.05) in CCL4 model. In the Vc/ Fe2+ model, the content of MDA in 50mg/ml, 25mg/ml, 12.5mg/ml and 6.25mg/ml groups of tea-poll decreased significantly compared with that of control group (P<0.05). In the CHP model, the content of MDA in 50mg/ml, 25mg/ml, 12.5mg/ml, 6.25mg/ml and 3.125 mg/ml groups of tea-poll decreased significantly compared with that of control group (P<0.05).In the second part, the bone marrow of rats in both tumor-bearing and irradiated groups were removed respectively, to detect the MDA, GSH, GSSG of bone marrow, and the differential expression of bone marrow proteins by using two-dimensional electrophoresis were analyzed after Co-yray local irradiation. Results showed the contents of MDA, GSSG in irradiated group were much higher than those in tumor-bearing group (PO.01) and the contentof GSH in irradiated group was much lower than that in tumor bearing group (P<0.01) . In two-dimensional electrophoresis maps, it was found that alterations of 24 proteins in irradiated group, including 2 new proteins, 4 down-regulated proteins, 1 up-regulated protein and 17 proteins disappeared.In the third part, the bone marrow of rats in control, tumor-bearing, irradiated and protective groups were removed respectively, to test level of the MDA, GSH, GSSG and the fluorescent intensity of cellular oxidized DHR and DCFH-DA which represented the level of ROS. The bone marrow of rats in tumor-bearing, irradiated and protective groups were removed respectively to analyze the differential expression of bone marrow proteins by using two-dimensional electrophoresis, image analysis, in gel digestion, peptide mass fingerprinting and bioinformatics method. Results showed the contents of MDA, GSSG in irradiated group were much higher than those in control, tumor-bearing and protective groups (P<0.01) , while the contents of MDA, GSSG in the protective group were much lower than those in irradiated group. The content of GSH in irradiated group was much lower than that in control, tumor-bearing and protective groups (jPO.OI ) , while the content of GSH in the protective group were much higher than that in irradiated group. The fluorescent intensity of cellular oxidized DHR and DCFH-DA in irradiated group were much higher than those in negative, tumor-bearing and protective groups (PO.01) , while fluorescent intensity of cellular oxidized DHR and DCFH-DA in the protective group were much lower than those in irradiated group. Multi-antioxidants could reverse 83 up-regulated, 87 down-regulated, 59 disappeared and 44 new appeared proteins of bone marrow caused by 60Co-y-ray local radiation. Eight of these proteins were likely to be ornithine aminotransferase, Cu/Zn superoxide dismutase, Carbonic anhydrase 1, Gapd protein, Spindlin-like protein 2, heme oxygenase 2, phosphoglycerate mutase type B subunit and zinc finger protein 371.These results demonstrated that tea-poll has antioxidantive effect with dose-effect relationship; 60Co-y-ray local irradiation can cause differentially...
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