The Protective Effect Of Dicliptera Chinensis Polysaccharides On The General Condition Of Salivary Glands With Radiation Injury And Its Effect On The Expression Of P53 In Salivary Glands

Objective To observe the protective effect of Dicliptera chinensis Polysaccharides（DCP1A）on the general condition of radioactive salivary glands injury in rats.To detect the effect of DCP1A on the expression of P53 in the parotid and submandibular glands of rats after ⁶⁰Coγ-ray.To provide a new idea for the drug treatment of the radiation injury of salivary glands.Methods 1.Establishing a radioactive injury model of salivary glands in rats.Each group of rats were given a certain dose of DCP1A or physiological saline（200mg/kg）by gavage during three days before radiation and four weeks after radiation.After the first,fourth,eighth,and twelfth weekends after radiation,we observed the general condition of rats after radiation by measuring body weight and spleen index of rats.2.Morphological changes of salivary glands were observed by HE staining in the control group,the DCP1A group,the radiation group,the DCP1A group with radiation.Detecting the apoptosis of salivary gland cells in different groups at the same time by TUNEL.3.The distribution and expression of P53 gene in salivary gland tissues were detected by immunohistochemistry（IHC）.Quantitative Real-time Polymerase Chain Reaction（RT-q PCR）was applied to detect the differences and changes of P53 expression in rat salivary glands.Results 1.At the same time point,there was no significant difference in body weight and spleen index between the control group and the DCP1A group,which could not be considered statistically significant（P>0.05）.After irradiation with ⁶⁰Coγ-ray,the weight and spleen index of two groups of rats were significantly lower than those of the two control groups.The difference was statistically significant（P<0.05）.However,the rats in the DCP1A group with radiation has a significant increase in body weight and spleen index compared with the radiation group（P<0.05）.2.The salivary glands structure of the control group and the DCP1A group was clear.The acinus was full and the rows was neat.The number of the apoptotic cells was very few,and the difference between the two control groups was not obvious（P>0.05）.After irradiation with ⁶⁰Coγ-ray,the tissue structure of the salivary glands of the two experimental groups of rats was disordered.Vacuole-like changes in acinar cells were significantly increased and blood vessel hyperplasia was expanded and congested.The number of apoptotic cells was significantly increased（P<0.05）.And no significant improvement in morphological damage of the salivary glands over time.However,the degree of morphological damage was slightly lower in the DCP1A group with radiation than in the radiation group,which slightly improved with time.And the apoptosis rate of DCP1A group with radiation was significantly lower than that of the radiation group,and the difference was statistically significant（P<0.05）.3.There was no significant difference in the expression of P53 protein and P53 m RNA in the salivary glands between the control group and the DCP1A group at each time point,which could not be considered statistically significant（P>0.05）.After irradiation with ⁶⁰Coγ-ray,the expression of P53 protein and P53 m RNA in rats of the two experimental groups were significantly increased（P<0.05）.However,the expression of P53 protein and P53 m RNA in the DCP1A group with radiation at the same time was lower than that in the radiation group.And the difference was statistically significant（P<0.05）.Conclusions DCP1A has protective effects on rat systemic and salivary glands after irradiation with ⁶⁰Coγ-ray.DCP1A inhibits the expression of P53 in the parotid and submandibular glands of rats.This experiment provides a basis for the clinical application of DCP1A in the treatment of salivary glands radiation injury.