The Protective Effect Of Dicliptera Chinensis Plosaccharide In Radiation Injury Rats And Expression Of Vascular Endothelial Growth Factor In Parotid Gland

OBJECTIVE:To observe the effect of Dicliptera Chinensis Polysaccharide（DCP）on radiation injury of rat general condition,the morphological function of parotid gland and the expression of vascular endothelial growth factor（VEGF）.The protective effect of DCP on the parasitic radioactive injury of rats was investigated.Methods:1.96 adult SPF healthy male SD rats（200²20g）were randomly divided into normal group（non-irradiated with 0.9%saline solution）,radiation group(18Gy ⁶⁰Coγ-ray irradiation with 0.9%saline solution),normal treatment group（non-irradiated with 200mg/kg DCP solution）and radiotherapy group(18Gy ⁶⁰Coγ-ray irradiation with 200mg/kg DCP solution).Each group had 24rats.2.The general conditions of rats were monitored by body weight and spleen index.3.Hematoxylin-Eosin Staining（HE）was used to observe morphological changes of parotid gland,and to observe the function of parotid gland by parotid index.4.Quantitative Real-time（RT-qPCR）and Western blot（WB）were used to detect the expression of VEGF.Results:1.At the same time point,there was no significant difference in body weight and spleen index between the normal group and the normal treatment group,which was not considered statistically significant（P>0.05）.After ⁶⁰Coγ-ray irradiation,the body weight and spleen index of the radiation group was significantly lower than that of the normal group and normal treatment group,and the difference was statistically significant（P<0.05）.After DCP treatment,the weight and spleen index of the rats in the radiotherapy group was significantly higher than that of the radiation group（P<0.05）.2.HE staining results showed that the parotid gland structure of the normal group and the normal treatment group was normal,neatly arranged,and the acinar was full;After ⁶⁰Coγ-ray irradiation,the parotid gland structure was abnormal in the radiation group,the acinar space was empty,the vesicles changed,and the vasodilatation was congested.Interestingly,there was obvious change with time.However,after treatment with Dicliptera Chinensis Polysaccharide,the cells of the radiotherapy group had less damage to the parotid cells and blood vessels,and slightly improved with time.3.At the same time point,there was no significant difference in parotid index between the normal group and the normal treatment group,which was not considered statistically significant（P>0.05）.After ⁶⁰Coγ-ray irradiation,the parotid index of the drug group was significantly lower than that of the normal group and normal treatment group,and the difference was statistically significant（P<0.05）.After DCP treatment,the parotid index of the rats in the radiotherapy group was significantly higher than that of the radiation group（P<0.05）.4.Real-time fluorescence quantitative polymerase chain reaction（RT-qPCR）showed that the relative expression of VEGF mRNA in the normal group and the normal treatment group was not significantly different at the same time point,and it was not considered statistically significant（P>0.05）;After ⁶⁰Coγ-ray irradiation,the relative expression of VEGF mRNA in the rats of the radiation group were decreased,while the relative expression of VEGF mRNA were increased in the parotid gland of the radiotherapy group（P<0.05）.5.Western Blot（WB）analysis showed that there was no significant difference in VEGF protein between the normal group and the normal treatment group at the same time point,which was not considered statistically significant（P>0.05）;After ⁶⁰Coγ-ray irradiation,the expression of VEGF protein in the rats of the radiation group were decreased（P<0.05）.while the relative expression of VEGF protein were increased in the parotid gland of the radiotherapy group（P<0.05）.Conclusion:DCP can promote the recovery of general condition after radiation in rats,reduce the damage of parotid gland tissue and up-regulate the expression of VEGF.It was suggested that DCP has a certain protective effect on the radial damage of the parotid gland.