Inhibitory Effect Of AGM In Mouse Infected With Respiratory Syncytial Virus

Objective: To evaluate the anti-RSV effect of AGM in BALB/c mice and to explore its antiviral mechanism.Methods: (1) Preparation of AGM and KGM. (2) HRSV is cultivated and passaged, and its tite is detected with Plaque Unit Forming Test to be selected for appropriate infective tite virus. (3) BALB/c mice Infected with hRSV are randomly grouped into experimental and control groups of 54 mice in each. On the basis of plan of factorial design,mice of the experimental groups are divided into 3 groups with different doses of AGM as 2.5μmol,0.25μmol or 0.025μmol. Each group is subdivided into 3 groups of 6 mice in each according to administration interval of AGM as 8 hours,12 hours or 24hours. Mice are anesthetized and inoculated with intranasal dripping with 100u1 106PFU/ml of RSV. After 12 hours,AGM is inhaled into mice with intranasal dripping. All the mice are sacrificed and removed of lungs on the 72th hour. These of control with KGM are same of those with AGM. (4) The general infomation of the mice are observed everyday. (5) The effects of AGM and KGM to the levels of RSV F mRNA in the lung tissue are mesured with RT-PCR. (6) Inflammation in the lung tissue is observed with HE staining method and Immunohistochemistry technique for ICAM-1 expression in the lung tissue.Results: (1) AGM and KGM were obtained successfully with concentration of 25μmol/L. (2) The valuable tite of RSV was 106PFU/ml. (3) BALB/C mice had been infected by RSV successfully and grouped according to the plan. (4) Most mice of the experimental groups didn't changed significantly on the general information such as hair,body weight and habits and so on. But 16 mice of the control groups were weakened significantly. Two of them had died before experiment was ended. (5) The results of RT-PCR showed that in the experimental groups, the levels of RSV F mRNA in the mice lung tissue were decreased along with AGM's concentration increasing, and rised following the extension of administration interval(P<0.05). Differently, those in control groups had no statistical significance (P>0.05). (6) In the lung tissue stained with HE there were fewer inflammation cells infiltrating in alveolus walls and bronchus stroma of the experimental groups than those of the control groups. The results of immunohistochemistry showed that the levels of ICAM-1 expressing in the membrane and starch of alveolar epitheliums,bronchus endotheliocytes and inflammation cells was lower in the experimental groups than those in the control groups(P<0.05). Those of control groups had no statistical significance (P>0.05).Conclusion: AGM has the anti-RSV effects. The data showed dose-depandent effect with concentration of AGM increasing and extention of administration interval. Compared with the control groups, it suggests amination is very important for the anti-RSV effect of AGM.