[Study on the effect of realgar nanoparticles on reducing the respiratory syncytial virus type A (RSV-a) replication in vitro].

This study was to establish a model to explore anti- RSV effect of different administration method of Chinese medicine realgar on respiratory syncytial virus type A (RSV-A) replication in Hep-2 cells. Using high-energy ball milling with distilled water to prepare realgar nanoparticles,the concentration of nanometer realgar was tested by molybdenum blue staining method and the size of realgar nanoparticles was tested on Nano Series. Cell culture with ribavirin as a positive control was applied to observe the effect of anti-respiratory syncytial virus type A replication through prevention, treatment or direct inactivation of three different drug administration methods. Realgar nano-particles was found to be a potential inhibitor of RSV-A in a concentration-dependent manner with the median toxic concentration(TC50) of 0.649 microg/mL in Hep-2 cell culture. The median inhibition concentration (IC50) was 0.20 microg/mL when drug was added before virus infection. The IC50 was 0.13 microg/mL when drug was added after virus infection,and it was 0.16 microg/mL when the drug was mixed with virus and added. The therapeutic index (TI) was 3.18, 4.99 and 4.11, respectively. The results showed realgar nanoparticles could inhibit the replication of the RSV and inactivate the RSV in vitro.