Abstract: In order to explore the antiviral effect of Radix Tetrastigmatis hemsleyani,we continue to choose n-Rutanol and Ethyl acetate extractions from Radix Tetrastigmatis hemsleyani’s ethanol extract to investigate their anti RSV activity by method of cytopathic effect (CPE) and the therapeutic index (TI).MA104 cell was used in this experiment.Thereby we can find out the effective fraction of Radix Tetrastigmatis hemsleyani against RSV and isolate the active ingredients.Results showed that the TI of n-Rutanol and Ethyl acetate extraction are 128 and 64 respectively,and the TI of ribavirin is 6.25,which has a significant inhibitory effect on RSV.The results indicated that n-Rutanol and Ethyl acetate extraction of Radix Tetrastigmatis hemsleyani had antiviral activity against RSV and were obviously superior to ribavirin.

Key words: Radix Tetrastigmatis hemsleyani, respiratory syncytial virus, Therapeutic index, Antivirus in vitro