| Abstract: | OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin. |
