Anthelmintic activity of steroidal saponins from Paris polyphylla

The present study was undertaken to investigate the anthelmintic activity of crude extracts and pure compounds from the rhizomes of Paris polyphylla. The methanol extract showed a promising anthelmintic activity against Dactylogyrus intermedius (EC(50) value=18.06 mg l(-¹). Based on these finding, the methanol extract was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording two known steroidal saponins showing potent activity, dioscin and polyphyllin D. Both dioscin and polyphyllin D exhibited significant activity against D. intermedius with EC(50) values of 0.44 and 0.70 mg l(-¹), respectively, which were more effective than the positive control, mebendazole (EC(50) value=1.25 mg l(-¹)). The acute toxicities (LC(50)) of dioscin and polyphyllin D for goldfish were 1.37 and 1.08 mg l(-¹), respectively. These results indicated that P. polyphylla extract and the isolated compounds are potential natural agents for the control of Dactylogyrus infestation. This is the first report on in vivo anthelmintic investigation for P. polyphylla.