In vivo anthelmintic activity of bruceine A and bruceine D from Brucea javanica against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus).

The present study was designated to ascertain the anthelmintic activity of the dried fruits of Brucea javanica and to isolate and characterise the active constituents. The methanol extract from the fruits of B. javanica showed significant anthelmintic activity against Dactylogyrus intermedius (EC(50) (median effective concentration) value=49.96 mg l(-1)). Based on this finding, the methanol extract was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording two known quassinoids showing potent activity, bruceine A and bruceine D. Both bruceine A and D exhibited significant activity against D. intermedius with EC(50) values of 0.49 mg l(-1) and 0.57 mg l(-1), respectively, which were more effective than the positive control, mebendazole (EC(50) value=1.25 mg l(-1)). In addition, the 48-h median lethal concentration (LC(50)) for bruceine A and D against the host (Carassius auratus) was 10.6-fold and 9.7-fold higher than the EC(50) for D. intermedius. These results provide evidence that the isolated compounds might be potential sources of new anti-parasitic drugs for the control of Dactylogyrus. This is the first report on an in vivo anthelmintic investigation for B. javanica against D. intermedius.