ABSTRACT
Background: Cassia occidentalis is traditionally used to treat helminth infestations in poultry. We investigated the in-vitro anthelmintic activity of the methanolic leaf extract of this plant against Heterakis gallinarum and Ascaridia galli worms and its acute toxicity. Methods: Leaves of the plant were air dried, ground into powder and extracted with 70% methanol, filtered and dried at 50℃ into a dark green semi-solid mass. The worms were isolated from fresh intestines of local chicken and pheasants or turkeys freshly slaughtered in Kampala markets. They were placed in conical flasks containing Goodwin’s solution, kept in a water bath set at 39°C and exposed to 8, 12, 16, 20 and 24mg/ml extract concentrations. Percent worm mortality was determined for each concentration at 12h intervals. piperazine and ivermectin were used as positive controls. For acute toxicity evaluation, Swiss mice were divided into 5 groups (n=6) and administered per os with extract doses of 5,000, 10,000, 15,000, 20,000 and 25,000mg/Kg. The EC50 was determined by a plot of mortality probits against log extract concentration. Results There was a concentration-dependent relationship with worm mortality. The mean worm mortality for A. galli was significantly higher for the extract than for piperazine at 16 and 20mg/ml (p<0.05) and 24 mg/ml concentrations (p<0.01). Activity against H. gallinarum was not significantly different from that of ivermectin. The EC50 of the extract was 11.78mg/ml for A. galli and 17.78mg/ml for H. gallinarum. The extract is safe according to OECD acute toxicity guidelines since no mortality and toxicity signs were observed in mice even at 25,000mg/kg. Conclusions: The study demonstrated the anthelmintic activity of C. occidentalis and this could explain its use in traditional medicine as a remedy against helminth infections over the generations in many parts of Uganda.