Abstract

The anthelmintic activity of acetone and water extracts from the shoots of Cotyledon orbiculata, Hermannia depressa and Nicotiana glauca were investigated using the egg hatch, larval development and larval mortality assays. In all extracts tested, C. orbiculatawater extracts at 7.5 mg/ml prevented nematode eggs from hatching with 82.63% success. Other extracts exhibited egg hatch inhibition in a degree of less than 50%. Similarly, C. orbiculata water extracts suppressed nematode larval development at 85.32% when the concentration of 2.5 mg/ml was used followed by 66.69% of H. depressa extract at 7.5 mg/ml concentration. However, N. glauca water and all acetone extracts induced the 100% larval development inhibition. The in vitro larval mortality rate revealed that the water extracts from all the plants were able to kill all larvae at 2.5 mg/ml within 48 to 96 h. The results from this study have shown that the extracts from the three plants have the potential to prevent and ameliorate diseases associated with gastrointestinal nematodes.

Key words: Cotyledon orbiculata, egg hatch assay, Hermannia depressa, larval development assay, larval mortality assay, Nicotiana glauca.