In-Vitro anthelmintic activity study of Plectranthus barbatus Andr. leaves on adult Haemonchus contortus worms

Abstract

The study investigated anthelmintic activity of Plectranthus barbatus (leaves) used by traditional medicine practitioners of Migori County using adult Haemonchus contortus worm as a model. 50 gm of ground powder of Plectranthus barbatus (leaves) was extracted separately with 300 ml each of methanol, acetone and water. The yields of the extracts were 3.32 gm, 3.98 gm and 3.36 gm for methanol, acetone and water respectively. The anthelmintic activity of 6.25 mg/ml, 12.5 mg/ml and 25 mg/ml concentrations of aqueous, acetone and methanol crude extracts of Plectranthus barbatus (leaves), were compared with the effect produced by the standard reference drug albendazole with Phosphate Buffered Saline (PBS) used as a negative control. Death of Haemonchus contortus worm was determined within a period of 24 hrs. Plectranthus barbatus (leaves) extract had mean mortality of 0-16.7 % at 6.25 mg/ml; 3.3-26.7 % at 12.5 mg/ml; 6.7-33.3 % at 25 mg/ml. All the extracts contained tannins only.