In vitro antifilarial potential of the leaves and stem extract of Pluchea lanceolata on the cattle filarial parasite Setaria cervi

The effect of alcohol and aqueous extracts of the leaves and stem of Pluchea lanceolata on the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi, and on the survival of microfilariae in vitro was studied. Alcohol and aqueous extracts of the leaves and stem of P. lanceolata caused the inhibition of spontaneous movements of the whole worm and the nerve muscle preparation of S. cervi, characterized by short lasting small increase in tone and amplitude of contractions followed by paralysis. The concentrations required to inhibit the movements of whole worm and nerve muscle preparations for alcohol extract were 200 and $25\;{\mu}g/ml$, and for aqueous extract were 250 and $100\;{\mu}g/ml$, respectively, suggesting a cuticular permeability barrier. Both the extracts (alcohol and aqueous) caused death of microfilariae in vitro, $LC_{50}$ and $LC_{90}$ being 12 and 18 ng/ml for alcohol extract and 25 and 40 ng/ml for aqueous extract, respectively.