Observations on in vitro and in vivo antimicrofilarial effects of Bishop's weed (Trachispermum ammi).

The antimicrofilarial efficacy of Trachispermum ammi extacts in vitro and in vivo using Setaria cervi as a model, was investigated. T. ammi seed extracts were prepared using different solvents (with increasing order of polarity of the solvent) including petroleum ether, diethyl ether, chloroform, ethyl acetate, acetone, ethanol, and methanol. The extracts were tested for in vitro antimicrofilarial activity. The ethanolic and the methanolic extracts showed maximum activity in causing flaccidity in the microfilariae. The extracts were potent even at concentrations as low as 5 μl/ml. When orally administered to experimentally infected rats, the extracts eliminated circulating microfilariae within 2 weeks. It is inferred that the antimicrofilarial molecule(s), are polar in nature. They induce flaccidity in the microfilariae, by possibly inhibiting monoamine oxidase. This communication supplements the ethnopharmacological information for the use of T. ammi as an antihelminthic, and indicates that T. ammi could be used as a potential source of antimicrofilarial drugs.