Solvent selection for plant extracts dissolution for in vitro acaricidal experiments

摘要

The effects of some solvents used for the preparation of plant extracts (methanol, ethanol, petroleum ether, ethyl acetate, chloroform, n-butanol, glycerine and liquid paraffin) on Boophilus microplus in vitro were studied. Adult ticks were transferred to petri dishes with filter paper treated with each of the solvents, then the petri dishes were maintained at 25 degrees C and 80+or-5% relative humidity for 24 h. Tick mortality was evaluated after 2, 4, 6, 12 or 24 h. Petroleum ether, chloroform and ethyl acetate resulted in 70+or-1.25, 80+or-1.75 and 100+or-00% mortality, respectively, after 2 h, and in 100% mortality (for each extract) after 24 h. Tick mortality was not recorded for glycerine and liquid paraffin at 2 h after treatment; however, the mortality of ticks exposed to these solvents reached 35+or-0.56 and 25+or-0.39% after 4 h, and 75+or-1.25 and 65+or-0.65% after 24 h, respectively. The results revealed that distilled water, followed by methanol and ethanol, are suitable vehicles for the dissolution of plant extracts for the analysis of acaricidal activity in vitro.