کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5805225 | 1555710 | 2012 | 6 صفحه PDF | دانلود رایگان |
We report a new bioassay “syringe test” (modified larval immersion test) for in vitro evaluation of acaricidal activity of crude plant extracts. Prepared syringes, containing eggs of tick, were incubated until 14Â d after hatching of eggs, when the bioassay was performed on the larvae. Lethal concentrations for 50% of larvae (LC50), LC90 and LC99 values were calculated for each tested product. 95% confidence intervals for LC50 were very narrow, indicating a high degree of repeatability for the new bioassay on larvae of R. microplus. Bioassays were applied to six crude aqueous-methanol extracts from five plants (Acacia nilotica, Buxus papillosa, Fumaria parviflora, Juniperus excelsa, and Operculina turpethum), of which three showed discernible effects. Twenty-four hours post exposure, LC99 values were 11.9% (w/v) for F. parviflora, 20.8% (w/v) and 29.2% (w/v) for B. papillosa and A. nilotica, respectively. After six days of exposure these values were; 9.1% (w/v), 9.2% (w/v) and 15.5 (w/v) for F. parviflora, A. nilotica and B. papillosa, respectively.
Journal: Veterinary Parasitology - Volume 188, Issues 3â4, 10 September 2012, Pages 362-367