The present study aims to evaluate the anthelmintic properties of aerial part of Macleaya
microcarpa (Maxim) Fedde. Bioassay-guided fractionation and isolation of the compounds
with anthelmintic activity were performed on the ethanolic extract of M. microcarpa
yielding five bioactive alkaloids namely: sanguinarine, cryptopine, beta-allocryptopine,
protopine and 6-methoxyl-dihydro-chelerythrine by comparing spectral data (UV, NMR,
and EI-MS) with literature values. According to in vivo anthelmintic assays, they
were found to be 100% effective at the concentrations of 0.7, 8.0, 8.0, 16.0 and 7.0
mgl(-1), and the median effective concentration (EC(50)) values for the five compounds
were 0.37, 3.31, 4.64, 8.13 and 3.63 mgl(-1), respectively. Additionally, the acute
toxicity on goldfish for the five active compounds was also investigated with median
lethal concentrations (LC(50)) values of 1.13, 16.12, 15.88, 21.69 and 10.91 mgl(-1),
respectively. The resulting therapeutic indices for sanguinarine, cryptopine, beta-allocryptopine,
protopine and 6-methoxyl-dihydro-chelerythrine were 3.03, 4.82, 3.40, 2.66 and 2.99
correspondingly. Correlations analysis between the logP and EC(50), LC(50) of the
five alkaloids revealed that the activity of the five alkaloids was well correlated
with their hydrophobicity and r(2)=0.45 is for anthelmintic activity while r(2)=0.47
is for acute toxicity for goldfish, respectively. These results provided evidence
that the studied plant extract, as well as the isolated compounds, especially sanguinarine,
might be potential plant-based medicines for the treatment of D. intermedius infection.
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