Farmaceutico

Veterinary Parasitology 183 (2011) 8–13

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Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar

Antiparasitic efficacy of dihydrosanguinarine and dihydrochelerythrine from Macleaya microcarpa against
Ichthyophthirius multifiliis in richadsin (Squaliobarbus curriculus)
Jia-yun Yao a , Zhi-ming Zhou a , Xi-lian Li b , Wen-lin Yin a , Hong-shun Ru a , Xiao-yi Pan a ,
Gui-jie Hao a , Yang Xu a , Jin-yu Shen a,∗ a b

Zhejiang Institute of Freshwater Fisheries, Huzhou, Zhejiang 313001, China
College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China

article

info

Article history:
Received 15 January 2011
Received in revised form 21 June 2011
Accepted 8 July 2011
Keywords:
Ichthyophthirius multifiliis
Dihydrosanguinarine
Dihydrochelerythrine
Antiparasitic

abstract
Ichthyophthirius multifiliis is a holotrichous protozoan that invades the gills and skin surfaces of fish and can cause morbidity and high mortality in most species of freshwater fish worldwide. The present study was undertaken to investigate the antiparasitic activity of crude extracts and pure compounds from the leaves of Macleaya microcarpa. The chloroform extract showed a promising antiparasitic activity against I. multifiliis. Based on these finding, the chloroform extract was fractionated on silica gel column chromatography in a bioactivity-guided isolation affording two compounds showing potent activity. The structures of the two compounds were elucidated as dihydrosanguinarine and dihydrochelerythrine by hydrogen and carbon-13 nuclear magnetic resonance spectrum and electron ionization mass spectrometry. The in vivo tests revealed that dihydrosanguinarine and dihydrochelerythrine were effective against I. multifiliis with median effective concentration
(EC50 ) values of 5.18 and 9.43 mg/l, respectively. The acute toxicities (LC50 ) of dihydrosanguinarine and dihydrochelerythrine