title: Identification and effect of two flavonoids from root bark of Morus alba against Ichthyophthirius multifiliis in grass carp.
abstract: Ichthyophthirius multifiliis (Ich) is an important ciliate that parasitizes gills and skin of freshwater fish and causes massive fish mortality. In this study, two flavonoids (kuwanons G and O) with anti-Ich activity were isolated by bioassay-guided fractionation from the root bark of Morus alba, an important plant for sericulture. The chemical structures of kuwanons G and O were elucidated by spectroscopic analyses. Kuwanons G and O caused 100% mortality of I. multifiliis theronts at the concentration of 2 mg/L and possessed a median effective concentration (EC50) of 0.8 ± 0.04 mg/L against the theronts. In addition, kuwanons G and O significantly reduced the infectivity of I. multifiliis theronts at concentrations of 0.125, 0.25, 0.5, and 1 mg/L. The median lethal concentrations (LC50) of kuwanons G and O to grass carp were 38.0 ± 0.82 and 26.9 ± 0.51 mg/L, which were approximately 50 and 35 times the EC50 for killing theronts. The results indicate that kuwanons G and O have the potential to become safe and effective drugs to control ichthyophthiriasis.
authors.affiliation: Key Laboratory of Aquatic Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Institute of Hydrobiology, Jinan University , West 601 Huangpu Avenue, Tianhe, Guangzhou, Guangdong 510632, People's Republic of China.
authors.forename: Jing-Han
authors.initials: JH
authors.lastname: Liang
authors.forename: Yao-Wu
authors.initials: YW
authors.lastname: Fu
authors.forename: Qi-Zhong
authors.initials: QZ
authors.lastname: Zhang
authors.forename: De-Hai
authors.initials: DH
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: De-Jie
authors.initials: DJ
authors.lastname: Lin
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D002347:Carps / Q000469:parasitology; D016770:Ciliophora Infections / Q000469:parasitology / Q000662:veterinary*; D005393:Fish Diseases / Q000469:parasitology; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D016803:Hymenostomatida / Q000187:drug effects; D015394:Molecular Structure; D031625:Morus / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry
chemical_list: D000981:Antiprotozoal Agents; D005419:Flavonoids; D010936:Plant Extracts
keywords: Ichthyophthirius multifiliis; Morus alba; antiparasitic effect; kuwanon G; kuwanon O