This article was downloaded by: [Department Of Fisheries] On: 16 November 2014, At: 23:47 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Journal of Aquatic Animal Health Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/uahh20 Screening Medicinal Plants for Use against Dactylogyrus intermedius (Monogenea) Infection in Goldfish Yang Hua, Jie Jib, Fei Lingb, Yunhe Chenb, Lin Lub, Qizhong Zhangc & Gaoxue Wangab a College of Science, Northwest A&F University, Yangling 712100, China b College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China c Institute of Hydrobiology, Jinan University, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering Minister of Education, Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institutes, Guangzhou 510632, China Published online: 03 Jul 2014. To cite this article: Yang Hu, Jie Ji, Fei Ling, Yunhe Chen, Lin Lu, Qizhong Zhang & Gaoxue Wang (2014) Screening Medicinal Plants for Use against Dactylogyrus intermedius (Monogenea) Infection in Goldfish, Journal of Aquatic Animal Health, 26:3, 127-136, DOI: 10.1080/08997659.2014.902872 To link to this article: http://dx.doi.org/10.1080/08997659.2014.902872 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. 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Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions Journal of Aquatic Animal Health 26:127–136, 2014 C American Fisheries Society 2014 ISSN: 0899-7659 print / 1548-8667 online DOI: 10.1080/08997659.2014.902872 ARTICLE Screening Medicinal Plants for Use against Dactylogyrus intermedius (Monogenea) Infection in Goldfish Yang Hu College of Science, Northwest A&F University, Yangling 712100, China Jie Ji, Fei Ling, Yunhe Chen, and Lin Lu College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China Qizhong Zhang* Institute of Hydrobiology, Jinan University, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering Minister of Education, Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institutes, Guangzhou 510632, China Gaoxue Wang* College of Science, Northwest A&F University, Yangling 712100, China; and College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China Abstract Methanol extracts of 24 traditional medicinal plants with potential anthelmintic activity against Dactylogyrus intermedius (Monogenea) in Goldfish Carassius auratus were investigated. Abrus cantoniensis, Citrus medica, Dioscorea collettii,andPolygonum multiflorum exhibited 100% activity and were selected for further evaluation by applying five solvents (petroleum ether, chloroform, ethyl acetate, methanol, and water) for the extraction of the samples, followed by an in vivo bioassay. Among the plants tested, water, methanol, and ethyl-acetate extracts of P. multiflorum showed the highest efficacies; EC50 values (median concentration that results in 50% of its maximal effect) were 1.9, 5.4, and 9.1 mg/L, respectively, and extracts showed 100% efficacy against Dactylogyrus intermedius at 100, 12.5, and 25 mg/L. This was followed by ethyl-acetate, chloroform, and methanol extracts of Dioscorea collettii, which demonstrated 100% efficacy at 80, 80, and 120 mg/L and had EC50 values of 19.7, 27.1, and 37.8 mg/L, respectively, after 48 h of exposure. Chloroform and ethyl-acetate extracts of C. medica, which exhibited 100% efficacy against Dactylogyrus intermedius at 100 and 125 mg/L, revealed similar activity and had EC50 values of 58.7 and 51.3 mg/L, respectively. The ethyl-acetate and methanol extracts of A. cantoniensis exhibited the lowest activity and had EC50 values of 279.4 Downloaded by [Department Of Fisheries] at 23:47 16 November 2014 and 64.3 mg/L. Acute toxicities of these active extracts were investigated on Goldfish for 48 h. The findings indicated that extracts of the four plants can be developed as a preferred natural antiparasitic for the control of D. intermedius. According to the Food and Agriculture Organization of the world’s largest producer of fish, which accounts for two-thirds of United Nations (FAO 2008), global aquaculture has developed the global production in 2009 (FAO 2008), and thus plays a vital rapidly in recent years and grown at an annual rate of 6.4% from and decisive role in aquaculture. However, intensive fish pro- 2002 to 2006. In addition, aquaculture in developing countries duction often results in increased incidences of diseases caused will continuously grow in the next 10 years (Food Business by viruses, bacteria, fungi, parasites, and other undiagnosed and Network 2008). China, the biggest developing country, is the emerging pathogens (Bondad-Reantaso et al. 2005). *Corresponding authors: [email protected]; [email protected] Received June 15, 2013; accepted February 11, 2014 127 128 HU ET AL. Dactylogyrus intermedius is an important monogenean para- imens have been deposited at the herbarium of the College of site that invades the skin and gills of cyprinid fishes and thereby Life Science, Northwest A&F University. The plant materials causes serious problems, such as gill inflammation, excessive were washed thoroughly with water and oven-dried at 45◦Cfor mucous secretions, respiratory distress, and mixed infections 48 h, then they were crushed and reduced to a fine powder using with other parasites and secondary bacterial infections (Reed a strainer (30–40 mesh) with an electrical disintegrator (model et al. 2009). Fish infected with D. intermedius can be treated FW177, Tianjin Taisite Instrument Company). The powdered effectively with a wide spectrum of parasiticides, such as for- samples were freeze-dried at −45◦C to ensure complete removal malin (Marshall 1999), trichlorfon (Goven and Amend 1982), of water. a triazine derivative (Schmahl 1993), and the two most effec- Screening experiment.—A 50-g dry powder sample of each tive treatments in practice, praziquantel (Schmahl and Mehlhorn of 24 different plants was extracted three times with methanol 1985) and mebendazole (Buchmann et al. 1993). However, these (500 mL) for 48 h. To get more or less solidified crude extracts, chemical parasiticides can present serious drawbacks through the methanol filtrates were separately filtered and evaporated frequent use, including the threats of anthelmintic resistance, under reduced pressure in a vacuum rotary evaporator (model risk of residue, environmental contamination, and toxicity to the R-201, Shanghai Shenshen) until the solvents were completely host (Goven et al. 1980; Klinger and Floyd 2002). Therefore, evaporated. The resulting extracts of different plants were dis- there is an urgent need for alternative therapies, including the solved in dimethyl sulfoxide (DMSO) and diluted with distilled use of natural products from medicinal plants, which are more water to obtain 0.6 g/mL (sample/solvent) of stock solutions, environmentally acceptable and generally have lower toxicity which were used for the preparations of the desired concentra- than chemicals. tions for the anthelmintic efficacy assay. Recently, medicinal plants and their extracts were tested for An in vivo study was designed to determine the anthelmintic their ability to control D. intermedius, and different extracts activity of extracts to D. intermedius according to the previous from several medicinal plants had significant killing effects in method of Ji et al. (2012). Five fish previously infected with the vivo (Wang et al. 2009, 2010a, 2010b; Liu et al. 2010; Wu et al. parasite were placed in plastic basins (N = 120) of 5 L capac- 2011; Ji et al. 2012; Lu et al. 2012). In our research, we exploited ity that were filled with 2 L of aerated groundwater. Extracts the crude extracts of different medicinal plants extracted by five with designed concentration gradients of 100, 200, 300, 400, solvents (petroleum ether, chloroform, ethyl acetate, methanol, 500, and 600 mg/L were added to the basins. Negative control and water) for anthelmintic activity against D. intermedius in groups containing no plant extract were set up under the same Goldfish Carassius auratus. conditions as used for the test