RESUMEN
Ichthyophthirius multifiliis, a global distributed protozoan parasite, causes "White spot disease" and leads to serious mortality of freshwater fish in aquaculture. The present study was conducted to assess the anti-I. multifiliis efficacy of active compound isolated from Sophora flavescens. The isolated active compound was identified as sophoraflavanone G (SG) with ESI-MS and NMR. In vitro tests, SG at concentrations of 0.5 mg/L and 2 mg/L resulted in death of all theronts and tomonts, respectively; SG at concentrations of 0.125 mg/L and 0.25 mg/L notably decreased theronts infectivity (p < 0.05). Additionally, the in vivo test results showed that a cumulative delivery of SG at concentration of 2 mg/L for 7 days protected fish from I. multifiliis infection. The 96-h LC50 (median lethal concentration) and safety concentration of SG to grass carp were 46.6 mg/L and 11.3 mg/L, respectively. The present work indicated that SG was a potential safe and effectively therapeutic agent in treating I. multifiliis.
Asunto(s)
Infecciones por Cilióforos , Enfermedades de los Peces , Hymenostomatida , Parásitos , Sophora , Animales , Infecciones por Cilióforos/tratamiento farmacológico , Infecciones por Cilióforos/parasitología , Infecciones por Cilióforos/veterinaria , Enfermedades de los Peces/tratamiento farmacológico , Enfermedades de los Peces/parasitología , FlavanonasRESUMEN
Enterocytozoon hepatopenaei (EHP) is a common parasite that invades the epithelial cytoplasm in the hepatopancreas of shrimp Litopenaeus vannamei and results in slow growth of the host shrimps to cause significant economic loss in shrimp aquaculture. In this study, a TaqMan probe-based qPCR for quantitative detection of EHP was established. A pair of specific primers and a TaqMan probe were designed based on the sequence of cysteine desulfurase gene (NFS1) of EHP. The standard curve between cycle threshold (Ct) and the logarithmic starting quantity (SQ) of the template was determined as Ct = - 3.231 lg (SQ) + 40.638, with a correlation coefficient (R2) of 0.998 and an amplification efficiency of 103.9%. The lower limit of quantification was 1.67 × 101 copies/µL for this TaqMan probe-based qPCR and 1.67 × 103 copies/µL for the conventional PCR. The TaqMan probe-based qPCR established in the research was 100 times more sensitive than the conventional PCR method. In addition, the results of clinical sample detection indicated that the present technique was efficient in detecting EHP in the hepatopancreas, feces, water, and pond bottom mud samples. Therefore, the established TaqMan probe-based qPCR is a suitable technique for detecting EHP in both shrimp and aquatic environment samples.
Asunto(s)
Enterocytozoon , Penaeidae , Animales , Enterocytozoon/genética , Hepatopáncreas , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Integrins, a family of cell adhesion transmembrane receptors, mediate cell adhesion, migration, proliferation, apoptosis, and phagocytosis. In the present study, an integrin ChIntα 4 from Crassostrea hongkongensis was characterized to investigate its role in defensing against pathogenic bacterium Vibrio alginolyticus. The full-length cDNA sequence of ChIntα 4 was 3572 bp with an open reading frame (ORF) of 3168 bp, which encoded a polypeptide with 1055 amino acids. The mRNA expression of ChIntα 4 in the hemocytes was significantly up-regulated at 6 h and 24 h post V. alginolyticus stimulation (p < 0.01). The recombinant ChIntα 4 protein could agglutinate the rabbit red blood cells and Gram-negative bacteria V. alginolyticus and Escherichia coli. Moreover, the phagocytic activity of the hemocytes was significantly down-regulated from 46.9% to 32.7% when blocked with anti-ChIntα 4 antibody, and it was significantly up-regulated from 42.7% to 59.5% post transfection with pCI-neo-ChIntα 4 plasmid (p < 0.05). In conclusion, these findings demonstrated that ChIntα 4 might be involved in resisting V. alginolyticus infection and regulating phagocytosis as a cell adhesion receptor in C. hongkongensis.
Asunto(s)
Crassostrea , Hemocitos , Animales , Crassostrea/metabolismo , Inmunidad Innata , Integrinas/genética , Integrinas/metabolismo , Fagocitosis , Filogenia , Conejos , Vibrio alginolyticusRESUMEN
The orange-spotted grouper (Epinephelus coioides) is an important marine farmed fish in China. It is affected by the bacterial pathogen Vibrio alginolyticus, which causes high mortality and substantial economic losses. We studied the transcriptional changes of the IgZ gene in E. coioides following V. alginolyticus stimulation and investigated the distribution of IgZ in different tissues. The highest expression level of IgZ occurred in the head kidney. When fish were stimulated with live and inactivated V. alginolyticus, the expression levels of IgZ in the head kidney, spleen, intestine, gills and blood cells were significantly upregulated. In an in situ hybridization study, IgZ mRNA-positive cells were detected in the head kidney, spleen and gill, but positive signals were not detected in the liver and intestine. IgZ-labelled cells increased in the head kidney, spleen and gills post-infection with V. alginolyticus for 21 days. The present study provides additional evidence that IgZ is involved in mucosal immune responses and helps explain the role of IgZ in E. coioides defence against V. alginolyticus infection.
Asunto(s)
Lubina , Enfermedades de los Peces/inmunología , Proteínas de Peces/genética , Perfilación de la Expresión Génica/veterinaria , Vacunación/veterinaria , Vibriosis/veterinaria , Vibrio alginolyticus/fisiología , Animales , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/inmunología , Enfermedades de los Peces/microbiología , Proteínas de Peces/metabolismo , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/metabolismo , Distribución Aleatoria , Vibriosis/inmunología , Vibriosis/microbiologíaRESUMEN
Carassotrema schistorchis is a digenea parasite whose juvenile and adult stages parasitize the intestinal tract of definitive host fish. There is no available ecological information about this parasitic infection in wild host fish. The present work aimed to investigate the infection rate and distribution of C. schistorchis in wild silver carp, Hypophthalmichthys molitrix, and to assess the influence of environmental factors on infection by the parasite. From October 2016 to May 2019, a total of 554 wild silver carp were collected from two reservoirs. These collected fish were weighed, measured, and dissected to observe the presence of C. schistorchis following standard methodology. Ecological analysis results showed that the frequency distribution of C. schistorchis in the host population was aggregated distribution. The abundance of C. schistorchis exhibited a positive correlation with the host age and condition factor of silver carp, but it showed no relationship with water temperature, pH or DO. The condition factor value of infected fish was significantly higher than that of uninfected fish. These results indicated that food intake, not environmental factors, directly determined infection by the parasite in the host, indicating that an increased food intake would increase the risk of infection. Thus, the number of parasites could be used as an indirect biological marker for assessing the effectiveness of silver carp in filter-feeding on plankton. The following analysis indicated that silver carp with a body length of 50-55 cm showed the highest efficiency in controlling phytoplankton biomass. This study provides important information for understanding the ecology of C. schistorchis in wild silver carp.
RESUMEN
To better explore the application potential of heat shock protein Hsp70s in diverse areas including biomonitoring, a further investigation of the details of the regulatory mechanism governing Hsp70 transcription is required. A transcriptional factor ChGATA-4 that displayed affinity to the ChHsp70 promoter of Crassostrea hongkongensis was isolated and identified by DNA affinity purification as well as mass spectrometry analysis. The ChGATA-4 cDNA is 2162 bp in length and the open reading frame encodes a polypeptide containing 482 amino acids with a conserved zinc finger domain. The over-expression of ChGATA-4 significantly inhibited the expression of ChHsp70 promoter in heterologous HEK293T cells. However, the depletion of ChGATA-4 mRNA by RNAi technique resulted in significant increase of ChHsp70 transcription in oyster hemocytes. The RT-PCR results demonstrated that the transcription of both ChHsp70 and ChGATA-4 were induced by heat, Cd, or NP (Nonyl phenol) stress. This suggested a potential correlation between ChHsp70 and ChGATA-4 in the stress-mediated genetic regulatory cascade. This study demonstrated that ChGATA-4 acts in a negative manner in controlling ChHsp70 transcription in C. hongkongensis and promotes to further understand the mechanisms leading Hsp70 transcription.
Asunto(s)
Crassostrea , Factor de Transcripción GATA4 , Proteínas HSP70 de Choque Térmico , Transcripción Genética , Animales , Crassostrea/genética , Crassostrea/metabolismo , Factor de Transcripción GATA4/genética , Factor de Transcripción GATA4/metabolismo , Proteínas HSP70 de Choque Térmico/biosíntesis , Proteínas HSP70 de Choque Térmico/genéticaRESUMEN
Ichthyophthirius multifiliis is a ciliate parasite of freshwater fish with a global distribution and results in severe economic losses in aquaculture. The present study aimed to investigate the efficacy and antiparasitic mechanism of active compounds isolated from Zingiber officinale against I. multifiliis. Three compounds were isolated from the Z. officinale extract and identified as 10-gingerol, 6-dehydroshogaol, and 6-dehydro-10-gingerol. 10-gingerol demonstrated the greatest antiparasitic efficacy in vitro. 10-gingerol resulted in 100% mortalities of theronts, nonencysted tomonts, and encysted tomonts at concentrations of 2, 8, and 16 mg/L, respectively. 10-gingerol significantly reduced theronts infectivity (p < 0.05) at a concentration of 1 mg/L, and it was effective in treating infected grass carp and protecting naïve fish from I. multifiliis infestation at a concentration of 4 mg/L. The antiparasitic mechanism might be attributed to the increase of intracellular osmotic pressure, accumulation of free radicals, and membrane damage of I. multifiliis post 10-gingerol treatment. The study demonstrated that 10-gingerol had the potential as a therapeutic agent against I. multifiliis.
Asunto(s)
Carpas , Catecoles/uso terapéutico , Infecciones por Cilióforos/tratamiento farmacológico , Infecciones por Cilióforos/veterinaria , Alcoholes Grasos/uso terapéutico , Enfermedades de los Peces/parasitología , Zingiber officinale/química , Animales , Antiparasitarios/uso terapéutico , Infecciones por Cilióforos/parasitología , Enfermedades de los Peces/tratamiento farmacológico , Distribución AleatoriaRESUMEN
The complement system plays an important role in host defense against invading microorganisms. Complement component C9 is the last component that is involved in the formation of the membrane attack complex (MAC) on the surface of target cells. In the present study, the full length C9 cDNA sequence of 1984 bp with an open reading frame (ORF) of 1809 bp was cloned from southern catfish (Silurus meridionalis). The deduced amino acid sequence showed similarity with other teleost fish. The mRNA expression of C9 was detected in the liver, spleen, stomach, intestine, and head kidney, with highest levels detected in the liver. The mRNA of C9 was first detected in the yolk syncytial layer at 34â¯h post fertilization (hpf) with whole mount in situ hybridization, followed by the liver at 36â¯h post hatching (hph). The mRNA expression of C9 was upregulated significantly in the liver, spleen, and intestine following the injection with Aeromonas hydrophila, suggesting that C9 played an important role in defense against invading pathogens in southern catfish. Therefore, these results provide important information to understand the functions of C9 during fish early development in fish.
Asunto(s)
Bagres/genética , Bagres/inmunología , Complemento C9/genética , Complemento C9/inmunología , Enfermedades de los Peces/inmunología , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Aeromonas hydrophila/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Complemento C9/química , Proteínas de Peces/química , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Perfilación de la Expresión Génica/veterinaria , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Alineación de Secuencia/veterinariaRESUMEN
The complement system plays an important role in protecting fish against attack by pathogens early in life. Complement component C3 is a central component in the complement system. The present work aimed to clone the full length C3 cDNA sequence of southern catfish (Silurus meridionalis), detect the tissue expression patterns of C3, investigate the ontogeny of C3 in embryo and larva, and assess the expression of C3 in response to pathogen infection. The full length C3 cDNA sequence of 5157 bp with an open reading frame (ORF) of 4938 bp was cloned from southern catfish. The deduced amino acid sequence showed similarity with other teleost fish. The mRNA expression of C3 was detected in liver, spleen, stomach, intestine, and head kidney with RT-PCR and in situ hybridization. Whole mount in situ hybridization results revealed that C3 was first expressed in the yolk syncytial layer at 34â¯h post fertilization (hpf), followed by the liver at 36â¯h post hatching (hph). When challenged with Aeromonas hydrophila, the transcripts of C3 showed a significant up-regulation in liver and spleen at 24â¯h. The results suggested that complement C3 played a key role in defense against invading pathogens in the early development stages of southern catfish. Therefore, these results provide important information to understand the functions of C3 during fish early development in Siluriformes.
Asunto(s)
Bagres/genética , Bagres/inmunología , Complemento C3/genética , Complemento C3/inmunología , Enfermedades de los Peces/inmunología , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Inmunidad Adaptativa/genética , Aeromonas hydrophila/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Complemento C3/química , Proteínas de Peces/química , Proteínas de Peces/genética , Proteínas de Peces/inmunología , Perfilación de la Expresión Génica/veterinaria , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Filogenia , Alineación de Secuencia/veterinariaRESUMEN
Dactylogyrus ctenopharyngodonid and Ichthyophthirius multifiliis are 2 important ectoparasites of fish. Both parasites can induce an immune response in fish that leads to a decrease in parasitic infection intensity and the development of resistance against parasitic reinfection. The present study evaluated whether grass carp Ctenopharyngodon idella that survived a D. ctenopharyngodonid infection could develop immunity against infection by D. ctenopharyngodonid and I. multifiliis. The results demonstrated that when grass carp were infected with D. ctenopharyngodonid, the number of red blood cells and the percentages of thrombocytes, monocytes, and neutrophils in the white blood cells increased significantly in the early stage of infection. The percentage of lymphocytes increased over time following parasitic infection. The mean infection intensity of D. ctenopharyngodonid decreased to 0 on Day 28. The activities of serum acid phosphatase, alkaline phosphatase, lysozyme, and superoxide dismutase increased significantly after D. ctenopharyngodonid infection. In addition, the grass carp that survived a previous D. ctenopharyngodonid infection could completely resist D. ctenopharyngodonid reinfection and partially resist I. multifiliis infection.
Asunto(s)
Carpas/parasitología , Infecciones por Cilióforos/veterinaria , Cilióforos/inmunología , Enfermedades de los Peces/parasitología , Platelmintos , Infecciones por Trematodos/veterinaria , Animales , Carpas/inmunología , Infecciones por Cilióforos/inmunología , Enfermedades de los Peces/inmunología , Infecciones por Trematodos/inmunologíaRESUMEN
Ichthyophthirius multifiliis is a ciliated parasite that infests almost all freshwater fish species and causes great economic losses to the aquaculture industry. In this study, a compound with anti-I. multifiliis activity was isolated from Polygonum cuspidatum and identified as emodin. In vitro anti-I. multifiliis results showed that emodin at 1â¯mg/L killed all I. multifiliis theronts for 96.0â¯min, and at 0.5â¯mg/L or lower concentrations could not kill all I. multifiliis theronts, but could significantly reduce the infectivity of theronts after pretreatment with emodin at the low concentrations mentioned above for 2â¯h. Additionally, emodin at 1â¯mg/L and 2â¯mg/L completely terminated the reproduction of nonencysted and encysted tomonts, respectively. In vivo tests, emodin at 0.5â¯mg/L could cure infected grass carp and protect naive fish from I. multifiliis infection by continuous adding emodin for 10 days. The 96â¯h median lethal concentration (LC50) of emodin to grass carp was 3.15â¯mg/L, which were approximately 18 and 7 times the median effective concentration (EC50) of emodin for killing theronts (0.18â¯mg/L) and nonencysted tomonts (0.45â¯mg/L), respectively. On the basis of these results, emodin is an effective compound for the development of a new drug against I. multifiliis.
Asunto(s)
Antiparasitarios/farmacología , Infecciones por Cilióforos/veterinaria , Emodina/farmacología , Fallopia japonica/química , Enfermedades de los Peces/tratamiento farmacológico , Hymenostomatida/efectos de los fármacos , Animales , Antiparasitarios/química , Antiparasitarios/aislamiento & purificación , Carpas , Infecciones por Cilióforos/tratamiento farmacológico , Infecciones por Cilióforos/parasitología , Emodina/química , Emodina/aislamiento & purificación , Enfermedades de los Peces/parasitologíaRESUMEN
Dactylogyrus ctenopharyngodonid and Ichthyophthirius multifiliis are two important ectoparasites of freshwater fish. Co-infection by the two parasites leads to high fish mortality and results in heavy economic losses. This study aimed to evaluate the efficacy of medicated feed and a ginger extract bath against D. ctenopharyngodonid and I. multifiliis on grass carp and investigate the hematological response of grass carp co-infected by the two parasites. These results demonstrated that red blood cell (RBC) and thrombocyte percentage among leucocytes significantly decreased after grass carp were co-infected by D. ctenopharyngodonid and I. multifiliis. The monocyte and neutrophil percentages significantly increased with the increment of parasite mean intensities, while the lymphocyte percentage decreased. The activities of serum acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), and superoxide dismutase (SOD) significantly increased after co-infection. When grass carp treated with medicated feed containing 4% of Astragalus membranaceus, Allium sativum, Morus alba, and Glycyrrhiza uralensis, the activities of ACP, AKP, LZM, and SOD were significantly enhanced, and the mean intensities of D. ctenopharyngodonid and I. multifiliis were significantly decreased. When grass carp was treated with medicated feed and a 4-mg/L ginger extract bath, all parasites were eliminated during 28 days. The bath of ginger extract at a concentration of 4 mg/L kept a low mean intensity of I. multifiliis and D. ctenopharyngodonid, then the two parasites were eliminated by oral administration of the medicated feed with an immunostimulant (Chinese medicine compound).
Asunto(s)
Carpas/parasitología , Infecciones por Cilióforos/veterinaria , Medicamentos Herbarios Chinos/uso terapéutico , Enfermedades de los Peces/parasitología , Hymenostomatida , Infecciones por Trematodos/veterinaria , Alimentación Animal , Animales , Infecciones por Cilióforos/tratamiento farmacológico , Coinfección , Ajo , Zingiber officinale , Hymenostomatida/efectos de los fármacos , Trematodos , Infecciones por Trematodos/tratamiento farmacológicoRESUMEN
Ichthyophthirius multifiliis is a ciliated parasite that elicits great economic losses in aquaculture. In the present study, a polyphenol compound, curcumin, was obtained from the rhizome of Curcuma longa by bioassay-guided isolation based on the efficacy of anti-I. multifiliis theronts. Anti-I. multifiliis efficacy of curcumin was evaluated in vitro and in vivo. Curcumin resulted in 100% mortality of I. multifiliis theronts at a concentration of 1mg/L within 21.7±1.2min and killed all tomonts at 8mg/L within 31.0±1.0min. Curcumin at 4mg/L for 16h exposure can completely terminate the reproduction of tomonts. The pretreatment with curcumin at concentrations of 0.5, 0.25, and 0.125mg/L for 2h significantly reduced the infectivity of I. multifiliis theronts. Curcumin at 4mg/L completely cured the infected grass carp and protected naive fish from I. multifiliis infection after 10days exposure. The 4h median effective concentration (EC50) of curcumin to I. multifiliis theronts and the 5h EC50 of curcumin to I. multifiliis tomonts were 0.303mg/L and 2.891mg/L, respectively. The 96h median lethal concentration (LC50) of curcumin to grass carp was 56.8mg/L, which was approximately 187.4 times EC50 of curcumin to theronts and 19.6 times EC50 of curcumin to tomonts. The results demonstrated that curcumin has the potential to be a safe and effective therapeutant for controlling ichthyophthiriasis in aquaculture.
Asunto(s)
Antiprotozoarios/farmacología , Carpas , Infecciones por Cilióforos/veterinaria , Curcumina/farmacología , Enfermedades de los Peces/tratamiento farmacológico , Hymenostomatida/efectos de los fármacos , Animales , Antiprotozoarios/efectos adversos , Infecciones por Cilióforos/tratamiento farmacológico , Infecciones por Cilióforos/parasitología , Curcumina/efectos adversos , Relación Dosis-Respuesta a Droga , Enfermedades de los Peces/parasitología , Hymenostomatida/fisiología , Distribución AleatoriaRESUMEN
Since malachite green was banned for using in food fish due to its carcinogenic and teratogenic effects on human, the search of alternative drug to treat Ichthyophthirius multifiliis becomes urgent. This study aimed to (1) evaluate the ethanol extracts of medicinal plants Cynanchum atratum, Zingiber officinale, Cynanchum paniculatum, immunostimulant (A), and immunostimulant (B) for their efficacy against I. multifiliis, and (2) determine effects of medicated feeds with C. atratum, Z. officinale, C. paniculatum, and immunostimulant (A) to treat I. multifiliis in grass carp. The results in this study showed that the minimum concentrations of C. atratum, Z. officinale, and C. paniculatum extracts for killing all theronts were 16, 8, and 16 mg/L, respectively. In vivo experiments, fish fed with medicated feeds of C. atratum for 10 days, or Z. officinale for 3 days, or combination of three plants for 10 days resulted in a significant reduction in the I. multifiliis infective intensity on grass carp after theronts exposure. Grass carp fed with medicated feeds of immunostimulant (A) for 21 days showed no infection and 100 % of survival 15 days post theronts exposure. Therefore, immunostimulant (A) is a promising feed supplement to treated I. multifiliis with good antiparasitic efficacy.
Asunto(s)
Antiparasitarios/farmacología , Carpas/parasitología , Infecciones por Cilióforos/tratamiento farmacológico , Infecciones por Cilióforos/veterinaria , Medicamentos Herbarios Chinos/farmacología , Enfermedades de los Peces/tratamiento farmacológico , Hymenostomatida/efectos de los fármacos , Animales , Apocynaceae/química , Enfermedades de los Peces/parasitología , Zingiber officinale/química , Extractos Vegetales/farmacología , Plantas Medicinales/química , Vincetoxicum/químicaRESUMEN
Infection by Ichthyophthirius multifiliis, a ciliated protozoan parasite, results in high fish mortality and causes severe economic losses in aquaculture. To find new, efficient anti-I. multifiliis agents, cynatratoside-C was isolated from Cynanchum atratum by bioassay-guided fractionation in a previous study. The present study investigated the anti-theront activity, determined the toxicity of cynatratoside-C to grass carp Ctenopharyngodon idellus and mammalian blood cells, and evaluated the protection of cynatratoside-C against I. multifiliis theront infection in grass carp. Results showed that all theronts were killed by 0.25 mg l-1 of cynatratoside-C in 186.7 ± 5.8 min. Cynatratoside-C at 0.25 mg l-1 was effective in treating infected grass carp and protecting naive fish from I. multifiliis infestation. The 96 h median lethal concentration (LC50) of cynatratoside-C to grass carp and 4 h median effective concentration (EC50) of cynatratoside-C to theront were 46.8 and 0.088 mg l-1, respectively. In addition, the hemolysis assay demonstrated that cynatratoside-C had no cytotoxicity to rabbit red blood cells. Therefore, cynatratoside-C could be a safe and effective potential parasiticide for controlling I. multifiliis.
Asunto(s)
Carpas/sangre , Infecciones por Cilióforos/veterinaria , Cilióforos/efectos de los fármacos , Enfermedades de los Peces/parasitología , Hemólisis/efectos de los fármacos , Secoesteroides/efectos adversos , Secoesteroides/uso terapéutico , Trisacáridos/efectos adversos , Trisacáridos/uso terapéutico , Animales , Infecciones por Cilióforos/prevención & control , Enfermedades de los Peces/inducido químicamente , Enfermedades de los Peces/tratamiento farmacológico , ConejosRESUMEN
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.
Asunto(s)
Antiprotozoarios/química , Antiprotozoarios/farmacología , Infecciones por Cilióforos/veterinaria , Flavonoides/química , Flavonoides/farmacología , Morus/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Animales , Antiprotozoarios/aislamiento & purificación , Carpas/parasitología , Infecciones por Cilióforos/parasitología , Enfermedades de los Peces/parasitología , Flavonoides/aislamiento & purificación , Hymenostomatida/efectos de los fármacos , Estructura Molecular , Corteza de la Planta/química , Extractos Vegetales/aislamiento & purificación , Raíces de Plantas/químicaRESUMEN
Ichthyophthirius multifiliis (Ich), a fish ectoparasite, comprises an important challenge in the aquaculture industry. In this study, a steroidal glycoside, cynatratoside-C, isolated from Cynanchum atratum roots by bioassay-guided fractionation was used to treat I. multifiliis. The cynatratoside-C at 0.25 mg/L demonstrated a 100% mortality of I. multifiliis in vitro after 5 h exposure. The 5 h median effective concentration (EC50) of cynatratoside-C to nonencysted tomonts was 0.083 mg/L. In addition, cynatratoside-C at concentrations of 0.125 and 0.06 mg/L could completely terminate the reproduction of encysted tomonts. The cynatratoside-C at 2 mg/L could cure the infected grass carp within 48 h. The exact mechanism of cynatratoside-C for killing I. multifiliis is unknown, but it manifests itself microscopically through loss of membrane integrity of nonencysted tomonts or through releasing immature theronts from encysted tomonts. The immature theronts finally died before infecting fish. On the basis of these results, cynatratoside-C could be used as a natural anti-I. multifiliis agent.
Asunto(s)
Apocynaceae/efectos de los fármacos , Carpas/parasitología , Secoesteroides/farmacología , Trisacáridos/farmacología , Vincetoxicum/química , AnimalesRESUMEN
Ichthyophthirius multifiliis (Ich), an important fish parasite, can cause significant losses in aquaculture. To find efficacious drugs to control Ich, the root bark of white mulberry Morus alba was evaluated for its antiprotozoal activity. Bark was powdered and extracted with 1 of 5 organic solvents: petroleum ether, chloroform, ethyl acetate, acetone, or methanol. The extracts were concentrated, dissolved in 0.1% (v/v) DMSO, and used for anti-Ich trials. Acetone and ethyl acetate extracts significantly reduced the survival of Ich tomonts and theronts. In vitro, acetone extract at 25 mg l-1 killed all non-encysted tomonts, at 50 mg l-1 eradicated all encysted tomonts, and at 8 mg l-1 caused mortality of all theronts. Ethyl acetate extract at 50 mg l-1 eliminated all non-encysted tomonts, at 100 mg l-1 killed all encysted tomonts and terminated tomont reproduction, and at 8 mg l-1 killed all theronts. Low concentrations (2 and 4 mg l-1) of acetone and ethyl acetate extracts could not kill all theronts after 4 h exposure, but a significant decrease in theront infectivity was observed following 30 min of pretreatment with the extracts. The 96 h LC(50) values of acetone and ethyl acetate extracts to grass carp were 79.46 and 361.05 mg l-1, i.e. much higher than effective doses for killing Ich theronts (8 mg l-1 for both extracts) and non-encysted tomonts (12.5 and 25 mg l-1, respectively). Thus M. alba extract may be a potential new, safe, and efficacious drug to control Ich.
Asunto(s)
Carpas , Cilióforos , Enfermedades de los Peces/microbiología , Morus/química , Extractos Vegetales/uso terapéutico , Infecciones Protozoarias en Animales/tratamiento farmacológico , Animales , Antiprotozoarios/efectos adversos , Antiprotozoarios/química , Antiprotozoarios/uso terapéutico , Corteza de la Planta/química , Extractos Vegetales/efectos adversos , Extractos Vegetales/química , Raíces de Plantas/química , Infecciones Protozoarias en Animales/parasitologíaRESUMEN
The purpose of the present study was to assess the anthelmintic property of plant-derived polyphenolic compounds extracted and isolated from Dryopteris crassirhizoma against Dactylogyrus intermedius in goldfish. The active ethyl acetate extract was loaded on an open silica gel column and eluted with chloroform-methanol. According to (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data, the structures of three purified compounds were identified as protocatechuic acid, sutchuenoside A, and kaempferitrin. Among these compounds, sutchuenoside A and kaempferitrin were observed to be effective with median effective concentration (EC50) of 3.01 and 2.71 mg L(-1), respectively. The alterations in the tegument of the parasites treated with isolated compound were examined using scanning electron microscopes. Ultrastructural micrographs revealed shrinkage of body surface, dense tegumental folds, and disheveled protuberances. The structural deformities in the treated parasites were indicative of an efficient anthelmintic activity of the isolated compound kaempferitrin. In addition, the 48-h median lethal concentration for sutchuenoside A and kaempferitrin against goldfish were 12.03- and 11.98-fold higher than corresponding EC50. The present results showed that ethyl acetate extract of D. crassirhizoma may be considered as a potent source, and sutchuenoside A and kaempferitrin as new natural parasitic agents against D. intermedius.