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Fei Ling - One of the best experts on this subject based on the ideXlab platform.

  • Antiparasitic efficacy and safety assessment of magnolol against Ichthyophthirius multifiliis in goldfish
    Aquaculture, 2018
    Co-Authors: Chenguang Song, Gaoxue Wang, Kaige Song, Fei Ling
    Abstract:

    Abstract Ichthyophthirius multifiliis causes high mortality rate of freshwater fish. It is necessary to find the effective alternatives that may both be affordable and environmentally acceptable since malachite green is banned to use. In this work, magnolol exhibited great anti-parasitic activity against all stages of I. multifiliis. Magnolol at concentrations of 0.6 mg/L or more resulted in 100% mortality of I. multifiliis theronts within 4 h exposure; and terminated reproduction of I. multifiliis post 6 h exposure of proTomonts and encysted Tomonts to 0.8 and 1.0 mg/L, respectively. Moreover, some of Tomonts presented morphological characteristic changes and a larger part of Tomonts were unable to reproduce. Magnolol possibly had a directly effect on the cell membrane, and more importantly, it could permeate into an encysted Tomont across the cyst wall and then impact on the Tomont proliferation. In vivo trials showed that 5 h exposure of infected fish to 1.5 mg/L of magnolol significantly reduced the number of theronts released from Tomonts. In addition to determination of anti-Ichthyophthirius activity, we also systematically evaluated the safety of magnolol against fish. First of all, the results of acute toxicity experiment showed that the 96 h median lethal concentration (LC50) of magnolol to goldfish was 6.02 mg/L. Furthermore, gene expression (cyp1a, hsp70, gst and sod) and enzyme activity (GSH, SOD and T-AOC) in liver, spleen and kidney could recover to the same level as the control group up to 48 h, though magnolol induced goldfish stress response during 6–24 h exposure. More than that, magnolol can be easily synthesized with low cost, and further embellished and modified for higher bioactivity and lower toxicity because of its simple and symmetry chemical structure. Therefore, magnolol has the potential to be a safe and effective therapeutant, and it also can be used as a probable leading compound for the development of commercial drug to control ichthyophthiriasis in aquaculture.

  • in vitro and in vivo assessment of the effect of antiprotozoal compounds isolated from psoralea corylifolia against ichthyophthirius multifiliis in fish
    International Journal for Parasitology-Drugs and Drug Resistance, 2015
    Co-Authors: Kaige Song, Qizhong Zhang, Fei Ling, Aiguo Huang, Wenjing Dong, Chao Jiang, Gaoxue Wang
    Abstract:

    Ichthyophthirius multifiliis, an external fish parasite, often causes significant economic damage to the aquaculture industry. Since the use of malachite green was banned, the search of alternative substance to control I. multifiliis infections becomes stringent. In present study, in vitro and in vivo anti-ich efficacies of isopsoralen and psoralidin, two active compounds isolated from methanol extract of Psoralea corylifolia by bioassay-guided fractionation based on the efficacy of anti-ich encysted Tomonts, were evaluated. In vitro antiprotozoal efficacy of psoralidin is much better than that of isopsoralen. Psoralidin can kill all theronts at concentrations of 0.8 mg/L or more during 4 h exposure; and terminate reproduction of I. multifiliis post 6 h exposure of proTomonts to 0.9 mg/L and encysted Tomonts to 1.2 mg/L. In vivo trials showed that 5 h exposure of infected fish to 2.5 mg/L of psoralidin significantly reduced the number of theronts released from Tomonts. Furthermore, we observed that a part of proTomonts, collected from infected fish post treatment, presented characteristic morphological changes of apoptosis after staining with Annexin V-EGFP/propidium iodide, indicating the possible mechanism of psoralidin against I. multifiliis trophont in situ. On the basis of these results, psoralidin can be used as a potential lead compound for the development of commercial drug against I. multifiliis.

  • antiprotozoal screening of traditional medicinal plants evaluation of crude extract of psoralea corylifolia against ichthyophthirius multifiliis in goldfish
    Parasitology Research, 2013
    Co-Authors: Fei Ling, Qizhong Zhang, Yanglei Yi, Cheng Lu, Xiao Tu, Aiguo Huang, Gaoxue Wang
    Abstract:

    Ichthyophthirius multifiliis (also called “ich”) is an external protozoan parasite that may infest almost all freshwater fish species and caused significant economic damage to the aquaculture industry. Since the use of malachite green was banned, there have been relatively few effective alternative strategies for controlling I. multifiliis infections. The present study was designed to screen potential antiparasitic medicinal plants based on our previous studies, and comprehensively evaluate in vitro and in vivo anti-ich activity of selected plant extracts. The screening results showed that the methanol extract of Psoralea corylifolia had the highest activity against I. multifiliis theronts. In vivo theront trials demonstrated that 1.25 mg/L or more concentrations of P. corylifolia methanol extract caused 100 % mortality during the 4-h exposure period, and the subsequent in vitro trials indicated that the minimum concentration of P. corylifolia methanol extract that prevented the initial infestation was 2.50 mg/L. ProTomonts and encysted Tomonts surviving trials suggested that encysted Tomonts were less susceptible to P. corylifolia methanol extract than proTomonts, and the methanol extract of P. corylifolia at a concentration of 5.00 mg/L could kill 100 % of proTomonts and 88.89 % of encysted Tomonts. It was also observed that after 12-h exposure of proTomonts or encysted Tomonts to 2.50 mg/L of P. corylifolia methanol extract, the theronts emerged from encysted Tomonts led to more infection level than the ones in the other groups. The results suggested that whether the proTomonts finish encystment is crucial to the survival, reproduction, and theronts infectivity. In addition, our results showed that long duration (24 h) and high concentration (5.00 mg/L) significantly reduced the survival and reproduction of I. multifiliis Tomont exited from the fish after in-bath treatment, and it is indicated that P. corylifolia methanol extract had a potential detrimental effect on I. multifiliis trophont in situ.

  • antiprotozoal activity of medicinal plants against ichthyophthirius multifiliis in goldfish carassius auratus
    Parasitology Research, 2012
    Co-Authors: Yanglei Yi, Xuegang Hu, Cheng Lu, Fei Ling, Gaoxue Wang
    Abstract:

    Ichthyophthiriasis is a widespread disease in aquaculture and causes mass mortalities of fish. The development of new antiprotozoal agents for the treatment of Ichthyophthirius multifiliis infections is of increasing interest. The aim of the present study was to investigate the efficacy of 30 medicinal plants against I. multifiliis. The results showed that the methanol extracts of Magnolia officinalis and Sophora alopecuroides displayed the highest antiprotozoal activity against theronts, with 4-h LC50 values estimated to be 2.45 and 3.43 mg L−1, respectively. Concentrations of 2.5, 5.0, 10.0, and 20.0 mg L−1 of M. officinalis extracts resulted in Tomont mortality of 9.7, 43.7, 91.3, and 100 % at 20 h, respectively. From 40 to 320 mg L−1 of S. alopecuroides extracts, Tomont mortality increased from 29.7 to 100 %. Antiprotozoal efficacy against settled Tomonts (2 and 10 h) was also applied; the results indicated that encysted I. multifiliis Tomonts were less susceptible to these plant extract treatments. In vivo experiments demonstrated that high concentrations of M. officinalis and S. alopecuroides extracts could kill Tomonts, and M. officinalis significantly reduced its reproduction (P < 0.05). These results suggested that the methanol extracts of M. officinalis and S. alopecuroides have the potential to be used as an eco-friendly approach for the control of I. multifiliis.

  • effect of potassium ferrate vi on survival and reproduction of ichthyophthirius multifiliis Tomonts
    Parasitology Research, 2011
    Co-Authors: Gaoxue Wang, Fei Ling, Jianguo Wang, Xiaoning Gong
    Abstract:

    Ichthyophthirius multifiliis is an important freshwater teleost pathogen that can infect most species of freshwater fish worldwide and often leads to significant economic losses to the aquaculture industry. Potassium ferrate(VI), as a potential therapeutic agent for external protozoan parasite infections, has been proven to kill I. multifiliis theronts effectively; however, no information is available on effects of potassium ferrate(VI) exposure to I. multifiliis Tomonts. This study evaluated the effects of potassium ferrate(VI) on the survival and reproduction of I. multifiliis Tomonts. The results of experiment 1 showed that potassium ferrate(VI) at concentrations of 2.4, 4.8, 9.6, and 19.2 mg/L resulted in Tomont survival rates of 82.2%, 34.2%, 14.6%, and 0, respectively, and significant differences were noted in Tomont reproduction between the treatments and the control (P < 0.05). Additionally, this study was designed to determine the effect of potassium ferrate(VI) toxicity on age of the Tomont. The results indicated that encysted I. multifiliis was more resistant to potassium ferrate(VI) treatments. In addition, this study was designed to investigate I. multifiliis Tomont survival and reproduction when collected from infested goldfish in potassium ferrate(VI) solutions at different concentrations (0, 2.4, 4.8, 9.6, and 19.2 mg/L) for 30 min. It was found that the Tomont survivals in the treatments were significantly lower than those in the control (P < 0.05). This study demonstrated that a bath with potassium ferrate(VI) possibly was an effective method to treat ichthyophthiriasis.

Nick G H Taylor - One of the best experts on this subject based on the ideXlab platform.

  • the anti protozoal activity of bronopol on the key life stages of ichthyophthirius multifiliis fouquet 1876 ciliophora
    Veterinary Parasitology, 2012
    Co-Authors: Andrew P Shinn, Sara M Piconcamacho, Denny Conway, Gil Ha Yoon, James E Bron, Nick G H Taylor
    Abstract:

    Abstract Pyceze™ (Novartis Animal Vaccines Ltd.) is licensed as a veterinary medicine to treat fungal infections in salmon, trout and their eggs. The active ingredient is bronopol, which due to its broad-spectrum activity has the potential to be an effective treatment against other important aquatic pathogens. In this study the efficacy of bronopol against Ichthyophthirius multifiliis was tested both in vitro and in vivo . In vitro trials demonstrated a 30 min exposure to 100 mg L −1 bronopol killed 51.7% of the infective theronts. In vitro exposure of the proTomonts to bronopol (0, 20, 50 and 100 mg L −1 ) for 30 min was observed to kill 0%, 76.2%, 97.2% and 100% respectively. ProTomonts surviving treatment, demonstrated delayed development with the time taken from proTomont until the release of theronts ranging from 28.3 h for 0 mg L −1 exposure, to 70 h for parasites in 20 and 50 mg L −1 exposure groups. These concentrations also caused asymmetric cell division of the encysted Tomonts. Exposure of encysted Tomonts (min. 8 cell stage) to 100 mg L −1 bronopol for 30 min, killed 50% within this period, with the remainder dying within the subsequent 42 h post exposure. Lower doses of bronopol were less effective in killing encysted Tomonts than the higher doses (3.3% of parasites were killed in 20 mg L −1 ; 10% in 50 mg L −1 ), but they still delayed theront release significantly (25.7 h for 0 mg L −1 to 46.2 h for parasites exposed to 20–50 mg L −1 ). Long, low dose (1 mg L −1 ) exposure to bronopol was also efficacious against theronts. Survival after 12 h was 29% (c.f. 100% in control parasites), and I. multifiliis (proTomonts, Tomont and theronts), thus suggesting that bronopol may serve a useful role in the control of I. multifiliis infections.

  • The anti-protozoal activity of bronopol on the key life-stages of Ichthyophthirius multifiliis Fouquet, 1876 (Ciliophora).
    Veterinary parasitology, 2011
    Co-Authors: Andrew P Shinn, Denny Conway, Sara M Picón-camacho, Gil Ha Yoon, James E Bron, Nick G H Taylor
    Abstract:

    Pyceze™ (Novartis Animal Vaccines Ltd.) is licensed as a veterinary medicine to treat fungal infections in salmon, trout and their eggs. The active ingredient is bronopol, which due to its broad-spectrum activity has the potential to be an effective treatment against other important aquatic pathogens. In this study the efficacy of bronopol against Ichthyophthirius multifiliis was tested both in vitro and in vivo. In vitro trials demonstrated a 30 min exposure to 100 mg L(-1) bronopol killed 51.7% of the infective theronts. In vitro exposure of the proTomonts to bronopol (0, 20, 50 and 100 mg L(-1)) for 30 min was observed to kill 0%, 76.2%, 97.2% and 100% respectively. ProTomonts surviving treatment, demonstrated delayed development with the time taken from proTomont until the release of theronts ranging from 28.3h for 0 mg L(-1) exposure, to 70 h for parasites in 20 and 50 mg L(-1) exposure groups. These concentrations also caused asymmetric cell division of the encysted Tomonts. Exposure of encysted Tomonts (min. 8 cell stage) to 100 mg L(-1) bronopol for 30 min, killed 50% within this period, with the remainder dying within the subsequent 42 h post exposure. Lower doses of bronopol were less effective in killing encysted Tomonts than the higher doses (3.3% of parasites were killed in 20 mg L(-1); 10% in 50 mg L(-1)), but they still delayed theront release significantly (25.7 h for 0 mg L(-1) to 46.2h for parasites exposed to 20-50 mg L(-1)). Long, low dose (1 mg L(-1)) exposure to bronopol was also efficacious against theronts. Survival after 12h was 29% (c.f. 100% in control parasites), and

Andrew P Shinn - One of the best experts on this subject based on the ideXlab platform.

  • the anti protozoal activity of bronopol on the key life stages of ichthyophthirius multifiliis fouquet 1876 ciliophora
    Veterinary Parasitology, 2012
    Co-Authors: Andrew P Shinn, Sara M Piconcamacho, Denny Conway, Gil Ha Yoon, James E Bron, Nick G H Taylor
    Abstract:

    Abstract Pyceze™ (Novartis Animal Vaccines Ltd.) is licensed as a veterinary medicine to treat fungal infections in salmon, trout and their eggs. The active ingredient is bronopol, which due to its broad-spectrum activity has the potential to be an effective treatment against other important aquatic pathogens. In this study the efficacy of bronopol against Ichthyophthirius multifiliis was tested both in vitro and in vivo . In vitro trials demonstrated a 30 min exposure to 100 mg L −1 bronopol killed 51.7% of the infective theronts. In vitro exposure of the proTomonts to bronopol (0, 20, 50 and 100 mg L −1 ) for 30 min was observed to kill 0%, 76.2%, 97.2% and 100% respectively. ProTomonts surviving treatment, demonstrated delayed development with the time taken from proTomont until the release of theronts ranging from 28.3 h for 0 mg L −1 exposure, to 70 h for parasites in 20 and 50 mg L −1 exposure groups. These concentrations also caused asymmetric cell division of the encysted Tomonts. Exposure of encysted Tomonts (min. 8 cell stage) to 100 mg L −1 bronopol for 30 min, killed 50% within this period, with the remainder dying within the subsequent 42 h post exposure. Lower doses of bronopol were less effective in killing encysted Tomonts than the higher doses (3.3% of parasites were killed in 20 mg L −1 ; 10% in 50 mg L −1 ), but they still delayed theront release significantly (25.7 h for 0 mg L −1 to 46.2 h for parasites exposed to 20–50 mg L −1 ). Long, low dose (1 mg L −1 ) exposure to bronopol was also efficacious against theronts. Survival after 12 h was 29% (c.f. 100% in control parasites), and I. multifiliis (proTomonts, Tomont and theronts), thus suggesting that bronopol may serve a useful role in the control of I. multifiliis infections.

  • in vitro assessment of the chemotherapeutic action of a specific hydrogen peroxide peracetic acetic and peroctanoic acid based formulation against the free living stages of ichthyophthirius multifiliis ciliophora
    Parasitology Research, 2012
    Co-Authors: Sara M Piconcamacho, Mar Marcoslopez, Alexandre Beljean, Sylvain Debeaume, Andrew P Shinn
    Abstract:

    Traditionally, malachite green administrated as in-bath treatment was the most effective and common strategy used in freshwater aquaculture systems to control infections of the ciliate protozoan parasite Ichthyophthirius multifiliis Fouquet, 1876. After the ban of malachite green in the USA and Europe to be used in fish for human consumption, there has been extensive research destined to find efficacious replacements. Recently, peracetic acid-based compounds have demonstrated a strong cytotoxic effect in vitro and in vivo against I. multifiliis. In the present study, we tested the efficacy of a hydrogen peroxide, peracetic, acetic and peroctanoic acid-based formulation (HPPAPA) to eliminate the free-living stages of I. multifiliis (Tomonts, cysts and theronts). The results obtained showed that the administration of low doses (8, 12 or 15 mg/l) of a specific HPPAPA-based product during a short window of exposure (60 min) kills nearly all free-living stages of I. multifiliis (theronts, Tomonts and cysts) within the window of treatment (∼100% mortality for all the stages; one-way ANOVA, P ≤ 0.001). Of note, even the lowest concentration of HPPAPA tested (8 mg/l) was able to disrupt normal cyst development and therefore theront release. The demonstrated in vitro efficacy of the peracetic acid-based product tested on the present study suggests its great potential to control I. multifiliis infections in commercial aquacultural systems.

  • The anti-protozoal activity of bronopol on the key life-stages of Ichthyophthirius multifiliis Fouquet, 1876 (Ciliophora).
    Veterinary parasitology, 2011
    Co-Authors: Andrew P Shinn, Denny Conway, Sara M Picón-camacho, Gil Ha Yoon, James E Bron, Nick G H Taylor
    Abstract:

    Pyceze™ (Novartis Animal Vaccines Ltd.) is licensed as a veterinary medicine to treat fungal infections in salmon, trout and their eggs. The active ingredient is bronopol, which due to its broad-spectrum activity has the potential to be an effective treatment against other important aquatic pathogens. In this study the efficacy of bronopol against Ichthyophthirius multifiliis was tested both in vitro and in vivo. In vitro trials demonstrated a 30 min exposure to 100 mg L(-1) bronopol killed 51.7% of the infective theronts. In vitro exposure of the proTomonts to bronopol (0, 20, 50 and 100 mg L(-1)) for 30 min was observed to kill 0%, 76.2%, 97.2% and 100% respectively. ProTomonts surviving treatment, demonstrated delayed development with the time taken from proTomont until the release of theronts ranging from 28.3h for 0 mg L(-1) exposure, to 70 h for parasites in 20 and 50 mg L(-1) exposure groups. These concentrations also caused asymmetric cell division of the encysted Tomonts. Exposure of encysted Tomonts (min. 8 cell stage) to 100 mg L(-1) bronopol for 30 min, killed 50% within this period, with the remainder dying within the subsequent 42 h post exposure. Lower doses of bronopol were less effective in killing encysted Tomonts than the higher doses (3.3% of parasites were killed in 20 mg L(-1); 10% in 50 mg L(-1)), but they still delayed theront release significantly (25.7 h for 0 mg L(-1) to 46.2h for parasites exposed to 20-50 mg L(-1)). Long, low dose (1 mg L(-1)) exposure to bronopol was also efficacious against theronts. Survival after 12h was 29% (c.f. 100% in control parasites), and

Gaoxue Wang - One of the best experts on this subject based on the ideXlab platform.

  • Antiparasitic efficacy and safety assessment of magnolol against Ichthyophthirius multifiliis in goldfish
    Aquaculture, 2018
    Co-Authors: Chenguang Song, Gaoxue Wang, Kaige Song, Fei Ling
    Abstract:

    Abstract Ichthyophthirius multifiliis causes high mortality rate of freshwater fish. It is necessary to find the effective alternatives that may both be affordable and environmentally acceptable since malachite green is banned to use. In this work, magnolol exhibited great anti-parasitic activity against all stages of I. multifiliis. Magnolol at concentrations of 0.6 mg/L or more resulted in 100% mortality of I. multifiliis theronts within 4 h exposure; and terminated reproduction of I. multifiliis post 6 h exposure of proTomonts and encysted Tomonts to 0.8 and 1.0 mg/L, respectively. Moreover, some of Tomonts presented morphological characteristic changes and a larger part of Tomonts were unable to reproduce. Magnolol possibly had a directly effect on the cell membrane, and more importantly, it could permeate into an encysted Tomont across the cyst wall and then impact on the Tomont proliferation. In vivo trials showed that 5 h exposure of infected fish to 1.5 mg/L of magnolol significantly reduced the number of theronts released from Tomonts. In addition to determination of anti-Ichthyophthirius activity, we also systematically evaluated the safety of magnolol against fish. First of all, the results of acute toxicity experiment showed that the 96 h median lethal concentration (LC50) of magnolol to goldfish was 6.02 mg/L. Furthermore, gene expression (cyp1a, hsp70, gst and sod) and enzyme activity (GSH, SOD and T-AOC) in liver, spleen and kidney could recover to the same level as the control group up to 48 h, though magnolol induced goldfish stress response during 6–24 h exposure. More than that, magnolol can be easily synthesized with low cost, and further embellished and modified for higher bioactivity and lower toxicity because of its simple and symmetry chemical structure. Therefore, magnolol has the potential to be a safe and effective therapeutant, and it also can be used as a probable leading compound for the development of commercial drug to control ichthyophthiriasis in aquaculture.

  • in vitro and in vivo assessment of the effect of antiprotozoal compounds isolated from psoralea corylifolia against ichthyophthirius multifiliis in fish
    International Journal for Parasitology-Drugs and Drug Resistance, 2015
    Co-Authors: Kaige Song, Qizhong Zhang, Fei Ling, Aiguo Huang, Wenjing Dong, Chao Jiang, Gaoxue Wang
    Abstract:

    Ichthyophthirius multifiliis, an external fish parasite, often causes significant economic damage to the aquaculture industry. Since the use of malachite green was banned, the search of alternative substance to control I. multifiliis infections becomes stringent. In present study, in vitro and in vivo anti-ich efficacies of isopsoralen and psoralidin, two active compounds isolated from methanol extract of Psoralea corylifolia by bioassay-guided fractionation based on the efficacy of anti-ich encysted Tomonts, were evaluated. In vitro antiprotozoal efficacy of psoralidin is much better than that of isopsoralen. Psoralidin can kill all theronts at concentrations of 0.8 mg/L or more during 4 h exposure; and terminate reproduction of I. multifiliis post 6 h exposure of proTomonts to 0.9 mg/L and encysted Tomonts to 1.2 mg/L. In vivo trials showed that 5 h exposure of infected fish to 2.5 mg/L of psoralidin significantly reduced the number of theronts released from Tomonts. Furthermore, we observed that a part of proTomonts, collected from infected fish post treatment, presented characteristic morphological changes of apoptosis after staining with Annexin V-EGFP/propidium iodide, indicating the possible mechanism of psoralidin against I. multifiliis trophont in situ. On the basis of these results, psoralidin can be used as a potential lead compound for the development of commercial drug against I. multifiliis.

  • antiprotozoal screening of traditional medicinal plants evaluation of crude extract of psoralea corylifolia against ichthyophthirius multifiliis in goldfish
    Parasitology Research, 2013
    Co-Authors: Fei Ling, Qizhong Zhang, Yanglei Yi, Cheng Lu, Xiao Tu, Aiguo Huang, Gaoxue Wang
    Abstract:

    Ichthyophthirius multifiliis (also called “ich”) is an external protozoan parasite that may infest almost all freshwater fish species and caused significant economic damage to the aquaculture industry. Since the use of malachite green was banned, there have been relatively few effective alternative strategies for controlling I. multifiliis infections. The present study was designed to screen potential antiparasitic medicinal plants based on our previous studies, and comprehensively evaluate in vitro and in vivo anti-ich activity of selected plant extracts. The screening results showed that the methanol extract of Psoralea corylifolia had the highest activity against I. multifiliis theronts. In vivo theront trials demonstrated that 1.25 mg/L or more concentrations of P. corylifolia methanol extract caused 100 % mortality during the 4-h exposure period, and the subsequent in vitro trials indicated that the minimum concentration of P. corylifolia methanol extract that prevented the initial infestation was 2.50 mg/L. ProTomonts and encysted Tomonts surviving trials suggested that encysted Tomonts were less susceptible to P. corylifolia methanol extract than proTomonts, and the methanol extract of P. corylifolia at a concentration of 5.00 mg/L could kill 100 % of proTomonts and 88.89 % of encysted Tomonts. It was also observed that after 12-h exposure of proTomonts or encysted Tomonts to 2.50 mg/L of P. corylifolia methanol extract, the theronts emerged from encysted Tomonts led to more infection level than the ones in the other groups. The results suggested that whether the proTomonts finish encystment is crucial to the survival, reproduction, and theronts infectivity. In addition, our results showed that long duration (24 h) and high concentration (5.00 mg/L) significantly reduced the survival and reproduction of I. multifiliis Tomont exited from the fish after in-bath treatment, and it is indicated that P. corylifolia methanol extract had a potential detrimental effect on I. multifiliis trophont in situ.

  • antiprotozoal activity of medicinal plants against ichthyophthirius multifiliis in goldfish carassius auratus
    Parasitology Research, 2012
    Co-Authors: Yanglei Yi, Xuegang Hu, Cheng Lu, Fei Ling, Gaoxue Wang
    Abstract:

    Ichthyophthiriasis is a widespread disease in aquaculture and causes mass mortalities of fish. The development of new antiprotozoal agents for the treatment of Ichthyophthirius multifiliis infections is of increasing interest. The aim of the present study was to investigate the efficacy of 30 medicinal plants against I. multifiliis. The results showed that the methanol extracts of Magnolia officinalis and Sophora alopecuroides displayed the highest antiprotozoal activity against theronts, with 4-h LC50 values estimated to be 2.45 and 3.43 mg L−1, respectively. Concentrations of 2.5, 5.0, 10.0, and 20.0 mg L−1 of M. officinalis extracts resulted in Tomont mortality of 9.7, 43.7, 91.3, and 100 % at 20 h, respectively. From 40 to 320 mg L−1 of S. alopecuroides extracts, Tomont mortality increased from 29.7 to 100 %. Antiprotozoal efficacy against settled Tomonts (2 and 10 h) was also applied; the results indicated that encysted I. multifiliis Tomonts were less susceptible to these plant extract treatments. In vivo experiments demonstrated that high concentrations of M. officinalis and S. alopecuroides extracts could kill Tomonts, and M. officinalis significantly reduced its reproduction (P < 0.05). These results suggested that the methanol extracts of M. officinalis and S. alopecuroides have the potential to be used as an eco-friendly approach for the control of I. multifiliis.

  • effect of potassium ferrate vi on survival and reproduction of ichthyophthirius multifiliis Tomonts
    Parasitology Research, 2011
    Co-Authors: Gaoxue Wang, Fei Ling, Jianguo Wang, Xiaoning Gong
    Abstract:

    Ichthyophthirius multifiliis is an important freshwater teleost pathogen that can infect most species of freshwater fish worldwide and often leads to significant economic losses to the aquaculture industry. Potassium ferrate(VI), as a potential therapeutic agent for external protozoan parasite infections, has been proven to kill I. multifiliis theronts effectively; however, no information is available on effects of potassium ferrate(VI) exposure to I. multifiliis Tomonts. This study evaluated the effects of potassium ferrate(VI) on the survival and reproduction of I. multifiliis Tomonts. The results of experiment 1 showed that potassium ferrate(VI) at concentrations of 2.4, 4.8, 9.6, and 19.2 mg/L resulted in Tomont survival rates of 82.2%, 34.2%, 14.6%, and 0, respectively, and significant differences were noted in Tomont reproduction between the treatments and the control (P < 0.05). Additionally, this study was designed to determine the effect of potassium ferrate(VI) toxicity on age of the Tomont. The results indicated that encysted I. multifiliis was more resistant to potassium ferrate(VI) treatments. In addition, this study was designed to investigate I. multifiliis Tomont survival and reproduction when collected from infested goldfish in potassium ferrate(VI) solutions at different concentrations (0, 2.4, 4.8, 9.6, and 19.2 mg/L) for 30 min. It was found that the Tomont survivals in the treatments were significantly lower than those in the control (P < 0.05). This study demonstrated that a bath with potassium ferrate(VI) possibly was an effective method to treat ichthyophthiriasis.

Jinyu Shen - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of nystatin isolated from streptomyces griseus sdx 4 against the ciliate ichthyophthirius multifiliis
    Parasitology Research, 2015
    Co-Authors: Yang Xu, Xuemei Yuan, Ting Xu, Jinyu Shen
    Abstract:

    The present study was conducted to evaluate the in vitro and in vivo antiparasitic efficacy of active compounds from the bacterial extracellular products of Streptomyces griseus SDX-4 against Ichthyophthirius multifiliis. Bioassay-guided fractionation and isolation of compounds with antiparasitic activity were performed on n-butanol extract of S. griseus yielding a pure bioactive compound, nystatin (Nys), identified by comparing spectral data (EI-MS, 1H NMR, and 13C NMR) with literature values. Results from in vitro antiparasitic assays revealed that Nys could be 100 % effective against I. multifiliis theronts and encysted Tomonts at the concentration of 6.0 mg L−1, with the median effective concentration (EC50) values of 3.1 and 2.8 mg L−1 for theronts and encysted Tomonts (4 h), respectively. Results of in vivo test demonstrated that the number of I. multifiliis trophonts on the gold fish treated with Nys was markedly lower than the control group at 10 days after exposed to theronts (p < 0.05). In the control group, 85.7 % mortality was observed owing to heavy I. multifiliis infection at 10 days after the exposure. On the other hand, only 23.8 % mortality owing to parasite infection was recorded in the groups treated with the Nys (4.0 and 6.0 mg L−1). In addition, our results showed that the survival and reproduction of I. multifiliis Tomont exited from the fish were significantly reduced after treated with the 6.0 mg L−1 Nys. The median lethal dose (LD50) of Nys for goldfish was 16.8 mg L−1. This study firstly demonstrated that Nys has potent antiparasitic efficacy against I. multifiliis, and it can be a good candidate drug for chemotherapy and control of I. multifiliis infections.

  • anti parasitic activities of specific bacterial extracellular products of streptomyces griseus sdx 4 against ichthyophthirius multifiliis
    Parasitology Research, 2014
    Co-Authors: Xincang Li, Yang Xu, Gang Li, Weiming Ai, Jinyu Shen
    Abstract:

    The ciliate Ichthyophthirius multifiliis is one of the most pathogenic parasites of fish maintained in captivity. In this study, effects of bacterial extracellular products of Streptomyces griseus SDX-4 against I. multifiliis were determined. The fermentation liquor of S. griseus was extracted successively in a separating funnel with petroleum ether, ethyl acetate, and n-butanol. In vitro assays revealed that the n-butanol extracts (NBu-E) and ethyl acetate extracts (Eto-E) of S. griseus were observed to be more effective against theronts than the other extracts with median effective concentration (EC50) values of 0.86 and 12.5 mg L−1, respectively, and significantly reduced the survival of the Tomonts and the total number of theronts released by the Tomonts (P < 0.05). All encysted Tomonts were killed when the concentration of NBu-E was 30.0 mg L−1. Results of in vivo test demonstrated that the number of I. multifiliis trophonts on the grass carp treated with NBu-E was markedly lower compared to the control group at 11 days after exposed to theronts (P < 0.05). In the control group, 100 % mortality was observed owing to heavy I. multifiliis infection at 11 days after the exposure. On the other hand, only 9.5 % mortality owing to parasite infection was recorded in the groups treated with the NBu-E (30 mg L−1). The median lethal dose (LD50) of NBu-E for grass carp was 152.4 mg L−1. Our results indicate that n-butanol extract of S. griseus will be useful in aquaculture for controlling I. multifiliis infections.