Institute of Hydrobiology, Jinan University, Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering Ministry of Education, Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institutes, Guangzhou 510632, PR China.
Vet Parasitol. 2013 Nov 15;198(1-2):45-53. doi: 10.1016/j.vetpar.2013.08.019. Epub 2013 Aug 29.
Ichthyophthirius multifiliis (Ich) is an important ectoparasitic ciliate that parasitizes gills and skin of freshwater fish resulting in massive mortality of fish. Currently there is no chemotherapeutant available to treat Ich effectively and economically. There is an urgent need to discover effective and safe parasiticides to control ichthyophthiriasis. In this study, anti-Ich efficacy of pentagalloylglucose, a compound extracted from the plant Galla chinensis was evaluated and the toxicity of the compound on channel catfish was determined. Pentagalloylglucose can kill all theronts at concentrations of 2.5-20 mg/L during 5.6-233.9 min and terminate reproduction of tomonts at 40 mg/L. Pentagalloylglucose significantly reduced infective ability of theronts at 1, 2 and 5 mg/L. The survival of naive channel catfish was 70% when treated with 10 mg/L and 100% when treated with 20 mg/L of pentagalloylglucose. For Ich infected catfish, the survival was 53.3% when treated with 10 mg/L and 93.3% when treated with 20 mg/L of pentagalloylglucose. Pentagalloylglucose at 20 mg/L was effective for treating Ich infected catfish or preventing naive catfish from Ich infestation. Median lethal concentration of the compound to catfish was 151.3 mg/L, which was 5 times the median effective concentration (30.5 mg/L) for killing tomonts. The compound killed Ich by destroying the plasma membrane of the parasite. The result demonstrated pentagalloylglucose as a safe, effective potential parasiticide against I. multifiliis.
多子小瓜虫（Ich）是一种重要的寄生纤毛虫，寄生在淡水鱼的鳃和皮肤上，导致鱼类大量死亡。目前尚无有效的化学治疗药物来治疗 Ich。因此，迫切需要发现有效和安全的驱虫剂来控制小瓜虫病。本研究评估了从中国五倍子植物中提取的化合物五倍子酰葡萄糖（PGG）对多子小瓜虫的抗 Ich 效果，并测定了该化合物对斑点叉尾鮰的毒性。PGG 在 5.6-233.9 分钟内，浓度为 2.5-20mg/L 时可杀死所有滋养体，在 40mg/L 时可终止包囊体的繁殖。PGG 在 1、2 和 5mg/L 时可显著降低滋养体的感染能力。10mg/L 处理组和 20mg/L 处理组斑点叉尾鮰的存活率分别为 70%和 100%。感染多子小瓜虫的斑点叉尾鮰经 10mg/L 和 20mg/L PGG 处理后，存活率分别为 53.3%和 93.3%。20mg/L 的 PGG 可有效治疗感染多子小瓜虫的斑点叉尾鮰或预防未感染斑点叉尾鮰感染多子小瓜虫。该化合物对斑点叉尾鮰的半数致死浓度为 151.3mg/L，是杀死包囊体的半数有效浓度（30.5mg/L）的 5 倍。该化合物通过破坏寄生虫的质膜杀死 Ich。结果表明，五倍子酰葡萄糖是一种安全、有效的多子小瓜虫潜在驱虫剂。
