Rattanachaikunsopon P, Phumkhachorn P
Department of Biological Science, Faculty of Science, Ubon Ratchathani University, Warin Chamrap, Ubon Ratchathani 34190, Thailand.
J Aquat Anim Health. 2010 Mar;22(1):14-20. doi: 10.1577/H09-021.1.
To develop antibiotic-free and chemical-free aquaculture, it is necessary to have natural substances to control diseases of aquatic animals. The aim of this study was to find an herb having therapeutic effect against columnaris, a fish disease caused by the bacterium Flavobacterium columnare. Of all tested herbs (including kalmegh Andrographis paniculata, candle bush Cassia alata, Asiatic pennywort Centella asiatica, mangosteen Garcinia mangostana, pomegranate Punica granatum, and guava Psidium guajava), the aqueous extract of Asiatic pennywort exhibited the strongest antimicrobial activity against F. columnare; the minimal inhibitory concentration was 31.25 lg/mL. It was also found to have a bactericidal effect on F. columnare. When experimental bath exposures of Nile tilapia Oreochromis niloticus to F. columnare were performed, the median lethal dose was determined to be 2.37 x 10(5) colony forming units/mL. For in vivo trials, six different concentrations (0, 20, 40, 60, 80, and 100 mg/L) of Asiatic pennywort aqueous extract were used as bath treatments to control experimentally induced columnaris in Nile tilapia. The decrease in fish mortality was dose dependent, and at a concentration of 100 mg/L no mortality or adverse effects were noted in the infected fish. This study suggests that Asiatic pennywort aqueous extract has the potential to control disease caused by F. columnare.
为了发展无抗生素和无化学物质的水产养殖，有必要使用天然物质来控制水生动物的疾病。本研究的目的是找到一种对柱状病具有治疗作用的草药，柱状病是由柱状黄杆菌引起的鱼类疾病。在所有测试的草药（包括穿心莲、翅荚决明、积雪草、山竹、石榴和番石榴）中，积雪草的水提取物对柱状黄杆菌表现出最强的抗菌活性；最低抑菌浓度为31.25μg/mL。还发现其对柱状黄杆菌有杀菌作用。当对尼罗罗非鱼进行柱状黄杆菌的实验性浸浴暴露时，确定半数致死剂量为2.37×10⁵菌落形成单位/mL。在体内试验中，使用六种不同浓度（0、20、40、60、80和100mg/L）的积雪草水提取物作为浸浴处理，以控制尼罗罗非鱼实验性诱导的柱状病。鱼类死亡率的降低呈剂量依赖性，在100mg/L的浓度下，感染的鱼未出现死亡或不良反应。本研究表明，积雪草水提取物有控制柱状黄杆菌引起的疾病的潜力。
