The current study evaluated the effects of a methanol extract from Chaetomorpha aerea (a green alga) on non-specific immune responses and resistance against Edwardsiella tarda infection in Labeo rohita. Different doses of the extract (5, 50 and 500 mg/kg of body weight) were injected into the fish intraperitoneally while a control group was injected with 0.2 mL of sterile physiological salt solution. Variations in several immunostimulatory parameters (i.e., neutrophil, serum lysozyme, myeloperoxidase, serum antiprotease, and ceruloplasmin activity), reactive oxygen species (ROS) and reactive nitrogen species (RNS) were assessed after 7, 14, 21, and 28 days of post stimulation. E. tarda culture was injected into the fish after 28 days of post stimulation to induce infection to monitor fish mortality within 14 days. Interestingly, all doses of methanolic extract enhanced neutrophil, lysozyme, and myeloperoxidase activity, ROS and RNS, while a dose of 50 mg/kg was the most effective. Fish injected with this optimal dose were also protected against infection with virulent strain of E. tarda. The results of the study suggest that C. aerea extract is a potential prophylactic agent against bacterial infections in finfish.

中文翻译：

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绿藻，拟南芥提取物对红唇蛙非特异性免疫反应和抗爱德华氏菌感染的抗病性的影响

目前的研究评估了甲壳木（Chaetomorpha aerea）（一种绿色藻类）的甲醇提取物对非特异性免疫反应和对Labeo rohita的爱德华氏菌感染的抗性的影响。将不同剂量的提取物（5、50和500 mg / kg体重）腹膜内注射到鱼中，而对照组则注射0.2 mL无菌生理盐溶液。在术后7、14、21和28天后评估几种免疫刺激参数（即中性粒细胞，血清溶菌酶，髓过氧化物酶，血清抗蛋白酶和铜蓝蛋白活性），活性氧（ROS）和活性氮（RNS）的变化。刺激。塔拉肠球菌刺激后28天后，将养殖鱼注射到鱼中以诱导感染以监测鱼在14天内的死亡率。有趣的是，所有剂量的甲醇提取物均可增强中性粒细胞，溶菌酶和髓过氧化物酶的活性，ROS和RNS，而50 mg / kg的剂量最为有效。注射此最佳剂量的鱼也受到保护，以免受到塔氏大肠杆菌强毒株的感染。该研究结果表明，C。aerea提取物是一种有可能预防鳍鱼细菌感染的药物。