Institute of Hydrobiology, Jinan University, Guangzhou, 510632, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
Institute of Hydrobiology, Jinan University, Guangzhou, 510632, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519000, China.
Ecotoxicol Environ Saf. 2020 Dec 15;206:111183. doi: 10.1016/j.ecoenv.2020.111183. Epub 2020 Sep 2.
Seaweed is an inherently important entity in marine ecosystems. It is not only consumed by aquatic animals but also improves environmental quality in the mariculture. Seaweed is also part of the diet of human beings. The purpose of the present study was to evaluate the antagonism of selenium (Se)-enriched Gracilaria lemaneiformis against heavy metals, specifically, the potential of dietary Se-enriched Gracilaria to protect against heavy metal toxicity in rabbitfish (Siganus oramin). Growth rate, heavy metal (Se, Cd, Pb, Cu, Zn and Cr) concentrations, malondialdehyde (MDA), metallothionein (MT), and the activity of the antioxidants, glutathione peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) were all assessed. The results showed that the total organic and inorganic Se concentration for the 250 mg L Se-enriched Gracilaria was significantly higher than those of the 50 and 10 mg L treatments after 3 days of enrichment. The mean total Se concentrations in Gracilaria were 42.5 μg g in the 250 mg L treatment, 13.5 μg g in the 50 mg L treatment and 2.5 μg g in the 10 mg L treatment, respectively. Organic Se accounts for 80-82% of total Se in Se-enriched Gracilaria. The Se concentration of rabbitfish fed Se-enriched Gracilaria was significantly higher than control. Furthermore, Se increased Cu and Zn absorption, and enhanced MT generation, and improved GPX, CAT, and SOD antioxidant activity, and decreased MDA concentrations and lipid peroxidation levels, all antagonistic to Cd, Pb and Cr. The effects of Se-enriched Gracilaria on waterborne Cd, Pb and Cr-induced toxicity occurred via both enzymatic and non-enzymatic antioxidative mechanisms in rabbitfish. Selenium had synergistic effects on Zn and Cu in rabbitfish. For the 50 mg L Se-enriched Gracilaria treatment, the Se, Cu, Zn, and antagonistic Cd, Pb, Cr, and the antioxidant enzymes CAT, SOD, GPX activities, and MT concentrations in rabbitfish were higher than that with the 250 mg L and 10 mg L Se-enriched Gracilaria treatments. The 50 mg L Se treatment of Gracilaria was deemed to be the optimum concentration to promote growth of rabbitfish. Therefore, the obtained results suggest Se-enriched Gracilaria can antagonize heavy metal toxicity, and is an advisable Se supplement to improve the edible safety of cultured animals.
海藻是海洋生态系统中固有的重要生物。它不仅被水生动物消耗，而且还可以改善海水养殖的环境质量。海藻也是人类饮食的一部分。本研究的目的是评估富硒龙须菜对重金属的拮抗作用，特别是膳食富硒龙须菜对防止重金属毒性对斑笛鲷（Siganus oramin）的潜在作用。评估了生长速度、重金属（硒、镉、铅、铜、锌和铬）浓度、丙二醛（MDA）、金属硫蛋白（MT）以及抗氧化剂谷胱甘肽过氧化物酶（GPX）、过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性。结果表明，在富硒 3 天后，250mg/L 富硒龙须菜的总有机和无机硒浓度明显高于 50 和 10mg/L 处理组。250mg/L 处理组龙须菜中的总硒含量分别为 42.5μg/g，50mg/L 处理组为 13.5μg/g，10mg/L 处理组为 2.5μg/g。富硒龙须菜中的有机硒占总硒的 80-82%。摄食富硒龙须菜的斑笛鲷体内的硒浓度明显高于对照组。此外，硒增加了铜和锌的吸收，增强了 MT 的生成，提高了 GPX、CAT 和 SOD 抗氧化活性，降低了 MDA 浓度和脂质过氧化水平，所有这些都拮抗了镉、铅和铬。富硒龙须菜对水生镉、铅和铬诱导的毒性的影响是通过鱼类的酶和非酶抗氧化机制发生的。硒对鱼类的锌和铜具有协同作用。对于 50mg/L 富硒龙须菜处理组，鱼类体内的硒、铜、锌以及拮抗的镉、铅、铬和抗氧化酶 CAT、SOD、GPX 活性和 MT 浓度均高于 250mg/L 和 10mg/L 富硒龙须菜处理组。50mg/L 富硒龙须菜处理组被认为是促进斑笛鲷生长的最佳浓度。因此，研究结果表明，富硒龙须菜可以拮抗重金属毒性，是提高养殖动物食用安全性的一种可接受的硒补充剂。
