University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia.
Ruđer Bošković Institute, Division for Marine and Environmental Research, Laboratory for Molecular Ecotoxicology, 10000, Zagreb, Croatia.
Environ Sci Pollut Res Int. 2021 Sep;28(35):49220-49231. doi: 10.1007/s11356-021-14110-2. Epub 2021 May 1.
Cyanobacteria are prolific producers of numerous toxic compounds, among which microcystins (hepatotoxins) are the most frequently found. Cyanobacterial bloom in freshwaters is an increasing problem, and there is still a need for rapid and reliable methods for the detection of toxic cyanobacterial samples. In the present study, the toxicity of crude extracts of 11 cyanobacterial strains from different genera has been assessed on two cell lines (human hepatocellular carcinoma HepG2 and rainbow trout (Oncorhynchus mykiss) liver-derived RTL-W1 cells), crustaceans (Daphnia magna and Artemia salina), and zebrafish (Danio rerio) embryos, as well as by protein phosphatase 1 (PP1) inhibition assay and ELISA test to determine whether the toxicity could be due to the presence of hepatotoxins/microcystins. All the tested strains exhibited toxicity on HepG2 cell line (IC from 35 to 702 μg mL), including Arthrospira (Spirulina) strains, while toxicity against the RTL-W1 cells was detected only in the positive reference Microcystis PCC 7806 and Nostoc 2S9B. Tested strains expressed higher toxicity to D. magna and zebrafish embryos in comparison to A. salina, whereby Nostoc LC1B and Nostoc S8 belonged to the most toxic strains. The PP1-inhibiting compounds have been detected by PP1 assay only in four strains (Microcystis PCC 7806, Oscillatoria K3, Nostoc LC1B, and Nostoc S8), indicating that their toxic potency can be attributed to these compounds. On the other hand, very low levels of microcystins, as confirmed by ELISA, were insufficient to explain toxicity and different toxic potencies of tested cyanobacteria. Results presented in this study suggested HepG2 cell line as a particularly suitable model for cyanobacterial toxicity assessment. In addition, they highlight terrestrial cyanobacterial strains as potent producers of toxic compounds.
蓝藻是许多有毒化合物的丰富生产者，其中微囊藻（肝毒素）最为常见。淡水中的蓝藻水华是一个日益严重的问题，因此仍然需要快速可靠的方法来检测有毒的蓝藻样品。在本研究中，评估了来自不同属的 11 株蓝藻菌株的粗提取物对两种细胞系（人肝癌 HepG2 和虹鳟鱼（Oncorhynchus mykiss）肝衍生 RTL-W1 细胞）、甲壳类动物（大型溞和卤虫）和斑马鱼（Danio rerio）胚胎的毒性，以及通过蛋白磷酸酶 1（PP1）抑制测定和 ELISA 试验来确定毒性是否归因于肝毒素/微囊藻的存在。所有测试的菌株对 HepG2 细胞系都表现出毒性（IC 为 35 至 702μg/mL），包括节旋藻（螺旋藻）菌株，而只有阳性参考微囊藻 PCC 7806 和念珠藻 2S9B 对 RTL-W1 细胞表现出毒性。与卤虫相比，测试的菌株对大型溞和斑马鱼胚胎表现出更高的毒性，其中念珠藻 LC1B 和念珠藻 S8 属于毒性最强的菌株。通过 PP1 测定仅在 4 株菌株（微囊藻 PCC 7806、颤藻 K3、念珠藻 LC1B 和念珠藻 S8）中检测到 PP1 抑制化合物，表明其毒性效力可归因于这些化合物。另一方面，ELISA 证实微囊藻的含量非常低，不足以解释测试蓝藻的毒性和不同的毒性强度。本研究结果表明 HepG2 细胞系特别适合用于评估蓝藻的毒性。此外，它们突出了陆生蓝藻菌株作为有毒化合物的有效生产者。
