Discipline of Pharmacology, Adelaide Medical School, Faculty of Health Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
Centre for Marine Bioproducts Development (CMBD), Australia and Medical Biotechnology, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide 5001, South Australia, Australia.
Food Funct. 2020 Jul 22;11(7):6509-6516. doi: 10.1039/d0fo01438a.
Brown seaweed (Phaeophyceae) polyphenolics such as phlorotannins are ascribed various biological activities, including neuroprotection. Of these seaweeds, Ecklonia radiata (E. radiata) is found abundantly along South Australian coastal regions; however it has not been explored for various biological activities relative to any component phlorotannins previously ascribed neuroprotective capacity. In the present study, we evaluated neuroprotective activity against the neurotoxic amyloid β protein (Aβ1-42) of an ethanol extract of E. radiata compared with various additional solvent-solubilised fractions in a neuronal PC-12 cell line. The ethyl acetate fraction comprising 62% phlorotannins demonstrated the most efficacious neuroprotective activity, inhibiting neurotoxicity at all Aβ1-42 concentrations. In addition, this fraction demonstrated a significant reduction in Aβ aggregate density, but did not alter overall aggregate morphology. Centrifugal partitioning chromatography was used to isolate the major component, eckol, in high yield and liquid chromatography-mass spectrometry was used to characterize the major components of the ethyl acetate fraction. Our results demonstrate that the prevalence of eckol-type phlorotannins are associated with neuroprotective bioactivity of E. radiata, suggestive of potential nutraceutical and biopharmaceutical uses of this brown seaweed phlorotannin in dementia.
褐藻（Phacophyceae）多酚，如岩藻多酚，具有多种生物活性，包括神经保护作用。在这些海藻中，Ecklonia radiata（E. radiata）在南澳大利亚沿海地区大量存在；然而，它尚未被探索用于与先前归因于神经保护能力的任何成分岩藻多酚相关的各种生物活性。在本研究中，我们评估了 E. radiata 的乙醇提取物相对于神经毒性淀粉样蛋白 β 蛋白（Aβ1-42）在神经元 PC-12 细胞系中的神经保护活性，以及各种其他溶剂可溶解的馏分。包含 62%岩藻多酚的乙酸乙酯馏分表现出最有效的神经保护活性，抑制了所有 Aβ1-42 浓度的神经毒性。此外，该馏分还显著降低了 Aβ 聚集体密度，但不改变总体聚集体形态。离心分配色谱用于高效分离主要成分，即 Eckol，并使用液相色谱-质谱法对乙酸乙酯馏分的主要成分进行了表征。我们的结果表明，Eckol 型岩藻多酚的普遍存在与 E. radiata 的神经保护生物活性相关，这表明这种褐藻岩藻多酚在痴呆症方面具有潜在的营养和生物制药用途。
