Functional Food Center, Korea Institute of Science and Technology, Gangneung Institute, Gangneung, Gangwon-do 210-340, Republic of Korea.
Appl Biochem Biotechnol. 2011 Nov;165(5-6):1296-307. doi: 10.1007/s12010-011-9347-3. Epub 2011 Sep 3.
Eisenia bicyclis (Kjellman) Setchell is a common brown alga that inhabits the middle Pacific coast around Korea and Japan. In this study, the ethanol extract and its serial solvent fractions were prepared from fresh E. bicyclis, and their hepatoprotective effects were investigated against hepatotoxicity in tert-butyl hyperoxide(t-BHP)-injured HepG2 cells. When these samples were used at a dose of 10-40 μg/mL⁻¹, they significantly protected the t-BHP-induced cell death in HepG2 cells. Among fractions, ethyl acetate fraction (EF) and n-butanol extract (BF) exhibited potent hepatoprotective activities (62.60% for EF and 64.86% for BF) in t-BHP-injured HepG2 cells at a concentration of 10 μg/mL⁻¹. To find the potential factors for this activity, the samples were characterized on total phenolics, chlorophylls, carotenoids, and radical scavenging activity. Among them, EF showed the highest content of total phenolics and the strongest antioxidant activity both in on- and offline assays. Five phlorotannin compounds, oligomers of phloroglucinol, were isolated chromatographically from this fraction and structurally identified by (1)H-NMR and liquid chromatography-electrospray ionization-mass spectrometry analyses as eckol(1), 6,6'-bieckol(2), 8,8'-bieckol(3), dieckol(4), and phlorofucofuroeckol A(5). Compound 5 among five purified compounds showed the strongest protective activity (45.54%) at a concentration of 10 μM. At the high dose (40 μM), the protective activities of three compounds (compound 2, 4, and 5) were higher than that of quercetin treated with 10 μM concentration. Therefore, we can speculate that they can be developed as potential candidates for natural hepatoprotective agents.
链形刚毛藻（Kjellman）Setchell 是一种常见的棕色海藻，栖息在韩国和日本周围的中太平洋海岸。在这项研究中，从新鲜的链形刚毛藻中制备了乙醇提取物及其连续溶剂级分，并研究了它们对叔丁基过氧化物（t-BHP）损伤的 HepG2 细胞的肝保护作用。当这些样品以 10-40μg/mL⁻¹的剂量使用时，它们可显著保护 HepG2 细胞免受 t-BHP 诱导的细胞死亡。在这些级分中，乙酸乙酯级分（EF）和正丁醇提取物（BF）在 10μg/mL⁻¹的浓度下对 t-BHP 损伤的 HepG2 细胞表现出有效的肝保护活性（EF 为 62.60%，BF 为 64.86%）。为了找到这种活性的潜在因素，对样品进行了总酚、叶绿素、类胡萝卜素和自由基清除活性的表征。其中，EF 显示出最高的总酚含量和最强的抗氧化活性，无论是在线和离线测定。从该级分中通过色谱法分离并通过（1）H-NMR 和液相色谱-电喷雾电离质谱分析鉴定了 5 种岩藻多酚化合物，即间苯三酚的低聚物。结构鉴定为 eckol（1）、6,6'-bieckol（2）、8,8'-bieckol（3）、dieckol（4）和 phlorofucofuroeckol A（5）。在 10μM 浓度下，五种纯化化合物中的 5 种化合物显示出最强的保护活性（45.54%）。在高剂量（40μM）下，三种化合物（化合物 2、4 和 5）的保护活性高于 10μM 浓度下处理的槲皮素。因此，我们可以推测它们可以作为天然肝保护剂的潜在候选药物。
