Abstract：
Sargassum horneri is a well-known edible brown alga that is widely abundant in the sea near China, Korea, and Japan and has a wide range of bioactive compounds. Fucosterol (FST), which is a renowned secondary metabolite in brown algae, was extracted from S. horneri to 70% ethanol, isolated via high-performance liquid chromatography (HPLC), followed by the immiscible liquid-liquid separation, and its structure was confirmed by NMR spectroscopy. The present study was undertaken to investigate the effects of FST against oxidative stress, inflammation, and its mechanism of action in tumor necrosis factor (TNF)-α/ interferon (IFN)-γ-stimulated human dermal fibroblast (HDF). FST was biocompatible with HDF cells up to the 120 μM dosage. TNF-α/IFN-γ stimulation significantly decreased HDF viability by notably increasing reactive oxygen species (ROS) production. FST dose-dependently decreased the intracellular ROS production in HDFs. Western blot analysis confirmed a significant increment of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) involvement in FST-treated HDF cells. In addition, the downregulation of inflammatory mediators, molecules related to connective tissue degradation, and tissue inhibitors of metalloproteinases were identified. TNF-α/IFN-γ stimulation in HDF cells increased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) mediators, and its phosphorylation was reduced with the treatment of FST in a dose-dependent manner. Results obtained from western blot analysis of the NF-κB nuclear translocation were supported by immunocytochemistry results. Collectively, the outcomes suggested that FST significantly upregulates the Nrf2/HO-1 signaling and regulates NF-κB/MAPK signaling pathways to minimize the inflammatory responses in TNF-α/IFN-γ-stimulated HDF cells.
摘要：
Sargassumhorneri是一种著名的可食用褐藻，在中国附近海域广泛丰富，韩国,和日本，并具有广泛的生物活性化合物。岩藻甾醇(FST),这是褐藻中一种著名的次生代谢产物，从S.horneri中提取到70％的乙醇，通过高效液相色谱（HPLC）分离，然后是不混溶的液-液分离，其结构经核磁共振波谱证实。本研究旨在研究FST对氧化应激的影响，炎症,及其在肿瘤坏死因子（TNF）-α/干扰素（IFN）-γ刺激的人真皮成纤维细胞（HDF）中的作用机制。FST与高达120μM剂量的HDF细胞是生物相容的。TNF-α/IFN-γ刺激通过显着增加活性氧（ROS）的产生来显着降低HDF的活力。FST剂量依赖性地降低HDF中的细胞内ROS产生。Western印迹分析证实，在FST处理的HDF细胞中，核因子红细胞2相关因子2（Nrf2）/血红素加氧酶-1（HO-1）的参与显着增加。此外,炎症介质的下调，与结缔组织降解有关的分子，并鉴定了金属蛋白酶的组织抑制剂。TNF-α/IFN-γ在HDF细胞中的刺激增加了核因子-κB（NF-κB）和丝裂原活化蛋白激酶（MAPK）介质的磷酸化，并且其磷酸化随着FST的治疗以剂量依赖性方式降低。免疫细胞化学结果支持了从NF-κB核易位的蛋白质印迹分析获得的结果。总的来说，结果表明,FST显著上调Nrf2/HO-1信号传导,并调节NF-κB/MAPK信号传导途径,以减少TNF-α/IFN-γ刺激的HDF细胞的炎症反应.
