海带是一种养殖广泛的优质海藻资源,具有良好的应用前景。在这项研究中,洋带岩藻聚糖(LF)是从洋带中提取的,并使用DEAE-SepharoseFastFlow凝胶柱纯化以获得四个不同等级。其中,LF4(Mw:165kDa),主要由岩藻糖(56.80%)组成,总糖含量最高(66.91%),硫酸盐含量最高(17.07%)。FT-RT和NMR结果表明,LF4主要由半乳糖化半乳糖岩藻糖组成,并且具有连接到岩藻糖C4的硫酸基。通过动物实验,结果表明,高脂血症小鼠的TC水平明显较高(5.52mmol/L),TG(2.28mmol/L)和LDL-C(5.12mmol/L)水平显著降低HDL-C(2mmol/L)。然而,LF具有调节高脂血症引起的脂质代谢紊乱的功效。以及调节血清中胆固醇转运的能力。此外,它调节了AMPK/ACC,PPAR-α/LAXRa,Nrf2/Nqo1、TLR4/NF-κB信号通路基因及蛋白在肝脏中的表达.此外,它促进了有益的短链脂肪酸(SCFA)的产生,同时改善了肠道菌群的组成和结构,包括平衡拟杆菌的丰度,Firmicutes,Muribaculaceae,Alloprevotella,大肠杆菌志贺氏菌,Prevotella和NK4A136。结果清楚地表明,LF4可以显着改善高脂血症,表明其作为功能性食品的应用前景。
Laminaria digitata is a high-quality seaweed resource that is widely cultured and has good application prospects. In this study, Laminaria digitata fucoidan (LF) was extracted from Laminaria digitata, and purified using DEAE-Sepharose Fast Flow gel column to obtain four different grades. Among those, LF4 (Mw:165 kDa), mainly composed of fucose(56.80 %), had the highest total sugar (66.91 %) and sulfate (17.07 %) content. FT-RT and NMR results showed that LF4 was mainly composed of galactosylated galactofucose, and has a sulfate group attached to fucose C4. With the animal experimentation, it was revealed that hyperlipidaemic mice had significantly higher levels of TC (5.52 mmol/L), TG (2.28 mmol/L) and LDL-C (5.12 mmol/L) and significantly lower levels of HDL-C (2 mmol/L). However, LF had the efficacy in modulating the lipid metabolism disturbances induced by hyperlipidemia, as well as the ability to regulate cholesterol transport in serum. Moreover, it regulated AMPK/ACC, PPAR-α/LAXRa, Nrf2/Nqo1, TLR4/NF-κB signaling pathway genes and proteins expression in the liver. In addition, it promoted the production of beneficial short-chain fatty acids (SCFAs) while improving the composition and structure of gut microbiota, including balancing the abundance of Bacteroidota, Firmicutes, Muribaculaceae, Alloprevotella, Escherichia-Shigella, Prevotella and NK4A136. The results clearly indicated that LF4 could significantly ameliorate hyperlipidemia, suggesting its prospective application as a functional food.