Wax apple (Syzygium samarangense) has received growing research interest for its high nutritional and medicinal value due to its constituents such as polysaccharide, organic acids, flavonoids, minerals, and other substances. In this study, wax apple polysaccharide (WAP) was isolated from this plant and its protective effect against ethyl carbamate (EC)-induced oxidative damage was evaluated in human hepatocytes (L02 cells). Firstly, a series of analyses such as high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), gas chromatography/mass spectrometry (GC/MS), and 1H and 13C nuclear magnetic resonance (NMR) were conducted to identify the structure of WAP. Thereafter, in vitro cell experiments were performed to verify the protective effects of WAP against EC-induced cytotoxicity, genotoxicity, and oxidative damage in L02 cells. Our results revealed that WAP is composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose in a molar ratio of 2.20:3.94:4.45:8.56:8.86:30.82:39.78:1.48. Using a combination of methylation and NMR spectroscopic analysis, the primary structure of WAP was identified as Araf-(1→, Glcp-(1→, →2)-Araf-(1→, →3)-Galp-(1→, →3)-Araf-(1→, and →6)-Galp-(1→. Cell experiments indicated that WAP exhibited significant protective effects on EC-treated L02 cells via suppressing cytotoxicity and genotoxicity, reducing reactive oxygen species (ROS) and O2•- formation, as well as improving mitochondrial membrane potential (MMP) and glutathione (GSH). In a nutshell, WAP has the potential as an important therapeutic agent or supplement for hepatic oxidative damage. Meanwhile, further studies are needed to prove the above effects in vivo at the biological and clinical levels.
莲雾（Syzygium samarangense）因其含有多糖、有机酸、类黄酮、矿物质等功能活性成分而具有很高的营养和药用价值，受到越来越多研究者的关注。本研究从莲雾中分离出水溶性多糖（WAP），并在人肝细胞（L02细胞）中评估了其对氨基甲酸乙酯（EC）诱导的氧化损伤的保护作用。首先采用高效液相色谱法（HPLC）、高效凝胶渗透色谱（HPGPC）、傅里叶变换红外光谱（FT-IR）、气相色谱/质谱（GC/MS）、1H和13C 核磁共振（NMR）等一系列分析方法来鉴定WAP的结构。随后进行体外细胞实验验证WAP对EC诱导的L02细胞中的细胞毒性、遗传毒性和氧化损伤的保护作用。结果表明，莲雾的WAP由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖和岩藻糖组成，其摩尔比为2.20:3.94:4.45:8.56:8.86:30.82:39.78:1.48。结合甲基化和NMR光谱分析，WAP的一级结构为Araf-(1→、Glcp-(1→、→2)-Araf-(1→、→3)-Galp-(1→、→3)-Araf-(1→和→6)-Galp-(1→。体外细胞实验表明，WAP通过抑制细胞毒性和遗传毒性，减少活性氧（ROS）和超氧根离子（O2•-）的形成，对EC诱导的L02细胞表现出显著的保护作用。综上所述，WAP具有作为肝脏氧化损伤的重要治疗剂或补充剂的潜力，但仍需通过体内生物学和临床研究进一步证实上述作用。.
莲雾（Syzygium samarangense）因其含有多糖、有机酸、类黄酮、矿物质等功能活性成分而具有很高的营养和药用价值，受到越来越多研究者的关注。本研究从莲雾中分离出水溶性多糖（WAP），并在人肝细胞（L02细胞）中评估了其对氨基甲酸乙酯（EC）诱导的氧化损伤的保护作用。首先采用高效液相色谱法（HPLC）、高效凝胶渗透色谱（HPGPC）、傅里叶变换红外光谱（FT-IR）、气相色谱/质谱（GC/MS）、1H和13C 核磁共振（NMR）等一系列分析方法来鉴定WAP的结构。随后进行体外细胞实验验证WAP对EC诱导的L02细胞中的细胞毒性、遗传毒性和氧化损伤的保护作用。结果表明，莲雾的WAP由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖和岩藻糖组成，其摩尔比为2.20:3.94:4.45:8.56:8.86:30.82:39.78:1.48。结合甲基化和NMR光谱分析，WAP的一级结构为Araf-(1→、Glcp-(1→、→2)-Araf-(1→、→3)-Galp-(1→、→3)-Araf-(1→和→6)-Galp-(1→。体外细胞实验表明，WAP通过抑制细胞毒性和遗传毒性，减少活性氧（ROS）和超氧根离子（O2 •-）的形成，对EC诱导的L02细胞表现出显著的保护作用。综上所述，WAP具有作为肝脏氧化损伤的重要治疗剂或补充剂的潜力，但仍需通过体内生物学和临床研究进一步证实上述作用。
Keywords: Ethyl carbamate; Hepatic oxidative stress; Polysaccharide characterization; Wax apple polysaccharide.