目的 研究长片金线兰多糖的结构特征以及对四氯化碳（CCl₄）致小鼠急性肝损伤的保护作用。方法 从长片金线兰中提取多糖，分析其相对分子质量、单糖组成、紫外与红外吸收特征。将48只ICR小鼠随机分为对照组、模型组、联苯双酯（150 mg/kg）组和长片金线兰多糖低、中、高剂量（100、200、400 mg/kg）组，给予相应药物干预9 d后，除对照组外，其余各组ip CCl₄造成急性肝损伤，16 h后检测各组小鼠血清中丙氨酸转氨酶（alanine aminotransferase，ALT）、天冬氨酸转氨酶（aspartate aminotransferase，AST）和乳酸脱氢酶（lactate dehydrogenase，LDH）活性；测定各组大鼠肝脏组织中超氧化物歧化酶（superoxide dismutase，SOD）、过氧化氢酶（catalase，CAT）活性以及谷胱甘肽（glutathione，GSH）和丙二醛（malondialdehyde，MDA）含量；采用苏木素-伊红（HE）染色法观察各组小鼠肝脏组织病理变化。结果 长片金线兰多糖的相对分子质量为4.254×10⁵，由甘露糖、鼠李糖、半乳糖醛酸、葡萄糖、半乳糖、木糖和阿拉伯糖组成（物质的量比为1∶0.11∶0.19∶11.15∶0.87∶0.36∶0.18），紫外与红外光谱扫描结果推测其可能为一种吡喃型杂多糖。与模型组比较，长片金线兰多糖能够显著降低CCl₄致肝损伤小鼠血清中ALT、AST和LDH活性（P<0.05、0.01），提高肝脏组织中SOD、CAT活性和GSH含量（P<0.05、0.01），降低MDA含量（P<0.01），减轻CCl₄对肝组织的病理损伤。结论 长片金线兰多糖对CCl₄致小鼠急性肝损伤具有一定的保护作用，其机制可能与抑制脂质过氧化有关。

Objective To study the structural characteristics of polysaccharides from Anoectochilus longilobus (ALP) against CCl₄-induced acute liver injury in mice. Methods Polysaccharide was isolated from A. longilobus, its total carbohydrate content, relative molecular weight and monosaccharide composition were measured. Its structural characteristics were analyzed by ultraviolet (UV) and infrared (IR) spectroscopy. Forty-eight ICR mice were randomly divided into control group, model group, bifendate (150 mg/kg) group, low-, medium-, and high-dose (100, 200, 400 mg/kg) ALP groups. After 9 d of intervention with corresponding drugs, except control group, rats in other groups were ip CCl₄ to cause acute liver injury. After 16 h, AST, ALT and LDH activities in serum and SOD, CAT activities, GSH, MDA contents in liver of mice in each group were measured. Hematoxylin-eosin (HE) staining method was used to observe pathological changes in liver of mice in each group. Results Relative molecular mass of ALP was 4.254×10⁵, which was composed of mannose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose with a molar ratio of 1:0.11:0.19:11.15:0.87:0.36:0.18. The results of UV and IR spectra showed that ALP may be a pyran-type heteropolysaccharide. Compared with model group, ALP significantly reduced ALT, AST and LDH activities in serum of mice with liver injury caused by CCl₄ (P < 0.05, 0.01), increased SOD, CAT activities and GSH content in liver tissue (P < 0.05, 0.01), reduced MDA content (P < 0.01), and reduced the pathological damage of liver tissue caused by CCl₄. Conclusion ALP has a certain protective effect on CCl₄-induced acute liver injury in mice, and its mechanism may be related to the inhibition of lipid peroxidation.

R285.5

国家自然科学基金资助项目（81773846）；国家自然科学基金资助项目（81603230）；福建省科技厅高校产学合作项目（2020Y4015）；福建省自然科学基金资助项目（2020J01735）