奶油栓孔菌子实体多糖的理化性质、抗氧化活性与保肝作用

本研究旨在探讨奶油栓孔菌子实体多糖（TLFPS）的化学性质和酒精性肝损伤的保护作用。首先用水提醇沉法提取得到多糖,通过化学组成分析、紫外吸收光谱法、傅里叶红外光谱法和刚果红染色法对多糖结构进行初步表征,以DPPH、ABTS、超氧阴离子自由基的清除能力和铁离子还原能力为指标评价了多糖体外抗氧化能力,在小鼠急性肝损伤之前连续灌喂多糖8d,比较各组小鼠血清和肝的相关生化指标以及组织病理切片来确定多糖对酒精性肝损伤小鼠的保护作用。结果显示：多糖具有β-吡喃糖环结构,含有较高含量的糖醛酸和硫酸根基团,空间构型不具备三股螺旋结构。在体外抗氧化活性方面,多糖对DPPH、ABTS和超氧阴离子自由基均有良好的清除活性,铁离子还原能力也呈良好的剂量依赖性。在小鼠保肝实验中,与模型组相比,多糖能够显著延长小鼠的醉酒时间和缩短醒酒时间,降低了酒精性肝损伤小鼠的肝指数,并且显著降低血清中谷丙转氨酶（alanine aminotransferase,ALT）、谷草转氨酶（aspartate aminotransferase,AST）、甘油三酯（triglyceride,TG）、总胆固醇（total cholesterol,TC）和肝脏中丙二醛（malondialdehyde,MDA）的含量,同时明显提高了肝脏中超氧化物歧化酶（superoxide dismutase,SOD）和过氧化氢酶（catalase,CAT）的活性。结果证实奶油栓孔菌子实体多糖具有良好的抗氧化能力,可以减轻由酒精引起的急性肝细胞损伤,而且对机体的毒害作用很小。肝组织病理切片也进一步证实了奶油栓孔菌多糖的保肝活性。研究结果不仅丰富了奶油栓孔菌的药用价值,而且对多糖在功能食品领域的应用提供了药效基础。

Physicochemical properties,antioxidant activities and liver protective effects of polysaccharides from fruiting bodies of Trametes lactinea

This study aims at exploration of the chemical properties and protective effects on acute alcoholic liver injury of Trametes lactinea fruiting body polysaccharides (TLFPS). Polysaccharides were extracted by decoction and alcohol sedimentation, and their characteristics were analysed preliminarily by chemical composition determination, ultraviolet absorption spectrometry, fourier transform infrared spectroscopy and Congo red staining. The antioxidant activity in vitro of TLFPS was assessed by determination of ferric ion reducing antioxidant ability and scavenging free radical of DPPH, ABTS and superoxide anion. Polysaccharides were administrated to mice once daily for eight days before occurrence of alcoholic liver damage, and the protective effects of TLFPS against acute alcoholic liver injury in mice were evaluated by comparing related biochemical parameters and pathological section between experimental groups. Results showed TLFPS was β-pyran type polysaccharides without a triple helix structure, having high content of uronic acid and sulfate radical. In terms of antioxidant activity in vitro, the polysaccharides exhibited remarkable scavenging activities against DPPH radicals, ABTS radicals and superoxide anion radicals, and ferric ion reducing antioxidant ability was also notably stronger. In terms of liver protective activity, the polysaccharides had significantly prolonged the time of drunkenness, shortened the time of hangover and reduced the liver index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC) in serum and malondialdehyde (MDA) in liver. Meanwhile, activity in liver of superoxide dismutase (SOD) and catalase (CAT) was increased. It was confirmed that TLFPS had higher antioxidative activity and obviously alleviate acute alcoholic liver injury without toxic effect on the body. The pathological section examination further confirmed the pharmacological activity of TLFPS. This study provided the pharmacodynamic basis for development of TLFPS in the field of functional food.