川麦冬多糖的结构特征及对过度运动小鼠肝损伤的改善作用

Structural characteristics of Ophiopogon japonicus polysaccharide and its ameliorative effect on liver injury induced by excessive exercise in mice

该文对川麦冬多糖的结构特征、抗氧化活性进行分析,探讨其对过度运动小鼠肝损伤的改善作用。采用水提醇沉法获得川麦冬多糖(Ophiopogon japonicus polysaccharides,POJ),通过高效液相色谱法确定POJ的单糖组成,利用红外光谱推测其特征基团,并构建过度运动疲劳小鼠肝损伤模型,评价POJ对肝损伤的改善作用机制。结果表明,POJ得率为5.4%,重均分子质量为19315 Da,数均分子质量为17005 Da;由葡萄糖、甘露糖、半乳糖、木糖组成,4种单糖的摩尔比为4.35∶5.21∶1.34∶1,其异头碳为β构型,POJ具有较强的清除自由基能力,且与多糖浓度具有显著的正相关;肝脏损伤模型结果显示,POJ能显著提高肝脏组织抗氧化酶活性,降低丙二醛、蛋白羰基化含量,同时还可降低血清中谷草转氨酶和谷丙转氨酶的含量,病理结构图显示POJ具有改善肝脏细胞损伤的作用;同时,POJ能激活腺苷酸活化蛋白激酶α(adenylate-activated protein kinase,AMPKα)/核因子E2相关因子2(nuclear factor erythroid-2 related factor 2,Nrf2)/血红素氧合酶-1(heme oxygenase-1,HO-1)信号通路,显著提高AMPKα、Nrf2、HO-1、超氧化物歧化酶、谷胱甘肽过物酶、过氧化氢酶的mRNA表达。研究表明,POJ能够激活AMPK/Nrf2/HO-1信号通路,促进下游抗氧化酶基因mRNA的表达,提高机体的抗氧化能力,从而缓解过度运动疲劳对肝脏造成的氧化损伤。该研究为川麦冬多糖在医药及运动功能性食品方面的开发应用提供了理论依据。

The structural characteristics and antioxidant activity of polysaccharides from Ophiopogon japonicus were analyzed to explore its improving effect on liver injury in overtraining mice.Ophiopogon japonicus polysaccharide(POJ)was obtained by water extraction and alcohol precipitation.The monosaccharide composition of POJ was determined by high-performance liquid chromatography,and its characteristic groups were inferred by infrared spectroscopy.A model of liver injury in mice with excessive exercise fatigue was constructed to evaluate the protection mechanism of POJ.Results showed that the yield of POJ was 5.4%,the average molecular weight of POJ was 19315 Da,and the number average molecular weight was 17005 Da,which was composed of glucose,mannose,galactose,and a small amount of xylose.The molar ratio of the four monosaccharides was 4.35∶5.21∶1.34∶1,and its anomeric carbon wasβ-configuration.POJ had strong free radical scavenging ability,and the free radical scavenging ability had a significant positive correlation with polysaccharide concentration.The results of the liver injury model showed that POJ could significantly increase the activity of antioxidant enzymes in liver tissue,and reduce malondialdehyde and protein carbonyl.It also reduced the content of aspartate aminotransferase and alanine aminotransferase in serum.The pathological structure map showed that POJ had the effect of repairing liver cell damage.In addition,it was also found that POJ could activate the adenylate-activated protein kinase(AMPKα)/nuclear factor erythroid-2 related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway and significantly increase AMPKα,Nrf2,HO-1,superoxide dismutase,glutathione peroxidase,and catalase mRNA expression.Studies have shown that POJ can activate the AMPK/Nrf2/HO-1 signaling pathway,promote the expression of downstream antioxidant enzyme genes,and improve antioxidant capacity,thereby alleviating oxidative damage to the liver caused by excessive exercise fatigue.This study could provide a theoretical basis for the development and application of Ophiopogon japonicus polysaccharides in medicine and sports functional food.