碱提桑黄菌丝体多糖的抗氧化活性

为了研究碱提桑黄菌丝体多糖PL-N的抗氧化活性。利用物理、化学方法分析了PL-N的化学组成及基本理化性质,在此基础上,通过体外抗氧化模型、细胞试验和D-半乳糖所致的小鼠亚急性衰老模型综合评价了PL-N对DPPH和羟自由基的清除作用、过氧化氢诱导SH-SY5Y神经细胞的保护作用及体内抗氧化活性。结果表明:PL-N的总糖和糖醛酸含量分别为84.92%和16.92%,不含蛋白质,主要由D-阿拉伯糖、D-木糖、D-葡萄糖和D-半乳糖组成,其分子摩尔比为5.5:7.8:1.8:1。PL-N具有明显的清除自由基能力,且呈剂量依赖关系,在2.0 mg/mL时,PL-N的DPPH和羟自由基清除率分别为72.1%和83.3%。同时,在80 μg/mL时,PL-N预处理对氧化损伤细胞的存活率达到88.7%,揭示其突出的体外抗氧化活性。与模型组相比,灌胃高剂量PL-N的小鼠脏器指数、血清和肝脏中的抗氧化酶活性和总抗氧化能力均极显著增加(P<0.01),丙二醛含量极显著降低(P<0.01)。由此可见,PL-N具有突出的抗氧化活性,可作为功能性食品应用于膳食、理疗中。

Antioxidant Activities of Polysaccharides from Phellinus linteus Mycelia by Alkaline Extraction

In this study,antioxidant activities of polysaccharides(PL-N)isolated from Phellinus linteus mycelia were investigated.The chemical compositions and preliminary physicochemical properties of the PL-N were analyzed by physical and chemical methods.On this basis,the scavenging abilities on DPPH and hydroxyl free radicals,the protective effects on hydrogen peroxide-induced neurotoxicity in SH-SY5 Y cells,and antioxidant activity in vivo of the PL-N were evaluated by using in vitro antioxidant trials,cell assay and D-galactose-induced aging mice models.The results showed that the carbohydrate and uronic acid contents of PL-N were 84.92%and 16.92%,respectively,and it had no proteins.PL-N was mainly composed of D-arabinose,D-xylose,D-glucose and D-galactose with the molar ratio of 5.5∶7.8∶1.8∶1.0.PL-N exhibited prominent freeradical scavenging capacities and antioxidant activities in vitro in dose-dependent manners.At a concentration of 2.0 mg/m L,the scavenging effects of PL-N on DPPH and hydroxyl radicals were 72.1%and 83.3%,respectively.Meanwhile,the viability of oxidative damaged cells reached 88.7%after PL-N pretreatment at a concentration of 80μg/m L,which revealed its outstanding antioxidant activity in vitro.Compared with the model group,the administration of high-dose of PL-N improved viscera indices of aging mice,enhanced the activity of antioxidant enzymes and total antioxidant capacity(P<0.01),and significantly reduced the content of malondiadehyde in the serum and liver of aging mice(P<0.01).Therefore,these findings implied that PL-N had prominent antioxidant activity and could be explored as a natural antioxidant for potentially used in functional foods or medicines.