连翘多糖纳米硒的制备及体外抗氧化和降血糖能力

Preparation, characterization, antioxidant and hypoglycemic activity of polysaccharide nano-selenium from Forsythia suspensa in vitro

摘要:

利用水提醇沉法从连翘中提取连翘多糖（FP），并经硝酸-亚硒酸钠法制备连翘多糖纳米硒（FP-SeNPs），采用UV-Vis、FTIR、XRD和SEM测定其吸收光谱、组织结构和表面形貌；采用1,1-二苯基-2-三硝基苯肼自由基（?DPPH）、羟基自由基（?OH）、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二胺阳离子自由基（?ABTS）清除实验考察FP-SeNPs的体外抗氧化能力；采用α-淀粉酶和α-葡萄糖苷酶活性抑制实验考察FP-SeNPs的体外降血糖能力。结果表明，FP-SeNPs中硒含量为908 mg/kg；FP-SeNPs形成了颗粒状分布的表面结构，改变了多糖的表面形态，但未破坏多糖的基本结构；其UV-Vis光谱在270 nm左右处生成了新的吸收峰，XRD谱图中在2θ=20°~30°内出现一个弥散峰，表明FP和SeNPs之间存在相互作用，形成了FP-SeNPs复合物。FP-SeNPs对?DPPH、?OH和?ABTS自由基的清除能力和对α-淀粉酶、α-葡萄糖苷酶的活性抑制能力均呈浓度依赖性，质量浓度为1.6 mg/mL的FP-SeNPs溶液对?DPPH、?OH和?ABTS自由基的清除率分别为91.98%、56.81%和87.44%，对α-淀粉酶、α-葡萄糖苷酶的活性抑制率分别为55.61%和72.73%，显著高于FP的自由基清除能力和酶活性抑制能力（P＜0.05）。

Abstract:

Water extraction and alc?OHol precipitation method was used to extract polysaccharides from Forsythia suspensa, and Forsythia suspensa polysaccharide nano selenium (FP-SeNPs) was prepared through nitric acid-sodium selenite method. UV-Vis, FTIR, XRD, and SEM were used to characterize their absorption spectra, tissue structure, and surface morphology. ?DPPH radical, ?OH radical, and ?ABTS radical were used to investigate the antioxidant capacity of FP-SeNPs in vitro. The hypoglycemic activity of FP-SeNPs was investigated by α-amylase and α-glucosidase inhibition assay. The results showed that the selenium content in FP-SeNPs was 908mg/kg; FP-SeNPs formed a surface structure with granular distribution, changing the surface morphology of polysaccharides, but did not destroy the basic structure of polysaccharides. A new absorption peak was generated at around 270 nm, and a diffuse peak was observed in the XRD pattern between 20°and 30°, which indicated that there was an interaction between FP and SeNPs, and the FP-SeNPs complex was formed. The scavenging ability of FP-SeNPs on ?DPPH, ?OH, and ?ABTS radicals and the inhibitory ability on α-amylase α-glucosidase were concentration-dependent. The scavenging rates of 1.6 mg/mL FP-SeNPs solution on ?DPPH, ?OH, and ?ABTS free radicals were 91.98%, 56.81%, and 87.44%, and the inhibitory rates on α-amylase and α-glucosidase were 55.61% and 72.73%, respectively, which were significantly higher than that of FP (P<0.05).