蔓三七叶多糖的理化性质及免疫调节活性研究

Physicochemical Characteristics and Immunomodulatory Activity of Polysaccharides from Gynura procumbens Leaves

以蔓三七叶为实验材料,采用水提醇沉法获得蔓三七叶多糖(GPLP),测定了其总糖、糖醛酸、硫酸根以及蛋白质的含量和单糖组成,并对其抗氧化活性和免疫调节活性进行了研究。采用苯酚-硫酸法测定总糖含量,硫酸-间羟基苯酚法测定糖醛酸含量,BaCl2-明胶法测定硫酸根含量,气相色谱法测定单糖组分和红外光谱测定多糖的结构。通过总抗氧化能力、DPPH自由基、OH自由基的清除能力评价GPLP的体外抗氧化能力,并探讨其对脂多糖(LPS)刺激RAW 264.7巨噬细胞免疫调节活性。结果表明,所得GPLP的得率为15.56%,粗多糖中的总糖含量为52.32±1.56 g/100 g;单糖组成为阿拉伯糖、木糖、葡萄糖、半乳糖,摩尔比为1.39:8.70:3.17:1。体外抗氧化实验结果表明GPLP的总抗氧化能力、DPPH和OH自由基清除效果明显。GPLP可显著提高RAW 264.7细胞内一氧化氮(NO)的浓度,在给药浓度为25.0μg/mL时,NO的分泌量达到最大,为31.24±2.30μM。GPLP可以提高免疫力,在功能食品的开发中,可以作为一个潜在的免疫调节剂。

In this study,Gynura procumbens leaves were used as the experimental material,and their polysaccharides(GPLP)were obtained by the water extraction method.The total sugar content,uronic acid content,sulfate content,protein content and monosaccharide composition of GPLP were determined,with their antioxidant and immunoregulatory activities also examined.The total sugar content was determined by the phenol-sulfuric acid method,and the uronic acid content was determined by sulfuric acid-m-hydroxyphenol method.The sulfate content was determined by the BaCl2-gelatin method,while the monosaccharide composition was determined by gas chromatography and the structure of polysaccharide was determined by infrared spectroscopy.The in vitro antioxidant capacity of GPLP was evaluated through measuring the total antioxidant activity and DPPH and OH free radicals scavenging capacities.The immunomodulatory activity against lipopolysaccharide(LPS)-induced RAW 264.7 macrophages was investigated.The results showed that the yield of GPLP was 15.56%,and the total sugar contend in the crude polysaccharide was 52.32±1.56 g/100 g with the monosaccharides being arabinose,xylose,glucose and galactose at a molar ratio of 1.39:8.70:3.17:1.The results of in vitro antioxidant tests showed significant total antioxidant activity and DPPH and OH free radicals scavenging capacities.GPLP could significantly increase the concentration of nitric oxide(NO)in RAW 264.7 cells,and at the GPLP dose of 25.0μg/mL,the secretion of NO reached to the maximum values(31.24±2.30μM).GPLP may improve immunity and can be used as a potential immunomodulator in the development of functional foods.