苹果皮果胶多糖的理化性质以及抑制人结肠癌细胞HT-29增殖活性的初步研究

Study on physicochemical properties of apple peel polysaccharides and its inhibitory activities against HT-29 cells in vitro

用水、质量分数0.5%草酸铵溶液、0.05 mol/L HCl溶液、1 mol/L KOH溶液从苹果皮中提取得到4种果胶多糖,分别是水溶性果胶多糖(WSP)、盐溶性果胶多糖(CSP)、酸溶性果胶多糖(ASP)和碱溶性果胶多糖(BSP)。测定了它们的总糖、糖醛酸和蛋白含量以及相对分子质量、单糖组成及摩尔比和红外光谱;并初步研究了4种苹果皮果胶多糖对人结肠腺癌细胞系HT-29细胞生长的抑制作用。结果显示:WSP、CSP、ASP和BSP的相对分子质量均大于4.0×105Da;气相色谱测定WSP、CSP、ASP和BSP的单糖组成及摩尔比,4种果胶多糖均含有半乳糖,而CSP所含的半乳糖醛酸含量最多,BSP不含半乳糖醛酸。WSP、CSP、ASP和BSP都能抑制人结肠腺癌细胞系HT-29细胞的增值,CSP的抑制活性最高(35.65%),BSP的抑制活性最低(10.30%),初步分析可能与苹果皮果胶多糖中半乳糖及半乳糖醛酸残基的含量相关。

In the present study, four components of apple pectins： water-soluble pectin （WSP） , chelate-soluble pectin （CSP） , acid-soluble pectin （ASP） and base-soluble pectin （BSP） , were extracted from apple peel by water, 0. 5% ammonium oxalate, 0. 05 mol/L HC1 and 1 mol/L KOH, respectively. Their physicochemieal properties, in- eluding monosaccharide composition with corresponding molar ratio, sugar content, uronic acid content, protein con- tent, relative molecular weight and FTIR spectra were investigated. Their in vitro inhibitory effects on the growth of HT-29 cells were preliminarily investigated. As a result, it was found that all the four pectin polysaccharides, WSP, CSP, ASP and BSP pssessed a relative molecular weight over 4.0 x 105 Da. CSP contains the most amount of galactu- ronic acids, while BSP had the most glucose without galacturonic acids. Meanwhile, all four pectin polysaccharides showed inhibitory activities against the proliferation of HT-29 cells, of which CSP had the highest activity and BSP had the lowest. The difference among four pectin polysaccharides in the inhibitory activity against HT-29 ceils may due to their different contents of galactose and galacturonic acid.