4种红藻寡糖提取物的制备及其免疫调节活性探究

Preparation and immunomodulatory activity study of four red algae oligosaccharide extracts

目的 探究红藻寡糖提取物潜在应用价值,对其免疫调节活性进行初步研究以实现红藻资源的高值利用。方法 以4种不同来源红藻为实验材料,固定料液比1∶40,以藻粉质量分数1%半纤维素酶在p H 4、50℃条件下酶辅助提取3 h;提取液升温至90℃,于0.01~0.02 mol/L盐酸终浓度下高温稀酸提取1~3 h;提取液经除杂、脱色、纳滤除盐及冷冻干燥制备获得4种红藻寡糖提取物。采用高效液相色谱法(HPLC)、比色法、1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生法等对4种红藻寡糖提取物进行相对分子质量、总糖含量、单糖组成等理化性质分析。体外评价了寡糖提取物对RAW264.7细胞的毒性以及NO、IL-6、IL-1β释放的影响。结果 采用酶提酸降解工艺制备得到了4种红藻寡糖提取物。在体外活性评价中,4种寡糖提取物在低浓度下显著提高RAW264.7细胞内NO的释放水平。另外,4种寡糖提取物剂量依赖性地减少了脂多糖(LPS)诱导的RAW264.7细胞中NO的释放,其中耳突麒麟菜寡糖提取物ECOS显著减少了LPS诱导的RAW264.7细胞IL-6的分泌。结论 4种红藻寡糖提取物具有免疫激活及炎症抑制的作用,表现出良好的免疫调节活性。

Objective In order to achieve high-value utilization of red algae resources and explore the potential application of red algae oligosaccharide extracts,a preliminary study was conducted on their immunomodulatory activities.Methods Four kinds of red algae from different sources were used as experimental materials.The ratio of material to liquid was 1∶40,and enzyme-assisted extraction with 1%hemicellulase by mass of algal powder at pH 4 and 50 ℃ for 3 h.The extraction solution was heated to 90 ℃for 1-3 h,with the final concentration of hydrochloric acid 0.01-0.02 mol/L.Four kinds of red algae oligosaccharide extracts were obtained through impurity removal,decolorization,nanofiltration desalination,and freeze drying.The molecular weight,total sugar content,monosaccharide composition and other physicochemical properties of the extracts were analyzed by HPLC,colorimetric method and PMP pre-column derivatization.The effects of oligosaccharide extracts on the cytotoxicity and release of NO,IL-6 and IL-1βof RAW264.7 were evaluated in vitro.Results Four red algae oligosaccharide extracts were prepared using an enzymatic extraction and acid degradation process.In vitro activity evaluation,four kinds of red algae oligosaccharide extracts significantly increased the release level of NO in RAW264.7 cells at low concentration.In addition,four oligosaccharide extracts significantly reduced LPS-induced NO release in RAW264.7 cells in a dose-dependent manner,with Eucheuma cottonii oligosaccharide extract ECOS significantly reducing LPSinduced IL-6 secretion in RAW264.7 cells.Conclusion Four red algae oligosaccharide extracts had the effects of immune activation and inflammation inhibition,exhibiting good immunoregulatory activity.