酸枣多糖及其降解物的生物活性比较

Comparison of the Bioactivities of Ziziphus jujuba Polysaccharide and Its Degradation Products

摘要:

【目的】研究比较酸枣多糖（Ziziphus jujuba polysaccharide，ZJP）及其不同降解产物在化学组成和生物活性上的差异。【方法】采用α-L-鼠李糖苷酶、纤维素酶、蜗牛酶、三氟乙酸对ZJP进行降解，制备不同的酸枣多糖降解产物ZJP-R、ZJP-C、ZJP-S、ZJP-T，比较其化学组成及降解效果。在体外抗氧化、益生活性检测的基础上，以秀丽隐杆线虫为模型系统比较了不同降解处理对ZJP在体内抗氧化、抗衰老、抗应激及神经保护活性上的差异。【结果】不同降解处理方式下的ZJP中还原糖质量分数及平均聚合度差异显著。此外，Sephadex G-50凝胶层析洗脱图谱显示ZJP-S含有更多不同相对分子质量的低聚糖片段。体外活性结果显示，降解处理可显著提高ZJP的自由基清除能力、总还原力和促益生菌生长活性。体内活性结果显示，ZJP及其降解物给药处理可显著降低秀丽隐杆线虫体内氧化应激条件下的ROS积累，增强SOD酶活力，降低MDA质量摩尔浓度，延长秀丽隐杆线虫寿命，减少脂褐素的积累，增强热应激、急性氧化应激抵抗能力。ZJP降解后生物活性提高，尤其是ZJP-S在多个指标评价中活性效果最显著。此外，ZJP-C及ZJP-S在亨廷顿病和阿尔茨海默病模型秀丽隐杆线虫中均表现出显著的神经保护活性。【结论】降解处理可增强ZJP的生物活性，其中ZJP-S更好的生物活性可能与蜗牛酶降解产生更丰富的低聚糖及还原糖片段相关，该研究为酸枣资源的开发利用提供了参考。

Abstract:

[Objective]This study aims to compare Ziziphus jujuba polysaccharide (ZJP) and its degradation products in terms of their chemical composition and bioactivities.[Method]ZJP was degraded by α-L-rhamnosidase, cellulase, snail enzyme, and trifluoroacetic acid to prepare different degradation products (ZJP-R, ZJP-C, ZJP-S, and ZJP-T), and the chemical composition and degradation effects were compared. On the basis of in vitro antioxidant and probiotic activities, the in vivo antioxidant, anti-aging, anti-stress, and neuroprotective activities of ZJP and its degradation products were compared with Caenorhabditis elegans as a model system.[Result]The mass fraction of reducing sugar and average degree of polymerization of ZJP showed significant variations among different degradation treatments. In addition, Sephadex G-50 gel chromatography elution profile showed that ZJP-S had more oligosaccharide fragments with different relative molecular mass. In vitro assays demonstrated that degradation treatments significantly enhanced the free radical scavenging ability and total reducing power of ZJP and the growth activity of probiotics exposed to ZJP. In vivo assays in C. elegans revealed that the treatments with ZJP and its degradation products significantly reduced the reactive oxygen species (ROS) accumulation, enhanced the superoxide dismutase (SOD) activity, and decreased the malondialdehyde (MDA) molality of C. elegans under oxidative stress. Furthermore, the treatments prolonged the lifespan, reduced the lipofuscin accumulation, and enhanced the resistance to heat stress and acute oxidative stress. ZJP demonstrated improved bioactivity after degradation, with ZJP-S exhibiting the most significant effects across multiple indicators. Additionally, both ZJP-S and ZJP-C showed significant neuroprotective activity in the C. elegans models of Huntington disease and Alzheimer’s disease.[Conclusion]Degradation treatment enhanced the bioactivity of ZJP. The greater bioactivity of ZJP-S might be associated with the more abundant oligosaccharides and reducing sugars from snail enzyme degradation. The findings provide a reference for the development and utilization of Z. jujuba resources.