羊栖菜抗衰老多糖级分的筛选及抗衰老机制的初步研究

The seaweed, Hizikia fusiformis, is a kind of Chinese traditional medicine, which is well acknowledged as life extension food. However, the components in H. fusiformis which display anti-aging effect and the related mechanisms are unkown. Our previous research showed that crude H. fusiformis polysaccharides activated ARE reporter gene and slowed down the aging process of D-galactose induced aging mice, which suggested that the crude Hizikia fusiformis polysaccharides contained anti-oxidative and anti-aging components. In this project, we propose to separate and purify the H. fusiformis polysaccharides, then screen the fractions with powerful anti-aging effect using ARE reporter gene, H2O2 induced premature senescence cell model and drosophila melanogaster model. Meanwhile, analyze the expression and phosphorylation pattern of transcriptional factor Nrf2 and the change of its upstream proteins at cell level, as well as the transcriptome in the drosophila melanogaster model to investigate the anti-aging mechanism of H. fusiformis polysaccharides. This research study will provide a theoretical knowledge for exploring anti-aging polysaccharides and contribute to understanding the anti-aging mechanism of polysaccharides.

羊栖菜是传统的药食两用海藻，被公认具益寿功效，称为"长寿菜"，但对其发挥抗衰老作用的物质基础及作用途径仍缺乏认识。申请人的前期工作表明，羊栖菜粗多糖可以激活ARE报告基因的表达，延缓D-半乳糖亚急性衰老小鼠的衰老进程，这暗示着羊栖菜粗多糖中含有抗氧化和抗衰老的有效成分。本项研究将依次通过冷水、热水和碱液浸提法提取粗多糖，再分别用离子交换层析柱和凝胶过滤层析柱进行纯化分级，并利用ARE报告基因法、H2O2促衰老细胞模型和黑腹果蝇模型逐级筛选不同纯化步骤获得的羊栖菜多糖，探明发挥抗衰老作用的多糖级分。随后，在细胞水平和个体水平上分别对Nrf2表达水平、磷酸化修饰模式及其上游蛋白进行研究，探明有效级分发挥抗氧化作用的机制；再结合对黑腹果蝇转录组的研究，初步探讨羊栖菜多糖有效级分发挥抗衰老作用的分子机理。本研究结果将为植物多糖抗衰老有效成分的开发提供借鉴，也为阐明多糖抗衰老的作用机制提供实验依据。

羊栖菜是传统的药食两用海藻，有“长寿菜”的美称。然而其发挥抗衰老作用的物质基础和作用机理尚不明确。本项目研究通过多糖系统分级和活性筛选，获得两组抗衰老活性优越的羊栖菜多糖级分：SFPS和SFP-2；随后分别在分子，细胞和机体水平对其作用机制进行了分析。结果表明，长期喂食羊栖菜多糖SFPS可以显著地提高机体的抗氧化能力，进而延缓衰老进程并延长果蝇的平均和最高寿命。研究发现，长期喂食羊栖菜多糖SFPS可以有效的改善肠道菌群结构，增强机体JNK/Nrf2/ARE信号通路。此外，利用比较蛋白质组学手段，共鉴定了53个蛋白显著响应长期喂食SFPS，通过生物信息学进一步分析，提示长期喂食SFPS抗衰老与提高机体代谢和线粒体活性存在密切相关。本项目研究结果为羊栖菜发挥“长寿菜”作用提供了直接的物质基础和理论依据，将为海藻多糖抗衰老有效成分的开发提供技术支持，也为阐明多糖抗衰老的作用机制提供科学借鉴。