新型人参多糖的发现: 发酵产物的结构表征、体外发酵特性及其通过Nrf2/HO-1途径对A β 诱导的PC12细胞的抗氧化机制

Discovery of a Novel Ginseng Polysaccharide： Structure Characterization， in vitro Fermentability and Anti-oxidative Mechanism of Fermented Product via the Nrf2/HO-1 Pathway on A β -induced-PC12 Cells

摘要

从人参中分离出一种新型多糖GPA-G2-H, 并对其结构特性、 体外酵解特性以及发酵产物FGPA-G2-H对Aβ_25-35诱导的PC12细胞的抗氧化机制进行了研究. 通过ζ电位分析、 傅里叶变换红外光谱(FTIR)、 高效液相色谱(HPLC)、 X射线衍射(XRD)、 气相色谱-质谱联用(GC-MS)和核磁共振波谱(NMR)等技术对其结构进行了表征. 结果表明, GPA-G2-H的主链主要由→4)-α-D-Glcp-(1→构成, 且支链主要连接于主链的O3位. 体外实验结果表明, GPA-G2-H能够被肠道菌群降解, 这一过程伴随着总糖含量和pH值的降低, 以及短链脂肪酸(SCFAs)含量的增加. 此外, GPA-G2-H可显著促进Lactobacillus, Muribaculaceae和Weissella的增殖, 对肠道菌群的群落组成产生了积极影响. 进一步研究发现, GPA-G2-H的发酵产物FGPA-G2-H能够激活Nrf2/HO-1信号通路, 显著增强HO-1, NQO1, SOD和GSH-Px的活性, 同时抑制Keap1, MDA和LDH的表达, 从而有效缓解Aβ诱导的PC12细胞氧化应激损伤. 研究结果为人参多糖作为功能性食品和抗氧化药物的进一步开发奠定了理论基础.

Abstract

In this study， a novel polysaccharide GPA-G2-H was derived from ginseng. Furthermore， the coherent study of its structural characteristics， fermented characteristics in vitro， as well as antioxidant mechanism of fermented product FGPA-G2-H on Aβ_25-35-induced PC12 cells were explored. The structure of GPA-G2-H was determined by means of zeta potential analysis， FTIR， HPLC， XRD， GC-MS and NMR. The backbone of GPA-G2-H was mainly composed of →4）-α-D-Glcp-（1→ with branches substituted at O-3. Notably， GPA-G2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing， and short-chain fatty acids（SCFAs） increasing. Moreover， GPA-G2-H significantly promoted the proliferation of Lactobacillus， Muribaculaceae and Weissella， thereby making positive alterations in intestinal microbiota composition. Additionally， FGPA-G2-H activated the Nrf2/HO-1 signaling pathway， enhanced HO-1， NQO1， SOD and GSH-Px， while inhabited Keap1， MDA and LDH， which alleviated Aβ-induced oxidative stress in PC12 cells. These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.

关键词

人参多糖 / 结构表征 / 肠道菌群 / 发酵性 / 氧化应激

Key words

Ginseng polysaccharide / Structural characterization / Intestinal microbiota / Fermentability / Oxidative stress