楮实子多糖的制备、分离及其对 Aβ25-35 诱导 的 SH–SY5Y 细胞损伤和 AChE 的抑制作用

Preparation and Isolation of Fructus Broussonetiae Polysaccharide and its Inhibitory Effect on AChE and SHSY5Y Cell Damage Induced by Aβ25-35

摘要:

〔摘 要〕 目的：探讨楮实子水提物多糖组分的构成及对 β– 淀粉样蛋白（Aβ）25–35 片段（Aβ25-35）诱导的 SH–SY5Y 细胞损伤和乙酰胆碱酯酶（AChE）的抑制作用。方法：首先采用 DEAE–52 柱层析法分级分离楮实子水提多糖，采用 Aβ25-35 诱导 SH–SY5Y 神经细胞损伤，观察楮实子多糖不同组分对 SH–SY5Y 神经细胞损伤的保护作用，采用改良的 Ellman 法对 分离纯化得到的多糖组分进行 AChE 抑制活性检测。结果：从楮实子水提物中分离，得到楮实子总多糖（FBP）的五个组 分（FBP–1，FBP–2，FBP–3、FBP–4、FBP–5），其中 FBP–2 纯度较高。对 Aβ25-35 诱导 SH–SY5Y 细胞损伤的保护作用比 较发现，FBP–2 可以显著提高细胞存活率。进一步采用 Ellman 法对组分 FBP–2 的 AChE 体外抑制活性进行测试，楮实子 FBP–2 显示出较好的 AChE 抑制活性，半抑制浓度（IC50）为 1.08 mg·mL-1 。结论：本研究从楮实子水提物中得到一种多 糖单一组分 FBP–2，研究发现 FBP–2 对 AChE 的抑制活性较好，且与其浓度成一定的线性相关；楮实子多糖组分 FBP–2 亦 可显著对抗 Aβ25-35 诱导的 SH–SY5Y 细胞损伤。

关键词:阿尔茨海默病;楮实子多糖;SH–SY5Y 细胞损伤;乙酰胆碱酯酶

Abstract:

〔Abstract〕 Objective To investigate the composition of polysaccharides from the water extraction of Fructus Broussonetiae and its inhibitory effect on acetylcholinesterase (AChE) and SH-SY5Y cell damage induced by Aβ25-35. Methods Firstly, DEAE-52 column chromatography was used to fractionate the water-extracted polysaccharides of Fructus Broussonetiae, and Aβ25-35 was used to induce the damage of SH-SY5Y nerve cells, and the protective effects of different components of the polysaccharide of Fructus Broussonetiae on SH-SY5Y nerve cells were observed. The modified Ellman method was used to detect the AChE inhibitory activity of the isolated and purified polysaccharide fractions. Results Five components (FBP–1, FBP–2, FBP–3, FBP–4, FBP–5) were separated from the water extraction of Fructus Broussonetiae, among which FBP–2 had a higher purity. The comparison of the protective effect of Aβ25-35 on SH-SY5Y cell injury found that FBP–2 can significantly improve the cell survival rate. Furthermore, the Ellman method was used to test the AChE inhibitory activity of the component FBP–2 in vitro, and the FBP–2 showed a high acetylcholinesterase inhibitory activity with IC50 of 1.08 mg/mL. Conclusion In this study, FBP–2 was obtained from the water extract of Fructus Broussonetiae. It was found that FBP–2 has a better inhibitory activity on acetylcholinesterase, presenting a certain linear correlation between inhibition and its concentration. FBP–2 also effectively protected against SH-SY5Y cell injury induced by Aβ25-35.

Key words:Alzheimer's disease; Polysaccharide of Fructus Broussonetiae; SH-SY5Y cell damage; Acetylcholinesterase