文冠果壳皂苷抑制胰脂肪酶活性的研究

Inhibitory Effect of Xanthoceras sorbifolia Nutshell Saponin on Pancreatic Lipase

摘要:

本文旨在确定文冠果壳皂苷作为减肥因子对胰脂肪酶活性的作用效果。通过对胰脂肪酶反应条件（pH、反应时间和反应物加入顺序）的摸索，确定AB-8大孔树脂纯化的文冠果壳皂苷对胰脂肪酶活性的影响，并通过紫外吸收光谱（200~340 nm）、荧光光谱（激发波长290 nm，扫描波长300~450 nm）确定文冠果壳皂苷对胰脂肪酶作用的机理。研究结果表明，文冠果壳皂苷对胰脂肪酶抑制率高达87.5%，最佳反应体系pH 7.4，反应时间15 min，反应物加入顺序为底物与文冠果壳皂苷预热后加入胰脂肪酶溶液反应。文冠果壳皂苷与胰脂肪酶作用后，改变了胰脂肪酶中发光氨基酸（Trp、Tyr）所在微环境，胰脂肪酶分子结构和构象发生变化，导致胰脂肪酶紫外吸收光谱最大吸收波长红移和荧光强度降低，胰脂肪酶活性抑制。文冠果壳皂苷可通过抑制胰脂肪酶发挥减肥因子的作用。

Abstract:

In this study, the influence of saponin from Xanthoceras sorbifolia nutshell (SXS) which was considered as a weight-reducing agent on pancreatic lipase activity was studied. The effects of SXS purified by AB-8 macroporous resin on pancreatic lipase were investigated by evaluating various experimental conditions (pH, reaction time, and order of adding reagents). The mechanism of SXS-mediated inhibition of pancreatic lipase was studied using ultraviolet absorption spectrometry (200~340 nm) and fluorescence spectrometry (excitation wavelength 290 nm, scanning wavelength 300~450 nm). The results indicated that the inhibition rate of SXS to pancreatic lipase activity could reach 87.5% using the optimal reaction system of pH 7.4, reaction time 15 min, and preheating the substrate and SXS together prior to adding the pancreatic lipase solution. Following the reaction of SXS and pancreatic lipase, the microenvironment of luminous amino acids (Trp, Tyr), the molecular structure, and the conformation of pancreatic lipase were changed. This resulted in a red-shift in the maximum absorption wavelength in the ultraviolet absorption spectrum of pancreatic lipase, and a reduction in fluorescence intensity. Further, pancreatic lipase activity was inhibited. Thus, SXS can act as a weight-reducing agent through the inhibition of pancreatic lipase.