Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
Int J Biol Macromol. 2020 May 1;150:31-37. doi: 10.1016/j.ijbiomac.2020.02.027. Epub 2020 Feb 5.
The inhibitory activity of taxifolin on three digestive enzymes were investigated in both vitro and vivo. Taxifolin exhibited inhibitory effect on α-glucosidase, α-amylase and pancreatic lipase with IC50 values of 0.038, 0.647 and 0.993 mg/mL, respectively. Inhibitory kinetics indicated that taxifolin was more like a competitive inhibitor of α-glucosidase and α-amylase, while it was a non-competitive inhibitor of pancreatic lipase. The binding of taxifolin caused the quenching of intrinsic fluorescence intensity of enzymes, and the binding constant (lgK) and the number of binding site (n) were further calculated through fluorescence titration. The values of lgK were in the range of 4.93-6.65, and the values of n were all close to 1. Molecular docking indicated that taxifolin could interact with α-glucosidase and α-amylase through many kinds of secondary interaction, such as hydrogen bond, π-π stack, etc. In vivo study revealed that pre-administration with taxifolin can significantly improve the postprandial hyperglycemia in rat. Furthermore, its can also decrease triglyceride absorption through the inhibition of pancreatic lipase.
研究了花旗松素对三种消化酶的体外和体内抑制活性。花旗松素对α-葡萄糖苷酶、α-淀粉酶和胰脂肪酶表现出抑制作用，IC50 值分别为 0.038、0.647 和 0.993mg/mL。抑制动力学表明，花旗松素更像是 α-葡萄糖苷酶和 α-淀粉酶的竞争性抑制剂，而对胰脂肪酶则是非竞争性抑制剂。花旗松素的结合导致酶的内源荧光强度猝灭，通过荧光滴定进一步计算结合常数（lgK）和结合位点数（n）。lgK 值在 4.93-6.65 范围内，n 值均接近 1。分子对接表明，花旗松素可通过氢键、π-π堆积等多种次级相互作用与 α-葡萄糖苷酶和 α-淀粉酶相互作用。体内研究表明，预先给予花旗松素可显著改善大鼠餐后高血糖。此外，它还可以通过抑制胰脂肪酶来减少甘油三酯的吸收。
