文献类型：期刊文献

英文题名：Camellia nitidissima Chi flower extracts inhibit alpha-amylase and alpha-glucosidase: In vitro by analysis of optimization of addition methods, inhibitory kinetics and mechanisms

作者：Zhang, Hai-long[1,2];Wu, Qing-xiao[1];Qin, Xiao-ming[1]

机构：[1]Guangdong Ocean Univ, Coll Food Sci & Technol, Guangdong Prov Key Lab Aquat Prod Proc & Safety, Zhanjiang 524088, Guangdong, Peoples R China;[2]Huaihua Univ, Coll Biol & Food Engn, Huaihua 418008, Hunan, Peoples R China

年份：2019

卷号：86

起止页码：177

外文期刊名：PROCESS BIOCHEMISTRY

收录：SCI-EXPANDED(收录号：WOS:000494882900022)、、WOS

语种：英文

外文关键词：Camellia nitidissima Chi flower extracts; alpha-Amylase; alpha-Glucosidase; Inhibition

外文摘要：We optimized four addition methods for Camellia nitidissima Chi flower extracts (Cnfe). Among four methods, the first (before meals) had the greatest inhibitory effect via binding of Cnfe with starch. Cnfe bound starch, and reduced inhibition of the enzymes. The higher binding percentage of Cnfe and the substrate starch led to less free Cnfe interaction with enzymes in solution. To determine the underlying inhibitory mechanism(s), we used enzymatic inhibition kinetics, fluorescence quenching and circular dichroism spectroscopies. We found that Cnfe possessed potential inhibitory activity against alpha-amylase (IC50 300 mu g/mL, K-i 162 mu g/mL, static quenching constant K-FQ 1.5 mL/mg) and alpha-glucosidase (45 mu g/mL, 89 mu g/mL and 8.5 mL/mg). Cnfe changed the microenvironment and conformation of the enzyme, making it a better digestive enzyme inhibitor. These experimental results suggest that Cnfe has the potential to control blood sugar, and that it may be used to improve diabetes by reducing postprandial hyperglycemia. Cnfe should be taken before meals and separately from foods with higher binding intensities.