Characterization of the structure, antioxidant activity and hypoglycemic activity of soy (Glycine max L.) protein hydrolysates.

This study aimed to hydrolyze soy isolate protein (SPI) using five enzymes (alcalase, pepsin, trypsin, papain, and bromelain) in order to obtain five enzymatic hydrolysates and to elucidate the effect of enzymes on structural and biological activities of the resulting hydrolysates. The antioxidant and hypoglycemic activities of the soy protein isolate hydrolysates (SPIEHs) were evaluated through in silico analysis, revealing that the alcalase hydrolysate exhibited the highest potential, followed by the papain and bromelain hydrolysates. Subsequently, the degree of hydrolysis (DH), molecular weight distribution (MWD), amino acid composition, structure, antioxidant activities, and hypoglycemic activity in vitro of SPIEHs were analyzed. After enzymatic treatment, the particle size, polymer dispersity index (PDI), ζ-potentials, ß-sheet content and α-helix content of SPIEHs was decreased, and the maximum emission wavelength of all SPIEHs exhibited red-shifted, which all suggesting the structure of SPIEHs was unfolded. More total amino acids (TAAs), aromatic amino acids (AAAs), and hydrophobic amino acids (HAAs) were found in alcalase hydrolysate. For 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, metal ion chelating activity, α-glucosidase inhibitory activity and α-amylase inhibitory activity, alcalase hydrolysate had the lowest IC50; alcalase hydrolysate and papain hydrolysate had the lowest IC50 for hydroxyl radical scavenging activity. Physiological activity of SPIEHs was evaluated thoroughly by 5-Axe cobweb charts, and the results revealed that alcalase hydrolysate exhibited the greatest biological activities.

[Antidepressant mechanism of Shugan Lipi recipe in regulating tryptophan metabolism and its common pharmacodynamic substances].

This article is to explore the antidepressant mechanism of Shugan Lipi recipe in regulating tryptophan metabolism,and to find out their common pharmacodynamic substances. UPLC-Q-TOF-MS technology was used to establish fingerprints of Shugan Lipi recipe,and 124 components were identified. The depressed mouse model was replicated by triple-one multiple stress method. Chaihu Shugan Powder,Sini Powder and Xiaoyao Powder were administered in groups to observe the changes in body weight and behavior of the mice. The results showed that compared with the model group,the body weight,sucrose preference percentage and autonomous activity behavior of each administration group were improved. Among them,the effect of Chaihu Shugan Powder was better than that of Sini Powder and Xiaoyao Powder. LC-MS/MS method was used to determine the contents of 5-hydroxytryptamine( 5-HT),kynurenine( KYN) and tryptophan( TPP) in blood,liver,brain,colon and other tissues,as well as TDO enzyme activity in liver. Western blot and RT-PCR were used to detect the protein and gene expression of TDO enzyme,respectively. It was found that the three prescriptions increased the ratio of 5-HT/KYN in different degrees,decreased the ratio of KYN/TRP in liver,colon and brain,and decreased the expression level and activity of TDO enzyme in liver. The order of their ability to regulate tryptophan metabolism was Chaihu Shugan Powder>Sini Powder>Xiaoyao Powder. In addition,the correlation between the chromatographic peaks in the fingerprints of Shugan Lipi recipes and the pharmacodynamic indexes of tryptophan metabolism was analyzed by the grey relation analysis. The grey relation analysis found that the chemical components with the highest correlation with tryptophan metabolism were mainly from Paeoniae Radix Alba,Citri Reticulatae Pericarpium,Aurantii Fructus Immaturus and Aurantii Fructus. UPLC-Q-TOF-MS was used to analyze the migration components in the plasma of mice after administration of Shugan Lipi recipe,and to verify the common pharmacodynamic substances of Shugan Lipi recipe. The migration of these detected components in plasma was studied,and a total of 18 prototype components and 36 metabolites were identified. Therefore,it was believed that Chaihu Shugan Powder,Sini Powder and Xiaoyao Powder could play an antidepressant role by reducing the expression of TDO enzyme in the liver and regulating the metabolism of tryptophan.The components contained in Paeoniae Radix Alba,Citri Reticulatae Pericarpium,Aurantii Fructus Immaturus and Aurantii Fructus were the common pharmacodynamic substances of Shugan Lipi recipe,which played an important role in regulating tryptophan metabolism.