The structural and functional properties of hemp protein isolate-epigallocatechin-3-gallate biopolymer covalent complex during heating.

BACKGROUND: It is well known that hemp proteins have the disadvantages of poor solubility and poor emulsification. To improve these shortcomings, an alkali covalent cross-linking method was used to prepare hemp protein isolate-epigallocatechin-3-gallate biopolymer (HPI-EGCG) and the effects of different heat treatment conditions on the structure and emulsifying properties of the HPI-EGCG covalent complex were studied. RESULTS: The secondary and tertiary structures, solubility, and emulsification ability of the HPI-EGCG complexes were evaluated using particle size, zeta potential, circular dichroism (CD), and fluorescence spectroscopy indices. The results showed that the absolute value of zeta potential of HPI-EGCG covalent complex was the largest, 18.6 mV, and the maximum binding amount of HPI to EGCG was 29.18 µmol g-1 . Under heat treatment at 25-35 °C, the α-helix content was reduced from 1.87% to 0%, and the ß-helix content was reduced from 82.79% to 0% after the covalent binding of HPI and EGCG. The solubility and emulsification properties of the HPI-EGCG covalent complexes were improved significantly, and the emulsification activity index (EAI) and emulsion stability index (ESI) were increased by 2.77-fold and 1.21-fold, respectively. CONCLUSION: A new HPI-EGCG covalent complex was developed in this study to provide a theoretical basis for the application of HPI-EGCG in food industry. © 2023 Society of Chemical Industry.

Effects of soy protein isolate interaction with brown rice starch on the multiscale structure of brown rice bread.

BACKGROUND: Gluten-free bread (GFB) has technical bottlenecks such as hard texture, rough taste and low nutrition in practical production. In order to solve these problems, this study used germinated brown rice starch as the main raw material, and investigated the effects of soybean isolate protein (SPI) on the multiscale structure of germinated brown rice starch and bread quality. RESULTS: A gluten-free rice bread process simulation system was established, and the interaction between SPI and starch in the simulation system was characterized. The result shows that the interaction forces between SPI and germinated brown rice starch were mainly represented by hydrogen bonds, and with the addition of SPI, the crystallinity of starch showed a downward trend. At the same time, when the amount of SPI was 3%, the appearance quality was the best and the specific volume of bread was 1.08 mL g-1. When the amount of SPI was 6%, the texture quality was the best. Compared with the bread without SPI, the hardness of the bread with 6% SPI was reduced by 0.13 times, the springiness was increased by 0.03 times, the color was the most vibrant, the L* value being 1.02 times the original, and the baking loss was reduced to 0.98 times the original. CONCLUSIONS: The interaction force between SPI and germinated brown rice starch and its effect on bread quality were clarified, and these results inform choices about providing a theoretical basis for the subsequent development of higher-quality GFB. © 2024 Society of Chemical Industry.

Characterization of structural and functional properties of soy protein isolate and sodium alginate interpenetrating polymer network hydrogels.

BACKGROUND: This study used enzymatic and Ca2+ cross-linking methods to prepare edible soy protein isolate (SPI) and sodium alginate (SA) interpenetrating polymer network hydrogels to overcome the disadvantages of traditional interpenetrating polymer network (IPN) hydrogels, such as poor performance, high toxicity, and inedibility. The influence of changes in SPI and SA mass ratio on the performance of SPI-SA IPN hydrogels was investigated. RESULTS: Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the structure of the hydrogels. Texture profile analysis (TPA), rheological properties, swelling rate, and Cell Counting Kit-8 (CCK-8) were used to evaluate physical and chemical properties and safety. The results showed that, compared with SPI hydrogel, IPN hydrogels had better gel properties and structural stability. As the mass ratio of SPI-SA IPN changed from 1:0.2 to 1:1, the gel network structure of hydrogels also tended to be dense and uniform. The water retention and mechanical properties of these hydrogels, such as storage modulus (G'), loss modulus (G"), and gel hardness increased significantly and were greater than those of the SPI hydrogel. Cytotoxicity tests were also performed. The biocompatibility of these hydrogels was good. CONCLUSIONS: This study proposes a new method to prepare food-grade IPN hydrogels with mechanical properties of SPI and SA, which may have strong potential for the development of new foods. © 2023 Society of Chemical Industry.

Generation of fully pluripotent female murine-induced pluripotent stem cells.

The high quality of induced pluripotent stem cells (iPSCs) has been determined to be high-grade chimeras that are competent for germline transmission, and viable mice can be generated through tetraploid complementation. Most of the high-quality iPSCs described to date have been male. Female iPSCs, especially fully pluripotent female iPSCs, are also essential for clinical applications and scientific research. Here, we show, for the first time, that a gender-mixed induction strategy could lead to a skewed sex ratio of iPSCs. After reprogramming, 50%, 70%, and 90% female initiating mouse embryonic fibroblasts at different male ratios resulted in 14.1 ± 6.8% (P < 0.05), 31.8 ± 5.4% (P < 0.05), and 80.1 ± 2.8% (P < 0.05) female iPSCs, respectively. Furthermore, these female iPSCs had pluripotent properties typical of embryonic stem cells. Importantly, these fully pluripotent female iPSCs could generate viable mice by tetraploid complementation. These findings indicate that high-quality female iPSCs could be derived effectively, and suggest that clinical application of female iPSCs is feasible.

Unveiling the role of PYGB in pancreatic cancer: a novel diagnostic biomarker and gene therapy target.

PURPOSE: Pancreatic cancer (PC) is a highly malignant tumor that poses a severe threat to human health. Brain glycogen phosphorylase (PYGB) breaks down glycogen and provides an energy source for tumor cells. Although PYGB has been reported in several tumors, its role in PC remains unclear. METHODS: We constructed a risk diagnostic model of PC-related genes by WGCNA and LASSO regression and found PYGB, an essential gene in PC. Then, we explored the pro-carcinogenic role of PYGB in PC by in vivo and in vitro experiments. RESULTS: We found that PYGB, SCL2A1, and SLC16A3 had a significant effect on the diagnosis and prognosis of PC, but PYGB had the most significant effect on the prognosis. Pan-cancer analysis showed that PYGB was highly expressed in most of the tumors but had the highest correlation with PC. In TCGA and GEO databases, we found that PYGB was highly expressed in PC tissues and correlated with PC's prognostic and pathological features. Through in vivo and in vitro experiments, we found that high expression of PYGB promoted the proliferation, invasion, and metastasis of PC cells. Through enrichment analysis, we found that PYGB is associated with several key cell biological processes and signaling pathways. In experiments, we validated that the MAPK/ERK pathway is involved in the pro-tumorigenic mechanism of PYGB in PC. CONCLUSION: Our results suggest that PYGB promotes PC cell proliferation, invasion, and metastasis, leading to poor patient prognosis. PYGB gene may be a novel diagnostic biomarker and gene therapy target for PC.

A study on the role of Taxifolin in inducing apoptosis of pancreatic cancer cells: screening results using weighted gene co-expression network analysis.

Pancreatic adenocarcinoma (PAAD) is a frequent malignant tumor in the pancreas. The incomplete understanding of cancer etiology and pathogenesis, as well as the limitations in early detection and diagnostic methods, have created an urgent need for the discovery of new therapeutic targets and drugs to control this disease. As a result, the current therapeutic options are limited. In this study, the weighted gene co-expression network analysis (WGCNA) method was employed to identify key genes associated with the progression and prognosis of pancreatic adenocarcinoma (PAAD) patients in the Gene Expression Profiling Interactive Analysis (GEPIA) database. To identify small molecule drugs with potential in the treatment of pancreatic adenocarcinoma (PAAD), we compared key genes to the reference dataset in the CMAP database. First, we analyzed the antitumor properties of small molecule drugs using cell counting kit-8 (CCK-8), AO/EB and Transwell assays. Subsequently, we integrated network pharmacology with molecular docking to explore the potential mechanisms of the identified molecules' anti-tumor effects. Our findings indicated that the progression and prognosis of PAAD patients in pancreatic cancer were associated with 11 genes, namely, DKK1, S100A2, CDA, KRT6A, ITGA3, GPR87, IL20RB, ZBED2, PMEPA1, CST6, and MUC16. These genes were filtered based on their therapeutic potential through comparing them with the reference dataset in the CMAP database. Taxifolin, a natural small molecule drug with the potential for treating PAAD, was screened by comparing it with the reference dataset in the CMAP database. Cell-based experiments have validated the potential of Taxifolin to facilitate apoptosis in pancreatic cancer cells while restraining their invasion and metastasis. This outcome is believed to be achieved via the HIF-1 signaling pathway. In conclusion, this study provided a theoretical basis for screening genes related to the progression of pancreatic cancer and discovered potentially active small molecule drugs. The experimental results confirm that Taxifolin has the ability to promote apoptosis in pancreatic cancer cells.

Elucidating the interaction mechanism of rice glutelin and soybean 11S globulin using multi-spectroscopy and molecular dynamics simulation methods.

Rice gluten, as the hydrophobic protein, exhibits restricted application value in hydrophilic food, which may be enhanced through interaction with soybean 11S globulin, characterized by favorable functional properties. This study aims at revealing their interaction mechanism via multi-spectroscopy and molecular dynamics simulation. The formation and structural change of rice glutelin-soybean 11S globulin complexes were detected using fluorescence, ultra-violet and circular dichroism spectra. The addition of 11S globulin increased the contents of α-helix, ß-turn and random coil, but decreased ß-sheet content, and the change in secondary structure was correlated with particle size. Moreover, exposure of hydrophobic groups and formation of disulfide bonds occurred in the complexes. Molecular dynamics simulation verified these experimental results through analyses of root mean square deviation and fluctuation, hydrogen bond, secondary structure, and binding free energy analysis. This study contributes to expounding the interaction mechanism of protein and protein from the molecular level.

Identification, in silico selection, and mechanism study of novel antioxidant peptides derived from the rice bran protein hydrolysates.

The work aimed to assess the antioxidant ability and obtain a new antioxidant peptide from rice bran protein. Rice bran protein was hydrolyzed by Alcalase, Neutral, Pepsin, Chymotrypsin, and Trypsin, separately. Trypsin hydrolysate (T-RBPH) showed high Fe2+ chelating activity (IC50, 2.271 ± 0.007 mg/mL), DPPH and hydroxyl radical scavenging ability (IC50, 0.191 ± 0.006 and 1.038 ± 0.034 mg/mL). Moreover, T-RBPH could alleviate the H2O2-induced oxidative damage in Caco-2. The T-RBPH was purified and identified by UF, GF, FPLC, and LC-MS/MS. Finally, 9-amino acid peptide-AFDEGPWPK with low molecular weight (1045.48 Da), high antioxidant activity, good safety, and solubility was screened by in silico method and chemical oxidation determination, and its interaction with Keap1 was also demonstrated. The ORAC and DPPH radical scavenging ability of AFDEGPWPK were 44.16 ± 0.79 and 28.38 ± 0.14 µmol TE/mM. Moreover, the Molecular docking and Western blot (WB) results showed that AFDEGPWPK could enter the binding pocket in the Kelch domain and activate Keap1/Nrf2/HO-1 pathway.

Effects of soybean isoflavone aglycone on osteoporosis in ovariectomized rats.

Postmenopausal osteoporosis is one of the most common metabolic diseases in old women, and supplementing estrogen through bioactive substances is one of the important ways to improve menopausal syndrome. Some studies have confirmed that soybean isoflavone has estrogenic activity, and the main active component of soybean isoflavones is isoflavone aglycones. However, few studies have investigated the improvement effect of high-purity soy isoflavone aglycones on postmenopausal osteoporosis. Thus, the effect of different doses of high-purity soybeans isoflavone aglycone on the ovariectomized female osteoporosis rat model was evaluated by oral gavage. The rats were divided into seven experimental groups including SHAM, OVX, EE, SIHP, AFDP-L, AFDP-M, and AFDP-H, which was administered for 60 days from 30 days after ovariectomy. We collected blood from the abdominal aorta of rats on the 30th, 60th, and 90th days respectively, analyzed its serum biochemistry, and took out the femur for micro-CT imaging and bone microstructure parameter analysis. Results showed that the intervention effect of AFDP-H group on osteoporosis rats at 60 and 90 days was similar to that of EE group, and superior to the OVX group, SIHP group, AFDP-L group, AFDP-M group. The AFDP-H group inhibited the decrease in serum bone markers, bone density, trabeculae quantity, trabeculae thickness, and bone volume fraction, and increased the trabecular separation caused by ovariectomy, thereby significantly improving bone microstructure. It also prevented continuous weight gain and increased cholesterol levels in female rats. This study provided theoretical to application of soybean isoflavone aglycone in the intervention of osteoporosis. and confirmed that could replace chemical synthetic estrogen drugs.

Identification and in silico analysis of novel antioxidant peptides in broken rice protein hydrolysate and its cytoprotective effect against H2O2-induced 2BS cell model.

Broken rice is an important by-product during milling process of rice, which is rich in protein. To increase the value of by-products and search for effective antioxidants, the antioxidant peptides from broken rice protein hydrolysate were separated and identified by ultrafiltration, gel filtration chromatography, fast protein liquid chromatography, and LC-MS/MS in this study. These identified peptides were further screened using a combined in silico and in vitro method and their antioxidant mechanism was explored by Western blot and molecular docking analysis. Ninety-eight peptides were obtained after antioxidant activity-oriented isolation and four novel peptides, SGDWSDIGGR, DFGSEILPR, GEPFPSDPKKQLQ, and GEKGGIPIGIGK, with excellent solubility, safety, and antioxidant activity were synthesized. Among these, SGDWSDIGGR showed good antioxidant activities in the extracellular assay (41.57 µmol TE/g and 29.41 % in ORAC and DPPH assay, respectively.), and it possessed a protective effect against H2O2-injured oxidative stress in 2BS cells in a dose-dependent manner. Furthermore, Western blot and molecular docking results showed that SGDWSDIGGR achieves antioxidant ability by occupying the Nrf2-binding site, activating the Keap1-Nrf2 signaling pathway, and upregulating the expression of antioxidant enzymes. This study extends the rice industry chain and provides insights into the selection and mechanisms research of antioxidant peptides.

Structural characterization and functional properties of CNPP, a byproduct formed during CPP preparation.

Casein nonphosphopeptide (CNPP), a byproduct formed during the preparation of casein phosphopeptide (CPP), is often discarded on a large scale. Although our previous studies have demonstrated the ameliorative effect of CNPP on muscle wasting disorders, its structure-function mechanism is still unclear. Therefore, considering the great influence of structural characteristics on function, this study aims to explain the potential mechanism by characterizing the physicochemical and functional properties of CNPP. The results of structural characterization indicated that CNPP was of low molecular weight and composed of the complete range of amino acids; it was particularly rich in leucine. Compared with casein, CNPP had a lower molecular size and total/free sulfhydryl content (reduced 2.44 and 2.02 µmol/g in CNPP, respectively). Additionally, Fourier transform infrared spectroscopic analysis revealed that enzymatic hydrolysis caused protein unfolding, and the content of ß-turns and random coils reached 50.20% and 10.67%, respectively. Fluorescence-dependent detection of CNPP indicated a reduction of spectral intensity and the occurrence of a red shift. The changes in the structure of CNPP significantly affected its functional characteristics. CNPP has better solubility, foaming, and digestion properties than those of casein and whey protein. Specifically, the foam stability and emulsification properties decreased in the order of casein > CNPP > whey protein. The present study can provide a substantial basis for future application of CNPP as a functional ingredient against sarcopenia.

Hemp (Cannabis sativa L.) Seed Protein-EGCG Conjugates: Covalent Bonding and Functional Research.

In order to make HPI have a wide application prospect in the food industry, we used EGCG to modify HPI. In this study, we prepared different concentrations (1, 2, 3, 4, and 5 mM) of (-)-epigallocatechin gallate (EGCG) covalently linked to HPI and use methods such as particle size analysis, circular dichroism (CD), and three-dimensional fluorescence spectroscopy to study the changes in the structure and functional properties of HPI after being covalently combined with EGCG. The particle size data indicated that the covalent HPI-EGCG complex was larger than native HPI, and the particle size was mainly distributed at about 200 µm. CD and three-dimensional fluorescence spectroscopy analyses showed that the conformation of the protein was changed by conjugation with EGCG. The ß-sheet content decreased from 82.79% to 66.67% after EGCG bound to the protein, and the hydrophobic groups inside the protein were exposed, which increased the hydrophobicity of the protein and changed its conformation. After HPI and 1 mM of EGCG were covalently bonded, the solubility and emulsifying properties of the covalent complex were improved compared with native HPI. These results indicated that HPI-EGCG conjugates can be added in some foods.

Evaluating the efficacy of endoscopic sphincterotomy on biliary-type sphincter of Oddi dysfunction: A retrospective clinical trial.

BACKGROUND: Although endoscopic sphincterotomy (EST) has a positive therapeutic effect on biliary-type sphincter of Oddi dysfunction (SOD), some patients still have little relief after EST, which implies that other functional abdominal pain may also be present with biliary-type SOD and interfere with the diagnosis and treatment of it. AIM: To retrospectively assess EST as a treatment for biliary-type SOD and analyze the importance of functional gastrointestinal disorder (FGID) in guiding endoscopic treatment of SOD. METHODS: Clinical data of 79 patients with biliary-type SOD (type I and type II) treated with EST at Affiliated Hospital of Guizhou Medical University from January 2014 to January 2019 were retrospectively collected to evaluate the clinical therapeutic effect of EST. The significance of relationship between FGID and biliary-type SOD was analyzed. RESULTS: Seventy-nine patients with biliary-type SOD received EST, including 29 type 1 patients and 50 type 2 patients. The verbal rating scale-5 (VRS-5) scores before EST were all 3 or 4 points, and the scores decreased after EST; the difference was statistically significant (P < 0.05). After EST, the serum indexes of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and total bilirubin in biliary-type SOD were significantly lower than before (P < 0.05). After EST, 67 (84.8%) and 8 (10.1%) of the 79 patients with biliary-type SOD had obviously effective (VRS-5 = 0 points) and effective treatment (VRS-5 = 1-2 points), with an overall effectiveness rate of 94.9% (75/79). There was no difference in VRS-5 scores between biliary-type SOD patients with or without FGID before EST (P > 0.05). Of 12 biliary-type SOD (with FGID) patients, 11 had abdominal pain after EST; of 67 biliary-type SOD (without FGID) patients, 0 had abdominal pain after EST. The difference was statistically significant (P <0.05). The 11 biliary-type SOD (with FGID) patients with recurrence of symptoms, the recurrence time was about half a year after the EST, and the symptoms were significantly relieved after regular medical treatment. There were 4 cases of post-endoscopic retrograde cholangiopancreatography pancreatitis (5.1%), and no cholangitis, bleeding or perforation occurred. Patients were followed up for 1 year to 5 years after EST, with an average follow-up time of 2.34 years, and there were no long-term adverse events such as sphincter of Oddi restenosis or cholangitis caused by intestinal bile reflux during the follow-up. CONCLUSION: EST is a safe and effective treatment for SOD. For patients with type I and II SOD combined with FGID, single EST or medical treatment has limited efficacy. It is recommended that EST and medicine be combined to improve the cure rate of such patients.