The effect of liver metastases on clinical efficacy of first-line programmed death-1 inhibitor plus chemotherapy in esophageal squamous cell carcinoma: A post hoc analysis of ASTRUM-007 and meta-analysis.

OBJECTIVE: To explore the efficacy of serplulimab plus chemotherapy in esophageal squamous cell carcinoma (ESCC) patients with liver metastases. METHODS: A post hoc exploratory analysis of ASTRUM-007 study was performed, focusing on the association between the liver metastases status and the clinical outcomes. A systematic literature search of electronic databases was conducted to identify eligible randomized controlled trials for the meta-analysis. Study-level pooled analyses of hazard ratios (HRs) for PFS according to liver metastases were performed. RESULTS: The post hoc analysis of ASTRUM-007 showed that although patients with liver metastases had a worse prognosis comparing with the non-liver metastases patients in both treatment arms (serplulimab plus chemotherapy arm: median PFS, 5.7 vs. 6.6 months, HR 1.57 [95% CI, 1.15-2.13]; median OS, 13.7 vs. 15.3 months, HR 1.48 [95% CI, 1.09-1.98]; placebo plus chemotherapy arm: median PFS, 4.3 vs. 5.5 months, HR 1.58 [95% CI, 1.01-2.39]; median OS, 10.3 vs. 11.2 months, HR 1.32 [95% CI, 0.84-2.00]), OS and PFS benefits derived from serplulimab plus chemotherapy versus placebo plus chemotherapy in this study were observed in both patients with liver metastases (HR of PFS: 0.60; 95% CI, 0.37-0.97; HR of OS: 0.68; 95% CI, 0.43-1.11) and the non-liver metastases patients (HR of PFS: 0.62; 95% CI, 0.49-0.80; HR of OS: 0.69; 95% CI, 0.55-0.87) with similar magnitude. Three randomized controlled trials were included in the meta-analysis. Pooled HRs demonstrated that the addition of anti-PD-1 antibodies significantly improved PFS compared to chemotherapy alone regardless of liver metastases status. CONCLUSIONS: This study reveals that the presence of liver metastases is a poor prognostic factor but does not affect the improvements in both PFS and OS brought by adding PD-1 blockade to chemotherapy in ESCC patients. Predictive biomarkers for survival in these patients warrant further investigation.

Colorimetric and Photothermal Dual-Modal Switching Lateral Flow Immunoassay Based on a Forced Dispersion Prussian Blue Nanocomposite for the Sensitive Detection of Prostate-Specific Antigen.

Prostate-specific antigen (PSA) is a key marker for a prostate cancer diagnosis. The low sensitivity of traditional lateral flow immunoassay (LFIA) methods makes them unsuitable for point-of-care testing. Herein, we designed a nanozyme by in situ growth of Prussian blue (PB) within the pores of dendritic mesoporous silica (DMSN). The PB was forcibly dispersed into the pores of DMSN, leading to an increase in exposed active sites. Consequently, the atom utilization is enhanced, resulting in superior peroxidase (POD)-like activity compared to that of cubic PB. Antibody-modified DMSN@PB nanozymes serve as immunological probes in an enzymatic-enhanced colorimetric and photothermal dual-signal LFIA for PSA detection. After systematic optimization, the LFIA based on DMSN@PB successfully achieves a 4-fold amplification of the colorimetric signal within 7 min through catalytic oxidation of the chromogenic substrate by POD-like activity. Moreover, DMSN@PB exhibits an excellent photothermal conversion ability under 808 nm laser irradiation. Accordingly, photothermal signals are introduced to improve the anti-interference ability and sensitivity of LFIA, exhibiting a wide linear range (1-40 ng mL-1) and a low PSA detection limit (0.202 ng mL-1), which satisfies the early detection level of prostate cancer. This research provides a more accurate and reliable visualization analysis methodology for the early diagnosis of prostate cancer.

Radiation and male reproductive system: Damage and protection.

Male fertility has been declining in recent decades, and a growing body of research points to environmental and lifestyle factors as the cause. The widespread use of radiation technology may result in more people affected by male infertility, as it is well established that radiation can cause reproductive impairment in men. This article provides a review of radiation-induced damage to male reproduction, and the effects of damage mechanisms and pharmacotherapy. It is hoped that this review will contribute to the understanding of the effects of radiation on male reproduction, and provide information for research into drugs that can protect the reproductive health of males.

Mannose enhances intestinal immune barrier function and dextran sulfate sodium salt-induced colitis in mice by regulating intestinal microbiota.

Background: Inflammatory bowel disease (IBD) greatly affects human quality of life. Mannose has been reported to be used to treat IBD, but the mechanism is currently unknown. Methods: C57/BL mice were used as research subjects, and the mouse acute colitis model was induced using dextran sulfate sodium salt (DSS). After oral administration of mannose, the body weights and disease activity index (DAI) scores of the mice were observed. The colon lengths, histopathological sections, fecal content microbial sequencing, colon epithelial inflammatory genes, and tight junction protein Occludin-1 expression levels were measured. We further used the feces of mice that had been orally administered mannose to perform fecal bacterial transplantation on the mice with DSS-induced colitis and detected the colitis-related indicators. Results: Oral administration of mannose increased body weights and colon lengths and reduced DAI scores in mice with DSS-induced colitis. In addition, it reduced the expression of colon inflammatory genes and the levels of serum inflammatory factors (TNF-α, IL-6, and IL-1ß), further enhancing the expression level of the colonic Occludin-1 protein and alleviating the toxic response of DSS to the intestinal epithelium of the mice. In addition, gut microbial sequencing revealed that mannose increased the abundance and diversity of intestinal flora. Additionally, after using the feces of the mannose-treated mice to perform fecal bacterial transplantation on the mice with DSS-induced colitis, they showed the same phenotype as the mannose-treated mice, and both of them alleviated the intestinal toxic reaction induced by the DSS. It also reduced the expression of intestinal inflammatory genes (TNF-α, IL-6, and IL-1ß) and enhanced the expression level of the colonic Occludin-1 protein. Conclusion: Mannose can treat DSS-induced colitis in mice, possibly by regulating intestinal microorganisms to enhance the intestinal immune barrier function and reduce the intestinal inflammatory response.

Mesenchymal Stem Cell Derived Exosomes Repair Uterine Injury by Targeting Transforming Growth Factor-ß Signaling.

Intrauterine adhesions (IUA) refer to adhesions within the uterine cavity and cervix caused by injuries from uterine surgery. They are a significant cause of female infertility. Exosomes derived from mesenchymal stem cells (MSCs) play an active role in the treatment of IUA. However, the mechanism by which they reduce fibrosis in the damaged endometrium remains unclear. In this paper, we demonstrate that exosomes derived from placental mesenchymal stem cells (PMSCs) can restore uterine functions and improve the fertility rate of injured animals. This is achieved by promoting cell proliferation, increasing endometrial thickness, and reversing fibrosis. Regarding the molecular mechanism behind these therapeutic effects, we identify three specific miRNAs, namely, miR-125b-5p, miR-30c-5p, and miR-23a-3p, enriched in PMSC-exosomes, as the key players in the treatment of IUA. Specifically, miR-125b-5p/miR-30c-5p and miR-23a-3p inhibit the expression of smad2 and smad3 by targeting their 3'-untranslated regions, resulting in the downregulation of the transforming growth factor-ß (TGF-ß)/smad signaling pathway and the reversal of fibrosis. Notably, the safety of PMSC-exosomes in intrauterine treatment was also been confirmed. In conclusion, we illustrate that exosomes derived from PMSCs possess the capability to repair endometrial damage and enhance fertility in injured animals by regulating the TGF-ß/smad pathway via miR-125b-5p, miR-30c-5p, and miR-23a-3p. This provides insights into the precision treatment of IUA through exosome-based cell-free therapy.

A global phase 3 study of serplulimab plus chemotherapy as first-line treatment for advanced squamous non-small-cell lung cancer (ASTRUM-004).

Combining immunotherapy with chemotherapy can provide improved survival in advanced squamous non-small-cell lung cancer (NSCLC) patients without targetable gene alterations. 537 previously untreated patients with stage IIIB/IIIC or IV squamous NSCLC without targetable gene alterations were enrolled and randomized (2:1) to receive serplulimab 4.5 mg/kg or placebo, both in combination with nab-paclitaxel and carboplatin, intravenously in 3-week cycles. The primary endpoint of progression-free survival (PFS) was met at the first interim analysis. At the second interim analysis, PFS benefit was maintained in serplulimab-chemotherapy group (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.42-0.67). At the final analysis, serplulimab-chemotherapy significantly improved median OS compared to placebo-chemotherapy (HR 0.73, 95% CI 0.58-0.93; p = 0.010). Grade ≥3 serplulimab or placebo-related adverse events occurred in 126 (35.2%) and 58 (32.4%) patients, respectively. Our results demonstrate that adding serplulimab to chemotherapy significantly improves survival in advanced squamous NSCLC patients, with manageable safety.

A modified nucleoside O6-methyl-2'-deoxyguanosine-5'-triphosphate exhibits anti-glioblastoma activity in a caspase-independent manner.

Resistance to temozolomide (TMZ), the frontline chemotherapeutic agent for glioblastoma (GBM), has emerged as a formidable obstacle, underscoring the imperative to identify alternative therapeutic strategies to improve patient outcomes. In this study, we comprehensively evaluated a novel agent, O6-methyl-2'-deoxyguanosine-5'-triphosphate (O6-methyl-dGTP) for its anti-GBM activity both in vitro and in vivo. Notably, O6-methyl-dGTP exhibited pronounced cytotoxicity against GBM cells, including those resistant to TMZ and overexpressing O6-methylguanine-DNA methyltransferase (MGMT). Mechanistic investigations revealed that O6-methyl-dGTP could be incorporated into genomic DNA, disrupting nucleotide pools balance, and inducing replication stress, resulting in S-phase arrest and DNA damage. The compound exerted its anti-tumor properties through the activation of AIF-mediated apoptosis and the parthanatos pathway. In vivo studies using U251 and Ln229 cell xenografts supported the robust tumor-inhibitory capacity of O6-methyl-dGTP. In an orthotopic transplantation model with U87MG cells, O6-methyl-dGTP showcased marginally superior tumor-suppressive activity compared to TMZ. In summary, our research, for the first time, underscores the potential of O6-methyl-dGTP as an effective candidate against GBM, laying a robust scientific groundwork for its potential clinical adoption in GBM treatment regimens.

MDM2-p53 mediate a miR-181c-3p/LIF axis to regulate low dose-rate radiation-induced DNA damage in human B lymphocytes.

PURPOSE: Prolonged exposure to low dose-rate radiation (LDRR) is of growing concern to public health. Recent evidences indicates that LDRR causes deleterious health effects and is closely related to miRNAs. The aim of our study is to investigate the relationship between miRNAs and DNA damage caused by LDRR. MATERIALS AND METHODS: In this study, we irradiated C57BL/6J mice with 12.5µGy/h dose of γ ray emitted from uranium ore for 8 h a day for 120 days at a total dose of 12 mGy, and identified differentially expressed miRNAs from the mice long-term exposed to LDRR through isolating serum RNAs, constructing small RNA library, Illumina sequencing. To further investigate the role of differential miRNA under LDRR，we first built DNA damage model in Immortal B cells irradiated with 12.5µGy/h dose of γ ray for 28 days at a total dose of 9.4 mGy. Then, we chose the highly conserved miR-181c-3p among 12 miRNA and its mechanism in alleviating DNA damage induced by LDRR was studied by transfection, quantitative PCR, luciferase assay, and Western blot. RESULTS AND CONCLUSIONS: We have found that 12 differentially expressed miRNAs including miR-181c-3p in serum isolated from irradiated mice. Analysis of GO and KEGG indicated that target genes of theses 12 miRNA enriched in pathways related to membrane, protein binding and cancer. Long-term exposure to LDRR induced upregulation of gamma-H2A histone family member X (γ-H2AX) expression, a classical biomarker for DNA damage in B cells. miR-181c-3p inhibited Leukemia inhibitory factor (LIF) expression via combining its 3'UTR. LIF, MDM2, p53, and p-p53-s6 were upregulated after exposure to LDRR. In irradiated B cells, Transfection of miR-181c-3p reduced γ-H2AX expression and suppressed LIF and MDM2 protein levels, whereas p-p53-s6 expression was increased. As expected, the effect of LIF inhibition on irradiated B cells was similar to miR-181c-3p overexpression. Our results suggest that LDRR alters miRNA expression and induces DNA damage. Furthermore, miR-181c-3p can alleviate LDRR-induced DNA damage via the LIF/MDM2/p-p53-s6 pathway in human B lymphocytes. This could provide the basis for prevention and treatment of LDRR injury.

Identification and target of action of cholecystokinin-releasing peptides from simulated digestion hydrolysate of wheat protein.

BACKGROUND: Wheat protein intake leads to improved appetite control. However, the active components causing appetite in wheat have not been fully clarified. Gut cholecystokinin (CCK) plays a vital role in appetite control. This study aimed to investigate the ability of wheat protein digest (WPD) to stimulate CCK secretion and clarify the active components and target of action. RESULTS: WPD was prepared by a simulated gastrointestinal digestion model. WPD treatment with a concentration of 5 mg mL-1 significantly stimulated CCK secretion in enteroendocrine STC-1 cells (P < 0.05). Furthermore, oral gavage with WPD in mice significantly increased plasma CCK level at 60 min (P < 0.01). Preparative C18 column separation was used to isolate peptide fractions associated with CCK secretion and peptide sequences were identified by liquid chromatography-tandem mass spectrometry. A new CCK-releasing peptide, RYIVPL, that potently stimulated CCK secretion was successfully identified. After pretreatment with a specific calcium-sensing receptor (CaSR) antagonist, NPS 2143, CCK secretion induced by WPD or RYIVPL was greatly suppressed, suggesting that CaSR was involved in WPD- or RYIVPL-induced CCK secretion. CONCLUSION: The present study demonstrated that WPD has an ability to stimulate CCK secretion in vitro and in vivo, and determined that peptide RYIVPL in WPD could stimulate CCK secretion through CaSR. © 2023 Society of Chemical Industry.

Surgical flip-dislocation of the bicolumnar approach without olecranon osteotomy versus olecranon osteotomy in type AO 13C3 distal humeral fracture: a matched-cohort study.

BACKGROUND: Our experience with the surgical flip-dislocation of the bicolumnar (SFDB) approach for type AO 13C3 humeral fractures indicates that this surgical approach can be performed safely and effectively in appropriately selected patients. We aimed to evaluate the clinical outcomes of the SFDB approach without olecranon osteotomy (OO) for type AO 13C3 distal humeral fractures. METHODS: We retrospectively reviewed 65 cases of type AO 13C3 distal humeral fractures treated between April 2008 and July 2018; 33 patients were treated with the SFDB approach, and the remaining were treated with OO. Propensity score matching was used to control for sex, age, and the American Society of Anesthesiology score. Elbow pain, range of motion, stability, and function were assessed using the Mayo Elbow Performance Index (MEPI) and the Disabilities of the Arm, Shoulder, and Hand questionnaire. Clinical complications, reoperation rates, and radiographic results were compared between the groups. RESULTS: Operative time and blood loss were significantly lower in the SFDB group than in the OO group (P = 0.001, P = 0.002, respectively). At the final follow-up, the mean postoperative MEPI did not significantly differ between the groups (P = 0.628). According to Morrey's criteria, a typical functional range of elbow motion was achieved in 12 and 15 patients in the SFDB and OO groups, respectively. CONCLUSIONS: The SFDB approach achieves superior exposure of the articular surface without injury to the extensor mechanism in type 13C3 articular surface fracture treatment. This approach also results in good early functional recovery and clinical outcomes, with a low risk of complications.

Characteristics and antioxidant activity of Maillard reaction products from ß-lactoglobulin and isomaltooligosaccharide.

Starch-derived isomaltooligosaccharide (IMO) is potentially used as prebiotics in infant formulas. Given that they are non-digestible carbohydrates rich in reducing substrates, it's crucial to understand if they can interact with ß-lactoglobulin (ß-LG) to produce Maillard reaction products (MRPs) and how these MRPs might influence the nutritional properties of ß-LG. In our investigation, we conjugated ß-LG with IMO to generate MRPs. Using a spectrophotometer, we identified the intermediates and assessed browning. We also evaluated changes in free amino groups and structural alterations. The antioxidative activity of the resulting compounds was assessed using DPPH and the ferric reducing/antioxidant power (FRAP) assay. Our data revealed increased visible absorption and fluorescence intensity, suggesting the formation of intermediate and browning products. The content of free amino groups diminished by 33%, supporting the conjugation of IMO with ß-LG. However, circular dichroism results indicated no significant alterations in the secondary structure of ß-LG. Notably, the ß-LG-IMO MRPs exhibited enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing/antioxidant power (FRAP). The findings provide insights into the characteristics and antioxidant activities of the conjugates derived from IMO and dairy protein in infant formula.

[Diagnosis and treatment of pediatric cervical bronchogenic cyst].

Objective:To investigate the clinical characteristics and surgical treatment outcomes of children with cervical bronchogenic cysts. Methods:A retrospective study of 6 pediatric patients with bronchogenic cysts in the neck region treated in our hospital during 2014 to 2020 was performed. All children underwent complete resection of cervical mass under general anesthesia. Results:There were 6 children, aged from 1 to 5 years, with a median of 2.25 years. There were 3 males and 3 females. The lesions were located on the left neck in 3 cases, the midline neck in 2 cases and the right neck in 1 case. The clinical manifestations were painless mass in 5 cases and recurrent neck infection in 1 case. The size of the mass ranged from 2.1 to 7.5 cm. There was no characteristic clinical or imaging features of bronchogenic cysts. Misdiagnosed as lymphangioma in 3 cases, thyroglossal cyst in 2 cases and piriform fistula in 1 case. The follow-up ranged from 1.50 to 7.75 years, with a median of 4.13 years. All 6 children had no recurrence or complications. Conclusion:Although rare, bronchogenic cysts should be considered in the differential diagnosis of cervical cystic masses in children. Surgery is the most effective way to treat cervical bronchogenic cyst, and histopathological examination is the gold standard for diagnosis.

Milk-derived small extracellular vesicles: a new perspective on dairy nutrition.

Milk contains bioactive compounds that have multiple essential benefits. Milk-derived small extracellular vesicles (M-sEVs) have emerged as novel bioactive milk components with various beneficial biological functions and broad applications. The M-sEVs from different mammalian sources have similar composition and bioactive functions. The digestive stability and biocompatibility of the M-sEVs provide a good foundation for their physiological functions. Evidence suggests that M-sEVs promote intestinal, immune, bone, neural, liver, and heart health and show therapeutic effects against cancer, indicating their potential for use in functional foods. In addition, M-sEVs can be developed as natural delivery carriers owing to their superior structural characteristics. Further studies are needed to elucidate the relationship between the specific components and functions of M-sEVs, standardize their extraction processes, and refine relevant clinical trials to advance the future applications of M-sEVs. This review summarizes the structure and composition of M-sEVs isolated from different milk sources and discusses several common extraction methods. Since the introduction of M-sEVs for digestion and absorption, studies have been conducted on their biological functions. Furthermore, we outline the theoretical industrial production route, potential application scenarios of M-sEVs, and the future perspectives of M-sEV research.

Overexpressing GmCGS2 Improves Total Amino Acid and Protein Content in Soybean Seed.

Soybean (Glycine max (L.) Merr.) is an important source of plant protein, the nutritional quality of which is considerably affected by the content of the sulfur-containing amino acid, methionine (Met). To improve the quality of soybean protein and increase the Met content in seeds, soybean cystathionine γ-synthase 2 (GmCGS2), the first unique enzyme in Met biosynthesis, was overexpressed in the soybean cultivar "Jack", producing three transgenic lines (OE3, OE4, and OE10). We detected a considerable increase in the content of free Met and other free amino acids in the developing seeds of the three transgenic lines at the 15th and 75th days after flowering (15D and 75D). In addition, transcriptome analysis showed that the expression of genes related to Met biosynthesis from the aspartate-family pathway and S-methyl Met cycle was promoted in developing green seeds of OE10. Ultimately, the accumulation of total amino acids and soluble proteins in transgenic mature seeds was promoted. Altogether, these results indicated that GmCGS2 plays an important role in Met biosynthesis, by providing a basis for improving the nutritional quality of soybean seeds.

Modified Stabilization Test to Diagnose Chronic Syndesmotic Injuries Based on Posture Control.

BACKGROUND: To propose and validate a modified noninvasive method for the diagnosis of chronic syndesmotic injuries. METHODS: This study included 16 patients with chronic ankle instability. Herein, we propose the Modified Stabilization Test, a new measurement for use in the diagnosis of chronic syndesmotic injury, as determined by wearing a 60-kPa pneumatic brace. The test combines the center of pressure and sensory organization test to measure postural control. For comparison, we also measured the tibiofibular clear space, tibiofibular overlap, and medial clear space using anteroposterior radiograph; a line marked horizontally above the tibial plaque using computed tomography (CT) to measure the syndesmotic gap and fibular rotation angle; and magnetic resonance imaging (MRI) scans to determine the presence of the λ sign. The distance of syndesmosis was confirmed in 16 individuals through arthroscopy, and the results of the examination were used to determine the diagnostic efficacy of each index. RESULTS: Receiver operating characteristic curve analysis revealed that the optimal cut-off value, sensitivity, and specificity of the Modified Stabilization Test for the diagnosis of chronic syndesmotic injuries were 0.80, 100%, and 87.5%, respectively. The area under the curve (AUC) of the Modified Stabilization Test was 0.906 (95% CI 0.656, 0.993; P < .001), which was superior to imaging indices such as radiography, CT, and MRI (AUC = 0.516-0.891). CONCLUSION: We developed the Modified Stabilization Test-a noninvasive diagnostic tool for the screening of chronic syndesmotic injuries. The test showed high sensitivity and specificity for the identification of chronic syndesmotic injuries and is helpful in the identification of chronic syndesmotic injuries. LEVEL OF EVIDENCE: Level II, diagnostic-investigating a diagnostic test.

Role of cancer-associated fibroblasts in colorectal cancer and their potential as therapeutic targets.

Cancer-associated fibroblasts (CAFs) are mesenchymal cells in the tumor microenvironment (TME). CAFs are the most abundant cellular components in the TME of solid tumors. They affect the progression and course of chemotherapy and radiotherapy in various types of tumors including colorectal cancer (CRC). CAFs can promote tumor proliferation, invasion, and metastasis; protect tumor cells from immune surveillance; and resist tumor cell apoptosis caused by chemotherapy, resulting in drug resistance to chemotherapy. In recent years, researchers have become increasingly interested CAF functions and have conducted extensive research. However, compared to other types of malignancies, our understanding of the interaction between CRC cells and CAFs remains limited. Therefore, we searched the relevant literature published in the past 10 years, and reviewed the origin, biological characteristics, heterogeneity, role in the TME, and potential therapeutic targets of CAFs, to aid future research on CAFs and tumors.

Combined Nano-Vector Mediated-Transfer to Suppress HIV-1 Infection with Targeted Antibodies in-vitro.

Introduction: Broadly neutralizing antibodies (bNAbs) have the ability to neutralize a considerable breadth of genetically diverse human immunodeficiency virus (HIV) strains. Passive immunization can potentially provide protection against HIV infection in animal models. However, the direct antibody infusion effect is limited due to the short half-life and deficient immunogenicity of the antibody. As an alternative strategy, we propose the use of nano viral vectors, specifically the adeno-associated virus (AAV), to continuously and systematically produce bNAbs against HIV. Methods: Plasmids expressing bNAbs PG9, PG16, 10E8, and NIH45-46 antibodies were constructed, targeting three different epitopes of HIV. Additionally, the bNAbs gene mediated by rAAV8 was administered to generate long-term expression with a single injection. We established both single and combined immunization groups. The neutralizing activity of antibodies expressed in mice sera was subsequently evaluated. Results: The expression of bNAbs in BALB/c mice can last for >24 weeks after a single intramuscular injection of rAAV8. Further studies show that neutralization of the HIV pseudovirus by sera from co-immunized mice with rAAV8 expressing 10E8 and PG16 was enhanced compared with mice immunized with 10E8 or PG16 alone. Conclusion: The prolonged expression of neutralizing antibodies can be maintained over long periods in BALB/c mice. This combined immunization is a promising candidate strategy for HIV treatment.

In vitro gastrointestinal digestion of buckwheat (Fagopyrum esculentum Moench) protein: release and structural characteristics of novel bioactive peptides stimulating gut cholecystokinin secretion.

Satiety hormone cholecystokinin (CCK) plays a vital role in appetite inhibition. Its secretion is regulated by dietary components. The search for bioactive compounds that stimulate CCK secretion is currently an active area of research. The objective of this study was to evaluate the ability of buckwheat (Fagopyrum esculentum Moench) protein digest (BPD) to stimulate CCK secretion in vitro and in vivo and clarify the structural characteristics of peptides stimulating CCK secretion. BPD was prepared by an in vitro gastrointestinal digestion model. The relative molecular weight of BPD was <10 000 Da, and peptides with <3000 Da accounted for 70%. BPD was rich in essential amino acids Lys, Leu, and Val but lacked sulfur amino acids Met and Cys. It had a stimulatory effect on CCK secretion in vitro and in vivo. Chromatographic separation was performed to isolate peptide fractions involved in CCK secretion, and five novel CCK-releasing peptides including QFDLDD, PAFKEEHL, SFHFPI, IPPLFP, and RVTVQPDS were successfully identified. A sequence length range of 6-8 and marked hydrophobicity (18-28) were observed among the most CCK-releasing peptides. The present study demonstrated for the first time that BPD could stimulate CCK secretion and clarify the structural characteristics of bioactive peptides having CCK secretagogue activity in BPD.

In vitro gastrointestinal digestion of highland barley protein: identification and characterization of novel bioactive peptides involved in gut cholecystokinin secretion.

BACKGROUND: The satiety hormone cholecystokinin (CCK) plays an important role in food intake inhibition. Its secretion is regulated by dietary components. The search for bioactive compounds that induce CCK secretion is currently an active area of research. The objective of this study was to evaluate the ability of highland barley protein digest (HBPD) to stimulate CCK secretion in vitro and in vivo and identify the responsible peptide sequences. RESULTS: HBPD was prepared by in vitro gastrointestinal digestion model. Peptides of <1000 Da in HBPD accounted for 82%. HBPD was rich in essential amino acids Leu, Phe and Val, but lack in sulfur amino acids Met and Cys. HBPD treatment at a concentration of 5 mg mL-1 significantly stimulated CCK secretion from enteroendocrine STC-1 cells (P < 0.05). Moreover, oral gavage with HBPD in mice significantly increased plasma CCK level. Chromatographic separation was performed to isolate peptide fractions involved in CCK secretion and peptide sequence was determined by ultra-performance liquid chromatography-tandem mass spectrometry. Two novel CCK-releasing peptides, PDLP and YRIVPL, were pointed out for their outstanding CCK secretagogue activity. CONCLUSION: This study demonstrated for the first time that HBPD had an ability to stimulate CCK secretion in vitro and in vivo and determined the bioactive peptides exerting CCK secretagogue activity in HBPD. © 2023 Society of Chemical Industry.