Search Results (161)

To enhance the screening efficiency of bioactive peptides, an AI-driven approach was employed to screen DPP-IV inhibitory peptides from goat blood proteins by an integrated in silico, in vitro, and machine learning strategy. Furthermore, the inhibitory mechanism of DPP-IV inhibitory peptides was elucidated by kinetics, molecular docking and simulation. Additionally, their in vitro digestive stability was assessed. In silico results revealed that goat blood proteins were promising precursors of DPP-IV inhibitory peptides, while bromelain was the optimal protease. Their peptide sequences were further identified by peptidomics and predicted by self-developed machine learning models (LightGBM) to identify the potent DPP-IV inhibitory peptides. Two novel DPP-IV inhibitory peptides were identified (FPL and FPHFDL). Enzyme kinetics, molecular docking and molecular simulation data indicated that FPL served as a competitive inhibitor, whereas FPHFDL was a non-competitive inhibitor. Overall, the integrative in silico and in vitro strategy is feasible for rapid screening of DPP-IV inhibitory peptides from goat blood proteins. Full article

During gastrointestinal digestion, dietary proteins are hydrolyzed into peptides and free amino acids that modulate enteroendocrine function and satiety-related hormone secretion along the gut–brain axis, thereby contributing to obesity prevention. We investigated whey protein concentrate (WPC) as a source of bioactive peptides and evaluated the effects of its digests on cholecystokinin (CCK) secretion in STC-1 enteroendocrine cells by integrating the standardized INFOGEST in vitro digestion protocol, peptidomics (LC–MS/MS), and in silico bioactivity prediction. In STC-1 cells, the <3 kDa intestinal peptide fraction exhibited the strongest CCK stimulation, positioning these low-molecular-weight peptides as promising bioactive components for satiety modulation and metabolic health applications. Peptidomic analysis of this fraction identified short sequences derived primarily from β-lactoglobulin (β-La) and α-lactalbumin (α-La), enriched in hydrophobic and aromatic residues, including neuropeptide-like sequences containing the Glu–Asn–Ser–Ala–Glu–Pro–Glu (ENSAEPE) motif of β-La f(108–114). In silico bioactivity profiling with MultiPep predicted antihypertensive, angiotensin-converting enzyme (ACE)–inhibitory, antidiabetic, dipeptidyl peptidase-IV (DPP-IV)–inhibitory, antioxidant, antibacterial, and neuropeptide-like activities. Overall, digestion of WPC released low-molecular-weight peptides and amino acids that enhanced CCK secretion in vitro; these findings support their potential use in nutritional strategies to enhance satiety, modulate appetite and energy intake, and improving cardiometabolic health. Full article

Type 2 diabetes mellitus (T2DM) poses a critical global health burden, necessitating safer multi-target therapies. We pioneer the exploration of novel bioactive peptides from Tenebrio molitor larvae—an underexplored, sustainable, and edible insect protein—through proteomics-guided screening and bioassays. Six unique peptides (DK-7, WK-6, GR-7, FK-8, SK-6, and DK-8) demonstrated significant α-glucosidase and dipeptidyl-peptidase IV (DPP-IV) inhibitory effects, and significant glucose consumption enhancement in insulin-resistant HepG2 cells. Molecular docking revealed a binding topology where peptides interacted with α-glucosidase at its active sites (Glu271, Arg643, Arg647, Arg653, Tyr733, Lys765, and Glu767) and with DPP-IV at active residues (Phe357, Tyr547, Trp629, Asp729, and Gln731) through dual hydrogen-bond networks and hydrophobic interactions, establishing a novel inhibition mechanism. We wish to propose that insect-derived biopeptides have potential value as next-generation therapeutics, simultaneously advancing sustainable drug discovery and approximating functional food bioresources to biomedicine. Full article

This study investigated the potential of scale-up mango leaf extract (MLE) as a treatment for diabetes, a global public health concern. MLE was prepared by boiling in water, yielding 12.07% (w/w), with a bioactive mangiferin content of 165.67 ± 10.88 μg/g in the crude powder. Mechanistically, MLE demonstrated a hypoglycemic effect by stimulating glucagon-like peptide-1 (GLP-1) secretion in NCI-H716 L-cells. This occurred through activation of the MAPK signaling pathway, evidenced by increased p-ERK1/2, p-p38, and p-c-Jun expression, and the Wnt signaling pathway, shown by increased β-catenin and decreased GSK-3β and Axin1 expression, consistent with molecular docking. In a type 2 diabetic rat model, MLE administration (40 mg/kg) significantly reduced metabolic parameters, including fasting blood glucose (FBG), body weight, cholesterol (CHOL), triglycerides (TGs), and HbA1c. Notably, MLE lowered serum insulin and the HOMA-IR index, and reduced serum dipeptidyl peptidase-IV (DPP-IV) levels, resulting in increased serum GLP-1, comparable to the drug sitagliptin. These findings suggest that MLE has great potential to lower blood glucose by inducing GLP-1 secretion via MAPKs and Wnt signaling pathways, positioning it as a promising candidate for alternative diabetes treatment or development as a dietary supplement. Full article

The study presents the potential of milkfish frame, a by-product of milkfish processing, as a source of dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant peptides with potential applications in type 2 diabetes management. Proteomic analysis identified key proteins, including 65 kDa warm temperature acclimation protein 1 and myosin heavy chain. In silico prediction (BIOPEP-UWM) guided the selection of proteases for generating DPP-IV inhibitory peptides. Enzymatic hydrolysates were produced and evaluated for bioactivity. Among the treatments, pepsin hydrolysis (2% v/v, 8 h) yielded the highest peptide content (283.64 mg/g), soluble protein (86.46%), and DPP-IV inhibitory activity (68.47%). The resulting milkfish frame pepsin hydrolysate (MFH) was further enhanced through ultrafiltration and simulated gastrointestinal digestion, which improved the DPP-IV inhibitory and antioxidant capacities. Cytotoxicity assays confirmed that MFH (0–100 μg/mL) was non-toxic to FL83B hepatocytes after 24 h. Moreover, treating TNF-α-induced FL83B cells with 10 μg/mL MFHs improved cell viability, reducing the toxicity induced by TNF-α in cells. These findings show that MFHs exhibit promising antidiabetic potential and could serve as natural alternatives to synthetic drugs for type 2 diabetes management. This also demonstrates the valorization of fish processing by-products into functional food ingredients, advancing sustainable approaches in food innovation. Full article

Dipeptidyl-peptidase IV (DPP4) inhibitors have shown potential anti-tumor properties. This study investigates the therapeutic potential of evogliptin, a DPP4 inhibitor, both as a single agent and in combination with temozolomide (TMZ), in glioma models. In vitro studies were performed using U87 and U373 glioma cell lines exposed to different concentrations of TMZ (250, 500 μM) and evogliptin (250, 500 ng/mL), either alone or together, for 24, 48, and 72 h. Cell viability was determined with the MTT assay. In vivo effectiveness was tested in a xenograft mouse model treated with intraperitoneal injections of evogliptin (60 mg/k g/day), TMZ (15 mg/kg/day), or their combination over 3 weeks. The combination of TMZ and evogliptin markedly reduced cell viability compared to single-agent treatments. DPP4 mRNA levels decreased more substantially with combination therapy. miRNA expression profiling with Affymetrix arrays indicated that certain miRNAs, such as miR-4440 and miR-6780b-5p, were upregulated after treatment with evogliptin or the combination regimen, whereas others were downregulated. These miRNAs could play a role in limiting glioma growth through DPP4 regulation. In the animal model, evogliptin alone did not provide a survival advantage. Analysis of TCGA data showed that glioma patients with decreased DPP4 expression had improved survival rates. The co-administration of evogliptin and temozolomide resulted in distinct miRNA profile changes. Nevertheless, both in vitro and in vivo, the added cytotoxicity from the combination was minimal. Full article

There is increasing interest in the health-promoting potential of plant protein-derived peptides for managing metabolic disorders. This study investigated the impact of pepsin digestion on pre-hydrolysed versus non-hydrolysed pea protein. Pepsin digestion resulted in a higher degree of hydrolysis in pre-hydrolysed samples (64%) compared to the non-hydrolysed samples (~40%). The pepsin hydrolysates from the pre-hydrolysed protein showed stronger inhibition of key metabolic enzymes compared to non-hydrolysed samples. After ultrafiltration to enrich peptides <10 kDa, inhibition of α-amylase, α-glucosidase, and ACE was markedly enhanced, achieving a maximum of 44.5%, 54% and 95%, respectively. Peptidomic analysis identified unique peptide sequences in the ultrafiltered pre-hydrolysed fraction, in silico prediction confirmed their bioactive potential. These findings demonstrate enhanced bioactivity in pre-hydrolysed pea protein samples following pepsin hydrolysis, which was most evident in the ultrafiltrated fractions. Overall, this approach highlights the relevance of enzymatic hydrolysis and peptide enrichment strategies in developing functional ingredients to support glucose regulation and cardiovascular health. Full article

Background/Objectives: Essential amino acid (EAA) supplementation is often employed in sportive and clinical nutrition due to EAAs’ role in muscle mass maintenance and growth. EAAs are also involved in insulin and glucagone regulation in diabetes management, but only few reports investigate their possible implication as dipeptidyl peptidase-IV (DPP-IV) inhibitors and their effect on the stability and secretion of enteroendocrine hormones. A blend of EAAs (called GAF) available as a food supplement, in a specific qualitative and quantitative ratio, was investigated to address its in vitro bioaccessibility, its hypoglycemic properties in vitro and in situ on cellular models, and its safety on intestinal Caco-2 cells. Methods: GAF was subjected to the INFOGEST static digestion protocol, producing the iGAF sample. iGAf DPP-IV inhibitory properties were investigated both in vitro and in situ on Caco-2 cells. Then, STC-1 enteroendocrine cells were employed alone and in co-culture with Caco-2 cells to evaluate iGAF’s impact on glucagon-like peptide 1 (GLP-1) hormone secretion. Results: The study demonstrates that the present EAAs blend is stable and bioaccessible after simulated gastrointestinal digestion, and it is safe at the intestinal cellular level. It inhibits DPP-IV enzyme both in vitro and in situ and promotes GLP-1 secretion by enteroendocrine cells. Conclusions: The sample demonstrated safety at the intestinal level and showed hypoglycemic properties by acting on a dual synergic mechanism that involves DPP-IV enzyme inhibition and GLP-1 hormone stimulation. Full article

Chicken feathers constitute a major by-product from the poultry industry, with a potential environmental impact and significant difficulties in their management. This study aimed to develop a sustainable method to hydrolyse chicken feathers and evaluate the effects of microwave (MW) irradiation pre-treatment in the generation of bioactive hydrolysates by simple or sequential hydrolysis with Alcalase. The hydrolysate with MW irradiation pre-treatment and Alcalase (2%, 2 h) (MWA) showed the highest overall antioxidant activity and neprilysin-inhibitory activity (55%), whereas samples without MW irradiation pre-treatment exerted the highest inhibitory activity of dipeptidyl peptidase IV (DPP IV) and angiotensin-converting enzyme (ACE-I), with values close to 50 and 70%, respectively. Mass spectrometry in tandem of bioactive hydrolysates was performed, and an in silico approach was used to characterise the obtained sequences. These results confirmed that MW irradiation pre-treatment improved Alcalase hydrolysis, leading to the generation of bioactive peptides with potential multifunctional properties, including antioxidant, antidiabetic, and antihypertensive activities. Moreover, this study highlights the potential of combining MW irradiation and enzymatic hydrolysis as a sustainable strategy for the revalorisation of chicken feathers. Full article

Goat caseins are highly polymorphic proteins that affect milk functional properties. In this study, an in silico approach was employed to analyze the influence of goat casein allelic variants on the quantity and bioactivity potential of peptides released after enzymatic hydrolysis. The reported protein sequences from the most frequent allelic variants in Capra hircus caseins (α-S1, β, α-S2, and κ-casein) were analyzed in the BIOPEP-UWM database to determine the frequency of occurrence of bioactive fragments from each casein. After specific hydrolysis with pepsin, trypsin, and chymotrypsin A, important differences in the peptide profile and bioactivity potential were observed within and between the casein allelic variants. The β-casein A and C alleles, α-S1-casein allele E, and α-S2-casein allele F presented the highest bioactivity potential, and some allele-specific peptides were also released, highlighting the impact of genotype on the predicted bioactivity. The inhibition of angiotensin-converting enzyme (ACE-I) and dipeptidyl peptidase IV (DPP-IV) activities was the most frequent bioactivity of the released peptides, suggesting possible antihypertensive and antidiabetic effects. Once confirmed by experimental studies, the use of goat casein genotyping could direct efforts to enhance the functional quality of goat milk. Full article

Sheep milk is a rich source of bioactive compounds with significant potential in functional foods and biomedical applications. It contains high levels of proteins, peptides, and fatty acids with numerous health-promoting properties for the human body. Key components such as lactoferrin, proline, orotic acid, and conjugated linoleic acid (CLA) support the prevention and treatment of chronic diseases such as diabetes, cardiovascular disease, obesity, cancer, and neurodegenerative disorders. Bioactive peptides from sheep milk regulate blood glucose levels by inhibiting enzymes such as dipeptidyl peptidase-IV (DPP-IV) and α-glucosidase, while conjugated linoleic acid improves lipid metabolism and reduces inflammation. The high-quality proteins in sheep milk are essential for tissue regeneration and maintaining muscle mass, which is particularly beneficial for the elderly and infants who are allergic to cow milk. Recently, there has been an increasing interest in hydrogel dressings enriched with bioactive substances from sheep milk, which support wound healing by supporting collagen synthesis, reducing inflammation, and having antimicrobial properties. Such hydrogels are particularly promising for the treatment of chronic wounds, burns, and diabetic ulcers, making them a valuable tool in regenerative medicine. The aim of this manuscript is to review the current reports on bioactive components of sheep milk and their potential for biomedical applications. Full article

Type 2 diabetes mellitus (T2DM) is a complex and prevalent metabolic disorder, and dipeptidyl peptidase 4 (DPP4) inhibitors have proven effective, yet the identification of novel inhibitors remains challenging due to the vastness of chemical space. In this study, we developed DPPPRED-IV, a web-based ensembled system integrating both binary classification and continuous regression Quantitative Structure Activity Relationships (QSAR) models to predict human DPP4 inhibitory activity. A curated dataset of 4 676 ChEMBL compounds was subjected to genetic algorithm descriptor selection and multiple machine learning algorithms; classification models were combined via a soft voting ensemble, while regression models estimated IC₅₀ values. All models underwent external 10-fold cross-validation and applicability domain analysis. The final models were integrated into a user-friendly web server, allowing predictions from SMILES inputs. Experimental testing of 29 MolPort compounds at 1.5 µM confirmed that 14 predicted actives exhibited significant inhibition, supporting the tool’s performance in early-stage screening. DPPPRED IV is freely available within the ChemoPredictionSuite and offers a resource to accelerate decision making, reduce costs and minimize animal use in T2DM drug discovery. Full article

Type 2 diabetes mellitus remains a critical global health challenge, driving the pursuit of novel therapeutic strategies. This study investigated the anti-diabetic efficacy of the peptide 1CBR, derived from sodium caseinate hydrolysate, administered orally at 25 mg/kg/day to db/db mice over a 4-week period. Glucose tolerance was evaluated via oral glucose tolerance tests (OGTT), while plasma dipeptidyl peptidase-IV (DPP-IV) activity, glucagon-like peptide-1 (GLP-1), and insulin concentrations were quantified using enzyme-linked immunosorbent assays (ELISA). Two bioactive peptides, GPFPLPD and APDSGNFR, were isolated and characterized, exhibiting half-maximal inhibitory concentrations (IC₅₀) of 99.12 µM and 73.07 µM for DPP-IV inhibition, respectively, and both significantly stimulated GLP-1 secretion in enteroendocrine cells in vitro. Pharmacokinetic analysis in Sprague–Dawley rats demonstrated oral bioavailability of 11.28% and 19.12% for these peptides, surpassing typical expectations for peptide-based agents. Collectively, these results provide compelling evidence that 1CBR-derived peptides exert glucose-lowering effects through the dual mechanisms of DPP-IV inhibition and GLP-1 stimulation, combined with favorable oral absorption profiles. These findings underscore the potential of 1CBR peptides as promising candidates for development into nutraceuticals or pharmaceutical agents for diabetes management. Full article

This work utilized seabuckthorn seed meal protein (SSP) to develop hypoglycemic peptides via controlled protease catalyzed hydrolysis. Among the SSP hydrolysates (SSPHs) obtained by means of various proteases, the SSP hydrolyzed by dispase (SSPD) exhibited extraordinary inhibitory abilities against three key enzymes involved in glucose metabolism: α-glucosidase, α-amylase, and dipeptidyl peptidase-IV (DPP-IV). Following process optimization and purification, SSPD displayed remarkable inhibitions to α-glucosidase (IC₅₀: 3.45 ± 0.18 mg/mL) and DPP-IV (IC₅₀: 5.01 ± 0.21 mg/mL), respectively. Molecular docking analysis and in vitro verification revealed three peptides in the SSPD with α-glucosidase inhibition: FHF, FFI, and FGI (IC₅₀: 3.98 ± 0.16 mM, 8.21 ± 0.21 mM, 11.57 ± 0.20 mM), and three peptides with DPP-IV inhibition: IYF, IGF, and LFF (IC₅₀: 5.32 ± 0.15 mM, 7.17 ± 0.14 mM, 7.62 ± 0.19 mM). These findings demonstrate that SSP holds promise as a significant natural resource for the creation of multifunctional hypoglycemic peptides, which can be utilized in nutritional and functional food applications. Full article

Antarctic krill (Euphausia superba) is a nutrient-rich marine resource. Although several terrestrial proteases have been used to prepare Antarctic krill peptides (AKPs), there has been no report on the preparation of AKPs using a marine protease. Here, marine bacterial protease A69 was used to prepare AKPs with multi-bioactivities. Through optimizing hydrolysis parameters, we established a process for AKPs preparation by hydrolyzing Antarctic krill powder with A69. In the prepared AKPs, peptides less than 3000 Da and 1000 Da accounted for 99.23% and 88.37%, respectively. The scavenging ratios of the AKPs to ABTS⁺, DPPH· and ·OH reached 93.23 ± 0.09%, 99.90 ± 0.15%, and 93.90 ± 0.47%, respectively. The AKPs also had high angiotensin-converting enzyme (ACE)-inhibitory activity, with an IC₅₀ of 0.22 ± 0.04 mg/mL. At 40 mg/mL, the AKPs inhibited α-glucosidase and dipeptidyl peptidase IV (DPP-IV) activities by 7.18% and 13.62%, respectively, and displayed antibacterial activity to Escherichia coli. Moreover, 14 antioxidant peptides, 24 ACE-inhibitory peptides, 2 α-glucosidase-inhibitory peptides, and 10 DPP-Ⅳ-inhibitory peptides were identified from the AKPs. These results demonstrate that the prepared AKPs contain diverse bioactive peptides and have multi-bioactivities. This study indicates that marine bacterial protease A69 has promising application potential in preparing AKPs with multi-bioactivities. Full article