Identification and characterization of DPP-IV inhibitory peptides from silver carp swim bladder hydrolysates

A novel robust inhibitor of papain-like protease (PLpro) as a COVID-19 drug

Regarding the significance of SARS-CoV-2, scientists have shown considerable interest in developing effective drugs. Inhibitors for PLpro are the primary strategies for locating suitable COVID-19 drugs. Natural compounds comprise the majority of COVID-19 drugs. Due to limitations on the safety of clinical trials in cases of COVID, computational methods are typically utilized for inhibition studies. Whereas papain is highly similar to PLpro and is entirely safe, the current study aimed to examine several plant secondary metabolites to identify the most effective papain inhibitor and validate the results using molecular dynamics and docking. This simulation was conducted identically for PLpro and the optimal inhibitor. The results indicated that the experimental results are comparable to those obtained In-Silico, and the inhibition effects of Chlorogenic acid (CGA) on papain attained in the experiment were validated (IC50=0.54 mM). CGA as an inhibitor was located in the active site of PLpro and papain (total energy -2009410 and -456069 kJ/mol, respectively) at the desired location and distance. The study revealed that CGA and its derivatives are effective PLpro inhibitors against SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Enrichment and Quantitation of Dipeptidyl Peptidase IV Inhibitory Peptides in Quinoa upon Systematic Malting

Food-derived peptides with an inhibitory effect on dipeptidyl peptidase IV (DPP-IV) can be used as an additive treatment for type 2 diabetes. The inhibitory potential of food depends on technological protein hydrolysis and gastrointestinal digestion, as the peptides only act after intestinal resorption. The effect of malting as a hydrolytic step on the availability of these peptides in grains has yet to be investigated. In this study, quinoa was malted under systematic temperature, moisture, and time variations. In the resulting malts, the DPP-IV inhibition reached a maximum of 45.02 (±10.28) %, whereas the highest overall concentration of literature-known inhibitory peptides was 4.07 μmol/L, depending on the malting parameters. After in vitro gastrointestinal digest, the inhibition of most malts, as well as the overall concentration of inhibitory peptides, could be increased significantly. Additionally, the digested malts showed higher values in both the inhibition and the peptide concentration than the unmalted quinoa. Concerning the malting parameters, germination time had the highest impact on the inhibition and the peptide concentration after digest. An analysis of the protein sizes before and after malting gave first hints toward the origin of these peptides, or their precursors, in quinoa.

Anti-diabetic properties of brewer's spent yeast peptides. In vitro, in silico and ex vivo study after simulated gastrointestinal digestion

Brewer's spent yeast (BSY) hydrolysates are a source of antidiabetic peptides. Nevertheless, the impact of in vitro gastrointestinal digestion of BSY derived peptides on diabetes has not been assessed. In this study, two BSY hydrolysates were obtained (H1 and H2) using β-glucanase and alkaline protease, with either 1 h or 2 h hydrolysis time for H1 and H2, respectively. These hydrolysates were then subjected to simulated gastrointestinal digestion (SGID), obtaining dialysates D1 and D2, respectively. BSY hydrolysates inhibited the activity of α-glucosidase and dipeptidyl peptidase IV (DPP-IV) enzymes. Moreover, although D2 was inactive against these enzymes, D1 IC50 value was lower than those found for the hydrolysates. Interestingly, after electrophoretic separation, D1 mannose-linked peptides showed the highest α-glucosidase inhibitory activity, while non-glycosylated peptides had the highest DPP-IV inhibitory activity. Kinetic analyses showed a non-competitive mechanism in both cases. After peptide identification, GILFVGSGVSGGEEGAR and IINEPTAAAIAYGLDK showed the highest in silico anti-diabetic activities among mannose-linked and non-glycosylated peptides, respectively (AntiDMPpred score: 0.70 and 0.77). Molecular docking also indicated that these peptides act as non-competitive inhibitors. Finally, an ex vivo model of mouse jejunum organoids was used to study the effect of D1 on the expression of intestinal epithelial genes related to diabetes. The reduction of the expression of genes that codify lactase, sucrase-isomaltase and glucose transporter 2 was observed, as well as an increase in the expression of Gip (glucose-dependent insulinotropic peptide) and Glp1 (glucagon-like peptide 1). This is the first report to evaluate the anti-diabetic effect of BSY peptides in mouse jejunum organoids.

Indenoquinoxaline-phenylacrylohydrazide hybrids as promising drug candidates for the treatment of type 2 diabetes: In vitro and in silico evaluation of enzyme inhibition and antioxidant activity

Existing drugs that are being used to treat type-2 diabetes mellitus are associated with several side effects; thus, exploring potential drug candidates is still an utter need these days. Hybrids of indenoquinoxaline and hydrazide have never been explored as antidiabetic agents. In this study, a series of new indenoquinoxaline-phenylacrylohydrazide hybrids (1-30) were synthesized, structurally characterized, and evaluated for α-amylase and α-glucosidase inhibitory activities, as well as for their antioxidant properties. All scaffolds exhibited varying degrees of inhibitory activity against both enzymes, with IC50 values ranging from 2.34 to 61.12 μM for α-amylase and 0.42 to 54.72 μM for α-glucosidase. Particularly, compounds 10, 16, 17, 18, 24, and 25 demonstrated the highest efficacy in inhibiting α-amylase, while compounds 6, 7, 8, 10, 12, 14, 13, 16, 17, 18, 24, and 25 were the most effective α-glucosidase inhibitors, compared to standard acarbose. Moreover, most of these compounds displayed substantial antioxidant potential compared to standard butylated hydroxytoluene (BHT). Kinetics studies revealed competitive inhibition modes by compounds. Furthermore, a comprehensive in silico study and toxicity prediction were also conducted, further validating these analogs as potential drug candidates. The structured compounds demonstrated enhanced profiles, underscoring their potential as primary candidates in drug discovery.

An Update on Dipeptidyl Peptidase-IV Inhibiting Peptides

Diabetes is a chronic metabolic disorder. According to the International Diabetes Federation, about 537 million people are living with diabetes. The two types of diabetes are type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), among which the population affected by T2DM is relatively higher. A major reason for T2DM is that insulin stimulation is hampered due to the inactivation of incretin hormones. Dipeptidyl peptidase-IV (DPP-IV) is a serine protease that is directly involved in the inactivation of incretin hormones, e.g., glucagon-like peptide-1 (GLP-1). Therefore, the inhibition of DPP-IV can be a promising method for managing T2DM, in addition to other enzyme inhibition strategies, such as inhibition of α-amylase and α -glucosidase. Currently, about 12 different gliptin drugs are available in the market that inhibit DPP-IV in a dose-dependent manner. Instead of gliptins, 'peptides' can also be employed as an alternative and promising way to inhibit DPP-IV. Peptide inhibitors of DPP-IV have been identified from various plants and animals. Chemically synthesized peptides have also been experimented for inhibiting DPP-IV. Most peptides have been analysed by biochemical assays, whereas some in vitro assays have also been reported. Molecular docking analysis has been applied to comprehend the mechanism of inhibition. In this review, certain aspects of natural as well as synthetic peptides are described that have been proven to inhibit DPP-IV.

Preparation, identification, activity prediction, and protective effects on IR-HepG2 cells of five novel DPP-IV inhibitory peptides from protein hydrolysate of skipjack tuna dark muscles

To produce peptides with high dipeptidyl peptidase IV (DPP-IV) inhibitory activity, neutrase was selected from five proteases (trypsin, neutrase, pepsin, alcalase and flavor protease) with the highest degree of hydrolysis (DH) (18.23 ± 1.08%) and DPP-IV inhibitory rate (53.35 ± 4.02%) to produce protein hydrolysate (NPH) from the dark muscles of skipjack tuna (Katsuwonus pelamis). Then, NPH-1 was isolated from NPH by gel permeation chromatography and found to possess the highest DPP-IV inhibitory rate (65.12 ± 7.94% at 0.5 mg ml-1) in the separated components (including NPH-1, NPH-2, NPH-3 and NPH-4). Subsequently, the available prediction models of tripeptides and tetrapeptides with the DPP-IV inhibitory rate were established using an artificial neural network (ANN). The RMSE (0.56 and 0.33 for the model established through collected tripeptides and tetrapeptides, respectively) and R2 (0.95 and 0.99 for the model established through collected tripeptides and tetrapeptides, respectively) of the ANN model's parameters were within acceptable limits, indicating that this model is available. Next, the ANN model was applied to predict tripeptides and tetrapeptides from the hydrolysate of skipjack tuna dark muscles, and five peptides (Ala-Pro-Pro (APP), Pro-Pro-Pro (PPP), Asp-Pro-Leu-Leu (DPLL), Glu-Ala-Val-Pro (EAVP) and Glu-Ala-Iie-Pro (EAIP)) possessing a noticeable DPP-IV inhibitory rate (with DPP-IV IC50 values of 42.46 ± 5.02, 37.71 ± 9.17, 58.85 ± 14.42, 49.94 ± 6.69 and 57.15 ± 6.13 μM, respectively) were screened from the protein hydrolysate. The above five peptides were proved to effectively promote glucose consumption in the insulin resistant-HepG2 (IR-HepG2) cell model considering that the glucose consumption rates of APP, PPP, DPLL, EAVP and EAIP treatment groups are all more than twice that of the dexamethasone group. Accordingly, mechanistic studies showed that these peptides interacted with PI3K/AKT and AMPK signaling pathways and promoted the phosphorylation of PI3K p110, AKT and AMPK (the protein expressions of PI3K p110, p-AKT and p-AMPK in APP, PPP, DPLL, EAVP and EAIP treatment groups are 1.64-2.22 fold compared with that in the dexamethasone group), thereby enhancing glucose uptake and further alleviating insulin resistance. These findings demonstrated that skipjack tuna dark muscle is a potential DPP-IV inhibitory peptide source, and five DPP-IV inhibitory peptides from its hydrolysate may exert potent anti-diabetic activity. In comparison, PPP may be the most potential active ingredient for healthy food against type 2 diabetes mellitus in the five screened peptides considering synthetically the DPP-IV inhibitory rate, bioavailability and synthesis cost.

Preparation, identification, and inhibitory mechanism of dipeptidyl peptidase IV inhibitory peptides from goat milk whey protein

This study explores potential hypoglycemic mechanisms by preparing and identifying novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from goat milk (GM) whey protein. Papain was used to hydrolyze the GM whey protein. After purification by ultrafiltration, the Sephadex column, and preparative RP-HPLC, the peptide inhibited DPP-IV, α-glucosidase, and α-amylase with IC50 of 0.34, 0.37, and 0.72 mg/mL, respectively. To further explore the inhibitory mechanism of peptides on DPP-IV, SPPEFLR, LDADGSY, YPVEPFT, and FNPTY were identified and synthesized for the first time, with IC50 values of 56.22, 52.16, 175.7, and 62.32 µM, respectively. Molecular docking and dynamics results show that SPPEFLR, LDADGSY, and FNPTY bind more tightly to the active pocket of DPP-IV, which was consistent with the in vitro activity. Furthermore, the first three N-terminals of SPPEFLR and FNPTY peptides exhibit proline characteristics and competitively inhibit DPP-IV. Notably, the first N-terminal leucine of LDADGSY may play a key role in inhibiting DPP-IV.

Postpartum Screening for Type 2 Diabetes Mellitus Among Women With Gestational Diabetes Mellitus at King Abdulaziz University Hospital: A Cross-Sectional Study

Background Diabetes is characterized by elevated blood glucose levels due to inadequate insulin production or abnormalities in cellular activity. Gestational diabetes mellitus (GDM) is one of the most prominent indicators of type 2 diabetes mellitus (T2DM), which develops in pregnant women whose pancreatic function is insufficient to control the insulin resistance associated with pregnancy. Moreover, it is the most common metabolic disorder, with the majority of cases beginning in the second or third trimester of pregnancy and affecting up to 25% of pregnant women. Objectives The objective of this study was to identify factors associated with postpartum T2DM screening in women with GDM at King Abdulaziz University Hospital (KAUH) between 2010 and 2022. The secondary objective was to assess the factors associated with providing information to the patients about the risks of increased blood glucose and postpartum lifestyle modification. Methods We conducted a retrospective cross-sectional study at KAUH to investigate potential factors associated with postpartum screening for T2DM. Out of 564 patients diagnosed with GDM between 2020 and 2022, we included 200 women aged over 18 years with a history of GDM, as they met the inclusion criteria for our study. Patients younger than 18 years with missing or incomplete baseline characteristics were excluded. Data were analyzed using SPSS Statistics version 21 (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.), and p-value <0.05 was considered significant. Results A total of 200 postpartum women with GDM were included in this study. Their mean age was 35.02±5.2 years. Many of them had a family history of diabetes (83.0%) and a previous diagnosis of GDM (60.5%). The patients who performed glucose testing six weeks after birth were previously diagnosed with GDM (37.0%) or with a family history of diabetes (45.5%). The significant variables in this analysis were mothers having frequent postpartum hospital follow-up visits (P<0.001), mothers with gestational weight gain (P=0.018), those who were informed about the risks of increased blood glucose (P=0.011), and those who were informed about plans for postpartum glucose screening (P=0.002). The mothers with a previous history of GDM were the highest to be informed of the risks of elevated blood glucose. Conclusion Frequent postpartum hospital follow-up visits, gestational weight gain, knowledge of the risks of elevated blood sugar, and postpartum glucose screening plans were all associated with postpartum glucose testing rates among women with GDM in Saudi Arabia.

Shifting archetype to nature's hidden gems: from sources, purification to uncover the nutritional potential of bioactive peptides

Contemporary scientific findings revealed that our daily food stuffs are enriched by encrypted bioactive peptides (BPs), evolved by peptide linkage of amino acids or encrypted from the native protein structures. Remarkable to these BPs lies in their potential health benefiting biological activities to serve as nutraceuticals or a lead addition to the development of functional foods. The biological activities of BPs vary depending on the sequence as well as amino acid composition. Existing database records approximately 3000 peptide sequences which possess potential biological activities such as antioxidants, antihypertensive, antithrombotic, anti-adipogenics, anti-microbials, anti-inflammatory, and anti-cancerous. The growing evidences suggest that BPs have very low toxicity, higher accuracy, less tissue accretion, and are easily degraded in the disposed environment. BPs are nowadays evolved as biologically active molecules with potential scope to reduce microbial contamination as well as ward off oxidation of foods, amend diverse range of human diseases to enhance the overall quality of human life. Against the clinical and health perspectives of BPs, this review aimed to elaborate current evolution of nutritional potential of BPs, studies pertaining to overcome limitations with respect to special focus on emerging extraction, protection and delivery tools of BPs. In addition, the nano-delivery mechanism of BP and its clinical significance is detailed. The aim of current review is to augment the research in the field of BPs production, identification, characterisation and to speed up the investigation of the incredible potentials of BPs as potential nutritional and functional food ingredient.

Identification of Novel Dipeptidyl Peptidase-IV Inhibitory Peptides in Chickpea Protein Hydrolysates

Dipeptidyl peptidase-IV (DPP-IV) is one of the main targets for blood sugar control. Some food protein-derived peptides are thought to have DPP-IV inhibitory (DPP-IVi) activity. In this study, chickpea protein hydrolysates (CPHs) obtained through Neutrase hydrolysis for 60 min (CPHs-Pro-60) exhibited the highest DPP-IVi activity. DPP-IVi activity after simulated in vitro gastrointestinal digestion was maintained at >60%. Peptide libraries are established after the identification of peptide sequences. Molecular docking verified that the four screened peptides (AAWPGHPEF, LAFP, IAIPPGIPYW, and PPGIPYW) could bind to the active center of DPP-IV. Notably, IAIPPGIPYW exhibited the most potent DPP-IVi activity (half maximal inhibitory concentration (IC₅₀): 12.43 μM). Both IAIPPGIPYW and PPGIPYW exhibited excellent DPP-IVi activity in Caco-2 cells. These results indicated that chickpea could be used as a source of natural hypoglycemic peptides for food and nutritional applications.

Purification and characterization of the dipeptidyl peptidase-IV inhibitory peptides from eel (Anguilla rostrata) scraps enzymatic hydrolysate for the treatment of type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a serious threat to human health. Owing to the action of dipeptidyl peptidase-IV (DPP-IV), the half-life of entero-insulin hormone after secretion is extremely short, causing insufficient insulin secretion in diabetic patients. Dipeptidyl peptidase-IV inhibitors can be used as a new treatment for T2DM. In this study, the proteins of eel (Anguilla rostrata) scraps hydrolyzed using Protamex protease (EPHs) were found to have strong DPP-IV inhibitory activity. The study also provided research ideas for the development and utilization of A. rostrata scraps.

RESULTS

The median inhibition concentration (IC₅₀ ) value of EPHs was 5.455 ± 0.24 mg mL^-1 . The peptide fractions with the highest DPP-IV inhibitory activity were sequentially separated by ultrafiltration, gel filtration chromatography (GFC), and reversed-phase high performance liquid chromatography (RP-HPLC) in a continuous hierarchical manner and analyzed using matrix-assisted laser desorption/ionization time-of-flight/ time-of-flight mass spectrometry/mass spectrometry (MALDI-TOF/TOF MS/MS). Three peptides that revealed significant inhibitory activity were screened among the identified sequences, with sequences of Phe-Pro-Arg (IC₅₀  = 62.14 ± 1.47 μM), Tyr-Pro-Pro-Ser-Phe-Ser (IC₅₀  = 102.65 ± 4.57 μM), and Tyr-Pro-Tyr-Pro-Ala-Ser (IC₅₀  = 68.30 ± 3.85 μM). Molecular docking simulations revealed that their inhibitory effect was mainly due to the formation of hydrogen bonds with amino acid residues in the active sites of DPP-IV. Analysis of the inhibition patterns of the synthetic peptides displayed that Phe-Pro-Arg and Tyr-Pro-Pro-Ser-Phe-Ser displayed competitive inhibition, whereas Tyr-Pro-Tyr-Pro-Ala-Ser showed mixed competitive/non-competitive inhibition.

CONCLUSIONS

The protein hydrolysates isolated from eel scraps are potential functional food ingredients for the treatment of T2DM. © 2023 Society of Chemical Industry.

Silver Carp (Hypophthalmichthys molitrix) Scales Collagen Peptides (SCPs): Preparation, Whitening Activity Screening and Characterization

This study involves the preparation of scale collagen peptides (SCPs) with whitening activity from silver carp (Hypophthalmichthys molitrix) and their characterization and peptide sequence identification. In this article, scanning electron microscopy (SEM) was used to observe structure changes of sliver carp scales; enzymatic hydrolysis was optimized through protease screening and response surface optimization. The ultrafiltration was used to separate SCPs and the whitening activity was comprehensively evaluated using radical scavenging rate and tyrosinase-inhibiting activity, among others. An optimal component was characterized and identified using various modern spectral analysis techniques. The results showed that the surface of silver carp scales after decalcification was smooth and clear. The pepsin had the highest peptide yield and tyrosinase-inhibiting activity (90.01% and 82.25%, respectively). The optimal enzymatic hydrolysis conditions were an enzyme dosage of 16.1%, a solid–liquid ratio of 1:15.6 and a time of 4.9 h. The proportions of hydrophobic and basic amino acids in the peptide composition were 32.15% and 13.12%, respectively. Compared with SCPs2, SCPs1 (6096.68–9513.70 Da) showed better ·OH scavenging ability, tyrosinase-inhibiting activity and moisture absorption. SCPs1 was a macromolecular fragment of type I collagen with a triple helix structure, containing three peptide sequences with the potential for tyrosinase activity inhibition (AGPPGADGQTGQRGE, SGPAGIAGPAGPRGPAGPNGPPGKD and KRGSTGEQGSTGPLGMRGPRGAA). These results show that SCPs1 is a collagen peptide product with whitening potential.

Synthesis, modification and application of fish skin gelatin-based hydrogel as sustainable and versatile bioresource of antidiabetic peptide

Gelatin hydrogel is widely employed in various fields, however, commercially available gelatin hydrogels are mostly derived from mammalian which has many disadvantages due to the supply and ethical issues. In this study, the properties of hydrogels from fish-derived collagen fabricated with varying Glutaraldehyde (GA) determined. The antidiabetic properties of salmon gelatin (SG) and tilapia gelatin (TG) was also evaluated against α-glucosidase. Glutaraldehyde-crosslinked salmon gelatin and tilapia gelatin were used, and compared with different concentrations of GA by 0.05 %, 0.1 %, and 0.15 %. Water absorbency, swelling, porosity, pore size and water retention of the hydrogels were dependent on the degree of crosslinking. The synthesis of hydrogels was confirmed by FTIR study. Scanning electron microscope (SEM) observation showed that all hydrogels have a porous structure with irregular shapes and heterogeneous morphology. Performance tests showed that gelatin-GA 0.05 % mixture had the best performance. Antidiabetic bioactivity in vitro and in silico tests showed that the active peptides of SG and TG showed a high binding affinity to α-glucosidase enzyme. In conclusion, SG and TG cross-linked GA 0.05 % have the potential as an antidiabetic agent and as a useful option over mammalian-derived gelatin.

Food-derived dipeptidyl peptidase IV inhibitory peptides: Production, identification, structure-activity relationship, and their potential role in glycemic regulation

Dipeptidyl Peptidase IV (DPP-IV) inhibitory peptides are attracting increasing attention, owing to their potential role in glycemic regulation by preventing the inactivation of incretins. However, few reviews have summarized the current understanding of DPP-IV inhibitory peptides and their knowledge gaps. This paper reviews the production, identification and structure-activity relationships (SAR) of DPP-IV inhibitory peptides. Importantly, their bioavailability and hypoglycemic effects are critically discussed. Unlike the traditional method to identifying peptides after separation step by step, the bioinformatics approach identifies peptides via virtual screening that is more convenient and efficient. In addition, the bioinformatics approach was also used to investigate the SAR of peptides. Peptides with proline (Pro) or alanine (Ala) residue at the second position of N-terminal are exhibit strong DPP-IV inhibitory activity. Besides, the bioavailability of DPP-IV inhibitory peptides is related to their gastrointestinal stability and cellular permeability, and in vivo studies showed that the glucose homeostasis has been improved by these peptides. Especially, the intestinal transport of DPP-IV inhibitory peptides and cell biological assays used to evaluate their potential role in glycemic regulation are innovatively summarized. For further successful development of DPP-IV inhibitory peptides in glycemic regulation, future study should elucidate their SAR and in vivo hypoglycemic effects .

Purification, identification and molecular mechanism of dipeptidyl peptidase IV inhibitory peptides from discarded shrimp (Penaeus vannamei) head

DPP-IV plays a key role for regulation of glucose metabolism in the body. The object of this study was to obtain DPP-IV inhibitors from discarded but protein-rich Penaeus vannamei (P. vannamei) head, and to explore the potential mechanism between DPP-IV and its inhibitors. P. vannamei head protein was hydrolyzed by five food grade proteases, respectively. The animal protease hydrolysate showed the highest inhibitory active. Then the hydrolysate was sequentially separated by ultrafiltration, gel filtration chromatography and reversed phase high-performance liquid chromatography (RP-HPLC), the peptides sequences were identified by LC-MS/MS and four potential peptides YPGE, VPW, HPLY, YATP showed superior DPP-IV inhibitory activity. Meanwhile, molecular docking effectively explored their mechanism through formed hydrogen bonds and hydrophobic regions. The four peptides showed better DPP-IV inhibitory activity stability with heating treatment, pH (1-10) treatment, and in vitro gastrointestinal digestion. Our results demonstrated that the protein hydrolysate from discarded P. vannamei head can be considered as a promising natural source of DPP-IV inhibitor for helping to improve glycaemic control in Type 2 diabetes.

Gestational diabetes mellitus - A metabolic and reproductive disorder

Maternal health associated with Gestational Diabetes Mellitus (GDM) has been gaining significant research attention due to its severe risk and adverse health effects. GDM is the leading health disease in pregnant women. It is the most common metabolic disease and it can affect up to 25% of women during pregnancy. Pregnancy is a sensitive period that impacts both pregnant women and their unborn children's long-term health. It is a well-known fact that the leading causes of disease and mortality worldwide are diabetes mellitus and cancer, and specifically, women with diabetes mellitus are at a higher risk of developing breast cancer (BC). Women who have diabetes are equally vulnerable to reproductive diseases. Reproductive dysfunctions with diabetes are mainly attributed to coexisting polycystic ovarian syndrome (PCOS), obesity, and hyperinsulinemia, etc. Moreover, India has long been recognized as the world's diabetic capital, and it is widely acknowledged that particularly pregnant and lactating women are among the most affected by diabetes. In India, one-third (33%) of women with GDM had a history of maternal diabetes. Nevertheless, the latest research suggests that gestational diabetes is also a risk factor for cardiometabolic diseases of the mother and offspring. Therefore, in the 21st century, GDM imposes a major challenge for healthcare professionals. We intend to explore the role of diabetes on female reproductive function throughout various stages of life in the perspective of the changing prognosis, prevalence, and prevention of GDM.

Bioactive Peptides as Potential Nutraceuticals for Diabetes Therapy: A Comprehensive Review

Diabetes mellitus is a major public health concern associated with high mortality and reduced life expectancy. The alarming rise in the prevalence of diabetes is linked to several factors including sedentary lifestyle and unhealthy diet. Nutritional intervention and increased physical activity could significantly contribute to bringing this under control. Food-derived bioactive peptides and protein hydrolysates have been associated with a number health benefits. Several peptides with antidiabetic potential have been identified that could decrease blood glucose level, improve insulin uptake and inhibit key enzymes involved in the development and progression of diabetes. Dietary proteins, from a wide range of food, are rich sources of antidiabetic peptides. Thus, there are a number of benefits in studying peptides obtained from food sources to develop nutraceuticals. A deeper understanding of the underlying molecular mechanisms of these peptides will assist in the development of new peptide-based therapeutics. Despite this, a comprehensive analysis of the antidiabetic properties of bioactive peptides derived from various food sources is still lacking. Here, we review the recent literature on food-derived bioactive peptides possessing antidiabetic activity. The focus is on the effectiveness of these peptides as evidenced by in vitro and in vivo studies. Finally, we discuss future prospects of peptide-based drugs for the treatment of diabetes.

Purification, identification, and molecular mechanism of DPP-IV inhibitory peptides from defatted Antarctic krill powder

Dipeptidyl peptidase-IV (DPP-IV) inhibitors can reduce the blood sugar levels of diabetic patients by preventing the rapid decomposition of incretin hormone and prolonging its physiological effects. In this study, DPP-IV inhibitory peptides FAGDDAPR and LAPPRGSL were isolated from defatted Antarctic krill powder (DAKP) protein by the sequential purification of ultrafiltration, gel filtration chromatography, and RP-HPLC, and IC₅₀ values of the two peptides were 349.70 ± 3.66 μM and 461.14 ± 0.87 μM, respectively. The FAGDDAPR and LAPPRGSL were identified by LC-MS/MS method, and the molecular models of DPP-IV and the two peptides were further constructed by AutoDock Vina software, the results revealed that the inhibition activity of FAGDDAPR and LAPPRGSL was mainly attributed to the formation of strong hydrophobic interactions and hydrogen bonds with amino acids of DPP-IV. PRACTICAL APPLICATIONS: DAKP is an economical by-product produced in the production of krill oil and contains high-quality protein, but these products were mainly used as fish feed and had low utility value in the past. DPP-IV inhibitors are an efficacious drug employed in the treatment of hyperglycemia processes. However, these drugs can cause undesirable side effects. Thus, the development of new natural hypoglycemic drugs with low side effects is a valuable strategy to be applied in therapeutic interventions.