In-Silico Analysis and Antidiabetic Effect of α-Amylase and α-Glucosidase Inhibitory Peptides from Lupin Protein Hydrolysate: Enzyme-Peptide Interaction Study Using Molecular Docking Approach

Shaping the bioactive potential, health-promoting properties, and bioavailability of o/w nanoemulsions by modulating the dose of a carotenoid preparation isolated from Calendula officinalis L

The use of nanotechnology in food production (in particular protein base nanoemulsion) is a solution that is gaining popularity, which allows to design of smart food with targeted health-promoting properties. This study aimed to assess the impact of the dose of the phytochemical extract (1%; 3%; 5% w/w) comprising isolated lipophilic compounds from Calendula officinalis L. on selected physicochemical properties of the emulsion, antioxidant, antidiabetic and antiaging effects, and its impact on carotenoids content and their in vitro bioavailability. The results showed that the use of a 3% extract dosage appears to be optimal for obtaining a nanoemulsion. This variant was characterized by the highest antidiabetic activity and there was no overloading of the nanostructure. Additionally, the use of a pea protein - lipophilic compounds - sunflower/hemp oil matrix to create nanoforms seems to be a promising solution in the context of pro-health properties and bioavailability of bioactive compounds.

Harnessing Phytochemicals to Regulate Catalytic Residues of Alpha-Amylase and Alpha-Glucosidase in Type 2 Diabetes

Type 2 diabetes (T2D), also known as non-insulin-dependent diabetes mellitus, represents the prevailing manifestation of diabetes, encompassing a substantial majority of cases, ~90-95%. Plant-derived antidiabetic leads are being intensively explored due to their safety and effectiveness. The main objective of the present study is to evaluate the anti-diabetic potential of the traditional formulation Karisalai Karpam through in-vitro and in-silico investigations. The in-vitro and in-silico investigation of traditional polyherbal preparation Karisalai Karpam (KK) chooranam were performed to ascertain its inhibitory potential against α-amylase and α-glucosidase enzymes along with antioxidant (DPPH and ABTS) and phytochemical analysis. The results of enzyme inhibitory activity of KK witnessed highest activity against α-glucosidase enzyme with a percentage inhibition of 84.66 ± 2.50% (IC50,187.9 ± 5.79 μg/ml) followed by moderate level of α-amylase inhibition exhibited with 72.94 ± 3.66% (IC50, 241.6 ± 9.76 μg/ml). Additionally, the strongest antioxidant activity was observed in quenching DPPH• (IC50,154.8 ± 14.53 μg/ml) and ABTS+• radicals (IC50,148.6 ± 29.74 μg/ml). The outcome of the molecular docking studies indicated that among the 17 compounds analysed, the lead such as acalyphin, apigenin, humulene, and indirubin exhibited a prominent binding affinity over the residual binding site of α-glucosidase. It's important to note that the catalytic site of the enzyme α-amylase is primarily occupied by amyrin, apigenin, arjunolic acid, β-sitosterol, geraniol, and tricetin. In conclusion, the formulation KK demonstrates robust alpha-glucosidase and alpha-amylase inhibitory activity. It's also worth noting that the formulation exhibits noteworthy antioxidant properties, which could provide additional health benefits. The binding mode and energies of the identified phytochemicals against the target enzymes further support the formulation's antidiabetic potential.

Inhibition of α-glucosidase activity by potential peptides derived from fermented spent coffee grounds

The control of α-glucosidase activity has been associated with managing diabetes. We previously identified three peptides with high bioactive indices derived from protein hydrolysates of fermented spent coffee grounds. In this study, the peptides YGF, GMCC, and RMYRY were synthesized and tested in vitro for their α-glucosidase inhibition activity, complemented by in silico analyses. Two of the three peptides significantly inhibited α-glucosidase activity, with the more efficient peptides being YGF and GMCC (0.42 mg/mL), resulting in decreased enzymatic activity of 95.31% and 89.79%, respectively. These peptides exhibited binding free energies with the α-glucosidase complex of -8.5 and - 6.6 kcal/mol, respectively, through hydrogen bonds and van der Waals interactions with amino acids from the active site. Pharmacokinetic analysis indicated that YGF and GMCC profiles were unrelated to toxicity. These results underscore the importance of focusing on food waste bioprocessing products to expand the range of alternatives that could aid in diabetes treatment.

A Deep Mining Strategy for Peptide Rapid Identification in Lactobacillus reuteri Based on LC-MS/MS Integrated with FBMN and De Novo Sequencing

Lactobacillus reuteri (L. reuteri) is widely recognized as a probiotic that produces prebiotics. However, studies on bioactive peptides or amino acid (AA) derivatives produced by L. reuteri are still lacking, whereas many bioactive peptides and AA derivatives have been found in other Lactobacillus species. In addition, rapid identification of peptides is challenged by the large amount of data and is limited by the coverage of protein databases. In this study, we performed a rapid and thorough profile of peptides in L. reuteri incorporating Global Natural Products Social Molecular Networking (GNPS) platform database searching, de novo sequencing, and deep mining, based on feature-based molecular networking (FBMN). According to FBMN, it was found that peptides containing identical or similar AA compositions were grouped into the same clusters, especially cyclic dipeptides (CDPs). Therefore, the grouping characteristics of clusters, differences in precursor ions, and characteristic fragment ions were utilized for the mining of deeply unknown compounds. Through this strategy, a total of 192 compounds, including 184 peptides, were rapidly identified. Among them, 53 CDPs, including four novel ones, were found for the first time in L. reuteri. Then, one of the novel CDPs, cyclo(5-OMe-Glu-4-OH-Pro), was isolated and characterized, which was consistent with the identification results. Moreover, some of the identified peptides exhibited considerable interactions with seven anti-inflammatory-related target proteins through molecular docking. According to the binding energies of peptides with different AA consistencies, it was considered that the existence of unnatural AAs in CDPs might contribute to their anti-inflammatory activity. These results provide a valuable strategy for the rapid identification of peptides, including CDPs. This study also reveals the substance basis for the potential anti-inflammatory effects exerted by L. reuteri.

Exploring the antidiabetic and anti-inflammatory potential of Lavandula officinalis essential oil: In vitro and in silico insights

Medicinal plants have been utilized for centuries in traditional medicine systems worldwide, providing a rich source of bioactive compounds with diverse biological activities. Lavandula officinalis, a member of the Lamiaceae family, has been recognized for its multifaceted pharmacological activities. In this current investigation, our primary objective was to scrutinize the in vitro inhibitory potential of L. officinalis essential oil (LOEO) against alpha-amylase and alpha-glucosidase, with the aim of understanding its antidiabetic effects. Additionally, the assay encompassed tyrosinase and lipoxygenase (LOX) to assess its anti-inflammatory attributes. Unraveling the underlying molecular mechanisms of these activities prompted an in-silico study. The purpose was to establish correlations between in-vitro observations and computational insights derived from molecular docking, which forecasts the interaction of LOEO molecules with their respective targets, alongside ADMET prediction. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis allow to identify eighteen compounds, with the dominance of L-camphor (43.12 %), 1,8-cineole (34.27 %) and borneol (8.60 %) in LOEO. The antidiabetic evaluation revealed that LOEO exhibited noteworthy inhibitory activity against both α-amylase and α-glucosidase, displaying IC50 values of 3.14 ± 0.05 mg/mL and 2.07 ± 0.03 mg/mL, respectively. The subsequent in-silico study highlighted the particularly strong binding affinity of (E)-Farnesene, with a binding score of -7.4 kcal/mol for alpha-glucosidase, while Germacrene D displayed the highest affinity among the ligands (-7.9 kcal/mol) for the alpha-amylase target. Furthermore, the investigation into in vitro anti-inflammatory activity unveiled LOEO efficacy against tyrosinase (IC50 = 42.74 μg/mL) and LOX (IC50 = 11.58 ± 0.07 μg/mL). The in-silico analysis echoed these findings, indicating α-Cadinene's notable binding affinity of 6 kcal/mol with tyrosinase and α-Cedrene's binding score of -6.5 kcal/mol for LOX. Impressively, for both COX-1 and COX-2, α-Cedrene exhibited significant binding affinities of -7.6 and -7.3 kcal/mol, respectively. The convergence between the in vitro and in silico outcomes underscores the potential of LOEO and its constituent compounds as potent inhibitors targeting both diabetes and the inflammatory processes.

Pulse Proteins and Their Hydrolysates: A Comprehensive Review of Their Beneficial Effects on Metabolic Syndrome and the Gut Microbiome

Pulses, as an important part of the human diet, can act as a source of high-quality plant proteins. Pulse proteins and their hydrolysates have shown promising results in alleviating metabolic syndrome and modulating the gut microbiome. Their bioactivities have become a focus of research, with many new findings added in recent studies. This paper comprehensively reviews the anti-hypertension, anti-hyperglycemia, anti-dyslipidemia and anti-obesity bioactivities of pulse proteins and their hydrolysates in recent in vitro and in vivo studies, which show great potential for the prevention and treatment of metabolic syndrome. In addition, pulse proteins and their hydrolysates can regulate the gut microbiome, which in turn can have a positive impact on the treatment of metabolic syndrome. Furthermore, the beneficial effects of some pulse proteins and their hydrolysates on metabolic syndrome have been supported by clinical studies. This review might provide a reference for the application of pulse proteins and their hydrolysates in functional foods or nutritional supplements for people with metabolic syndrome.

Molecular docking studies on α-amylase inhibitory peptides from milk of different farm animals

Milk-derived peptides have emerged as a popular mean to manage various lifestyle disorders such as diabetes. Fermentation is being explored as one of the faster and efficient way of producing peptides with antidiabetic potential. Therefore, in this study, an attempt was made to comparatively investigate the pancreatic α-amylase (PAA) inhibitory properties of peptides derived from milk of different farm animals through probiotic fermentation. Peptide's identification was carried out using liquid chromatography-quadrupole time-of-flight mass spectrometry and inhibition mechanisms were characterized by molecular docking. Results obtained showed a PAA-IC50 value (the amount of protein equivalent needed to inhibit 50% of enzymes) between 2.39 and 36.1 µg protein equivalent for different fermented samples. Overall, Pediococcus pentosaceus MF000957-derived fermented milk from all animals indicated higher PAA inhibition than other probiotic derived fermented milk (PAA-IC50 values of 6.01, 3.53, 15.6, and 10.8 µg protein equivalent for bovine, camel, goat, and sheep fermented milk). Further, molecular docking analysis indicated that camel milk-derived peptide IMEQQQTEDEQQDK and goat milk-derived peptide DQHQKAMKPWTQPK were the most potent PAA inhibitory peptides. Overall, the study concluded that fermentation derived peptides may prove useful in for managing diabetes via inhibition of carbohydrate digesting enzyme PAA.

Alpha-Glucosidase Inhibitory Peptides: Sources, Preparations, Identifications, and Action Mechanisms

With the change in people's lifestyle, diabetes has emerged as a chronic disease that poses a serious threat to human health, alongside tumor, cardiovascular, and cerebrovascular diseases. α-glucosidase inhibitors, which are oral drugs, have proven effective in preventing and managing this disease. Studies have suggested that bioactive peptides could serve as a potential source of α-glucosidase inhibitors. These peptides possess certain hypoglycemic activity and can effectively regulate postprandial blood glucose levels by inhibiting α-glucosidase activity, thus intervening and regulating diabetes. This paper provides a systematic summary of the sources, isolation, purification, bioavailability, and possible mechanisms of α-glucosidase inhibitory peptides. The sources of the α-glucosidase inhibitory peptides were introduced with emphasis on animals, plants, and microorganisms. This paper also points out the problems in the research process of α-glucosidase inhibitory peptide, with a view to providing certain theoretical support for the further study of this peptide.

Preparation and Identification of Peptides with α-Glucosidase Inhibitory Activity from Shiitake Mushroom (Lentinus edodes) Protein

The shiitake mushroom is the most commonly cultivated edible mushroom in the world, and is rich in protein. This study aims to obtain the peptides with α-glucosidase inhibition activity from shiitake mushroom protein hydrolysate. The conditions of enzymatic hydrolysis of shiitake mushroom protein were optimized by response surface test. The results showed that the optimal conditions were as follows: the E/S was 3390 U/g, the solid-liquid ratio was 1:20, the hydrolysis temperature and time were 46 °C and 3.4 h, respectively, and the pH was 7. The active peptides were separated by gel filtration and identified by LC-MS/MS analysis and virtual screening. The results indicated that fourteen peptides were identified by LC-MS/MS. Among them, four new peptides (EGEPKLP, KDDLRSP, TPELKL, and LDYGKL) with the higher docking score were selected and chemically synthesized to verify their inhibition activity. The IC50 values of EGEPKLP, KDDLRSP, TPELKL, and LDYGKL for α-glucosidase inhibition activity ranged from 452 ± 36 μmol/L to 696 ± 39 μmol/L. The molecular docking results showed that the hydrogen bond and arene-cation bond were the two major interactions between four peptides and 2QMJ. The hydrogen bonds were crucial to the inhibition activity of α-glucosidase. The results indicate the potential of using the peptides from shiitake mushroom protein as functional food with α-glucosidase inhibition activity.

Preparation, structural properties, and in vitro and in vivo activities of peptides against dipeptidyl peptidase IV (DPP-IV) and α-glucosidase: a general review

Diabetes is one of the fastest-growing and most widespread diseases worldwide. Approximately 90% of diabetic patients have type 2 diabetes. In 2019, there were about 463 million diabetic patients worldwide. Inhibiting the dipeptidyl peptidase IV (DPP-IV) and α-glucosidase activity is an effective strategy for the treatment of type 2 diabetes. Currently, various anti-diabetic bioactive peptides have been isolated and identified. This review summarizes the preparation methods, structure-effect relationships, molecular binding sites, and effectiveness validation of DPP-IV and α-glucosidase inhibitory peptides in cellular and animal models. The analysis of peptides shows that the DPP-IV inhibitory peptides, containing 2-8 amino acids and having proline, leucine, and valine at their N-terminal and C-terminal, are the highly active peptides. The more active α-glucosidase inhibitory peptides contain 2-9 amino acids and have valine, isoleucine, and proline at the N-terminal and proline, alanine, and serine at the C-terminal.

Effect of Debittering with Different Solvents and Ultrasound on Carotenoids, Tocopherols, and Phenolics of Lupinus albus Seeds

Lupin seeds represent a rich nutritional source of bioactive compounds, including antioxidant molecules such as carotenoids, tocopherols, and phenolics. However, before consumption, the lupin seeds must be debittered in order to remove their bitter and toxic alkaloids. This study analyzed the impact on the bioactive compounds of Lupinus albus seeds of a recent time- and water-saving debittering method, which employs alternative washing solutions (0.5% or 1% of either NaCl or citric acid), with or without the assistance of ultrasound. The results were compared with those of two control methods using water or a NaCl solution. The sonication, when it was significant, led to a large loss of bioactive compounds, which was most likely due to its extraction capability. The seeds that were debittered without ultrasound presented high concentrations of tocopherols (172.8-241.3 mg/kg DM), carotenoids (10.9-25.1 mg/kg DM), and soluble-free (106.9-361.1 mg/kg DM), soluble-conjugated (93.9-118.9 mg/kg DM), and insoluble-bound (59.2-156.7 mg/kg DM) phenolics. The soluble-free fraction showed the greatest loss after a prolonged treatment. Overall, debittering with citric acid or NaCl preserved the highest concentration of antioxidant compounds by shortening the treatment time, thus preventing extensive leaching.