Highest Α-glucosidase Research Articles

Benzimidazole-phenoxy-1,2,3-triazole-benzyl Derivatives as the New Potent α-glucosidase Inhibitors: Design, Synthesis, In Vitro, and In Silico Biological Evaluations.

α-Glucosidase inhibitors play an important role in the treatment of type 2 diabetes mellitus. Inhibitors of the latter enzyme that are available on the market created gastrointestinal side effects and achieve to a high potent and low side effect potent α-glucosidase inhibitors is a valuable target for medicinal chemists. In this study, derivatives of benzimidazole-phenoxy-1,2,3-triazole-benzyl skeleton were introduced as new α-glucosidase inhibitors. Twelve derivatives 8a-l of target scaffold were synthesized via simple chemical re-actions with a yield between 65 and 88%. The in vitro α-glucosidase inhibition activities of these compounds was evaluated against yeast form of this enzyme. After the determination of most potent compound, the interaction of this compound with α-glucosidase was evaluated in vitro by kinetic study and in silico by docking study. Drug-likeness, pharmacokinetics, and toxicity profiles of the most potent compound were predicted by an online software. Anti-α-glucosidase assay demonstrated that all synthesized derivatives 8a-l were more potent that standard inhibitor acarbose. Representatively, 2-(4-((1-benzyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-1H-benzo[d]imidazole (compound 8a) as the most potent derivative was 150-times more potent than positive control. Kinetic study of compound 8a revealed that this compound is an uncompetitive inhibitor against α-glucosidase. Furthermore, molecular docking study showed that compound 8a with favorable binding energy attached to important residues in the α-glucosidase active site. This compound also can be an oral drug with favorable toxicity profile. Benzimidazole-phenoxy-1,2,3-triazole-benzyl derivatives 8a-l synthesized and evaluated for anti-α-glucosidase activity. All these compounds were excellent α-glucosidase inhibitor, and compound 8a demonstrated the most significant inhibition effect when com-pared with positive control.

Supercritical carbon dioxide extraction of essential oils from Madhuca Longifolia flowers and its characterization

Madhuca longifolia (mahua), a deciduous tree growing throughout the subtropical region of the India is a potential source of differentiated essential oils (EOs) with distinct bioactives. The study aimed to assess the effect of extraction methods on the quantitative and qualitative divergence in the chemical composition of flavor compounds of mahua flower EO. The advanced supercritical CO2 extraction (SCFE) and ultrasound-assisted solvent extraction (UAE) was compared to the conventional extraction techniques such as hydrodistillation (HD), enzyme-assisted hydrodistillation (HDE) and soxhlet (SOX) for their high-quality essential oil (EO) extraction efficiency. The maximum EO yield of 2.074% was obtained by SCFE followed by HD (1.64%). The presence of significant amount of terpenoids, including 2-acetyl-1-pyrroline, γ-terpinene, myrcene, α-terpineol, limonene, and L-linalool in EO was noticed with chemical profiling using GC-MS and E-Nose. SCFE method yielded EOs with best terpenoids as compared to other extraction methods. Furthermore, EO extracted using SCFE had higher total phenol and flavonoid content of 92.56mg GAE/g, 62.18mg QE/g respectively, and DPPH (100.06µg/mL), FRAP (91.52µM Fe(II)/g) antioxidant activity as compared to other extraction methods. A significantly (p<0.05) higher α-glucosidase and α-amylase inhibition of 37.16% and 43%, respectively, was shown by SCFE EOs. Total carotenoid content of EOs produced using all the extraction techniques ranged from 9.94 (HDE) to 29.673 (SCFE) mg/100g β-carotene. The “van krevelen” plots of CHNS analysis revealed ‘core metabolites’. This study illustrates that SCFE is a more effective method for EO extraction of high quality from low fat plant materials such as mahua flowers as compared to HD, HDE, SOX, and UAE.

Effect of Complexation with Different Molecular Weights of Oat β-Glucan and Sea Buckthorn Flavonoid on the Digestion of Rice Flour.

The complex of oat β-glucan (OBG) and flavonoids hampered the digestion of starch-based food and retarded the blood glucose response; however, its effect on gastric emptying and its relative mechanism have not been thoroughly investigated. By using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), antioxidant ability, and enzymic inhibitory tests for the characterization and in vitro semi-dynamic digestion of complexes of OBG (high and low molecular weights) and sea buckthorn flavonoids, we found that the higher molecular weight complex (FU) exhibited stronger ABTS and DPPH radical scavenging abilities and higher α-glucosidase and α-amylase inhibition rates. Mice fed with rice flour with FU addition exhibited the slowest gastric emptying and intestinal propulsion rates and blood glucose rise and had the lowest activity of digestive enzymes and levels of insulin, ghrelin, motilin (MTL), and relevant gene (ghrelin and GHSR mRNA) expression than those in the control and low-molecular-weight groups. This study provided scientific data for the development of foods with delayed gastric rate and hypoglycemic index for specific populations.

Enzymatic synthesis of Artemisia capillaris-derived prebiotic oligosaccharide using Leuconostoc mesenteroides MKSR dextransucrase and its potential health functional effects

This study focuses on the enzymatic synthesis of prebiotic oligosaccharide from Artemisia capillaris (AC) using Leuconostoc mesenteroides MKSR dextransucrase and explores their antidiabetic, antidementia, and antioxidant effects through in vitro experiments. A Box-Behnken design was used to optimize transglycosylation conditions to produce Artemisia capillaris-derived oligosaccharide (ACOD) containing isomaltooligosaccahrides (IMO), dextran, and A. capillaris-derived substances with high α-glucosidase inhibition (AGI). The optimized conditions were 3.62 brix of AC, 182.54 mM sucrose, and 11.304 mM maltose. ACOD completely inhibited α-glucosidase activity, with 1.52-fold increase compared to other samples, such as OD (IMO and dextran, transglycosylated by dextransucrase without AC) and AC + OD (a simple mixture of AC and OD). Additionally, ACOD showed noteworthy acetylcholinesterase (103.91%) and butyrylcholinesterase (103.30%) inhibitory activity and potent antioxidant properties in terms of DPPH radical scavenging activity (70.04%), reducing power (100%), and ferric reducing antioxidant power (FRAP). ACOD (3.60) showed a higher prebiotic index compared with AC (-23.11), OD (-2.27), and AC + OD (-9.12). In conclusion, ACOD offers enhanced multi-biological activities as a potential health-functional prebiotic. These findings hold promise for applications in functional foods and pharmaceuticals, expanding our understanding of prebiotic functionality.

In Vitro Hypoglycemic Activities of Lactobacilli and Bifidobacterium Strains from Healthy Children's Sources and Their Effect on Stimulating GLP-1 Secretion in STC-1 Cells.

A long-term use of chemical drugs cannot cure type II diabetes mellitus (T2DM) and their numerous toxic side effects can be harmful to human health. In recent years, probiotics have emerged as a natural resource to replace chemical drugs in alleviating many human ailments. Healthy children's intestines have a lot of colonized Lactobacilli and Bifidobacterium, and these beneficial bacteria can help promote overall health. The objective of this study was to isolate potential antidiabetic probiotic strains from healthy children and evaluate their application prospects. Firstly, Lactobacillus and Bifidobacterium strains were isolated from healthy children's feces and identified by the pheS or clpC genes with their respective 16S rRNA genes. Then, hydrophobicity, artificial gastrointestinal fluid tolerance, α-Glucosidase and Dipeptidyl peptidase IV (DPP-IV) inhibitory activities of isolated strains were determined, and antioxidant activities and promoting secretion of GLP-1 in STC-1 cells of candidate strains were tested. Results showed that 6 strains of Lactobacillus and Bifidobacterium were obtained from the feces of healthy children aged 3 years, respectively, including Lacticaseibacillus paracasei L-21 and L-25, Levilactobacillus brevis L-16, Lentilactobacillus buchneri L-9, Lactiplantibacillus plantarum L-8 and L-3, Bifidobacterium bifidum 11-1 and B-84, Bifidobacterium longum subsp. longum 6-1, 6-2, B42 and B53. The hydrophobicity and auto-aggregation levels of all these strains were higher than 30% and 50%, respectively, and the decrease in the number of colonies of all strains in the artificial gastrointestinal fluid was less than 2 log CFU/mL. Strains L-3, L-8, L-9, L-21, 6-1, 11-1, B53 and B84 were selected based on their high α-glucosidase inhibitory activity and DPP-IV inhibitory activity, and results of the antioxidant capacity assay showed that the remaining strains all had intense comprehensive antioxidant activity. Additionally, Lacticaseibacillus paracasei L-21 and Bifidobacterium longum subsp. longum B-53 had the most substantial prompting effect on GLP-1 secretion in the STC-1 cell line. These results indicated that Lacticaseibacillus paracasei L-21 and Bifidobacterium longum subsp. longum B-53 could be used as a potential antidiabetic strain; thus, its application as a food supplement and drug ingredient could be recommended after in vivo mitigation of type II diabetes test.

New Garden Rose (Rosa × hybrida) Genotypes with Intensely Colored Flowers as Rich Sources of Bioactive Compounds

Garden roses, known as Rosa × hybrida, hold a prominent position as one of the most important and economically valuable plants in horticulture. Additionally, their products—essential oil, rose water, concrete, and concentrate—find extensive use in the cosmetic, pharmaceutical, and food industries, due to their specific fragrances and potential health benefits. Rose flowers are rich in biologically active compounds, such as phenolics, flavonoids, anthocyanins, and carotenoids. This study aims to investigate the potential of five new garden rose genotypes with intensely colored flowers to serve as sources of biologically active compounds. Phenolic profile was evaluated by determination of total phenolic (TPC), flavonoid (TFC), and monomeric anthocyanins (TAC) contents and LC-MS/MS analysis of selected compounds. Antioxidant activity was evaluated via DPPH and FRAP assays, neuroprotective potential via acethylcholinesterase inhibition assay, and antidiabetic activity viaα-amylase and α-glucosidase inhibition assays. The flowers of investigated genotypes were rich in phenolics (TPC varied from 148 to 260 mg galic acid eq/g de, TFC from 19.9 to 59.7 mg quercetin eq/g de, and TAC from 2.21 to 13.1 mg cyanidin 3-O-glucoside eq/g de). Four out of five genotypes had higher TPC than extract of R. damascene, the most famous rose cultivar. The dominant flavonoids in all investigated genotypes were glycosides of quercetin and kaempferol. The extracts showed high antioxidant activity comparable to synthetic antioxidant BHT, very high α-glucosidase inhibitory potential, moderate neuroprotective activity, and low potential to inhibit α-amylase.

Investigation of Phytochemical, Antioxidant and Antidiabetic Potentials of Scabiosa L. (Caprifoliaceae) Species with Chemometric Methods.

In this research, the total phenolic and flavonoid amounts, phenolic compositions, in vitro antioxidant, antibacterial and antidiabetic properties of the methanol extracts obtained from Scabiosa L. (Caprifoliaceae) species distributed in the flora of Türkiye were investigated using chemometric methods. For this purpose, principal component (PCA) and agglomerative hierarchical clustering analysis were performed as chemometric methods. Chlorogenic acid, quinic acid and cyranoside were determined in the extracts. According to chemometric analysis, S. columbaria subsp. ochroleuca var. ochroleuca and S. triniifolia species were found to be valuable in terms of methanol extract yields, total phenolic and flavonoid contents, antioxidant and antidiabetic activities while S. columbaria subsp. ochroleuca var. webbiana species were found to be valuable in terms of phenolic composition. The methanol extracts of Scabiosa species showed high antioxidant activity, with high phenolic and flavonoid contents. Among the tested 13 bacteria, Scabiosa extracts showed only low activity against Klebsiella pneumoniae, Streptococcus pneumoniae and Pseudomonas aeruginosa. The extracts showed high α-amylase and α-glucosidase inhibitory activity. The results show that Scabiosa methanol extracts may be a source of alternative antioxidants that may be beneficial in slowing or preventing the progression of various oxidative stress-related diseases.

Baker's yeast of the ttkhmor with high α-glucosidase activity for cultivation on whey

Utilization of cottage cheese whey is a complex problem in terms of environmental pollution due to its high content of organic nutrients. This whey is usually discharged into the city sewer, which poses a very difficult problem for the wastewater treatment system. On the other hand, whey is widely used in bakery to improve the quality and nutritional value of bakery products, but its use is limited to this only as one of the improvers. Although it is known that yeast grown on whey is a source of essential amino acids (lysine, tyrosine, arginine), which is important in terms of enriching bread with them. However, to date, no commercially viable process has been developed for processing cottage cheese whey that completely eliminates organic waste and essentially converts cottage cheese whey into a commercially useful yeast product to use in the baking industry.

Bassia longifolia (= Madhuca longifolia): Isolation of flavan-3-ols and their contribution to the antibacterial and antidiabetic activity in vitro

Bassia longifoliaKOENIG (= Madhuca longifolia (L.) is an evergreen tree that is widely distributed throughout Nepal, India, and Sri Lanka. The bark has various traditional uses: as a paste in the treatment of cuts and wounds or internally as a decoction that is given to diabetic patients. Chemical-analytical and pharmacological investigations regarding the bark are not sufficiently available. We focused on the isolation of flavan-3-ols from the methanolic extract and their contribution to the described traditional uses in wound healing and diabetes treatment. Therefore, an antibacterial assay and an α-glucosidase assay were performed. The isolation process was performed by a combination of Sephadex®-, MCI®-Gel-, and RP-18 chromatography. The structures of the isolated compounds were elucidated by 1H- and 13C-NMR-spectroscopy including COSY, ROESY, HSQC, and HMBC methods. Optical characterization was performed by polarimetry and circular dichroism. Two monomeric, seven dimeric, six trimeric, and one tetrameric flavan-3-ols were found including one dimer and three trimers with rare epiafzelechin units. Two compounds were isolated for the first time. A fraction containing higher oligomeric and polymeric proanthocyanidins (PAs) was examined by 13C NMR spectroscopy and revealed an average degree of polymerization of 8–9. PA with cis-configurated subunits predominated at 90 % and the presence of further monohydroxylated flavan-3-ols was revealed. Minimal inhibitory concentrations (MICs) were investigated by the serial microdilution broth assay with Staphylococcus aureus. The bacterial suspension was inoculated on agar plates for determining the MICs. The α-glucosidase assay was performed in 96 well plates with α-glucosidase from Bacillus stearothermophilus. For the detection of enzyme inhibition, p-nitrophenyl-α-d-glucopyranoside was used as a substrate and after incubation absorbance was measured at 405 nm. Antibacterial effects were only found for fractions enriched with PAs or containing higher oligomeric and polymeric flavan-3-ols. All tested substances showed high α-glucosidase inhibition. Whereby 4β→8 conjugated dimers and the monomers showed the lowest inhibition, procyanidin (PC) B5 as 4β→6 conjugated and cinnamtannin A2 as tetrameric flavan-3-ol showed the highest. PAs with epiafzelechin units are rarely found in nature but their reoccurring appearance in B. longifolia could be characteristic of this plant. For its traditional uses, the antibacterial activity of the PA-enriched fractions could contribute to the wound healing process when applied to the injured skin. Moreover, all tested substances and fractions showed α-glucosidase inhibition, which could also explain the use of a decoction in the treatment of diabetes. In conclusion, pharmacological investigations could provide scientific evidence for traditional uses of B. longifolia.

Ultrasound-assisted preparation of protein–polyphenol conjugates and their structural and functional characteristics

Herein, ultrasound-assisted conventional covalent binding methods (alkali treatment, free radical mediation, and an enzymatic method) were used to prepare soybean protein isolate (SPI)-(−)-epigallocatechin gallate (EGCG) conjugates to investigate the enhancement effect of the ultrasound synergistic treatment. In addition, the influence of EGCG grafting on the structure and properties of SPI was evaluated via reactive group analysis, spectral analysis, surface hydrophobicity measurements, emulsification property assessment, and α-glucosidase inhibition analysis. The obtained results revealed that the enzymatic method produced the highest polyphenol grafting content among the conventional techniques. Meanwhile, ultrasound treatment increased the amount of grafted polyphenol species during the alkali treatment and free radical mediation procedure, decreased the grafting efficiency in the enzymatic method, and maximized the grafting efficiency during the alkali treatment. In addition, reactive group and spectral analyses demonstrated that EGCG formed C–N and C–S bonds with SPI and decreased the α-helix content in the protein structure, thereby increasing the molecular flexibility of SPI. It also produced hydrogen bonds and hydrophobic interactions, as demonstrated by the results of molecular docking. Furthermore, the EGCG grafting of SPI conducted under the ultrasound-assisted conditions endowed SPI with unique functional characteristics, including good emulsification and antioxidant properties and high α-glucosidase inhibitory activity, while the ultrasound-assisted alkali treatment resulted in the optimal functional properties. The results of this study provide new insights into the effective preparation of SPI–EGCG complexes with multiple functionalities, thereby expanding the scope of high-value SPI utilization.

Bioactive potential of ripened white cheeses manufactured in different geographical regions of Turkey.

This study investigated the potential bioactive properties of white cheeses produced in different regions of Turkey, including their potential antioxidant, antihypertensive, antidiabetic, antimicrobial, and anticancer activities. The cheese samples were analyzed both before and after in vitro digestion. The study found that all cheese samples exhibited significant angiotensin-converting enzyme inhibition activity both before (45.5%-70.1% for 0.03gcheese/mL) and after in vitro digestion (25.5%-63.5% for 0.0167g cheese/mL), whereas α-amylase inhibition activity was present in all samples (in the range of 5.1%-50.0% for 3.0×10-5 gcheese/mL) but disappeared after digestion, and α-glucosidase inhibition activity was only detected after in vitro digestion (from 20.5% to 60.4% for 5.6×10-5 gcheese/mL), indicating potential antidiabetic properties. However, antimicrobial and anticancer activities were not observed in any of the samples. The results also suggest that the bioactivity potential of white cheese may vary depending on the region of production, as cheeses from the Marmara region exhibited high α-glucosidase inhibition activity after digestion. In conclusion, while white cheese is a valuable addition to the diet due to its high nutritional value and potential health benefits. This study revealed the bioactive potential of ripened white cheese and in vivo investigations of the cheese components would better show their possible benefits. PRACTICAL APPLICATION: Although the bioactivity potentials varied among the ripened white cheese samples produced in different regions of Turkey, a consistent trend was observed in terms of their presence or absence. Our research revealed that all ripened cheese samples demonstrated significant potential antioxidant and antihypertensive activities, as well as potential antidiabetic properties. Moreover, it can be interpreted that ripened white cheese has the potential to reduce the digestion of carbohydrates when consumed with carbohydrate-rich foods. Although the present results provide limited practical findings directly applicable to the industry, if the data and information obtained from this study are further explored and further studies delving into specific mechanisms of bioactive components could emerge.

Comparison of inhibitory activities of 50 Salvia species against α-Glucosidase.

Type 2 diabetes is a common metabolic disease affecting millions of people worldwide. α-Glucosidase inhibitors can be used as one of the therapeutic approaches to decrease the postprandial glucose levels through the inhibition of carbohydrate hydrolysis. Medicinal plants are one of the main sources of α-glucosidase's natural inhibitors. In this study, we report the inhibitory effects of 50 different accessions of 32 Salvia species against α-glucosidase. To estimate the relative potency of the crude extracts, the inhibitory activities of the 80% methanol of the plants extracts were determined in three different concentrations (1000, 500 and 250µg/ml) and compared to that of acarbose as the positive control. S. multicaulis, S. santolinifolia, S. dracocephaloides, and S. eremophila were stronger inhibitors than acarbose (p < 0.05) with IC50 values in the range of 26.23- 92.35µg/mL. According to the LC-PDA-ESIMS and NMR analysis of crude extracts of the studied Salvia species, 8 phytochemicals including luteolin-7-O-glucoside (1) luteolin-7-O-glucuronide (2), apigenin-7-O-glucoside (3), apigenin-7-O-glucuronide (4), Hispidulin-7-O-glucuronide (5), hispidulin-7-O-glucoside (6), rosmarinic acid (7), carnosol (8) and carnosic acid (9) were identified as the most common α-glucosidase inhibitors. The above compounds constituted the major compounds in the active Salvia species in the range of 1.5-95.0%. Among them rosmarinic acid (39-95%) was detected in almost all potent α -glucosidase inhibitor species. Therefore, it can be considered as a biochemical marker in the antidiabetic Salvia species in addition to the other minor compounds. Considering the high α-glucosidase inhibitory potential of the four- out of fifty Salvia species, they are suggested for further in vivo antidiabetic tests as potential medicinal plants.

Oral administration of Bifidobacterium longum WHH2270 ameliorates type 2 diabetes in rats.

Accumulating evidence suggests that specific probiotic strains exert hypoglycemic effects on type 2 diabetes mellitus (T2DM), and probiotic strains within Bifidobacterium exhibit potential beneficial effects on T2DM. In this study, α-glucosidase inhibitory activities of 14 Bifidobacterium strains were assessed in vitro. The hypoglycemic effects of Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity (42.03%) were then investigated in a high-fat diet/streptozotocin-induced T2DM rat model. Oral administration of WHH2270 (4 × 109 CFU/kg/day) for 8weeks significantly reversed the reduced body weight and ameliorated the levels of fasting blood glucose, serum triglyceride, serum total cholesterol, glucose tolerance, and insulin resistance in T2DM rats. Using 16S rRNA high-throughput sequencing of feces, WHH2270 was revealed to reshape the gut microbiome composition by increasing the abundances of Lactobacillus and Bifidobacterium and decreasing the abundances of UCG_005, Clostridium, and Faecalibacterium in T2DM rats. Besides, the fecal levels of short-chain fatty acids (SCFAs) including acetate, propionate, and butyrate were also elevated after WHH2270 administration. Moreover, the gene expressions of SCFA receptors FFAR2 and FFAR3 in the colon and pancreas of T2DM rats were restored by WHH2270 administration, accompanied by increased levels of serum acetate. In summary, these results provide evidence that WHH2270 has the potential to improve T2DM symptoms by alleviating hyperglycemia, which was associated with changes in the gut microbiome composition and SCFA production. PRACTICAL APPLICATION: Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity may serve as a promising hypoglycemic agent for the treatment of T2DM.

Optimization of microwave assisted extraction and biological activities of total flavonoids from grape seed using response surface methodology

Aiming to reduce the environmental contamination and resource wastage generated by discarded grape seed, the management of discarded grape seed should be carried out and their potential bioactivities and pharmacological properties ought to be exploited to the fullest extent possible. A Box–Behnken design of response surface methodology was employed to further optimize microwave-assisted extraction setting for grape seed total flavonoids (GSFE). In addition, the extract (GSFE) of total flavonoids obtained were refined through AB-8 macroporous resin for obtaining more pure flavonoid (GSFP) with determination of their in vitro hypoglycemic activity and antioxidant activity. The results indicated that following optimized extraction conditions were achieved: ethanol concentration 50% liquid-solid ratio 21:1 mL/g, microwave power 540 W, microwave time 126 s. Below mentioned conditions, the extraction yield reached an average experimental value (1.979 mg/g), representing 1.69 times higher than that of water extraction (1.17 mg/g). In contrast to GSFE, the purity of GSFE after purification (GSFP) exhibited a high degree of purity at 13.753 mg/g, representing nearly 2.50 times that of GSFE (3.926 mg/g). GSFP possessed high α-glucosidase and α-amylase inhibitory activities as well as DPPH and ABTS+ free radical scavenging activities with an IC50 value of 0.00641, 0.0257, 0.0669 and 0.0708 mg/mL, inferior to that of GSFE (0.0514, 0.186, 0.129 and 0.223 mg/g). Within present work, the microwave technique for extraction of total flavonoids from grape seeds was investigated with an efficient and cost-effective extraction method. Total flavonoids of grape seeds have certain in vitro blood glucose and antioxidant activity, and the purified total flavonoid biological activity has improved, laying the foundation for further study of its pharmacological activity.

Optimisation of ultrasonic-assisted extraction and biological activity of total flavonoids from leaves of Murrayae exotica using response surface methodology

ABSTRACT Murrayae exotica is a traditional Chinese medicine widely grown in southeast China. A Box–Behnken design of response surface methodology was employed to further optimise ultrasonic-assisted extraction conditions for M. exotica leaves total flavonoids (MELTF). The results showed that the optimised extraction conditions were an ultrasonic power of 240 W, an ultrasonic temperature of 60 °C, a solvent concentration of 76%, an ultrasonic time of 55 min and a liquid–solid ratio of 22 mL · g−1. Under these conditions, 8.59 ± 0.34 mg · g−1 was achieved as the mean experimental value of extraction yield, which amounts to 2.56 times that of ethanol leaching extraction. As compared to MELTF, MELTF after purification (MELPTF) had a higher purity of 9.96%, which was nearly nine times higher than that of MELTF (1.26%). As compared to MELTF, MELPTF had higher α-glucosidase and α-amylase inhibitory activities as well as DPPH· and ABTS·+ scavenging activities with IC50 values of 0.021, 0.094, 0.245 and 0.113 mg · mL−1, which are 1.33, 2.12, 3.17 and 1.78 times higher than those of MELTF (0.028, 0.199, 0.777 and 0.201 mg · mL−1). The study thus demonstrates the eligibility of MELPTF to be considered as a multifunctional bioactive ingredient having potential applications in anti-hyperglycaemic pharmaceutical formulation and as an antioxidant in functional foods.

Sericin mediated gold/silver bimetallic nanoparticles and exploration of its multi-therapeutic efficiency and photocatalytic degradation potential

The current investigation aimed at bimetallic gold-silver nanoparticles (Au/Ag NPs), here called BM-GS NPs, synthesis using sericin protein as the reducing agent in an easy, cost-effective, and sustainable way. The obtained BM-GS NPs were characterized by UV–Visible spectroscopy, Transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS), atomic force microscopy (AFM), Dynamic light scattering (DLS) and Zeta potential, X-ray Powder Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and Thermogravimetric analysis followed by evaluation of its multitherapeutic and photocatalytic degradation potentials. The TEM analysis revealed its spherical nature and the EDS result displayed the presence of both Ag and Au elements, confirming the synthesis of BM-GS NPs. The XRD pattern verified the crystalline nature of the nanoparticles (NPs). The DLS analysis showed an average size of 86.08 d nm and the zeta potential showed a highly negative value (−26.3 mV) which specifies that the generated bimetallic NPs are stable. The BM-GS NPs exhibited positive wound healing potential (with 63.38% of wound closure rate at 25 μg/ml, as compared to 54.42% by the untreated control) with very negligible toxicity effect on the cell viability of the normal keratinocyte cells. It also demonstrated promising antioxidant properties with 65.00%, 69.23%, and 63.03% activity at 100 μg/ml concentration for ABTS (2, 2-azinobis) (3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (1, 1 diphenyl-2-picrylhydrazyl) and SOD (superoxide dismutase enzyme) assays respectively, antidiabetic potential (with a significantly high α-glucosidase inhibition potential of 99.69% at 10μg/ml concentration and 62.11% of α-amylase enzyme inhibition at 100 μg/ml concentration) and moderate tyrosinase inhibitory potential (with 17.09% at 100 μg/ml concentration). Besides, it displayed reasonable antibacterial potential with the diameter of zone of inhibition ranging between 10.89 and 12.39 mm. Further, its antibacterial mode of action reveals that its effects could be due to being very smaller, the NPs could have penetrated inside the cellular membrane thereby causing rupture and damage to the interior materials leading to cellular lysis. The photocatalytic evaluation showed that synthesized BM-GS NPs have the efficiency of degrading methylene blue dye by 34.70% within 3 h of treatment. The above findings revealed the multi-therapeutic efficacy of the sericin globular protein-mediated BM-GS NPs and its potential future applications in the cosmetics and food sector and environmental contamination management industries.

Identification of novel α-glucosidase inhibitory peptides in rice wine and their antioxidant activities using in silico and in vitro analyses

Many peptides are contained in rice wine, which may have various bioactivities, and need to be investigated. The aim of this study was to identify novel peptides with high α-glucosidase inhibition and antioxidant activities in rice wine and to illustrate their underlying mechanisms. Peptide composition, α-glucosidase inhibition and antioxidant activities of the different elution fractions from macroporous resin adsorption chromatography were investigated. Potentially bioactive peptides were screened via in silico analyses and validated by in vitro experiments, and then, their mechanisms were further investigated by molecular docking and molecular dynamics simulations. Results showed that the peptides from 50% ethanol-eluted rice wine (50%-RP) exhibited strong α-glucosidase inhibition and antioxidant activities. Three novel peptides, SSLFR, QFTPR and FTYPR screened out by in silico analyses, were confirmed to have good α-glucosidase inhibition and antioxidant activities, and FTYPR exhibited the best bioactivities. These peptides could bind to ABTS and DPPH radicals and the active site of α-glucosidase through hydrogen bonding, Pi bonding and van der Waals forces. This study may not only provide new knowledge for the health effects of rice wine, but also supply theoretical bases for the development of health products of rice wine to improve its economic value.

Polyphenol Profile and In Vitro Antioxidant and Enzyme Inhibitory Activities of Different Solvent Extracts of Highland Barley Bran

Five different solvent extracts of highland barley bran were analyzed and compared for their polyphenol profile, antioxidant activity, and α-glucosidase and α-amylase inhibitory activities. The highland barley bran acetone extract had the highest total phenolic content, total flavonoid content, and antioxidant capacity. It was followed by the methanol and ethanol extracts, while n-butanol and ethyl acetate extracts exhibited lower measured values. Diosmetin, luteolin, protocatechuic acid, vanillic acid, ferulic acid, phlorogucinol, diosmin, isoquercitrin, catechin, and isovitexin were among the most abundant phenolic compounds identified in different solvent extracts, and their concentrations varied according to the solvent used. The highest α-glucosidase and α-amylase inhibitory activity were observed in the ethyl acetate extract of highland barley bran, followed by the acetone and methanol extracts. In contrast, n-butanol and ethanol extracts exhibited lower measured values. The different solvent extracts were effective inhibitors for α-glucosidase and α-amylase with activity reaching to 34.45-94.32% and 22.08-35.92% of that of positive control acarbose, respectively. There were obvious correlations between the phenolic content and composition of different solvent extracts and their in vitro antioxidant activity, α-glucosidase inhibition activity and α-amylase inhibition activity. Black barley bran is an excellent natural raw material for developing polyphenol-rich functional foods and shows good antioxidant and hypoglycemic potential to benefit human health.

Optimization and Molecular Mechanism of Novel α-Glucosidase Inhibitory Peptides Derived from Camellia Seed Cake through Enzymatic Hydrolysis.

In recent years, food-derived hypoglycemic peptides have received a lot of attention in the study of active peptides, but their anti-diabetic mechanism of action is not yet clear. In this study, camellia seed cake protein (CSCP) was used to prepare active peptides with α-glucosidase inhibition. The optimization of the preparation of camellia seed cake protein hydrolyzed peptides (CSCPH) was conducted via response surface methodology (RSM) using a protamex with α-glucosidase inhibition as an indicator. The optimal hydrolysis conditions were pH 7.11, 4300 U/g enzyme concentration, 50 °C hydrolysis temperature, and 3.95 h hydrolysis time. Under these conditions, the α-glucosidase inhibition rate of CSCPH was 58.70% (IC50 8.442 ± 0.33 mg/mL). The peptides with high α-glucosidase inhibitory activity were isolated from CSCPH by ultrafiltration and Sephadex G25. Leu-Leu-Val-Leu-Tyr-Tyr-Glu-Tyr (LLVLYYEY) and Leu-Leu-Leu-Leu-Pro-Ser-Tyr-Ser-Glu-Phe (LLLLPSYSEF) were identified and synthesized for the first time by Liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) analysis and virtual screening with IC50 values of 0.33 and 1.11 mM, respectively. Lineweaver-Burk analysis and molecular docking demonstrated that LLVLYYEY was a non-competitive inhibitor of α-glucosidase, whereas LLLLPSYSEF inhibited α-glucosidase, which displayed a mixed inhibition mechanism. The study suggests the possibility of using peptides from Camellia seed cake as hypoglycaemic compounds for the prevention and treatment of diabetes.

An epidemiological analysis of Nocardia seriolae isolated from a wide range of aquatic animals in Taiwan, based on their genotype and enzymatic activity.

Chronic disease following Nocardia seriolae infection in a wide range of aquatic animals has been reported in many Asian countries and recently in America and Mexico. This study aimed to investigate the epidemiological relationship among N. seriolae isolates in Taiwan by investigating their genotype and enzymatic activities. A total of 66 strains isolated from 14 known and four unknown host fish from five sites in Taiwan were characterized using five combined methods. High genotypic diversity was recognized among the isolates with 10 pulsotypes being identified from the pulsed-field gel electrophoresis method and 21 reptypes from the repetitive extragenic palindromic amplification method; however, no natural plasmids were detected in this bacterial population. Pulsotypes A8 and RI analysed by PFGE and repPCR, respectively, were found to be predominant within five sites in Taiwan over 17 years of isolation. Enzymatically, the majority of isolates displayed high leucine arylamidase, β-glucosidase and α-glucosidase activities but were negative for lipase, α-galactosidase, β-glucuronidase, N-acetyl-glucosaminidase, α-mannosidase and α-fucosidase activities. We identified a strong association between genotype and enzymatic activity since the majority of pulsotypes displayed the same type of enzymatic profile. This study provides comprehensive and potential epidemiological data, which will aid the fish farming activities and prevention method development.