Α-amylase Activity Research Articles

Disruption of the OsWRKY71 transcription factor gene results in early rice seed germination under normal and cold stress conditions

Abstract Background Early seed germination in crops can confer a competitive advantage against weeds and reduce the time to maturation and harvest. WRKY transcription factors regulate many aspects of plant development including seed dormancy and germination. Both positive and negative regulators of seed germination have been reported in many plants such as rice and Arabidopsis. Using a transient expression system, we previously demonstrated that OsWRKY71 is a negative regulator of gibberellin (GA) signaling in aleurone cells and likely forms a “repressosome” complex with other transcriptional repressors. Hence, it has the potential to impact seed germination properties. Results In this study, we demonstrate that OsWRKY71, a Group IIa WRKY gene, appeared at the same time as seed-bearing plants. Rice mutants lacking OsWRKY71 have seeds and embryos that germinate earlier than wildtype controls. In oswrky71 aleurone layers, α-amylase activity was hypersensitive to stimulation by GA3 and hyposensitive to inhibition by abscisic acid (ABA). Early germination in oswrky71 intact seeds was also hyposensitive to ABA. Transcriptomic profiling during embryo germination and early post-germination growth demonstrates that OsWRKY71 influences the expression of 9–17% of genes in dry and imbibing embryos. Compared to wildtype embryos, the mutant transcriptomes have large temporal shifts at 4, 8 and 12 h after imbibition (HAI). Importantly, many genes involved in the ABA-dependent inhibition of seed germination were downregulated in oswrky71-1. This mutant also displayed altered expression of multiple ABA receptors (OsPYLs/RCARs) that control ABA signaling and the VP1-SDR4-DOG1L branch of ABA signaling that promotes seed dormancy. Association studies reveal an OsWRKY71-containing quantitative trait locus involved in low-temperature seed germinability, qLTG-2. Indeed, oswrky71 seeds germinated early at 15 °C. Conclusions Rice Group-IIa WRKY transcription factor OsWRKY71 is a master regulator of germination that influences the expression of 9–17% of genes in dry and imbibing embryos. It is also most likely the primary candidate of low-temperature seed germinability QTL, qLTG-2. We propose that knockouts of OsWRKY71 can generate rice varieties with improved germination properties under normal or low-temperature conditions.

Assessment of the germination power and α-amylase activity in the soil rhizospheric compartment amended with olive mill waste waters.

Olive mill wastewater (OMWW) was used in ferti-irrigation due to its high water content, as well as its organic and mineral richness. However, this by-product also contains elevated levels of polyphenols, which may pose phytotoxic risks to soil microbiota and plants over time. To address this concern, we conducted a thorough examination of the phenolic composition of OMWW and the phenolic content of amended soils using HPLC analysis. Additionally, we assessed the residual phytotoxicity of OMWW across various soil rhizospheric layers (0-30 cm, 30-60 cm, and 60-90 cm). Standard germination tests were performed using soil extracts with sorghum (Sorghum bicolor) and tomato (Solanum lycopersicum) seeds. We also measured α-amylase activities in the germinated seeds for both species, comparing them to raw OMWW and control soil extracts. HPLC analysis revealed that tyrosol, ferulic acid, and hydroxytyrosol were the predominant phenolic compounds in crude OMWW, while no detectable compounds were found in the soil extracts. Germination tests indicated minimal toxicity in the topsoil amended with OMWW, with a noticeable reduction in residual phytotoxicity at greater depths. These results aligned with the α-amylase activity assessments, which demonstrated significantly higher enzyme activity in the deeper soil layers (30-60 cm and 60-90 cm), with no substantial differences compared to control extracts.

Discovery of α-amylase and α-glucosidase dual inhibitors from NPASS database for management of Type 2 Diabetes Mellitus: A chemoinformatic approach.

Postprandial hyperglycemia, typical manifestation of Type 2 Diabetes Mellitus (T2DM), is associated with notable global morbidity and mortality. Preventing the advancement of this condition by delaying the rate of glucose absorption through inhibition of α-amylase and α-glucosidase enzymatic activities is of utmost importance. Finding a safe antidiabetic drug is essential since those that are currently on the market have drawbacks like unpleasant side effects. The current study utilized computer-aided drug design (CADD), as a quick and affordable method to find a substitute drug template that can be used to control postprandial hyperglycemia by modulating the activity of α-amylase and α-glucosidase enzymes. The Natural Products Activity and Species database (NPASS) (30,926 compounds) was screened in silico, with a focus on evaluating drug-likeness, toxicity profiles and ability to bind on a target protein. Two molecules NPC204580 (Chrotacumine C) and NPC137813 (1-O-(2-Methoxy-4-Acetylphenyl)-6-O-(E-Cinnamoyl)-Beta-D-Glucopyranoside) were identified as potential dual inhibitors for α-amylase and α-glucosidase with free binding energies of -14.46 kcal/mol and -12.58 kcal/mol for α-amylase, and -8.42 kcal/mol and -8.76 kcal/mol for α-glucosidase, respectively. The molecules showed ionic, H-bonding and hydrophobic interactions with critical amino acid residues of both enzymes. Moreover, 100 ns molecular dynamic simulations showed that both molecules are stable on the receptors' active sites based on root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the Generalized Born surface area (GBSA) energy calculated. The two compounds are thus promising therapeutic agents for T2DM that merit further investigation due to their excellent binding energies, encouraging pharmacokinetics, toxicity profiles, and stability as demonstrated in simulated studies.

Phytochemical Compounds, and Antioxidant, Anti-Hyperglycemic, and Anti-Inflammatory Activity of Microencapsulated Garambullo (Myrtillocactus geometrizans) Extract During In Vitro Digestion and Storage

Garambullo fruit (Myrtillocactus geometrizans) is a rich source of phytochemical compounds that exhibit antioxidant, anti-hyperglycemic, and anti-inflammatory activities, helping to prevent diseases associated with oxidative stress. The objective of this study was to evaluate phenolic compound (PC), betalain (BL), betaxanthin (BX), and betacyanin (BC) contents, and in vitro biological activities (antioxidant, anti-hyperglycemic, and anti-inflammatory) in microencapsulated garambullo extract during in vitro gastrointestinal digestion and storage. Microencapsulation was performed using spray drying. Arabic Gum (GA, 10% in feed solution) and soy protein isolate (SPI, 7% in feed solution) were used as wall materials. After in vitro digestion, the microcapsules (GA, SPI) exhibited higher bioaccessibility (p ≤ 0.05) of PC, BL, BX, and BC, and higher antioxidant activity (AA), compared to the non-encapsulated extract. Both microcapsules showed bioaccessibility in anti-hyperglycemic activity: α-amylase (GA: 90.58%, SPI: 84.73%), α-glucosidase (GA: 76.93%, SPI: 68.17%), and Dipeptidyl peptidase-4 (DPP-4) (GA: 52.81%, SPI: 53.03%); and in anti-inflammatory activity: cyclooxygenase-1 (COX-1) (GA: 78.14%, SPI: 77.90%) and cyclooxygenase-2 (COX-2) (GA: 82.77%, SPI: 84.99%). During storage, both microcapsules showed a similar trend with a significant decrease (p ≤ 0.05) in PC (GA: 39.29%, SPI: 39.34%), BL (GA: 21.17%, SPI: 21.62%), BX (GA: 23.89%, SPI: 23.45%), BC (GA: 19.55%, SPI: 19.84%), and AA (GA: 41.59%, SPI: 42.51%) after 60 days at 30 °C. Both microcapsules retained anti-hyperglycemic activity evaluated by the inhibitory activity of α-amylase (GA: 68.84%, SPI: 70.18%), α-glucosidase (GA: 59.93%, SPI: 58.69%), and DPP-4 (GA: 52.81%, SPI: 53.01%), and anti-inflammatory activity evaluated by the inhibitory activity of COX-1 (GA: 82.18%, SPI: 82.81%) and COX-2 (GA: 81.11%, SPI: 81.08%). Microencapsulation protected the phytochemical compounds and in vitro biological activities by allowing controlled release during in vitro digestion compared to the non-encapsulated extract. However, after 60 days storage at 30 °C, 60% of PC and AA, 80% of BL, BX, and BC, and 20–45% of the anti-hyperglycemic and anti-inflammatory activity were lost.

Green Synthesis of Iron Oxide NPs (IONPs) by Using Aqueous Extract of Parthenium hysterophorus Linnaeus for the In-vitro Antidiabetic and Anti-inflammatory Activities

The Parthenium hysterophorus Linnaeus is one of the anti-inflammatory and antidiabetic ethnomedicine. Therefore the formulation of this plant as nanoparticles will be fruitful anti-inflammatory and antidiabetic as compared to conventional extract. In the current study, the aqueous kernel extract from Parthenium hysterophorus Linnaeus was subjected to synthesize iron oxide nanoparticles (IONPs) and explored their anti-inflammatory and anti-diabetic potentials. The results indicate that the aqueous kernel extract effectively produced IONPs, which were verified using standard analytical methods. UV-visible spectrophotometer analysis was used to check the formation of IONPs. The Fourier-transform infrared spectroscopy (FTIR) was used to check numerous functional groups from the valuable phytochemicals present in the extract. These functional groups play crucial roles as reducing, capping, and stabilizing agents during the synthesis of IONPs. Additionally, scanning electron microscopy (SEM) were utilized to investigate the surface characteristics of the nanoparticles. Notably, the IONPs fabricated from the extract demonstrated promising anti-inflammatory activity, inhibiting Human RBC by 79% and Heat Induced Hemolysis by 72%, as well as showing anti-diabetic potential with 60% inhibition of yeast glucose uptake and 72% inhibition of α-amylase activity, all at a concentration of 100 μg mL-1. These effects were partly comparable to standard drugs with anti-inflammatory activity of 85% inhibition of Human RBC and 78% inhibition of Heat Induced Hemolysis, and anti-diabetic activity of 67% inhibition of yeast glucose uptake and 78% inhibition of alpha amylase.

Association of the Volumes of Limbic Brain Structures with the Development of Psychoneurological Disorders in Patients with Ischemic Stroke

Post-stroke depressive disorders (PSD) and post-stroke cognitive impairments (PCI) are frequent consequences of ischemic stroke (IS). The study was focused on exploring possible associations between relative volumes of cortical and limbic brain structures during the acute period of IS, and changes in biochemical indices of hypothalamic-pituitary-adrenal, sympathoadrenal medullary and inflammatory systems, with the development of PSD or PCI after mild or moderate IS. Patients developing PSD later on had significantly smaller relative volumes of the hippocampus, entorhinal cortex, and temporal pole versus patients without depressive symptoms. PCI development was associated with significantly smaller volumes of temporal pole and supramarginal gyrus versus patients without cognitive changes. Multiple logistic regression analysis showed higher likelihood of developing PSD in patients with smaller temporal pole volume (β0 =10.9; β = –4.27; p = 0.04) and in-creased salivary α-amylase activity (β0 = –3.55; β = 2.68e–05; p = 0.02). PCI likelihood was higher in patients with smaller supramarginal gyrus volume (β0 = 3.41; β = –0.99; p = 0.047), smaller temporal pole volume (β0 = 3.41; β = –3.12; p = 0.06), and increased hair cortisol concentration at admission (index of accumulated stress load within a month before IS; β0 = 3.41; β = –0.05; p = 0.08). The data support the hypothesis suggesting predisposition to PSD and PCI and multi hit scenarios of their pathogenesis with IS providing a final hit.

The Heating Under Micro Variable Pressure (HUMVP) Process to Decrease the Level of Saponin in Quinoa: Evidence of the Antioxidation and the Inhibitory Activity of α-Amylase and α-Glucosidase

To reduce the level of saponin while preserving essential nutrients and antioxidative properties in quinoa (Chenopodium quinoa), this study delves into the optimization of the HUMVP process and thoroughly examines its effects on antioxidation as well as its inhibitory influence on α-amylase and α-glucosidase. The optimal HUMVP conditions involved wetting quinoa grains with 6% water (pH = 6.0) and subjecting them to a 4 min treatment under 0.35 MPa pressure. The values of •OH, DPPH, and ABTS•+ scavenging rate of the extracts from the quinoa sample (named Q2HUMVP) treated under the optimum HUMVP process were 70.02, 87.13, and 50.95%, respectively. Furthermore, the treatment preserved 95.20% of polyphenols and 73.06% of flavonoids, while the saponin content was reduced to 23.13% of that in raw quinoa. Notably, Q2HUMVP extracts demonstrated superior inhibitory activity against α-amylase and α-glucosidase compared to dehulled quinoa samples. The inhibition exhibited by the quinoa sample extracts on α-amylase and α-glucosidase was found to be reversible.

Enzyme Inhibitory Activities and RP-HPLC Analysis of Geranium and Erodium Species.

The genera Geranium and Erodium (Geraniaceae) have been documented to possess diverse ethnopharmacological uses, including diabetes mellitus. Relevant to their ethnopharmacological use, the current study aimed to evaluate the α-glucosidase, α-amylase, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzyme inhibitory activity of ethanol extracts from 46 samples belonging to thirty-one species of Geranium (20) and Erodium (11) collected throughout Türkiye. The majority of the extracts displayed a marked α-glucosidase and α-amylase inhibitory activity. Besides, 23 extracts out of 46 exhibited a concentration-dependent inhibitory effect over 50 % towards AChE. The highest AChE inhibition was found in G. subcaulescens collected from Konya with an IC50 value of 4.73±2.96 μg/mL. E. somanum, E. leucanthum, and E. sipthorpianum exhibited the most potent α-glucosidase inhibitory activity, while E. birandianum and E. pelargoniiflorum were the most active extracts against AChE and BChE, respectively. Three extracts that had inhibitory activity over 50 % against four of the enzymes were selected and proceeded to RP-HPLC analysis. Geraniin and ellagic acid were identified as major compounds in the active extracts. Most species screened in the current study were examined for the first time against α-glucosidase, α-amylase, AChE, and BChE.

DESIGN, SYNTHESIS, AND BIO PROFILING OF 2, 3-DIHYDROQUINAZOLIN-4(1H)-ONE DERIVATIVE AS TYPE II DIABETES AGENTS: A COMPREHENSIVE IN SILICO, IN VITRO, AND IN VIVO STUDY

Objective: Diabetes mellitus is a significant global health challenge, with Type 2 Diabetes Mellitus (T2DM) being a leading cause of mortality worldwide, demanding the need for effective interventions by developing innovative therapeutic strategies or novel antidiabetic agents. This study explores in silico, in vitro, and in vivo approaches to identify the most potent 2,3-Dihydroquinazolin-4(1H)-One derivative molecule with antidiabetic activity. Methods: Eleven new derivatives were designed, studied in silico to identify the most promising compounds, synthesized, studied spectrally to describe them, and evaluated for both in vitro and in vivo investigations. Alpha amylase and alpha-glucosidase inhibitory activities were investigated in vitro. The endogenous suppression of glucose synthesis in Hepatoblastoma cell line 2(HepG2) cells and the in vitro glucose absorption assay on cultivated L6 cell lines were conducted. To assess the ability of the newly synthesized compounds to prevent diabetes, in vivo investigations were conducted on Streptozotocin (STZ)-induced diabetic rats and the effects on various biochemical parameters were identified.Results: Leveraging computational methods, the QZ9 molecule was identified with stable interactions with key biomolecules associated with T2DM. Subsequent in vitro assays confirmed the inhibitory effects of QZ2, QZ8, and QZ9 on alpha-amylase and alpha-glucosidase activities, suggesting their potential as enzyme inhibitors. Additionally, QZ8 and QZ9 demonstrated enhanced glucose uptake and production inhibition in HepG2 cells, indicating their role in improving glucose homeostasis. In vitro, the top-ranked molecules QZ2, QZ8, and QZ9 were analyzed to validate the in silico findings and assess their potential as therapeutic agents for T2DM. The inhibition of α-amylase activity by QZ2, QZ8, and QZ9 was dose-dependent, with maximum inhibition observed at 1000 µg/ml: 57.33% for QZ2, 52.21% for QZ8, and 87.16% for QZ9. Similarly, α-glucosidase inhibition at 1000 µg/ml was 59.96% for QZ2, 53.50% for QZ8, and 81.51% for QZ9. Both QZ8 and QZ9 significantly increased glucose uptake and inhibited glucose production in HepG2 cells, with maximum glucose production inhibition at 100 µg/ml: 62.22% for QZ8 and 62.35% for QZ9. These findings suggest that QZ8 and QZ9 contribute to glucose homeostasis. QZ9 demonstrated superior enzyme inhibition compared to QZ2 and QZ8, with α-amylase and α-glucosidase inhibition up to 87.16% and 81.51%, respectively, at 1000 µg/ml. In vivo investigations in Diabetic rat models further confirmed the efficacy of these compounds by showing significant reductions in blood glucose levels. These results suggests the potentiality of QZ9 as a promising novel Antidiabetic agent.Conclusion: Combining computational predictions with experimental validations, this integrated approach highlights the promise of 2,3-Dihydroquinazolin-4(1H)-One derivative QZ9 as a novel antidiabetic agent, warranting further investigation for clinical translation.

Efficient synthesis and molecular docking of new organoselenium and organosulphur compounds as dual inhibitors for the therapy of Alzheimer's disease as well as Diabetes Mellitus

There are several oxidative stress-related pathways interconnecting Alzheimer's disease and type II diabetes, two public health problems worldwide. Therefore, development of potential multifunctional agents for dual therapy of AD and T2D has received much attention. The present study was aimed to synthesize a new selenocarbonyl and thiocarbonyl compounds and evaluating multifunctional ability of them in the AD and T2D dual therapy. [(PhP(Se)(μ-Se)]2, the selenium counterpart of the well-known sulfur transfer Lawesson's reagent, is a useful reagent for the synthesis of selenocarbonyl compounds. For the conversion of various carbonyl compounds into thiocarbonyl derivatives was formulated by its reaction with LR, [(p-MeOC6H4)P(S)(μ-S)]2. The reactions are carried out under mild conditions and afforded the seleno and thio compounds in good yields. By measuring the newly created compounds' overall antioxidant capacity, iron-reducing ability, and scavenging activity against DPPH and ABTS radicals, they were investigated as antioxidant molecules. Additionally, all the compounds were subjected to further investigation by testing their acetylcholinesterase, α-amylase and α-glucosidase inhibiting activity. According to our findings, the amide derivatives exhibited more promising biological inhibitory actions in comparison to the other compounds. With a total antioxidant capacity (TAC) of 75.11 ± 0.04 mg gallic acid/gm, an iron-reducing power (IRP) of 69.86 ± 0.04 µg/mL, a DPPH radical-scavenging activity (%) of 55.89 ± 0.03 (IC50 = 6.19 ± 0.03 µg/ml), and an ABTS radical-scavenging activity (%) of 61.14 ± 0.03 (IC50 = 4.97 ± 0.06 µg/mL), benzoselenoamide derivative 11b in particular showed the highest antioxidant activities when compared to ascorbic acid. It also affected the activity of acetylcholinesterase through competitive inhibition, which was on par with Donepezil as indicated by in vitro percentage of inhibition 57.44 ± 0.07 % (IC50 = 5.13 ± 0.03 µg/mL). Additionally, it exhibited a comparable level of inhibition to Acarbose in the in vitro percentage of inhibition for α-amylase and α-glucosidase activity, 53.17 ± 0.03 (IC50 = 4.32 ± 0.02) and 42.92 ± 0.03 (IC50 = 2.99 ± 0.02) respectively. Furthermore, molecular docking calculations were made to explain the dual inhibitors for the therapy of Alzheimer's as well as Diabetes Mellitus for all synthesized compounds. In silco docking results revealed that compound 11b were the top docked bioactive compounds against the target proteins (AChE as a cholinergic enzyme and 11-Beta-Hydroxysteroid dehydrogenase-1(11β-HSD1)). After these calculations, ADMET analysis was performed to examine the drug properties of all novel compounds. Overall, the results demonstrated that the organoselenium-based compounds might serve as possible drugs for the therapy of Alzheimer's disease as well as Diabetes Mellitus.

Chemical composition and influence of essential oil from Croton pulegiodorus Baill. leaves on the nutrition and survival of Sitophilus zeamais Mots. (Coleptera: Dryophthoridae) as well as survival and behavior of Nasutitermes corniger Mots. (Blattodea: Termitidae)

Essential oils have been studied to develop sustainable alternatives for controlling pest-species. This study determined the chemical composition and toxicity of an essential oil from Croton pulegiodorus leaves against Sitophilus zeamais and Nasutitermes corniger. Ascaridole (22.75%) and camphor (18.11%) were the major compounds. The essential oil showed toxicity upon ingestion on S. zeamais, with LC50 and LC90 of 24.24 and 46.76 μL/g for 15 days, respectively. It presented a moderate (10.0 and 12.5 μL/g) to strong (15 μL/g) deterrent effect, interfering with nutritional parameters, causing a reduction in the relative consumption rate, relative biomass gain rate and efficiency in conversion of ingested food. Furthermore, it stimulated in vitro S. zeamais β-D-xylanase (+33.39%), endoglucanase (+8.28%), exoglucanase (+84.77%), and α-amylase (+359.18%) activities and reduced in vitro the activity of trypsin-like enzymes (-79.67%). The essential oil showed fumigant effect against N. corniger termites with LC50 and LC90 (24 h) of 0.57 and 3.26 μL/mL of air for workers and 1.63 and 4.74 μL/mL of air for soldiers respectively. In workers, it caused 100% mortality through contact in 2.08 and 0.49 min (at 0.4 μL/μL and neat oil). A significant increase in the number of self-cleaning and falls indicated behavioral changes induced by the oil in N. corniger workers. The study shows the potential of the essential oil of C. pulegiodorus leaves as an alternative method in the management of maize weevil and N. corniger.

Hypoglycemic activity of enzymatically extracted Eucommia ulmoides polysaccharide (EUL-w1) on IR-HepG2 cell via the AMPK/PI3K/Akt signaling pathway

This study devised optimal conditions to extract Eucommia ulmoides leaf (EUL) polysaccharides using a cellulase and pectinase composite enzyme system based on one-way experiments and response surface methodology. Crude EUL polysaccharides (EULPs) were extracted and purified using a DEAE chromatography column. The polysaccharides EUL-w, EUL1, EUL2, and EUL3 were obtained by elution with water, 0.1 mol/L NaCl, 0.2 mol/L NaCl, and 0.3 mol/L NaCl, respectively. The EUL-w fraction had the highest hypoglycemic activity based on its α-amylase and α-glucosidase activities. The preliminary structure of purified EUL-w1 was elucidated. In vitro hypoglycemic activity studies and metabolomics analyses suggested that EUL-w1 modulated glucose metabolism by mediating the AMPK/PI3K/Akt signaling pathway. Our findings provide novel insights and data support for the utilization of EULPs as an emerging food resource in functional foods.

Identification of new structure of indol-3-acetyl-arylsulfonohydrazide as potent α-glucosidase and α-amylase inhibitors and molecular docking

Herein this work, indole analogs (1-16) were synthesized by treating 2-(1H-indol-3-yl)acetohydrazide with various aryl sulfonyl chloride in pyridine as solvent and screened for α-amylase and α-glucosidase inhibitory activity under positive control of standard drug acarbose (IC50 = 12.80 ± 0.10 μM /12.90 ± 0.10 μM. All analogs of the series appeared with excellent to good inhibitory activity as compared to standard drug. The inhibitory activity range for α-amylase is 0.70 ± 0.01 μM to 19.40 ± 0.40 μM, while for α-glucosidase inhibitory activity is 1.20 ± 0.10 μM to 20.40 ± 0.40 μM respectively. Most of the analogs appeared with excellent inhibitory activity, and some analogs like 5, 6, 7, 8, 9, 10,13 and 14 for both enzymes displayed many folds better inhibitory activity than standard drug acarbose. The influences of substituents on inhibitory activity were superficially resonated via structure activity relationship. Docking studies were established to confirm the binding interaction between analogs and active sites of enzymes.

Structural changes of potato starch and activity inhibition of starch digestive enzymes by anthocyanin from lingonberry (Vaccinium uliginosum L.) retarded starch digestibility

The effects of anthocyanins on in vitro and in vivo digestibility of potato starch were evaluated in this study. Then the influence of anthocyanins on physicochemical property of potato starch and the activity of starch digestive enzymes (α-amylase and α-glucosidase) were also investigated to understand the mechanism of anthocyanins on starch digestibility. Results have shown that dietary anthocyanins could effectively inhibit the biological activities of α-amylase and α-glucosidase to delay the peak of postprandial blood glucose. Characterization of physicochemical properties of potato starch indicates a structural change due to the presence of anthocyanins, hindering its access to starch digestive enzymes. Among all anthocyanins, lingonberry anthocyanin significantly promoted the retrogradation of potato starch (7.153 % to 25.913 %) and exert promising inhibition on α-amylase and α-glucosidase. Lingonberry anthocyanins mainly interacted with potato starch through hydrogen bonds, which reduce the amount of amylose molecules leached from potato starch and loosen the three-dimensional (3D) network structure of starch gel. This study could provide theoretical evidence for utilization of anthocyanins in diabetic-management function food.

Hesperetin-copper (II) complex improves liver glucose metabolism by regulating the IRS-1/PI3K/AKT signaling pathway in T2DM mice

The metal complexes of flavonoids have attracted widespread attention because of their distinct structural and functional characteristics. Hesperetin-Cu(II) complex [Hsp-Cu(II)] showed good hypoglycemic potential, but its hypoglycemic effect and mechanism in vivo are still vague. This study aimed to investigate the hypoglycemic effects of Hsp-Cu(II) on type 2 diabetic (T2DM) mice and its underlying mechanism. The results showed that Hsp-Cu(II) (50 mg/kg) effectively improved hyperglycemia and dyslipidemia, increased the fast insulin level and HOMA-IR to alleviate the insulin resistance in the T2DM mice. Compared with the Diseased group, treatment of Hsp-Cu(II) at 50 mg/kg reduced the activities of α-amylase, phosphoenolpyruvate carboxy kinase (PEPCK) and glucose 6-phosphatase (G6Pase) by 31.7%, 45.5% and 35.1%, respectively; elevated the level of glutathione and activities of superoxide dismutase and catalase by 27.2%, 71.7% and 36.7%, respectively, and decreased the malondialdehyde content by 23.6% to improve the liver antioxidant abilities; reduced the activities of alanine aminotransferase and aspartate aminotransferase by 15.6% and 28.1%, as well as the levels of inflammatory factors to relieve liver damage. In addition, Hsp-Cu(II) activated the insulin receptor substrate-1/phosphoinositide-3-kinase/protein kinase B (IRS-1/PI3K/AKT) signaling pathway to up-regulate the protein expression levels of phospho-glycogen synthase kinase-3β (p-GSK-3β) and phospho-fork head box transcription factor O1 (p-FoxO1) and down-regulate the mRNA expression of PEPCK and G6Pase. Therefore, Hsp-Cu(II) may regulate hepatic glucose metabolism through IRS-1/PI3K/AKT‒GSK3β pathways to increase the hepatic glycogen content and IRS-1/PI3K/AKT‒FoxO1‒PEPCK/G6Pase pathways to inhibit gluconeogenesis, maintain hepatic glucose homeostasis, thus exerting the hypoglycemia effect in T2DM. These discoveries may provide a scientific basis for developing Hsp-Cu(II) as a food function factor to alleviate T2DM.

Encapsulation in β-lactoglobulin-chlorogenic acid complexes enhances digestibility and enzyme inhibitory activity of curcumin

Polyphenols could effectively prevent and alleviate many chronic diseases. However, the low solubility, poor stability, and bioaccessibility of certain bioactive ingredients have limited the development of functional foods. In this study, ultrasonication, free radical and their combination (ultrasonication/free radical) were used to prepare β-lactoglobulin (LG)-chlorogenic acid (CA) complexes. The complex was used as a shell to encapsulate curcumin (Cur), forming a ternary complex through anti-solvent method. Moreover, the digestive properties of the delivery system were evaluated by in vitro digestion simulation. Encapsulation by LG/LG-CA resulted in a controlled release of Cur which decreased Cur release in the oral and gastric phases while increased Cur release in intestinal digestion phase. In addition, LG-CA-Cur complex significantly inhibited the enzymatic activity of α-amylase and α-glucosidase. These findings indicated the potential of LG-CA complexes as an efficient carrier for Cur delivery and could be further used to develop functional dairy products with hypoglycemic activity.

Construction of Bacillus subtilis chassis strain with enhanced α-amylase expression capability based on CRISPRi screening

Bacillus subtilis has been widely used in the expression of recombinant proteins due to its food safe and powerful secretion characteristic, but the current production level cannot meet the increasing industrial needs. To enhance the production of recombinant protein, we first screened target key genes that are directly or indirectly involved in protein synthesis, using CRISPRi technology targeting the whole genome, with industrial valuable Bacillus stearothermophilus α-amylase as the model protein. Then the screened key genes were combined, yielding a chassis strain that owning enhanced protein expression capability. Following overlaying molecular chaperone GroES/L and peptidoglycan glycosyltransferase PonA, α-amylase activity reached 102,893 U/mL in a 3-L fermenter, the highest level reported till now. Finally, transcriptome analysis showed that the enhanced recombinant expression may be due to more rational allocation of energy and resources. These strategies can be well implicated in engineering other microbial cell factories for higher industrial production.

Microbial biosurfactant-mediated green synthesis of zinc oxide nanoparticles (ZnO NPs) and exploring their role in enhancing chickpea and rice seed germination

Malnutrition is one of the greatest challenges faced by humanity, which may be addressed by improving crop productivity to ensure food security. However, extensive use of synthetic fertilizers can lead to soil fertility degradation. This study highlights the potential of combining nanotechnology with biotechnology to enhance the germination rates of commercially important crop seeds. Bacterial biosurfactant extracted from a newly isolated Klebsiella sp. strain RGUDBI03 was used as a reducing and capping agent for the synthesis of zinc oxide nanoparticles (ZnO NPs) through a simple method. Extensive characterization of ZnO NPs through electron microscopic analysis showed well-dispersed, homogeneous NPs with a size range of 2–10 nm. High-resolution transmission electron microscopy (HR-TEM) images also revealed molecular fringes of 0.26 nm in single crystal ZnO NPs, with approximately 50% of the NPs exhibiting a size range of 2–4 nm. X-ray diffraction (XRD) results of ZnO NPs indicated the presence of (100), (002), (101), (102), (200), and (112) planes, confirming their crystalline nature. The presence of C = C–H, C = C, C–H, and C = C groups in both the bacterial biosurfactant and ZnO NPs, as depicted by Fourier-transform infrared spectroscopy (FTIR) spectra, confirmed the function of the biosurfactant as a reducing and capping agent. The nano-primed chickpea (Cicer arietinum) and rice (Oryza sativa) seeds showed an increase in water uptake rate, 89% and 92% respectively, compared to the control (73% and 44%), leading to an enhanced germination rate of 98% and 76%, compared to their respective controls (80% and 30%) under optimized conditions. Additionally, the nano-primed seeds exhibited higher levels of α-amylase activity in both seeds (0.37 mg/g for chickpea and 2.49 mg/g for rice) compared to the control. Notably, the ZnO NP priming solution exhibited no cytotoxicity on red blood cells and earthworms (Eudrilus eugeniae), indicating their non-cytotoxic and eco-friendly nature for future field trials.

Study on the effects of endogenous polyphenols on the structure, physicochemical properties and in vitro digestive characteristics of Euryales Semen starch based on multi-spectroscopies, enzyme kinetics, molecular docking and molecular dynamics simulation

Euryales Semen (ES) is a highly nutritious food with low digestibility, which is closely associated with its endogenous phenolic compounds. In this study, five phenolic compounds (naringenin, isoquercitrin, gallic acid, epicatechin and quercetin) with high concentrations in ES were selected to prepare starch-polyphenol complexes. Subsequently, the effects of endogenous polyphenols on the structure, physicochemical properties and digestion characteristics of ES starch were studied using multiple techniques. The addition of phenolic compounds markedly reduced the in vitro digestibility, swelling power, gelatinization enthalpy, while increased the solubility of ES starch. Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that phenolic compounds interacted with the starch through non-covalent bonds. Five phenolic compounds inhibited α-amylase activity through a mixed competitive inhibition mechanism, with the inhibition potency ranked as follows: quercetin > epicatechin > gallic acid > isoquercitrin > naringenin. The spectroscopic analysis and molecular dynamics simulations confirmed that five phenolic compounds interacted with the amino acid residues of α-amylase through hydrogen bonding and hydrophobic interactions, caused α-amylase static fluorescence quenching, and altered its conformation and microenvironment. This study provides a better understanding of the interaction mechanisms between ES starch and polyphenols, and supports the development of ES as a food that lowers sugar levels.

Screening, identification, engineering, and characterization of Bacillus-derived α-amylase for effective tobacco starch degradation

In this study, two high-performing α-amylase-producing strains, CK3–5 and A8–1 were successfully isolated and characterized, which were taxonomically confirmed as Bacillus velezensis through whole-genome sequencing and bioinformatics. Bioinformatic sequence analysis and molecular docking revealed the catalytic triad (Asp173-Glu208-Asp274) essential for α-amylase function. Through metabolic engineering, the recombinant strain BAX-5/PT17amy(A8–1)SP002 was developed, which exhibited the highest α-amylase activity of 1440 U/mL upon fermentation optimization, marking a 9.2-fold enhancement over the wild-type strain A8–1, and it successfully degraded 6 % of the starch in the tobacco leaves within 48 h, while the content of 13 harmful substances, including acetamide, pyridine, and acetonitrile, was reduced by 8.6 % to 25.2 %. This study reveals a novel α-amylase gene from B. velezensis and establishes an efficient expression system in B. amyloliquefaciens, offering valuable insights for industrial α-amylase production.