Α-glucosidase Activity Research Articles

Impact of a Fruit-Vegetable Preparation Fortified with Potato Starch Resistant Dextrin on Selected Health Indicators in Overweight Children.

Developing modified dietary fibers that maintain prebiotic benefits without significantly affecting meal taste is of high importance in the midst of the obesity pandemic. These benefits include regulating the composition of gut microbiota, increasing feelings of fullness, and improving human metabolic parameters. This study investigated the use of a resistant dextrin (RD) derived from potato starch, which possesses prebiotic properties, as a potential additive in vegetable-fruit preparations that aid weight loss and improve health markers in overweight children. HPLC was employed to examine metabolites like lactic acid, short-chain fatty acids (SCFAs; formic, acetic, propionic, butyric, and valeric acids), and branched-chain fatty acids (BCFAs; isobutyric and isovaleric acids). The activities of α-glucosidase, β-glucosidase, α-galactosidase, β-galactosidase, and β-glucuronidase enzymes in fecal samples were measured using spectrophotometric analysis at a wavelength of 400 nm. Incorporating the RD into vegetable-fruit preparations yielded favorable outcomes in terms of increased concentrations of the tested metabolites (SCFAs and BCFAs) and enhanced fecal enzyme activities after 6 months of consuming the preparations. Furthermore, these effects were found to last for an extended period of 3 months even after discontinuing the treatment. The study has shown that including RD into vegetable-fruit preparations enhances the metabolic parameters of obese and overweight children, hence providing a strong rationale for the widespread usage of these preparations in the industry.

From waste to wonder: exploring the hypoglycemic and anti-oxidant properties of corn processing by-products.

Introduction: The industrial processing of corn (Zeamays L.) generates by-products such as corn silk, straw peels, and straw core, which contribute to adverse environmental impacts. Our study aimed to investigate sustainable approaches for mitigating these effects by evaluating the hypoglycemic potential and mechanisms of ethyl acetate fractions derived from these corn derivatives. Methods: We employed glucose consumption assays, high glucose stress tests, UPLC-QE-Orbitrap-MS analysis, molecular docking, and simulations to assess their components and efficacy. Antioxidant capacities were evaluated using DPPH, FRAP, ABTS, and •OH scavenging assays. Results: Notably, the ethyl acetate fraction extracted from straw peels (SPE) exhibited a high concentration of flavonoids and phenolic compounds along with pronounced hypoglycemic activity and antioxidant capacity. SPE significantly enhanced glucose consumption in insulin-resistant HepG2 cells while protecting HUVECs against damage caused by high glucose levels. Molecular docking analyses confirmed the interaction between active compounds and α-glucosidase as well as α-amylase, while molecular dynamic simulations indicated stability at their binding sites. Discussion: In conclusion, the hypoglycemic and antioxidative properties observed in corn by-products such as straw peels, corn silk, and straw core can be attributed to the inhibition of α-glucosidase and α-amylase activities, coupled with their rich phenolic and flavonoid content. These findings highlight the potential of these by-products for applications in healthcare management and their sustainable utilization, demonstrating significant value in the use of agricultural residues.

In Vivo Glycemic Response of Fruit-Based Mango (Mangifera indica) and Pineapple (Ananas comosus) Bars in In Vitro and In Silico Enzyme Inhibitory Effects Studies.

The habitual consumption of snacks has the potential to enrich or harm the diet. They can contribute to excessive caloric intake and hyperglycemia. Thus, there is an increasing interest in snacks with health-promoting properties. This study aimed to demonstrate the beneficial effect of two fruit-based bars on glucose levels through in vitro, in vivo, and in silico assays. Mango (Mangifera indica L.) and pineapple (Ananas comosus L.) bars (MB and PB) were prepared, and chemical composition, postprandial glycemic response, glycemic index (GI), and glycemic load (GL) were evaluated. The inhibitory effect of fruit bar extracts on α-amylase and α-glucosidase activity and their respective molecular docking was assessed. MB and PB showed the lowest postprandial glycemic response vs. the control bar (p < 0.005), a lower GI (CB: 64.20, PB: 53.20, MB: 40.40), and a GL of 10.9 (CB), 7.9 (PB), and 6.1 (MB), (p < 0.05). MB and PB showed the highest inhibition % of α-amylase (61.44 and 59.37%, respectively) and α-glucosidase (64.97 and 64.57%). Naringenin (-1692.5985 and -2757.674 kcal/mol) and ferulic acid (-1692.8904 and -2760.3513 kcal/mol) exhibited more favorable interaction energies against α-amylase and α-glucosidase activity. The presence of polyphenols from the fruit influenced enzymatic inhibition. Likewise, the dietary fiber in the bars evaluated allowed us to observe a positive effect that favors glycemic control, making them a healthy alternative for snacking.

Study on ferritin glycation with dextran: Physicochemical characterization and its application in the delivery of resveratrol

Ferritin exhibits promising prospects for nanoencapsulation applications, however, its susceptibility to environmental factors as a standalone carrier necessitates further consideration. In this study, the recombinant human H-chain ferritin (rHuHF) was modified with dextran (Dex) to enhance its physicochemical and functional properties. Moreover, the glycated rHuHF cavity was utilized for the encapsulation of resveratrol (Res). The results demonstrated that the glycoconjugates (Dex–rHuHF) achieved the highest grafting degree of 34.71% under the following conditions: Dex molecular weight of 40 kDa, mass ratio of rHuHF to Dex at 1:2, pH value of 7.8, relative saturation humidity of 79%, reaction temperature at 50 °C, and reaction time of 30 h. Dex interacted with rHuHF and exhibited protective effects on rHuHF under extremely acidic conditions. Each Dex–rHuHF cavity encapsulated approximately 22 Res molecules with an encapsulation rate of 10.84%. The Dex–rHuHF–Res nanoparticles displayed excellent photothermal stability and sustained release properties. Furthermore, the Dex–rHuHF–Res simulated digesta showed enhanced abilities in scavenging DPPH free radicals and inhibiting α-glucosidase activity. This work investigated the impact of Dex on the physicochemical properties of rHuHF and developed a novel approach by grafting Dex onto rHuHF for encapsulating hydrophobic substances like resveratrol, which holds potential applications in water-based food and nutraceutical formulations.

Evaluating the anti-yeast, anti-diabetic, wound healing activities of Moringa oleifera extracted at different conditions of pressure via supercritical fluid extraction

Plants represent a great source of medicines, and for their components to be discovered, extraction processes must be developed, especially methods based on green technology. Supercritical fluid extraction (SFE) was employed as a green method for Moringa oleifera extraction in the present investigation. The maximum yield of extraction was obtained at 25 MPa. Moreover, the extraction at 25 MPa induced the release of various phenols and flavonoids, as analyzed via high-performance liquid chromatography. The investigation revealed the concentrations of chlorogenic, gallic, rosmarinic, and coumaric acids to be 150.59, 89.90, 44.75, and 29.41 µg/mL, respectively at 25 MPa. However, their concentrations were 0.73, 1.53, 0.24, and 0.04 µg/mL, respectively at 15 MPa; vs. 4.73, 2.62, 1.06, and 0.50 at 35 MPa, respectively. Totals of saponin, flavonoid, phenolic, tannins, and alkaloid were recorded in maximum yield at 25 MPa. Moringa oleifera extracted at 35 MPa reflected highest inhibition zones of 27 ± 0.1, 30 ± 0.2, and 30 ± 0.1 mm against C. glabrata, C. tropicalis, and C. albicans, correspondingly. α-Amylase and α-glucosidase activities were greatly suppressed by the M. oleifera extract at 25 MPa with less IC50 (12.97 µg/mL and 6.0 µg/mL), than the IC50 (53.46 and 22.02 µg/mL) at 15 MPa, compared with acarbose IC50 (5.52 and 2.64 µg/mL), correspondingly.

Anti-Diabetic Activities of the Extracts from Euphorbia hirta L. (Euphorbiaceae) Specie found in Burkina Faso Using α-Glucosidase Inhibitor

Euphorbia hirta L. is an herbaceous plant used in traditional medicine to treat several diseases. In the present work, different fractions of Euphorbia hirta L. hydroalcoholic extract were investigated for their anti-diabetic properties on α-glucosidase’s inhibition activities. Chemical screening realized following Folin-Ciocalteu and AlCl3 methods showed that ethyl acetate (AcOET) and butanol (BuOH) extracts contain 432.687 ± 1.832 µg and 332.433 ± 1.255 µg GAE/mg of extract for phenolic compounds. The same extracts contained high levels of total flavonoids estimated at 417.850 ± 15.941 µg and 227.640 ± 2.657 μg QE/mg of extract respectively. The anti-diabetic activities revealed that AcOET and BuOH have a very significant inhibitory potential on the enzymatic activity of α-glucosidase with an IC50 values of 1.295 ± 0.035 μg/mL and 2.188 ± 0.204 μg/mL respectively compared to acarbose (IC50 = 214.825 ± 3.816 μg/mL).

Unveiling the Impact of Soil Prebiotics on Rhizospheric Microbial Functionality in Zea mays L.

Prebiotics, a subset of biostimulants, have garnered attention for their potential to enhance soil conditions and promote plant growth, offering a promising alternative to conventional agricultural inputs. This study explores how two commercial prebiotics, K1® and NUTRIGEO L® (SPK and SPN), impact soil functions compared to a control (SP). The experiment involved agricultural soil amended with organic wheat straws and cultivated with Zea mays L. Previous research demonstrated substantial effects of these prebiotics on plant biomass, soil parameters, and microbial community ten weeks after application. The present study delves deeper, focusing on soil microbial abundance, enzyme activities, and metabolic diversity. Analysis revealed that SPN notably increased the fungi-to-bacteria ratio, and both prebiotics elevated the activity of several key enzymes. SPN enhanced α-glucosidase and β-galactosidase activities, while SPK increased arylsulfatase, phosphatase, alkaline phosphatase, and urease activities. Enzymatic indexes confirmed the positive impact on soil functional diversity and fertility. Additionally, prebiotic treatments showed distinct metabolic profiles, with SPK degrading eleven carbon sources more rapidly across five groups and SPN accelerating the decomposition rate of four carbon sources from three groups. These findings highlight the ability of prebiotics to shape microbial communities and enhance soil fertility by modulating their functional activity and diversity.

Magnetic ligand fishing protocol combined with HPLC-FT-ICR-MS for screening potential α-Glucosidase inhibitors from UCG and in silico analysis

Uremic Clearance Granule (UCG) is a traditional Chinese medicines (TCMs) that has been recognized as potentially effective treatment for diabetic nephropathy (DN). However, the chemical composition and the hypoglycemic ingredients of UCG remain unclear. In this experiment, a magnetic ligand fishing protocol combined with HPLC coupled Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FT-ICR-MS) technology was developed to screen and identify α-Glucosidase inhibitors from UCG. First, constituents of UCG was identified by HPLC-FT-ICR-MS. Next, α-Glucosidase coated Fe3O4@SiO2@NH2 (Fe3O4@SiO2@NH2@α-Glucosidase) nano composites was synthesized. The essential parameters (concentration of Glutaraldehyde (GA), ratio of Fe3O4@SiO2@NH2 to enzyme, crosslinking time and immobilization time) were optimized to obtain maximum enzyme activity and the performance of immobilized enzyme was compared with that of free enzyme. The α-Glucosidase inhibitory activities were then evaluated using autodock and the 4-Nitrophenyl-α-D-glucopyranoside (pNPG) method. As a result, 142 compounds were identified were identified by comparing the retention time, molecular ions and fragmentation behaviors with the reference compounds or the in-house database. 20 possible α-Glucosidase activity inhibitory components were identified using HPLC-FT-ICR-MS. Molecular docking and inhibition studies showed that 4 compuunds including Limonexic acid, Sanggenol A, Glabrone, Matrine were more likely to stronger α-Glucosidase inhibitory activities than acarbose. In conclusion, the proposed approach, which combined highly specific screening with HPLC-FT-ICR-MS, provided a powerful platform for discovering bioactive components from multi-component and multi-target traditional Chinese medicines (TCMs).

Comprehending the inhibition mechanism of indole-based bis-acylhydrazone compounds on α-glucosidase: Spectral and theoretical approaches

Indole-based bis-acylhydrazone compounds can inhibit the activity of α-glucosidase and control the concentration of blood glucose. In this paper, the characteristics of three indole-based bis-acylhydrazone compounds with different inhibitory activities of α-glucosidase as well as the interaction with α-glucosidase were studied by experiments and computational simulation techniques. Enzyme kinetic and spectral experiments showed that the indole-based bis-acylhydrazone compounds were able to inhibit enzyme activity through mixed inhibition dominated by competitive inhibition, and during the binding reaction, indole-based bis-acylhydrazone compounds can quench the intrinsic fluorescence of α-glucosidase through static quenching and an aggregation of the indole-based bis-acylhydrazone with α-glucosidase produces a stable complex with a molar ratio of 1:1, and the combination of indole-based bis-acylhydrazone compounds could lead to slight change in the conformation of α-glucosidase. The theoretical simulation demonstrated that the stability of the complex systems was positively correlated with the inhibitory activity of indole-based bis-acylhydrazone compounds, and the indole-based bis-acylhydrazone compounds occupied the active site in the multi-ligand system, resulting in a significant decrease in the binding ability of starch to active amino acids. These results suggested that indole-based bis-acylhydrazone compound was expected to be a new type of α-glucosidase inhibitor.

Study on the in Vitro Inhibitory Activity of Peony Seed Blended Oil on α-Amylase and α-Glucosidase

In recent years, China has been suffering from an increasing number of patients with chronic diseases such as diabetes, hypertension, and heart disease, which are gradually showing a "younger" trend. As health problems become more prominent, choosing good cooking oil has become crucial. People are beginning to realize the significance of a balanced diet and healthy eating habits in maintaining good health. Peony seed oil is rich in nutrients, and its content of unsaturated fatty acids can reach over 85%, with the highest content of α-linolenic acid, which effectively lowers blood sugar. Suppose soybean oil and rapeseed oil are combined and added. In that case, the original efficacy of peony seed oil can be complemented and enhanced, its mechanism of action network can be sound, and its nutritional composition can be enriched. We can obtain an optimal ratio for mixing the above several oils by studying their effects and roles. This paper explored the inhibitory effects of peony seed oil, soybean oil, and rapeseed oil on α-amylase activity and α-glucosidase activity, and their optimal ratios were determined by a one-way test and response surface method. The results showed that the optimal ratio was peony seed oil: soybean oil: rapeseed oil = 60:27:13. The results provide specific technology and reference for the development and utilization of peony and provide a particular theoretical basis for the development of hypoglycemic drugs or health food.

Deciphering the Potential Therapeutic Effects of Hydnocarpus wightianus Seed Extracts using in vitro and in silico approaches

Phytocompounds possess the potential to treat a broad spectrum of disorders due to their remarkable bioactivity. Naturally occurring compounds possess lower toxicity profiles, which making them attractive targets for drug development. Hydnocarpus wightianus seeds were extracted using ethanol, acetone, and hexane solvents. The extracts were evaluated for phytochemicals screening and other therapeutic characteristics, such as free radicals scavenging, anti α-amylase, anti α-glucosidase, and anti-bacterial activities. The ethanolic extract exhibited noteworthy antibacterial characteristics and demonstrated considerable antioxidant, and anti-diabetic effects. The IC50 value of the ethanolic extract for Dpph, α-amylase, and α-glucosidase were found to be 77.299 ± 3.381 μg/mL, 165.56 2.56 μg/mL, and 136.58 ± 5.82 μg/mL, respectively. The ethanolic extract was effective against Methicillin resistant Staphylococcus aureus (26 mm zone of inhibition at 100 μL concentration). Molecular docking investigations revealed the phytoconstituent's inhibitory mechanisms against diabetic, free radicals, and bacterial activity. Docking score for phytocompounds against targeted protein varies from −7.2 to −5.1 kcal/mol. The bioactive compounds present in the ethanolic extract were identified by Gas chromatography/Mass spectrometry analysis, followed by molecular docking and molecular dynamic simulation studies to further explore the phytoconstituent's inhibitory mechanism of α-glucosidase, ∝-amylase, radical scavenging, and bacterial activity. The electronic structure and possible pharmacological actions of the phytocompound were revealed through the use of Density Functional Theory (DFT) analysis. Computational and in vitro studies revealed that these identified compounds have anti-diabetic, anti-oxidant, and anti-bacterial activities against antibiotic-resistant strain of Staphylococcus aureus.

In vitro study of the inhibitory potentials of cold and hot aqueous extract of Vernonia amygdalina, Calotropis procera, and Persea americana on α-glucosidase

Background: The surge in the incidence of diabetes mellitus has spurred heightened interest on alternative and complementary therapies, particularly those derived from medicinal plants. Objective: To assess the α-glucosidase inhibitory activity of cold and hot aqueous extracts of Vernonia amygdalina (bitter leaf), Calotropis procera (locally known as “bomubomu” leaves), and Persea americana (also known as avocado pear) to explore their medicinal applicability. Method: The leaves of V. amygdalina, C. procera, and the seed of P. americana were subjected to cold and hot extraction methods using distilled water. These extracts were specifically targeted for their potential inhibitory effects on α-glucosidase activity, a key enzyme involved in carbohydrate digestion. Results: The α-glucosidase inhibitory assay showed that the extracts from the plants had maximum inhibitory effects at 20 mg/mL. Cold and hot aqueous extracts of V. amygdalina exhibited maximal inhibitory activities of 100% and 86%, respectively, at 20mg/mL. Cold and hot aqueous extracts of C. procera displayed 100% and 91% inhibitory activities, respectively, at 20mg/mL. Similarly, cold and hot extracts of P. americana exhibited the highest inhibitory activities of 77% and 63%, respectively, at 20mg/mL concentration. Conclusions: The findings demonstrated that cold and hot aqueous extracts of Vernonia amygdalina, Calotropis procera, and Persea americana exhibited significant inhibitory activities against α-glucosidase. The observed inhibitory effects suggest the therapeutic potential of these plant extracts as natural remedies for managing post-prandial hyperglycaemia in Type 2 Diabetes mellitus.

HPLC phytochemical profiling, antioxidant activity and in vitro evaluation of inhibitory effects of Terminalia catappa stem bark extract on enzymes linked to diabetes, hypertensive vasoconstriction and erectile dysfunction

BackgroundTerminalia catappa is a traditional medicinal plant used for several ailments among the local folks. Among the locals, the stem bark is an important constituent of polyherbal remedies for the treatment of cancer and metabolic diseases; however, there is a paucity of scientific reports on it. This study aimed to evaluate the in vitro antidiabetic, antihypertensive and antierectile dysfunction effects of Terminalia catappa stem bark extract (TSBE). MethodsThe HPLC phytochemical profiling, total phenol content, total flavonoid content and antioxidant capacity of the extract were delineated. The inhibitory effects of TSBE on activities of α-glucosidase, α-amylase, acetylcholinesterase (AChE), arginase, phosphodiesterase-5′ (PDE-5′), angiotensin-converting enzyme (ACE) and ecto-5 nucleotidase (Ecto-5-NTD) were estimated following standard procedures. ResultsHPLC of TSBE profiled ferulic acid, gallic acid, caffeic acid, catechin, rutin, p-coumaric acid, chlorogenic acid, kaempferol, apiginin and quercetin. TSBE had IC50 values of 49.19 µg/mL and 55.42 µg/mL in terms of scavenging DPPH and NO radicals, respectively. The TSBE inhibited α-glucosidase and α-amylase activities with IC50 values of 71.53 µg/mL and 105.11 µg/mL, respectively. The inhibitory effects of TSBE on AChE, arginase, PDE-5′, and ACE revealed IC50 values higher than that of standards. TSBE demonstrated a stimulatory effect on ecto-5-NTD activity. ConclusionTSBE revealed promising antioxidant, antidiabetic, antihypertensive and antierectile dysfunction (anti-ED) properties which may be associated with the bioactive compounds present in the extract.

α-Glucosidase inhibitory flavonol glycosides from Cyclocarya paliurus (Batalin) Iljinskaja and their kinetics characteristics

Seven previously undescribed flavonol glycosides including four rare flavonol glycoside cyclodimers, dicyclopaliosides A-C (1-3) with truxinate type and dicyclopalioside D (4) with truxillate type, as well as three kaempferol glycoside derivatives cyclopaliosides A-C (5–7), were obtained from the leaves of Cyclocarya paliurus. Their structures were elucidated by extensive spectroscopic methods and chemical analyses. All compounds were evaluated for their inhibitory α-glucosidase activities. Among them, compounds 1–4 display strong inhibitory activities with IC50 values of 82.76 ± 1.41, 62.70 ± 4.00, 443.35 ± 16.48, and 6.31 ± 0.88 nM, respectively, while compounds 5–7 showed moderate activities with IC50 values of 4.91 ± 0.75, 3.64 ± 0.68, and 5.32 ± 0.53 μΜ, respectively. The structure-activity relationship analysis assumed that the cyclobutane cores likely contribute to the enhancement of α-glucosidase inhibitory activities of dimers. Also, the interaction mechanism between flavonol glycoside dimers and α-glucosidase were explored by the enzyme kinetic assay, indicating that compounds 1–3 exhibited mixed-type inhibition, while 4 showed uncompetitive inhibition. Additionally, the active compounds have also undergone molecular docking evaluation.

Relationships between degree of polymerization and activities: A study on condensed tannins from the bark of Ficus altissima

Condensed tannins were isolated from the bark of Ficus altissima and fractionated into four subcomponents on a Sephadex LH-20 column with 60 %, 80 %, 100 % methanol, and 70 % acetone, separately. Their structures were characterized by MALDI-TOF MS coupled with HPLC-ESI-MS and confirmed to be polymers of B-type procyanidin glucosides, procyanidins, and prodelphinidin glucosides. The degree of polymerization (DP) of these polymers was as high as 21, and the mDPs of the four subcomponents were calculated as 2.4, 6.6, 10.5 and 13.4, respectively. They competitively or noncompetitively suppressed the activities of tyrosinase and α-glucosidase through hydrogen bonding and hydrophobic interaction. And they also showed a powerful antioxidative activity. Correlation analyses verified that the anti-tyrosinase capacity exhibited a significant positive correlation (R2monophenolase = 0.9167 and R2diphenolase = 0.9302) with mDP within the methanol-water system, and the anti-α-glucosidase activity also showed a significant positive correlation with the mDP (R2 = 0.9187). In contrast, the antioxidant capability showed a significant negative correlation with the mDP (R2DPPH = 0.9258, R2ABTS = 0.9372). This study confirmed that condensed tannins from the bark of F. altissima were desirable anti-tyrosinase, anti-α-glucosidase, and antioxidant agents, and elucidated the relationships of their mDP (molecular weight) and activities, which provided a scientific basis for the comprehensive utilization of these polymers in the food, cosmetics, medicine and other fields.

Optimization of Ultrasound-Assisted Deep Eutectic Solvent Extraction, Characterization, and Bioactivities of Polysaccharide from Pericarpium Citri Reticulatae.

The ultrasonic-assisted deep eutectic solvent method was used to extract the polysaccharides of Pericarpium Citri Reticulatae (PCRP), and the ultrasound-assisted DES extraction process was optimized by Box-Behnken response surface test using the extraction rate of the PCRP as an index; the in vitro activities of purified the PCRP(PCRPs-1) were investigated by determining the scavenging rate of DPPH• and ABTS•+ as well as by enzyme inhibition assay. The monosaccharide composition was analyzed by HPLC. The best process conditions for response surface optimization were a material-liquid ratio of 1:37g/mL, water content of 44%, time of 89min, and power of 320 W. The polysaccharide extraction rate was measured to be 5.41%, which was well optimized when compared with that of the ordinary aqueous extraction method of 3.92%. By α-glucosidase and α-amylase inhibition activity test, it showed that the PCRPs-1 had hypoglycemic activity. The DPPH radical scavenging activity test and ABTS + scavenging activity test indicated that the PCRPs-1 had good biological activity. Analysis of the monosaccharide fractions showed that the PCRPs-1 consisted of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, and arabinose, with molar ratios of 1:39.24:4.41:8.91:7.83:86.00:1.02:9.17. The activity studies showed that PCRPs-1 possessed certain hypoglycaemic and antioxidant activities.

Does Erodium trifolium (Cav.) Guitt exhibit medicinal properties? Response elements from phytochemical profiling, enzyme-inhibiting, and antioxidant and antimicrobial activities

Abstract Geraniaceae are typically used as diuretic, anti-diarrhoeal, stomachic, and anti-hemorrhagic drugs. This study examined the phytochemicals and bioactivities in methanolic extract (ME) and petroleum ether extract (PEE) of the Erodium trifolium aerial part. Inductively coupled plasma mass spectrometry was used to assess the mineral profiles, high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) and high-performance liquid chromatography with diode-array detection (HPLC-DAD) were used to assess the phenolic content of ME, and gas chromatography-mass spectrometry (GC-MS) was used to assess the fatty acid and volatile composition of the PEEs. In addition, the bioactivities of extracts were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl, ABTS, and cupric reducing antioxidant capacity assays, including enzyme inhibition against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, α-glucosidase activities, and antibacterial properties. HPLC-MS identified eight compounds in ME: rutin, catechin, and caffeine were the major phenolic compounds detected. HPLC-DAD analysis showed that 11 compounds detected among epicatechin, catechin, chlorogenic acid, and gallic acid were predominant. GC-MS analysis revealed 30 fatty acids in PEE, with palmitic acid and oleic acid being predominant. The mineral content showed that Fe was the abundant microelement, and Ca and K were the abundant macroelements. The ME exhibited the highest activity compared to the PEE in all tests regarding antioxidant and antibacterial activities. Furthermore, all the extracts showed moderate inhibition against AChE, BChE, α-amylase, and α-glucosidase. In conclusion, E. trifolium may be employed to separate novel bioactive metabolites with potential pharmaceutical activities.

Apigenin potentiates glucose-stimulated insulin secretion through the PKA-MEK kinase signaling pathway independent of K-ATP channels

AimApigenin, a natural bioflavonoid, is reported as an anti-diabetic agent since it possesses the ability to inhibit α-glucosidase activity, cause stimulation of insulin action and secretion, manage ROS, and prevent diabetes complications. Apigenin was identified as a new insulin secretagogue that enhances glucose-stimulated insulin secretion and seems like a better antidiabetic drug candidate. Here we explored the insulinotropic mechanism(s) of apigenin in vitro in mice islets and in vivo in diabetic rats. MethodsSize-matched pancreatic islets were divided into groups and incubated in the presence or absence of apigenin and agonists or antagonists of major insulin signaling pathways. The secreted insulin was measured by ELISA. The intracellular cAMP was estimated by cAMP acetylation assay. The acute and chronic effects of apigenin were evaluated in diabetic rats. Resultsapigenin dose-dependently enhanced insulin secretion in isolated mice islets, and its insulinotropic effect was exerted at high glucose concentrations distinctly different from glibenclamide. Furthermore, apigenin amplified glucose-induced insulin secretion in depolarized and glibenclamide-treated islets. Apigenin showed no effect on intracellular cAMP concentration; however, an additive effect was observed by apigenin in both forskolin and IBMX-induced insulin secretion. Interestingly, H89, a PKA inhibitor, and U0126, a MEK kinase inhibitor, significantly inhibited apigenin-induced insulin secretion; however, no significant effect was observed by using ESI-05, an epac2 inhibitor. Apigenin improved glucose tolerance and increased glucose-stimulated plasma insulin levels in diabetic rats. Apigenin also lowered blood glucose in diabetic rats upon chronic treatment. ConclusionApigenin exerts glucose-stimulated insulin secretion by modulating the PKA-MEK kinase signaling cascade independent of K-ATP channels.

Honokiol as an α-glucosidase inhibitor.

Honokiol, a naturally occurring compound from Magnolia obovata Thunb., has many biological activities, but its anti-α-glucosidase activity is still unclear. Therefore, we determined its inhibitory effects against α-glucosidase. Activity assays showed that honokiol was a reversible mixed-type inhibitor of α-glucosidase, and its IC50 value was 317.11 ± 12.86μM. Fluorescence results indicated that the binding of honokiol to α-glucosidase caused a reduction in α-glucosidase activity. 3D fluorescence and CD spectra results indicated that the binding of honokiol to α-glucosidase caused conformational change in α-glucosidase. Docking simulated the detailed interactions between honokiol and α-glucosidase, including hydrogen and hydrophobic bonds. All findings showed that honokiol could be used as a natural inhibitor to develop α-glucosidase agents.

Green synthesis, characterization, antidiabetic, antioxidant and antibacterial applications of silver nanoparticles from Syzygium caryophyllatum (L.) Alston leaves

Syzygium caryophyllatum (L.) Alston, an ethnobotanically acclaimed antidiabetic plant, was utilized for the first time in this study to synthesize silver nanoparticles (SC-AgNPs). Characterization revealed spherical SC-AgNPs (∼30 nm) with a silver content of 49.10 %, displaying diverse functional groups and significant antibacterial activity against Staphylococcus aureus and Proteus vulgaris. SC-AgNPs exhibited notable antidiabetic properties by inhibiting α-amylase and α-glucosidase activities, while enhancing glucose uptake in L6 and yeast cells. Moreover, SC-AgNPs demonstrated profound antioxidant activities by scavenging reactive oxygen species, which led to increased catalase activity and decreased glutathione-S-transferase activity. These properties surpassed those of the plant extract. SC-AgNPs were found to show low toxicity towards L6 cells when compared to the contemporary silver nanoparticles. The eco-friendly synthesis method and comprehensive biological assessments highlight the value of this work in advancing nanomedicine for diabetes management.