Α-glucosidase Inhibitory Activity Research Articles

Gamma-aminobutyric acid fermentation and its fermented extracts on α-glucosidase inhibition and anti-obesity effect.

Levilactobacillus brevis KCL010 was fermented in a simple medium containing 8% (w/v) of rice bran extract. We modified the carbon, nitrogen, and initial pH conditions using 10g/L of sucrose, 10g/L of yeast extract, and 5.0 of pH, respectively. To minimize the pH increase due to decarboxylation, we fermented 100mL of modified synthetic medium containing citrate-phosphate buffer (CPB, pH 5.0) of 25-200mM in 250mL Erlenmeyer flasks. After 72h of fermentation with 50mM CPB, the maximum GABA concentration and conversion efficiency were 3.42g/L and 22.39%. Furthermore, the potential α-glucosidase inhibitory activity, MTT assay, and oil red O staining were determined by fermented extracts of L. brevis KCL010. At the highest concentration of 500μg/mL, the α-glucosidase inhibition percentages for non-fermented rice bran (NFRB), rice bran fermented by L. brevis (RBFL), and GABA (analytical standard) extracts were 55.03%, 58.37%, and 59.48%, respectively. All extracts exceeded 80% viability, suggesting that there was no cytotoxic to 3T3-L1 adipocytes. The rice bran fermented by L. brevis (RBFL) extract shows a high inhibition of lipid accumulation by 29.33% compared to those of extracts.

New α-glucosidase inhibitors and antioxidants in optimized Psychotria malayana Jack leaves extract identified by gC-MS-based metabolomics and in silico molecular docking

Our earlier research demonstrated α-glucosidase inhibitory (AGI) and antioxidant activities of the optimised extract of Psychotria malayana leaves. It was reported having numerous compounds, although it was unclear which compounds exhibit the bioactivities as well as their binding interaction to the enzyme. This study aimed to identify the compounds possessing AGI and antioxidant activities in the extract utilising GC-MS-based metabolomics, and to analyse the ligand-enzyme binding interactions via in-silico molecular docking. A partial least square was employed to correlate the metabolite profile and bioactivities. The loading plot reveals the bioactive compounds in this extract. The AGI activity of 1-cyclohexene-1-carboxylic, propanoic, butanedioic and D-gluconic acid together with the antioxidant activity of some compounds were reported for the first time through this study. The docking study reveals that all compounds, except for 1-cyclohexene-1-carboxylic acid, exhibit binding to the enzyme’s catalytic site. This discovery demonstrates the potential of this plant for diabetes therapy.

Exploring Hyaluronidase and Alpha-Glucosidase Inhibition Activities of the Hydrothermal Extract of Coffee Silverskin Obtained from a Central Composite Design

Coffee silverskin (CS), the main by-product of coffee roasting production, contains various valuable bioactive compounds in its chemical compositions. Hydrothermal water extraction (HDTE) is one of the promising techniques for valorizing the organic fraction of CS into functional bioactive ingredients, which can be further exploited in various applications. This study aimed to evaluate the hyaluronidase and α-glucosidase inhibition activities of the CS extracts obtained under optimized water extraction conditions. Process optimization was performed using central composite design response surface methodology (CCD-RSM) with a broader range of extraction temperatures (25, 137.5, and 250 °C), reaction times (5, 38.5, and 72 min), and solid-to-liquid ratios (1:10, 1:80, and 1:150). The highest yield of 39.62% was obtained at 137.5 °C, with a reaction time of 72 min and an S/L ratio of 1:80. The total caffeoylquinic acid contents (T-CQA) were quantified based on the sum of three major isomers, including 3-CQA, 4-CQA, and 5-CQA. The results revealed that the highest T-CQA (2.76 ± 0.20 mg/g CS) was significantly obtained (p < 0.05) by subcritical water extraction (SWE) at 143.2 °C with an S/L ratio of 1:10 and an extraction time of 10.41 min. At such conditions, the total phenolic content (TPC), antioxidant properties (AP), and caffeine were 96.13 mg gallic acid equivalence per gram (GAE/g) CS, 20.85 ± 0.17 mg Trolox equivalence per gram (TE/g) CS, and 10.84 ± 1.25 mg/g CS, respectively. The 50% inhibition capacity (IC50) of hyaluronidase and α-glucosidase inhibition of the CS extracted were 5.00 mg/mL and 9.00 mg/mL, respectively. Our results supported the potential direct or indirect applications of CS, such as hydrothermal CS extract (HDT-CSE), in functional food or drinks. Repurposing CS residue to manufacture new products can efficiently reduce the amount of organic waste in landfills, thus conserving resources and energy and contributing to a lower overall carbon footprint in coffee production.

Optimizing Polyphenolic Extraction from Wild Guava Leaves: A Response Surface Methodology Approach to Antioxidant and α-Glucosidase Inhibitory Activities

Objective Elevated concentrations of total phenolic content (TPC) and total flavonoid content (TFC) in extracts from wild Psidium guajava L. leaves are associated with their antioxidant and α-glucosidase inhibitory activities. This study aimed to determine the optimal ultrasound-assisted extraction conditions to maximize TPC, TFC yield, as well as antioxidant and α-glucosidase inhibitory potential. Methods The central composite design (CCD) of Response Surface Methodology (RSM) was employed for empirical model development with three levels of factors, including ethanol concentration (33.18 to 66.82% in distilled water), extraction time (1.59 to 18.41 min) and solvent-to-solid ratio (5.79 to 14.20 mL/g). Results The results indicated that under optimal conditions, the total phenolic content (TPC) and total flavonoid content (TFC) values were 152.954 mg GAE/g DW and 113.871 mg QE/g DW, respectively. These conditions included an ethanol concentration of 51.94%, an extraction time of 9.56 min, and a solvent-to-solid ratio (v/w) of 10.84 mL/g. Furthermore, the maximum values for DPPH and ABTS radical scavenging activities were 124.990 mg TE/g DW and 194.730 mg TE/g DW, respectively and the lowest IC50 for α-glucosidase inhibitory activity recorded at 11.946 µg/mL. The validated models exhibited strong consistency between the predicted and experimental values, with variations of less than 5% under optimal conditions. Additionally, Principal Component Analysis (PCA) also confirmed the appropriate model to predict the extraction yield of total polyphenol and flavonoid content, as well as their biological activities, including DPPH and ABTS radical scavenging and alpha-glucosidase inhibitory activities. Conclusions The enhancement of antioxidant and antidiabetic extraction processes in both the pharmaceutical and food industries through the use of ultrasound-assisted extraction from Wild Guava leaves can increase production to meet high demand. This efficiency is particularly noteworthy, as it demonstrates the advantages of using ultrasound in the extraction process.

Composition, Anti-Diabetic, and Antioxidant Potential of Raphanus sativus Leaves.

Limiting and/or slowing down the starch digestion process and consequently the release of glucose can be an important strategy for the prevention of type 2 diabetes (T2D). The aim of the current in vitro study was to assess the anti-diabetic and antioxidant potential of red radish leaves of the Carmen, Jutrzenka, Saxa, and Warta cultivars. In the context of anti-diabetic activity, the effect of leaves on potato starch digestion and free glucose binding, as well as inhibitory effects of leaf extracts against α-amylase and α-glucosidase and non-enzymatic glycation (AGEs) were determined. The basic chemical composition, quantitative composition of phenolic compounds, and antioxidant activity of leaves were also estimated. This study showed that all radish leaves inhibited the breakdown of potato starch and showed their ability to bind glucose. This activity was correlated with the content of hydroxycinnamic acids, protein and dietary fiber while flavones was probably responsible for glucose binding. Leaf extracts inhibited α-glucosidase activity and formation of AGEs but were practically inactive towards α-amylase. Inhibition of α-glucosidase activity was related to the content of proanthocyanidins and inhibition of AGEs formation to flavonols. These results point to radish leaves, especially the Warta and Jutrzenka cultivars, as a potential natural remedy for treating T2D.

Two new sesquiterpenol caffeates from Bauhinia brychycarpa wall. and their α-glucosidase inhibitory activity

Two new sesquiterpenol caffeates, bausesquitate A (1) and bausesquitate B (2), were isolated from the stems and leaves of Bauhinia brychycarpa Wall. Structures of two compounds were confirmed by UV, IR, HR-ESI-MS, 1D and 2D NMR, ECD spectra and DP4+ probability analysis. In vitro, compounds 1 and 2 showed better inhibitory effect on α-glucosidase than acarbose (IC50 = 280.50 ± 6.27 μM) with the IC50 values of 1.81 ± 0.12 μM and 3.79 ± 0.27 μM. Additionally, molecular docking and molecular dynamics simulation were performed to analyze the potential binding sites.

Highly oxygenated cyclohexenes from the leaves of Uvaria grandiflora Roxb. ex Hornem and their cytotoxic and α-glucosidase inhibitory activities

Highly oxygenated cyclohexenes from the leaves of Uvaria grandiflora Roxb. ex Hornem and their cytotoxic and α-glucosidase inhibitory activities

Studies on inhibition of α-glucosidase using debittered formulation of Bacopa monnieri juice: Enzyme inhibition kinetics, interaction strategy, and molecular docking approach

Bacopa monnieri juice (BMJ) is traditionally used, reported, and scientifically validated for memory enhancement. However, its efficacy against diabetes is less explored. The extreme bitterness of BMJ restricts its commercial applications. This study investigates the reduction of bitterness of BMJ followed by evaluation for its α-glucosidase inhibitory activity. Initially, debittering of 30 % (v/v) BMJ using ZnSO4 (15 mM) was optimized by time-intensity analysis and molecular docking of ZnSO4 as well as bacoside A3, the main active compound in BMJ, with TAS2R14 taste receptor. The study indicated 5 hydrogen bonds to be involved in binding with bacoside A3 with binding energy of −11.82 Kcal/mol, while hydrogen bond, salt bridges and metal complexes were involved in binding of ZnSO4 with binding energy of −6.65 Kcal/mol. Subsequently, BMJ, ZnSO4 and BMJ + ZnSO4 (debittered juice) were also found to be potent inhibitors of α-glucosidase in dose-dependent manner. These inhibitors showed parabolic mixed inhibition of α-glucosidase, altered the secondary structure, and quenching of fluorescence. In silico studies revealed hydrogen bonding and hydrophobic interactions between inhibitors and α-glucosidase with lowest binding energy of −15.53 and −7.54 Kcal/mol being recorded for bacoside A3 and ZnSO4, respectively. Molecular docking of other bioactive compounds in BMJ such as apigenin, luteolin, quercetin and bacopasaponin C also showed lower binding energy than the standard drug, acarbose (−5.84). This study inferred the binding of bacoside A3 at the active site of α-glucosidase and of ZnSO4 with other sites on the protein. The study proposes a debittered BMJ formulation to control hyperglycemia.

Oxygen influences in vitro assessment for phenolic compounds: Digestive stability, α-glucosidase inhibitory activity and bioavailability

Phenolic compounds are popular in screening novel hypoglycemic agents, but the impact of oxidative degradation on the determination of α-glucosidase inhibitory activity and bioavailability is unclear. Here we showed 12 phenolic compounds structure-dependently degraded during standard simulated digestion, while in physiological hypoxia their retention rates were all over 87.89 %. This enhancement of digestive stability resulted in the biggest drop of 31.72 % in IC50 against α-glucosidase and a significant increase in bioavailability. Enzyme kinetic and multi-spectroscopic analysis confirmed oxygen weakened the affinity of compounds to α-glucosidase, but the mechanisms were not changed. Moreover, a two-chamber culture system was designed to meet conflicting demands for oxygen between epithelium and cavity, and better α-glucosidase inhibitory activities (51.61 % maximum reduction in glucose production) and absorption rates (up to 1.10 % from undetectable) were obtained than those of uncontrolled oxygen. Hence, the oxygen level should be monitored to assess the activities of phenolic compounds in vitro.

Co, Cu, Ni, and Zn complexes of N-[(3-phenoxy phenyl)methylidene]-l-valine as α-glycosidase and α-amylase inhibitors: Synthesis, molecular docking & antimicrobial evaluation

The ligand N-[(3-phenoxyphenyl)methylidene]-l-valine (HL) and its Co, Ni, Cu, and Zn derivatives (1–4) were synthesized and characterized. These compounds were tested for α-glucosidase and α-amylase inhibition activity, showing IC50 values of 10.51–51.36 µg/mL and 15.38–46.74 µg/mL, respectively, compared to Ascarbose. In silico molecular docking studies revealed strong binding affinities for α-glucosidase (−207.78 to –222.04 kcal/mol) and α-amylase (−159.5 to −161.82 kcal/mol), and potential anticancer activity against CDK2 (−119.6 to −126.53 kcal/mol). Antimicrobial assays against E. coli and C. albicans demonstrated significant activity, with inhibition zones of 12.5–16.8 mm and 13.5–20.05 mm, respectively. The results reveal a fascinating array of pharmacological properties of these compounds and suggest their potential for future drug development.

Improving the functional components and biological activities of navel orange juice through fermentation with an autochthonous strain Lactiplantibacillus paraplantarum M23

The fermentation of navel orange juice with lactic acid bacteria (LAB) has rarely been investigated. In this study, an autochthonous LAB strain isolated from navel orange, Lactiplantibacillus paraplantarum M23, was found to effectively ferment navel orange juice, producing a juice with enhanced functional activities and organoleptic quality. The viable bacterial count in the fermented orange juice remained consistently above 8.51 log CFU/mL throughout the entire 7-day fermentation period. The content of vitamin C (VC), total phenolic content (TPC), total flavonoid content (TFC), and hesperidin in the fermented orange juice increased by a maximum of 28.88, 1.21, 1.13, and 1.16 times, respectively, compared to the unfermented orange juice. The fermented juice exhibited significantly higher antioxidant activity than the unfermented juice, with an increase of up to 255 % and 347 % based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP) assays, respectively. This may be attributed to the increase in VC and flavonoids, as demonstrated by Pearson's correlation analysis. Additionally, the fermented orange juice demonstrated improved α-glucosidase inhibition, anti-MRSA, and anti-glycation activities compared to the unfermented juice. Furthermore, the fermented juice notably reduced the levels of NO and ROS in Raw 264.7 cells without any negative impact on cell viability. The findings of this study may help in the development of nutritious and healthy fermented navel orange juice products, and serve as a reference for the production of fermented beverages from other fruits using autochthonous strains.

Synthesis and biological evaluation of esculetin derivatives as antidiabetic agents

Esculetin derivatives 4a-4j (including six novel hydroxylated/halogenated derivatives 4a, 4d, 4e, 4f, 4g, 4h) were synthesized through Perkin reaction with 2,4,5-trihydroxybenzaldehyde and appropriate phenylacetic acid as raw materials, and screened for α-glucosidase and α-amylase inhibitory activities. Among these compounds, compound 3-(3-iodophenyl)-6,7-dihydroxy-2H-chromen-2-one (4d) showed promising hypoglycaemic activity with half maximal inhibitory concentration (IC50) values of 0.18±0.03 mM and 1.82±0.18 mM against α-glucosidase and α-amylase, respectively, classifying it as a mixed-type inhibitor. Compound 4d could statically quench the intrinsic fluorescence of enzymes, which bound to enzymes mainly through hydrogen bonding and hydrophobic interactions affecting the microenvironment of proteins. Compound 4d also exhibited antioxidant activity, which demonstrated good scavenging effects for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals. Furthermore, compound 4d still maintained a certain degree of hypoglycemic and antioxidant activities after simulated gastrointestinal digestion. The oral toxicity study showed that compound 4d had no significant effect on the serum biochemical indices and organs of mice, indicating its safety profile. This study suggests that esculetin may be a potential skeleton to the development of hypoglycaemic drugs.

Antibiofilm, Antidiabetic and Antioxidant Potentials of Vitis labrusca L. Skin Extracts

This study examined the antioxidant, antimicrobial, antibiofilm, and α-glucosidase inhibitory activities and the total phenolic and flavonoid contents of the different solvent (methanol, 50:50% methanol:water, and water) extracts from Vitis labrusca L. skin parts. The 50:50 methanol:water extract exhibited the highest antioxidant activity, exhibiting 153 µM TEAC and 0.0947 mg/mL SC50, as determined by the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging assays, respectively. Additionally, the data demonstrated that the 50:50 methanol:water extract of the skin part of V. labrusca exhibited a higher total phenolic content, with 141 µg/mL GAE. The α-glucosidase enzyme activity of the 50:50% methanol:water extract (IC₅₀; 0.103 mg/mL) was observed to be higher than that of the other solvent extracts. The MIC values of the 50:50% methanol:water, water and methanol extracts of skin part of V. labrusca was determined as 12.5, 25 and 6.25 mg/mL, aganist to clinical antibiotic resistance Acinetobacter baumanii respectively. The results of this study indicate that the methanol, water and 50:50% methanol:water extracts were found to reduce the biofilm-forming capacity of the Acinetobacter baumannii isolate by approximately 1.7, 1.6 and 1.3-fold, respectively. The findings of our investigation suggest that skin parts of V. labrusca may serve as a promising candidate for the prevention and treatment of diseases associated with oxidative damage and bacterial infections. The results show that the components found in the waste skin extracts of these genotypes can be evaluated in terms of antioxidant, antidiabetic and antibacterial properties.

Comparative Study on the Antioxidative Effects and α-Glucosidase Inhibitory Potential In Vitro among Ellagic Acid and Its Metabolites Urolithins.

The current study compared the radical scavenging and α-glucosidase inhibition potentials of ellagic acid (EA) and its metabolites, urolithins (Uros), and further explored the structure-activity relationship. The outcomes indicated that urolithin M5 (Uro-M5), EA, and urolithin M6 (Uro-M6) exhibited superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity; EA and urolithin D (Uro-D) expressed better ABTS scavenging ability, and EA and Uro-M5 showed preferable α-glucosidase inhibition activity. The results of CD spectra and fluorescence spectral analysis explained the interaction between Uros and α-glucosidase. Correlation analysis indicated that hydroxyl groups were crucial for the antioxidative effect, while C-8 OH contributed greatly to the α-glucosidase inhibition activity. Quantum mechanical analysis showed that both EA and Uros exhibited strong electrophilic properties. These comparative results showed a biological discrepancy between Uros and provided essential information for exploring the bioactive application of EA as a functional ingredient or dietary supplement.

Application of Chalcone in the Structural Modification of Natural Products: An Overview.

Natural products frequently display a range of biological activities, yet many exhibit only moderate efficacy during initial evaluations. Often, these natural substances necessitate structural alterations to yield promising lead compounds. Chalcones, characterized by their β-unsaturated carbonyl aromatic ketone structure, are prevalent in plant life and serve as fundamental scaffolds for the biosynthetic precursors of flavonoids and isoflavones. Due to their straightforward synthesis and extensive spectrum of biological effects, chalcones have found extensive application in medicinal chemistry. Chalcone analogs have demonstrated significant potential for drug discovery and development, as structural modifications can both amplify pharmacological efficacy and effectively mitigate toxic side effects. This paper endeavors to delve into the applications of chalcones in the structural modification of natural products, providing a theoretical foundation for future endeavors in derivatization and drug development. The full paper is organized into categories based on the biological activities of the derivatives, including anti-dyslipidemic, antibacterial, antimalarial, anti-inflammatory, anticancer, anti-Alzheimer, and α-glucosidase inhibitory activities.

Discovery and synthesis of novel phenoxyacetate ester Schiff base α-glucosidase inhibitors

A phenoxyacetate ester Schiff base lead compound 4a (ZINC20073984) was firstly discovered through molecular docking screening and molecular dynamics (MD) simulation, which could be used as an α-glucosidase (PDB: 3A4A) inhibitor. Then a series of α-glucosidase inhibitors 4b-4r with novel structures were designed and synthesized with the lead ZINC20073984 as a template. The results of in vitro α-glucosidase inhibitory activity show that the synthesized phenoxyacetate ester Schiff base compounds 4e, 4o-4r (IC50 values range from 5.44 ± 0.52 μM to 33.67 ± 9.1 μM) exhibit good activity. Among them, ethyl (Z)-2-(2,4-dinitro-5-(2-(1-(2,4,6-trimethoxyphenyl) ethylidene) hydrazineyl) phenoxy) acetate (4r) and ethyl (Z)-2-(2,4-dinitro-5-(2-(1-(1-(4-ethoxyphenyl) ethylidene) hydrazineyl) phenoxy) acetate (4p) exert the best inhibitory activity, with IC50 values of 5.44 ± 0.52 μM and 5.80 ± 1.4 μM, respectively, which are superior to the standard drug acarbose (IC50 = 8.36 ± 0.02 μM). Molecular docking results indicate that the good inhibitory activity of 4r and 4p may be attributed to multiple hydrogen-bonding interactions with the α-glucosidase. Furthermore, the drug-likeness of all synthesized compounds was evaluated using the pkCSM tool, and ADMET predictions were conducted for compound 4r. The results demonstrated that all compounds follow Lipinski’s rules, and 4r possesses favorable pharmaceutical properties. In an in vitro cytotoxicity assay, the most potent 4r shows non-cytotoxicity to the 3T3 cells with an CC50 value > 40 µM. In both antioxidant and anti-cancer capacity assays, compound 4r has demonstrated promising potential. The results of this study might be helpful in the discovery of new drugs for the treatment of diabetes mellitus type-2 and bladder cancer.

Chemical profiling, in-vitro and in silico α-glucosidase inhibition, antioxidant and antibacterial activities of Hypotrachyna cirrhata (Fr.) Hale ex Sipman

Natural products are essential in drug development, with increasing interest in lichen-derived compounds for their therapeutic potential. This study investigates the bioactivity of the methanolic extract of Hypotrachyna cirrhata through in vitro and in silico approaches. The ethyl acetate fraction demonstrated the highest DPPH radical scavenging activity, with an IC50 of 10.37 ± 0.62 μg/mL, while the methanolic extract exhibited an IC50 of 72.30 ± 0.55 μg/mL. For α-glucosidase inhibition, the ethyl acetate fraction and crude extract showed IC50 values of 1.17 ± 0.50 μg/mL and 5.00 ± 0.45 μg/mL, respectively. Antibacterial assays revealed zones of inhibition of 12 and 11 mm against Staphylococcus aureus at 25 mg/mL, with the strain showing sensitivity to the methanolic extract (MIC of 20.0 × 10−4 mg/mL). LC-MS analysis identified eight metabolites in the ethyl acetate extract, salazinic acid (1), roccellaric acid (2), constictic acid (3), protolichesterinic acid (4), mannitol (5), penta hydroxyicosatrienoicacid (6), methyl pentahydroxyoxoheptacosanoate (7), and one unknown compound. Five major compounds (1-5) were selected for computational analysis and highlighted that salazinic acid as a potential lead compound, displaying a non-competitive binding with α-glucosidase and a binding affinity of −9.9 kcal/mol. These findings suggest salazinic acid's promise as an α-glucosidase inhibitor.

A Green Method for Preparation of Cyanidin-3-glucoside from Carissa carandas Fruits and α-Glucosidase Inhibitory Activity Evaluation

A Green Method for Preparation of Cyanidin-3-glucoside from Carissa carandas Fruits and α-Glucosidase Inhibitory Activity Evaluation

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.

Bioactivity-Based Analysis and Chemical Characterization of Hypoglycemic Components from Helicteres angustifolia L.

Helicteres angustifolia L. (H. angustifolia), a well-known traditional Chinese medicine, has been demonstrated to have hypoglycemic activity. We found that the EtOAc extract of H. angustifolia (HAEF) showed stronger α-glucosidase inhibitory activity than that of positive control. Furthermore, the hypoglycemic activity of HAEF was evaluated in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats. The results demonstrated that HAEF reduced the drinking quantity, feeding quantity, and controlled weight loss in diabetic rats. Besides, the fasting blood glucose (FBG), viscera index, and the area under time-blood glucose curve (AUC) were significantly decreased, and the oral glucose tolerance was also improved after 5 weeks. Then, the high-performance liquid chromatography with quadrupole time of flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS) method was performed for qualitative analysis of the chemical constituents in HAEF. Twenty-one compounds were identified from in HAEF. Four compounds were further isolated from HAEF and subjected to α-glucosidase inhibition experiments. At the end, molecular docking was empolyed simulate the interaction of three compounds with α-glucosidase. This is the first report on major hypoglycaemic components has been identified in the roots of H. angustifolia. These findings provide a material basis for the use of H. angustifolia in the treatment of diabetes.