Therapeutic potential of α-glucosidase inhibitors in type 2 diabetes mellitus: an evidence-based review

In vivo anti-hyperglycemic activity and toxicity evaluation of two bis-coumarin derivative as potential α-glucosidase inhibitors

Objectives

The in vivo assay is a key step in the development of a new compound as a drug. In the present work, bis-4-aminocoumarin derivative 3,3'-(p-tolylmethylene)bis(4-amino-2H-chromen-2-one) (PTBAC) and bis-4-hydroxycoumarin derivative 3,3'-((4-((1-(2-chlorobenzyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)methylene)bis(4-hydroxy-2H-chromen-2-one) (2CTMBHC) that showed high anti-α-glucosidase activity on the yeast form of this enzyme were selected for in vivo anti-hyperglycemic assay.

Methods

The in vivo anti-hyperglycemic effect of PTBAC and 2CTMBHC was assessed using oral starch tolerance test in streptozotocin-induced diabetic albino mouse model, and the results were compared with acarbose as a representative inhibitor of intestinal α-glucosidase enzyme. Toxicity of the selected compounds was also evaluated in vivo.

Results

The obtained results revealed that both selected compounds, PTBAC and 2CTMBHC, showed more anti-diabetic effects when compared with acarbose as a standard drug. In vivo anti-diabetic assays also demonstrated that bis-4-hydroxycoumarin derivative 2CTMBHC was more potent than bis-4-aminocoumarin derivative PTBAC. In vivo results were also confirmed by in vitro and in silico studies. Moreover, there was not any apparent signs of toxicity and mortality in in vivo toxicity assay.

Conclusions

In summary, in vivo anti-hyperglycemic effects of two synthetic compounds PTBAC and 2CTMBHC was confirmed in this study. Given that these compounds exhibited no evidences of toxicity and mortality in mice, therefore, they are good candidates for further investigations.

Graphical Abstract

Synthesis, structural insights and bio-evaluation of N-phenoxyethylisatin hydrazones as potent α-glucosidase inhibitors

Effective α-glucosidase inhibitors are vital for managing type 2 diabetes, emphasizing the need for novel and potent compounds. A series of novel N-phenoxyethylisatin hydrazones 1(a-l) have been synthesized and characterized by their spectral data, and in the case of 1l by its single crystal X-ray analysis. All the synthesized compounds were in vitro evaluated for their inhibition potential against the α-glucosidase enzyme. Interestingly, most of these compounds exhibited significant inhibitory activity against the α-glucosidase enzyme, with IC50 values ranging from 3.64 ± 0.13 to 94.89 ± 0.64 μM compared to the standard drug, acarbose (IC50 = 873.34 ± 1.67 μM). The compound 1e was found to be the most active compound of the series having an IC50 value of 3.64 ± 0.13 μM. Molecular docking studies revealed a binding score of -9.7 kcal mol-1 for 1e, slightly surpassing that of acarbose (-9.4 kcal mol-1). Unlike acarbose, which primarily relies on hydrogen bonding, the binding interactions of 1e are dominated by π-interactions. ADMET profiling confirmed favourable pharmacokinetics for these compounds, including good oral bioavailability, balanced hydrophilicity, and minimal predicted toxicity. These findings highlight the potential of these compounds as promising candidates for the development of more effective treatments for hyperglycemia.

Potential Antidiabetic Activity of Nordihydroguaiaretic Acid: An Insight into Its Inhibitory Mechanisms on Carbohydrate-Hydrolyzing Enzymes, the Binding Behaviors with Enzymes, and In Vivo Antihyperglycemic Effect

The inhibitory mechanisms and binding behaviors of nordihydroguaiaretic acid (NDGA) to α-glucosidase/α-amylase were investigated by in vitro multispectroscopic methods and in silico modeling technique. The results demonstrated that NDGA reversibly and uncompetitively inhibited α-glucosidase, exhibiting stronger inhibition than acarbose, while it displayed noncompetitive inhibition against α-amylase. Additionally, NDGA could spontaneously bind to α-glucosidase/α-amylase mainly through hydrogen bonds and hydrophobic forces, thus altering the spatial structure of enzymes and reducing their catalytic activity. The presence of crowding reagents/polysaccharides/undigested milk proteins would decrease the inhibitory ability of NDGA, whereas fatty acids exhibited the opposite phenomenon on α-glucosidase. Furthermore, the antidiabetic activity of NDGA in vivo was evaluated using the diabetic Drosophila model induced by a high-sugar diet. It was found that NDGA significantly reduced the glucose levels of diabetic Drosophila. These findings suggested that NDGA was a potential inhibitor of α-glucosidase/α-amylase and could be used as a nutritional adjuvant to prevent diabetes.

Comparison of glucose fluctuation between metformin combined with acarbose or sitagliptin in Chinese patients with type 2 diabetes: A multicenter, randomized, active-controlled, open-label, parallel design clinical trial

BACKGROUND

Alpha-glucosidase inhibitors or dipeptidyl peptidase-4 inhibitors are both hypoglycemia agents that specifically impact on postprandial hyperglycemia. We compared the effects of acarbose and sitagliptin add on to metformin on time in range (TIR) and glycemic variability (GV) in Chinese patients with type 2 diabetes mellitus through continuous glucose monitoring (CGM).

METHODS

In this multicenter, randomized, open-label, active-controlled study, we recruited patients with type 2 diabetes mellitus aged 18-65 years with body mass index (BMI) within 19-40 kg/m2 and hemoglobin A1c (HbA1c) between 6.5% and 9.0%. Eligible patients were randomized to receive either metformin combined with acarbose 100 mg three times daily or metformin combined with sitagliptin 100 mg once daily for 28 days. After the first 14-day treatment period, patients wore CGM and entered another 14-day treatment period. The primary outcome was the level of TIR after treatment between groups. We also performed time series decomposition, dimensionality reduction, and clustering using the CGM data.

RESULTS

A total of 701 participants received either acarbose or sitagliptin treatment in combination with metformin. There was no statistically significant difference in TIR between the two groups. Time below range (TBR) and coefficient of variation (CV) levels in acarbose users were significantly lower than those in sitagliptin users. TBR below target level <3.9 mmol/L (TBR3.9): Acarbose: 2.86 ± 6.98% vs. Sitagliptin: 3.89 ± 9.43%, P = 0.042; TBR3.0: Acarbose: 0.96 ± 4.41% vs. Sitagliptin: 1.64 ± 6.73%, P = 0.033; CV: Acarbose: 22.44 ± 5.08% vs. Sitagliptin: 23.96 ± 5.19%, P <0.001. No significant difference was found in the complexity of glucose time series index (CGI) between acarbose users and sitagliptin users. By using time series analysis and clustering, we distinguished three groups of patients with representative metabolism characteristics, especially in GV.

CONCLUSIONS

Acarbose had slight advantages over sitagliptin in improving GV and reducing the risk of hypoglycemia. Time series analysis of CGM data may predict GV and the risk of hypoglycemia.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2000039424.

Synthesis of modified Schiff base appended 1,2,4-triazole hybrids scaffolds: elucidating the in vitro and in silico α-amylase and α-glucosidase inhibitors potential

The current study involves the synthesis of Schiff bases based on 1,2,4-triazoles skeleton and assessing their α-amylase and α-glucosidase profile. Furthermore, the precise structures of the synthesized derivatives were elucidated using various spectroscopic methods such as 1H-NMR, 13C-NMR and HREI-MS. Using glimepiride as the reference standard, the in vitro α-glucosidase and α-amylase inhibitory activities of the synthesized compounds were evaluated in order to determine their potential anti-diabetic properties. All analogues showed varied range of inhibitory activity having IC50 values ranging from 17.09 ± 0.72 to 45.34 ± 0.03 μM (α-amylase) and 16.35 ± 0.42 to 42.31 ± 0.09 μM (α-glucosidase), respectively. Specifically, the compounds 1, 7 and 8 were found to be significantly active with IC50 values of 17.09 ± 0.72, 19.73 ± 0.42, and 23.01 ± 0.04 μM (against α-amylase) and 16.35 ± 0.42, 18.55 ± 0.26, and 20.07 ± 0.02 μM (against α-glucosidase) respectively. The obtained results were compared with the Glimepiride reference drug having IC50 values of 13.02 ± 0.11 μM (for α-glucosidase) and 15.04 ± 0.02 μM (for α-amylase), respectively. The structure-activity relationship (SAR) studies were conducted based on differences in substituent patterns at varying position of aryl rings A and B may cause to alter the inhibitory activities of both α-amylase and α-glucosidase enzymes. Additionally, the molecular docking study was carried out to explore the binding interactions possessed by most active analogues with the active sites of targeted α-amylase and α-glucosidase enzymes.

Structural Characterization of Dendrobium officinale Polysaccharides and Their Regulation Effect on Intestinal Microbiota During In Vitro Fermentation

Polysaccharides derived from Dendrobium officinale have been demonstrated to exhibit metabolic regulatory properties. However, the correlation between their structure and function, particularly their mechanism of action through gut microbiota, remains underexplored. This study systematically elucidates the structural characteristics of Dendrobium officinale polysaccharide (DOP) from the Guizhou (GZ) and Zhejiang (ZJ) provinces of China using nuclear magnetic resonance (NMR) and a series of chromatographic analyses, revealing their unique molecular features. Additionally, the metabolic regulatory activities were assessed through α-glucosidase inhibitory assay and in vitro intestinal flora activity assay. The findings include the following: (1) both DOP-GZ and DOP-ZJ predominantly consist of glycosidic linkages of β-1,4-Manp and β-1,4-Glcp; (2) zhe monosaccharide composition ratios of mannose to glucose are 2.51:1 for DOP-GZ and 2.66:1 for DOP-ZJ, with molecular weights of 356 kDa and 544 kDa, respectively, indicating significant structural differences between DOPs from different sources; (3) treatment with DOP-GZ and DOP-ZJ led to alterations in the α-diversity indices and Firmicutes-to-Bacteroidota ratios; (4) more importantly, DOP-GZ and DOP-ZJ significantly increase the abundance of beneficial bacteria (e.g., g_Proteobacteria_unclassified) while suppressing the growth of pathogenic bacteria (e.g., f_Enterobacteriaceae_unclassified), with statistically significant results. These findings not only uncover a novel mechanism by which DOPs regulate metabolism through gut microbiota but also provide a crucial theoretical basis for the application of DOPs in functional foods and pharmaceutical development.

Identification and Molecular Mechanism of Novel α-Glucosidase Inhibitory Peptides from the Hydrolysate of Hemp Seed Proteins: Peptidomic Analysis, Molecular Docking, and Dynamics Simulation

There is a growing demand for natural and potent α-glucosidase inhibitors due to the rising prevalence of diabetes. In this study, newly identified α-glucosidase inhibitory peptides were identified from the tryptic hydrolysate of hemp seed proteins based on peptidomics and in silico analysis. A total of 424 peptides, primarily derived from four cupin-type-1 domain-containing proteins, were identified, and 13 ultimately were selected for validation based on their higher PeptideRanker scores, solubility, non-toxicity, and favorable ADMET properties. Molecular docking revealed that these 13 peptides primarily interacted with α-glucosidase via hydrogen bonding and hydrophobic interactions. Among them, three novel peptides-NPVSLPGR (-8.7 kcal/mol), LSAERGFLY (-8.5 kcal/mol), and PDDVLANAF (-8.4 kcal/mol)-demonstrated potent α-glucosidase inhibitory activity due to their lower binding energies than acarbose (-8.1 kcal/mol), the first approved α-glucosidase inhibitor for type 2 diabetes treatment. The molecular mechanism analysis revealed that the peptides NPVSLPGR and LSAERGFLY inhibited α-glucosidase by simultaneously blocking substrate entry through occupying the entrance of the active site gorge and preventing catalysis by binding to active sites. In contrast, the peptide PDDVLANAF primarily exerted inhibitory effects by occupying the entrance of the active site gorge. Molecular dynamics simulation validated the stability of the complexes and provided additional insights into the molecular mechanism determined through docking. These findings contribute essential knowledge for the advancement of natural α-glucosidase inhibitors and offer a promising approach to effectively manage diabetes.

Computational investigation to identify multi-targeted anti-hyperglycemic potential of substituted 2-Mercaptobenzimidazole derivatives and synthesis of new α-glucosidase inhibitors

One of the most widespread diseases recognized all over the world is diabetes, accounting for 1.5 million deaths each year. Recent studies have demonstrated benzimidazole derivatives as potential antidiabetic agents. Hence, the present study is focused on designing new derivatives of 2-mercaptobenzimidazole by C-S cross-coupling reaction and are subjected to computational screening to identify the most promising candidate. Molecular docking and MM-GBSA calculations were performed to ascertain the binding potential with different antidiabetic targets, including α-glucosidase, PPaR-γ, DPP-4, and AMPK. We observed somewhat moderate binding interactions of the synthesized compound against the α-glucosidase. Since binding affinities can be improved using synthetic chemistry approaches, synthesis of analogues (A-18a-c) by designing hybrids at sites such as the acidic functionality of A-18 was done. The analogue A-18a, with p-fluorobenzyl substitution, exhibited enhanced binding affinity (-4.339 Kcal/mol) with the α-glucosidase compared to the parent compound (-3.827 Kcal/mol). The synthesized analogues were also subjected to an in-vitro α-glucosidase inhibitory assay. Among them, A-18a exhibited the most significant inhibitory potential, with an IC50 value of 0.521 ± 0.01 µM as compared to the standard drug Acarbose (IC50 21.0 ± 0.5 µM). This aligns with the computational study findings, where A-18a exhibited stronger binding interactions within the active site of the enzyme. Hence, a promising analogue of the designed compound was synthesized through a computationally guided approach as an anti-hyperglycaemic agent. Additionally, most of the designed compounds showed significantly greater binding affinity with PPaR-γ as compared to the standard pioglitazone. A-18 was successfully synthesized by S-arylation reaction using CuI in 89% yield and was subjected to MD-simulation against PPaR-γ, which revealed stable binding throughout the 200 ns run. Future studies will focus on exploring the activity of the designed drugs against PPaR-γ through in-vitro and in-vivo assays.

Structural Diversity and Anti-Diabetic Potential of Flavonoids and Phenolic Compounds in Eriobotrya japonica Leaves

Eriobotrya japonica (Thunb.) Lindl., commonly known as loquat, is a plant belonging to the Rosaceae family. While its fruit is widely consumed as food and used in traditional medicine, research on other parts of the plant remains insufficient. Therefore, the chemical constituents and biological activities of its leaves were investigated. Phytochemical analysis of E. japonica leaves identified 30 compounds, including flavonoids, phenolics, and megastigmanes. The flavonoids isolated from the leaves include flavones, flavans, flavolignans, flavonoid glycosides, and coumaroyl flavonoid glycosides. Coumaroyl flavonoid rhamnosides were characteristically present in E. japonica leaves, and the configurations of coumaric acids, as well as the binding position to the rhamnose in each compound, were identified through detailed NMR analysis. Notably, three of them were isolated from this plant for the first time. Phenolic compounds were found to be present as conjugates with organic acids, such as quinic acid, shikimic acid, and glucose. Flavonoid and phenolic compounds demonstrated significant antioxidant and α-glucosidase inhibitory effects, whereas megastigmanes showed little activity. Notably, coumaroyl flavonoid rhamnosides, which consist of flavonoids combined with the phenolic acid, coumaric acid, exhibited excellent anti-diabetic effects. Further molecular docking analysis confirmed that these compounds effectively bind to the α-glucosidase enzyme. In conclusion, the present study identified flavonoid and phenolic components with various structures in E. japonica leaves and clarified their anti-diabetic and antioxidant effects. These findings support the beneficial potential of E. japonica leaves for the treatment and/or prevention of metabolic diseases.

Design, Synthesis, and In Silico Molecular Docking Studies of Adamantanyl Hydrazinylthiazoles as Potential Antidiabetic Agents

Diabetes mellitus (DM) is a widespread disease that poses a major threat to millions of people. To address this issue, we have synthesized seventeen new 4-(adamantan-1-yl)-(2-(arylidene)hydrazinyl)thiazoles (3a-q) via Hantzsch synthetic approach. The molecular structures of all the compounds were confirmed using FT-IR, 1H- and 13C-NMR spectroscopy, and HR-mass spectrometry. Protein kinase, α-amylase, glycation, and oxidation inhibition potential of all compounds were also investigated, and it was found that compounds 3b, 3c, 3e-3g, and 3i-3q have shown excellent α-amylase inhibition (IC50 = 7.91 ± 0.07 to 28.57 ± 0.1 µM), compounds 3c, 3e, 3i, 3k, and 3p (IC50 = 30.6 ± 0.06 to 37.8 ± 0.005 ppm) were found to be highly potent anti-glycating agents, and compounds 3c, 3g, 3h, 3k, and 3m were found to be more potent protein kinase inhibitors as compared to standards. The compounds 3b, 3c, 3d, 3e, 3f, 3g, 3i, 3k, 3l, 3m, 3n, 3p, and 3q have shown good antioxidant potential (IC50 = 27.5 ± 0.09 to 48.8 ± 0.09 µM) as compared to standard ascorbic acid (IC50 = 51.3 ± 0.1 µM). The biocompatibility of all samples was also tested by employing brine shrimp lethality and in vitro hemolytic assays and was found to be safe to human erythrocytes at tested concentrations. Furthermore, the molecular docking simulation study also revealed that almost all synthesized compounds have potential interactions with target proteins at the molecular level.

Rare diphenylheptanoid-phenylheptanoid hybrids with α-glucosidase inhibitory effects from the pollen of Typha angustifolia

Two rarely occurring diphenylheptanoid-phenylheptanoid hybrid dimers (1 and 2) and one new oxygenated fatty acid (3), as well as two known fatty acid analogues (4 and 5), were isolated from the 70% EtOH extract of the pollen of Typha angustifolia. Their planar structures were established by interpretation of MS and NMR spectroscopic data, and the absolute configurations of 1 and 2 were determined by Mosher's method and quantum chemical TD-DFT calculations of ECD spectra. An in vitro anti-diabetic evaluation of these isolates revealed that compounds 1 and 2 exhibited promising inhibitory activity against α-glucosidase with IC50 values of 11.85 ± 0.69 and 17.06 ± 3.08 μM, respectively. It is the first report on both diphenylheptanoid constituents and α-glucosidase inhibitors from the title plant, which represents a significant phytochemical progress of this herbal species and may serve as a reference for its future medicinal applications.

The Intricate Mechanisms of Functional Foods Oyster Mushroom and Fenugreek on Type 2 Diabetic Animal Model

Mushrooms and fenugreek are widely used to reduce hyperglycemia, and fenugreek is also used as a culinary ingredient to enhance flavor and aroma. This study is aimed at investigating the underlying mechanisms of the hypoglycemic effects of mushrooms and fenugreek in a Type 2 diabetic rat model. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) functions to reduce hyperglycemia through insulin-independent pathways and protects beta-cells. Diabetic model rats were administered standard diets supplemented with 5% oyster mushroom powder (mushroom-treated (MT) group) and 5% fenugreek seed powder (fenugreek-treated (FT) group) for 8 weeks. The results showed improvements in both glycemic and lipid profiles, with both oyster mushroom and fenugreek enhancing the phosphorylation of AMPK in muscle tissue. However, no effect on insulin secretion was observed. These findings suggest that both substances reduce hyperglycemia through an insulin-independent pathway. In silico analysis of both mushroom and fenugreek seed extracts revealed bioactive compounds having a strong binding affinity to α-glucosidase, which suggests mushroom and fenugreek supplements might control postprandial blood glucose levels.

In vivo anti-diabetic and anti-lipidemic evaluations of an excellent synthetic α-glucosidase inhibitor with dihydropyrano[3,2-c]quinoline skeleton

Objectives

The in vivo assay is a key step in the development of a new bioactive compound as a lead drug structure. Based on importance of α-glucosidase inhibitors in the control of blood glucose level (BGL) in diabetes, in the present work, 3-amino-1-(4-chlorophenyl)-12-oxo-11,12-dihydro-1H-benzo[h]pyrano[3,2-c]quinoline-2-carbonitrile (ACODDHBPQC) that showed excellent inhibitory activity on the yeast form of α-glucosidase was selected for in vivo anti-diabetic assay.

Methods

The in vivo anti-diabetic and anti-lipidemic effects of this synthetic compound were evaluated using by a streptozotocin (STZ)-induced diabetic Wistar rat model. In silico docking study of ACODDHBPQC was performed by Atodock tools and absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of this compound was predicted by PreADMT online software.

Results

The obtained results revealed that selected compound ACODDHBPQC showed a significant anti-diabetic effect on diabetic rats. In vivo anti-lipidemic assay also demonstrated that ACODDHBPQC had favorable effects on cholesterol and LDL levels. Furthermore, in silico studies showed that ACODDHBPQC interacted with key residues of the α-glucosidase active site and had good pharmacokinetic and toxicity properties.

Conclusion

In summary, anti-hyperglycemic effects of ACODDHBPQC was confirmed by in vivo study. However, more evaluations are needed to introduce ACODDHBPQC as a lead drug compound.

Graphical abstract

Design, synthesis, biological evaluation, and molecular modeling studies of some quinazolin-4(3H)-one-benzenesulfonamide hybrids as potential α-glucosidase inhibitors

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia, posing serious health risks and becoming increasingly prevalent. Prolonged hyperglycemia can lead to complications such as nephropathy, neuropathy, retinopathy, cardiovascular damage, and blindness. Controlling hyperglycemia through α-glucosidase inhibitors, which slow down carbohydrate breakdown, is an effective treatment strategy. However, current inhibitors like acarbose, voglibose, and miglitol while used to manage type 2 diabetes, have significant side effects. Therefore, developing new α-glucosidase inhibitors that are more effective and have fewer side effects is crucial. In this study, a series of novel quinazolin-4(3H)-one-benzenesulfonamide hybrid compounds were designed, synthesized, and evaluated for in vitro α-glucosidase inhibitory activity. The compounds showed higher enzyme inhibition potency, with IC50 values ranging between 129.2 ± 0.5 and 558.7 ± 13.7 µM, compared to acarbose (IC50=814.3 ± 13.5 µM). Among the tested compounds, compound 10, bearing a 4-chlorophenyl ring on the nitrogen atom of the sulfonamide group, was the most active, with an IC50 value of 129.2 ± 0.5 µM. Enzyme kinetics analyses and molecular modeling studies were conducted to understand their inhibition mechanisms and interactions with the enzyme. The kinetic studies revealed a mixed-type inhibition model, indicating that the compounds bind to the enzyme-substrate complex with higher affinity than to the free enzyme. Molecular modeling results confirmed these findings. Additionally, in silico prediction studies showed that the selected compounds have favourable physicochemical and drug-like properties. These results suggest these compounds have potential for further optimization and development as effective α-glucosidase inhibitors for diabetes treatment.

Discovery of novel thiazole derivatives containing pyrazole scaffold as PPAR-γ Agonists, α-Glucosidase, α-Amylase and COX-2 inhibitors; Design, synthesis and in silico study

A novel series of thiazole derivatives with pyrazole scaffold 16a-l as hybrid rosiglitazone/celecoxib analogs was designed, synthesized and tested for its PPAR-γ activation, α-glucosidase, α-amylase and COX-2 inhibitory activities. Regarding the anti-diabetic activity, all compounds were assessed in vitro against PPAR-γ activation, α-glucosidase and α-amylase inhibition in addition to in vivo hypoglycemic activity (one day and 15 days studies). Compounds 16b, 16c, 16e and 16 k showed good PPAR-γ activation (activation % ≈ 72-79 %) compared to that of the reference drug rosiglitazone (74 %). In addition, the same derivatives 16b, 16c, 16e and 16 k showed the highest inhibitory activities against α-glucosidase (IC50 = 0.158, 0.314, 0.305, 0.128 μM, respectively) and against α-amylase (IC50 = 32.46, 23.21, 7.74, 35.85 μM, respectively) compared to the reference drug acarbose (IC50 = 0.161 and 31.46 μM for α-glucosidase and α-amylase, respectively). The most active derivatives 16b, 16c, 16e and 16 k also revealed good in vivo hypoglycemic effect comparable to that of rosiglitazone. In addition, compounds 16b and 16c had the best COX-2 selectivity index (S.I. = 18.7, 31.7, respectively) compared to celecoxib (S.I. = 10.3). In vivo anti-inflammatory activity of the target derivatives 16b, 16c, 16e and 16 k supported the results of in vitro screening as the derivatives 16b and 16c (ED50 = 8.2 and 24 mg/kg, respectively) were more potent than celecoxib (ED50 = 30 mg/kg). In silico docking, ADME, toxicity, and molecular dynamic studies were carried out to explain the interactions of the most active anti-diabetic and anti-inflammatory compounds 16b, 16c, 16e and 16 k with the target enzymes in addition to their physiochemical parameters.

Polydatin from Polygoni Cuspidati Rhizoma et Radix regulates glucolipid metabolism in the liver of diabetic rats: Multiscale analysis of network pharmacology and multiomics

BACKGROUND

Polygoni Cuspidati Rhizoma et Radix (Huzhang in Chinese), refers to the root and rhizome of Polygonum cuspidatum Sieb. et Zucc. Huzhang is commonly used in clinical practice for the prevention and treatment of diabetes and its complications, but its active components and regulatory mechanisms have not yet been thoroughly analyzed.

PURPOSE

The network pharmacology combined with multi-omics analysis will be employed to dissect the substance basis and action mechanism of Huzhang in exerting its anti-diabetic activity.

METHODS

This study employed phenotypic indicators for baseline assessment, followed by integrated analysis using network pharmacology, metabolomics, transcriptomics, and qPCR technology to elucidate the active components and pharmacological mechanisms of Huzhang.

RESULTS

The analysis of network pharmacology revealed that polydatin is a potential active component responsible for the anti-T2DM pharmacological effects of Huzhang. In vivo experimental results demonstrated that polydatin significantly regulates blood glucose, lipid levels, liver function, and liver pathological damage in diabetic rats. Analysis results from transcriptomics, metabolomics, and qPCR validation showed that polydatin comprehensively regulates glucose and lipid metabolism in T2DM by modulating bile acid metabolism, fatty acid oxidation, and lipogenesis.

CONCLUSION

Polydatin is a key component of Huzhang in treating T2DM, and its regulatory mechanisms are diverse, indicating significant development potential.

Anti-Hyperglycemic Medication Management in the Perioperative Setting: A Review and Illustrative Case of an Adverse Effect of GLP-1 Receptor Agonist

A host of anti-hyperglycemic agents are currently available and widely prescribed for diabetes and weight loss management. In patients undergoing surgery, use of these agents poses a clinical challenge to surgeons, anesthesiologists, and other perioperative care providers with regard to optimal timing of discontinuation and resumption of use, as well as possible effects of these agents on physiology and risk of postoperative complications. Here, we provide a comprehensive review of anti-hyperglycemic medications' effects on physiology, risks/benefits, and best practice management in the perioperative setting. Additionally, we report an illustrative case of small bowel obstruction in a patient taking semaglutide for 6 months prior to an otherwise uncomplicated laparoscopic hysterectomy and bilateral salpingo-oophorectomy. This review is meant to serve not as a replacement of, but rather as a consolidated complement to, various society guidelines regarding perioperative anti-hyperglycemic agent management.

Novel 3,5‐Dimethylpyrazole‐Linked 1,2,4‐Triazole‐3‐thiols as Potent Antihyperglycemic Agents: Synthesis, Biological Evaluation, and In Silico Molecular Modelling Investigations

In this work, a series of pyrazole‐linked 1,2,4‐triazole‐3‐thiol derivatives (3a–i) were prepared and identified by 13C NMR, 1H NMR, and mass spectrometry (ESI‐MS) data. The newly synthesized molecules were also evaluated in vitro for their α‐amylase and α‐glucosidase inhibitory potential. All newly synthesized compounds exhibited potent α‐glucosidase inhibition activity with IC50 in the range of 1.016 ± 0.70 to 24.40 ± 0.02 µM and good α‐amylase inhibitory with IC50 in the range of 49.91 ± 0.32 to 500 µM, as compared to acarbose. The most potent compound among this series is derivative 3e, with IC50 value of 1.016 ± 0.70 µM, which is many folds more than that of acarbose. In addition, in docking studies, both compounds exhibited good interactions at the active region of target proteins. Therefore, this study may lead via structural modifications to the discovery of new potent α‐amylase and α‐glucosidase inhibitors useful in the diabetes treatment.

Advancing drug discovery: Thiadiazole derivatives as multifaceted agents in medicinal chemistry and pharmacology

In this dispensation of rapid scientific and technological advancements, significant efforts are being made to curb health-related diseases. Research discoveries have highlighted the value of heterocyclic compounds, particularly thiadiazole derivatives, due to their diverse pharmacological activities. These compounds play a crucial role in therapeutic medicine and the development of effective drugs. Thiadiazoles are five-membered heterocyclic compounds consisting of one sulfur and two nitrogen atoms. This review explores advanced synthesis techniques, including the use of heterogeneous catalysts, microwave-assisted methods, ultrasound-assisted synthesis, solvent-free processes, multicomponent reactions, copper-catalyzed aerobic oxidative annulation, intramolecular cyclization, click-chemistry supported synthesis, and alkali-promoted, transition-metal-free mediated synthesis. These methods enhance the diversity and potential applications of thiadiazole compounds. Furthermore, this study provides up-to-date information on the key pharmacological activities of thiadiazole derivatives, highlighting their potential in therapeutic medicine for drug development. The structure-activity relationship (SAR) is also discussed to better understand their interactions and safety in biological systems. This work aims to expand on the reported chemistry and pharmacological potential of the thiadiazole moiety to validate their efficacy as promising pharmacophores in drug design and development.

α-Glucosidase inhibition assay of galbanic acid and it amide derivatives: New excellent semi-synthetic α-glucosidase inhibitors

α-Glucosidase inhibitory activity of galbanic acid and its new amide derivatives 3a-n were investigated. Galbanic acid and compounds 3a-n showed excellent anti-α-glucosidase activity with IC50 values ranging from 0.3 ± 0.3 μM to 416.0 ± 0.2 μM in comparison to positive control acarbose with IC50 value of = 750.0 ± 5.6. In the kinetic study, the most potent compound 3h demonstrated a competitive mode of inhibition with Ki = 0.57 µM. The interaction of the most potent compound 3h with the α-glucosidase was further elaborated by in vitro Circular dichroism assessment and in silico molecular docking and Molecular dynamics studies. Compound 3h was also non-cytotoxic on human normal cells. In silico study on pharmacokinetics and toxicity profile of the most potent galbanic acid derivatives demonstrated that these compounds are valuable lead compounds for further study in order to achieve new anti-diabetic agents.

Evaluating the Preferences and Willingness-to-Pay for Oral Antidiabetic Drugs Among Patients with Type 2 Diabetes Mellitus in China: A Discrete Choice Experiment

PURPOSE

To quantify the preferences for an oral antidiabetic drug (OAD) among patients with type 2 diabetes mellitus (T2DM) in China.

METHODS

A discrete choice experiment (DCE) with hypothetical OAD profiles was performed among patients with T2DM recruited from both online and offline sources. Each patient completed 12 DCE choice tasks. The attributes, elicited through mixed methods, include blood glucose level decrease, blood glucose level stability, frequency of medication, gastrointestinal side effects, dose adjustment and out-of-pocket expense. The conditional logit regression model was used to analyze the data. Patients' willingness-to-pay (WTP) was also calculated. Subgroup analyses based on patient characteristics were also conducted.

RESULTS

A total of 741 respondents were included in the analysis sample, covering 456 respondents online and 285 offline. The result showed that all attributes and levels were statistically significant, except one level "dose adjustment required for patients with hepatic or renal insufficiency" in the attribute of dose adjustment. WTP results showed that patients were willing to pay 12.06 and 23.20 yuan, respectively to reduce the frequency of medication from "once per day" and "three times per day" to "once every 2 weeks", respectively. Subgroup analyses showed that the frequency of medication (once versus two to three times per day) had the largest impact and influenced most coefficient estimates.

CONCLUSION

The results suggest that Chinese patients with T2DM prioritized better efficacy, less frequency of medication, lower gastrointestinal side effects, no dose adjustment required for patients with hepatic or renal insufficiency, and less out-of-pocket expense of OAD treatment.

Effectiveness of dual combination therapy of acarbose plus metformin and acarbose plus myo-inositol in ameliorating the metabolic and endocrinologic complications of polycystic ovary syndrome - A randomized controlled trial

INTRODUCTION

PCOS, beyond being characterized by reproductive disturbances, is a complicated rapid expanding metabolic and endocrinologic disorder of the recent times. Nearly 70% PCOS women show resistance to insulin.

AIM

The aim of the study is to determine and compare the effectiveness of acarbose plus metformin and acarbose plus myo-inositol combination therapy in alleviating the metabolic and endocrinologic complications of PCOS.

MATERIALS AND METHODS

An open labelled RCT was conducted on 168 PCOS women attending the gynaecology clinic at SRM MCH & RC, Chengalpattu and the trial was registered in CTRI (No. CTRI/2022/04/041877). Group A (n = 56) received metformin 500 mg/TID alone; group B (n = 54) received (acarbose 25 mg/TID for 4 weeks then 50 mg/TID for other 20 weeks) along with metformin 500 mg/TID and group C (n = 54) received (acarbose 25 mg/TID for 4 weeks then 50 mg/TID for other 20 weeks) along with myoinositol 1000 mg/BD. All parameters were measured at baseline and at the end of 6 months.

RESULTS

Significant reduction of LH, LH: FSH, TT, HOMA-IR was observed in all the groups. FSH increased only in metformin group. Increase in serum progesterone and reduction in FI, TGL, LDL were significant only in acarbose plus myo-inositol group. SHBG and HDL increased significantly only in acarbose plus metformin group. No changes in BMI, TC and VLDL were observed in any group.

CONCLUSION

Therefore, decrease in FI, HOMA-IR, TGL, LDL seen in acarbose plus myo-inositol group indirectly contributes to cardio-metabolic safety in PCOS. Similarly, a significant increase in SHBG levels with acarbose plus metformin group shows correction of the excess androgen and restoration of ovulation.

Antioxidant, In Vitro Cytotoxicity, and Anti-diabetic Attributes of a Drug-Free Guar Gum Nanoformulation as a Novel Candidate for Diabetic Wound Healing

The escalating intersection of diabetes and impaired wound healing poses a substantial societal burden, marked by an increasing prevalence of chronic wounds. Diabetic individuals struggle with hindered recovery, attributed to compromised blood circulation and diminished immune function, resulting in prolonged healing periods and elevated healthcare expenditures. To address this challenge, we report here a drug-free novel guar gum (GG)-based nano-formulation which is effective against diabetic wound healing. Nanoparticles with an average particle size of 32.4 nm display stability with negative zeta potential. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) analysis reveal alterations in thermal properties and molecular structures induced by the nano-particulation process. In vitro studies highlight the antioxidant potential of GGNP through concentration-dependent free radical scavenging activity in DPPH and ABTS assays. The nanoformulation also exhibits inhibitory effects on α-glucosidase and α-amylase enzymes. Cell viability studies have indicated moderate cytotoxicity in L929 cells and significant proliferation and migration in HaCaT cells, suggesting a positive impact on skin cells. In vitro enzymatic activity assessments under hyperglycaemic conditions reveal the potential of GGNP to modulate glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase activities as well as decreasing lipid peroxidation (LPO) levels, showcasing an antioxidant response. These results suggest GGNP as a promising candidate in diabetic wound healing.

A new route to the synthesis of 2-hydrazolyl-4-thiazolidinone hybrids, evaluation of α-glucosidase inhibitory activity and molecular modeling insights

One of the multifactorial worldwide health syndromes is diabetes mellitus which is increasing at a disturbing rate. The inhibition of α-glucosidase, an enzyme that catalyzes starch hydrolysis in the intestine, is one helpful therapeutic approach for controlling hyperglycemia related to type-2 diabetes. To discover α-glucosidase inhibitors, some 2-hydrazolyl-4-thiazolidinone hybrids (3a-e) were synthesized from new one-pot reaction procedures. Next, their chemical structures were confirmed by 1H NMR, 13C NMR, and FT-IR spectra, and elemental analysis technique. Then, the α-glucosidase inhibitory activity of the titled compounds was evaluated. Among them, derivatives 3b and 3c revealed the highest activity against α-glucosidase compared to acarbose as a drug. Enzyme kinetic studies of the most active derivative (3b) indicated a competitive inhibition. Finally, molecular modeling studies were accomplished to describe vital interactions of the most potent compounds (3b and 3c) with the α-glucosidase enzyme.

Medicinal plants of Southeast Asia with anti-α-glucosidase activity as potential source for type-2 diabetes mellitus treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus, a widespread chronic illness, affects millions worldwide, and its incidence is increasing alarmingly, especially in developing nations. Current pharmacological treatments can be costly and have undesirable side effects. To address this, medicinal plants with antidiabetic effects, particularly targeting α-glucosidase for controlling hyperglycaemia in type-2 diabetes mellitus (T2DM), hold promise for drug development with reduced toxicity and adverse reactions.

AIM OF THIS REVIEW

This review aims to succinctly collect information about medicinal plant extracts that exhibit antidiabetic potential through α-glucosidase inhibition using acarbose as a standard reference in Southeast Asia. The characteristics of this inhibition are based on in vitro studies.

MATERIALS AND METHODS

Relevant information on medicinal plants in Southeast Asia, along with α-glucosidase inhibition studies using acarbose as a positive control, was gathered from various scientific databases, including Scopus, PubMed, Web of Science, and Google Scholar.

RESULTS

About 49 papers were found from specific counties in Southeast Asia demonstrated notable α-glucosidase inhibitory potential of their medicinal plants, with several plant extracts showcasing activity comparable to or surpassing that of acarbose. Notably, 19 active constituents were identified for their α-glucosidase inhibitory effects.

CONCLUSIONS

The findings underscore the antidiabetic potential of the tested medicinal plant extracts, indicating their promise as alternative treatments for T2DM. This review can aid in the development of potent therapeutic medicines with increased effectiveness and safety for the treatment of T2DM.

Design, synthesis and inhibition evaluation of novel chalcone amide α-glucosidase inhibitors

Aim: The purpose of this study is to design and synthesize a series of novel chalcone amide α-glucosidase (AG) inhibitors (L1-L10) based on virtual screening and molecular dynamics (MD) simulation. Materials & methods: Target compounds (L1-L10) were synthesized from 2-hydroxyacetophenone and methyl 4-formylbenzoate. Results: In vitro activity test shows that most compounds have good AG inhibition. Specially, compound L4 (IC50 = 8.28 ± 0.04 μM) had the best inhibitory activity, superior to positive control acarbose (IC50 = 8.36 ± 0.02 μM). Molecular docking results show that the good potency of L4 maybe attributed to strong interactions between chalcone skeleton and active site, and the torsion of carbon nitrogen bond in amide group. Conclusion: Compound L4 maybe regard as a good anti-Type II diabetes candidate to preform further study.

New phenylthiosemicarbazide-phenoxy-1,2,3-triazole-N-phenylacetamides as dual inhibitors against α-glucosidase and PTP-1B for the treatment of type 2 diabetes

This study describes the design, synthesis, and evaluation of a novel series of phenylthiosemicarbazide-phenoxy-1,2,3-triazole-N-phenylacetamide derivatives (7a-l) as dual inhibitors of α-glucosidase and protein tyrosine phosphatase 1-B (PTB-1B). The latter enzymes are two important targets in the treatment of type 2 diabetes. The in vitro obtained data demonstrated that all title compounds 7a-l were more potent than the standard inhibitor acarbose against α-glucosidase while only four derivatives (7a, 7g, 7h, and 7h) were more potent than the standard inhibitor suramin against PTP-1B. Furthermore, these data showed that the most potent α-glucosidase inhibitor was compound 7i, with sixfold higher inhibitory activity than acarbose, and the most potent PTP-1B inhibitor was compound 7a with 3.5-fold higher inhibitory activity than suramin. Kinetic studies of compounds 7i and 7a revealed that they inhibited their target enzymes in a competitive mode. The docking study demonstrated that compounds 7i and 7a well occupied the active site pockets of α-glucosidase and PTP-1B, respectively. In silico pharmacokinetic and toxicity assays of the most potent compounds were performed, and the obtained results were compared with those of the standard inhibitors.

Therapeutic potential of acarbose in ameliorating the metabolic and endocrinological complications of polycystic ovarian syndrome: a review

Polycystic ovarian syndrome is a perplexed condition addressing endocrinal, cardiometabolic and gynaecological issues. It affects women of adolescent age and is drastically increasing in the Indo-Asian ethnicity over the recent years. According to Rotterdam criteria, PCOS is characterized by clinical or biochemical excess androgen and polycystic ovarian morphology; however, it has been established in the recent years that PCOS exacerbates to further serious metabolic conditions on the long term. This is a narrative literature review and not systematic review and is based on PubMed searches with relevant keywords "Polycystic ovarian syndrome AND acarbose OR metformin OR myoinositol; PCOS AND metabolic syndrome OR cardiovascular disease OR menstrual irregularity OR infertility OR chronic anovulation OR clinical hyperandrogenism" used in the title and are limited to articles published in English language with no time limits. A prominent aspect of PCOS is hyperandrogenaemia and hyperinsulinemia. About 50-70% of afflicted women have compensatory hyperinsulinemia and close to one tierce suffer from anovulation and infertility. Insulin resistance leads to metabolic complications and works with luteinizing hormone in increasing the ovarian androgen production. This excess androgen leads to clinical manifestations, irregular menstrual cycles and infertility. There isn't an entire cure, only the symptomatic clinical factors are considered rather than focusing on the underlying long-term complications. Therefore, the article focuses on a potent alpha glucosidase inhibitor, acarbose which suppresses the post meal glucose and insulin by delaying the absorption of complex carbs. It exhibits cardio-metabolic and hormonal benefits and is well tolerable in the south asian population. This review highlights the safety, effectiveness of acarbose in ameliorating the long-term complications of PCOS.

The Evaluation of the Phytochemical Profiles and Antioxidant and α-Glucosidase Inhibitory Activities of Four Herbal Teas Originating from China: A Comparative Analysis of Aqueous and Ethanol Infusions

Recent research has demonstrated the positive impact of herbal tea consumption on postprandial blood glucose regulation. This study conducts a comparative analysis of aqueous and ethanol extractions on four herbal teas (Mallotus, Cyclocarya, Rubus, and Vine) to assess their phytochemical profiles and functional attributes. Phytochemical contents, antioxidant activities, α-glucosidase inhibitory activities, and chemical compositions are investigated via colorimetric analyses and UPLC-Q-Orbitrap HRMS/MS, respectively. Results indicate that Vine, among the teas studied, exhibits the most pronounced glucose-regulating effects under both extraction methods. While ethanol extractions yield higher phytochemical content overall, the compositions vary. Conversely, aqueous extracts demonstrate unexpectedly potent antioxidant activities and comparable α-glucosidase inhibitory activities to ethanol extracts. Phytochemical contents correlate positively with antioxidant activities and α-glucosidase inhibitory activities. However, antioxidant activities exhibit a weak positive correlation with α-glucosidase inhibitory activities. These findings provide evidence that aqueous extracts from herbal teas contain valuable phytochemical compositions beneficial for antioxidants and individuals with hyperglycemia, suggesting their potential as functional ingredients to enhance the nutritional value of herbal food products.

Design, synthesis, molecular docking study, and α-glucosidase inhibitory evaluation of novel hydrazide-hydrazone derivatives of 3,4-dihydroxyphenylacetic acid

A series of novel Schiff base derivatives (1-28) of 3,4-dihydroxyphenylacetic acid were synthesized in a multi-step reaction. All the synthesized Schiff bases were obtained in high yields and their structures were determined by 1HNMR, 13CNMR, and HR-ESI-MS spectroscopy. Except for compounds 22, 26, 27, and 28, all derivatives show excellent to moderate α-glucosidase inhibition. Compounds 5 (IC50 = 12.84 ± 0.52 µM), 4 (IC50 = 13.64 ± 0.58 µM), 12 (IC50 = 15.73 ± 0.71 µM), 13 (IC50 = 16.62 ± 0.47 µM), 15 (IC50 = 17.40 ± 0.74 µM), 3 (IC50 = 18.45 ± 1.21 µM), 7 (IC50 = 19.68 ± 0.82 µM), and 2 (IC50 = 20.35 ± 1.27 µM) shows outstanding inhibition as compared to standard acarbose (IC50 = 873.34 ± 1.67 µM). Furthermore, a docking study was performed to find out the interaction between the enzyme and the most active compounds. With this research work, 3,4-dihydroxyphenylacetic acid Schiff base derivatives have been introduced as a potential class of α-glucosidase inhibitors that have remained elusive till now.

Acyl pyrazole sulfonamides as new antidiabetic agents: synthesis, glucosidase inhibition studies, and molecular docking analysis

Diabetes mellitus is a multi-systematic chronic metabolic disorder and life-threatening disease resulting from impaired glucose homeostasis. The inhibition of glucosidase, particularly α-glucosidase, could serve as an effective methodology in treating diabetes. Attributed to the catalytic function of glucosidase, the present research focuses on the synthesis of sulfonamide-based acyl pyrazoles (5a-k) followed by their in vitro and in silico screening against α-glucosidase. The envisaged structures of prepared compounds were confirmed through NMR and FTIR spectroscopy and mass spectrometry. All compounds were found to be more potent against α-glucosidase than the standard drug, acarbose (IC50 = 35.1 ± 0.14 µM), with IC50 values ranging from 1.13 to 28.27 µM. However, compound 5a displayed the highest anti-diabetic activity (IC50 = 1.13 ± 0.06 µM). Furthermore, in silico studies revealed the intermolecular interactions of most potent compounds (5a and 5b), with active site residues reflecting the importance of pyrazole and sulfonamide moieties. This interaction pattern clearly manifests various structure-activity relationships, while the docking results correspond to the IC50 values of tested compounds. Hence, recent investigation reveals the medicinal significance of sulfonamide-clubbed pyrazole derivatives as prospective therapeutic candidates for treating type 2 diabetes mellitus (T2DM).

Indenoquinoxaline-phenylacrylohydrazide hybrids as promising drug candidates for the treatment of type 2 diabetes: In vitro and in silico evaluation of enzyme inhibition and antioxidant activity

Existing drugs that are being used to treat type-2 diabetes mellitus are associated with several side effects; thus, exploring potential drug candidates is still an utter need these days. Hybrids of indenoquinoxaline and hydrazide have never been explored as antidiabetic agents. In this study, a series of new indenoquinoxaline-phenylacrylohydrazide hybrids (1-30) were synthesized, structurally characterized, and evaluated for α-amylase and α-glucosidase inhibitory activities, as well as for their antioxidant properties. All scaffolds exhibited varying degrees of inhibitory activity against both enzymes, with IC50 values ranging from 2.34 to 61.12 μM for α-amylase and 0.42 to 54.72 μM for α-glucosidase. Particularly, compounds 10, 16, 17, 18, 24, and 25 demonstrated the highest efficacy in inhibiting α-amylase, while compounds 6, 7, 8, 10, 12, 14, 13, 16, 17, 18, 24, and 25 were the most effective α-glucosidase inhibitors, compared to standard acarbose. Moreover, most of these compounds displayed substantial antioxidant potential compared to standard butylated hydroxytoluene (BHT). Kinetics studies revealed competitive inhibition modes by compounds. Furthermore, a comprehensive in silico study and toxicity prediction were also conducted, further validating these analogs as potential drug candidates. The structured compounds demonstrated enhanced profiles, underscoring their potential as primary candidates in drug discovery.

Synthesis and Biological Evaluation of New Dihydrofuro[3,2-b]piperidine Derivatives as Potent α-Glucosidase Inhibitors

Inhibition of glycoside hydrolases has widespread application in the treatment of diabetes. Based on our previous findings, a series of dihydrofuro[3,2-b]piperidine derivatives was designed and synthesized from D- and L-arabinose. Compounds 32 (IC50 = 0.07 μM) and 28 (IC50 = 0.5 μM) showed significantly stronger inhibitory potency against α-glucosidase than positive control acarbose. The study of the structure-activity relationship of these compounds provides a new clue for the development of new α-glucosidase inhibitors.

3,5-Disubstituted-thiazolidine-2,4-dione hybrids as antidiabetic agents: Design, synthesis, in-vitro and In vivo evaluation

Diabetes is one of the fastest-growing metabolic disorders, nearly doubling the number of patients each year. There are different treatment approaches available for the management of diabetes, which lacks due to their side effects. The inhibition of enzymes involved in the metabolism of complex polysaccharides to monosaccharides has proven beneficial in patients with type 2 diabetes mellitus. Two enzymes, α-amylase and α-glucosidase, have emerged as potential drug targets and are widely explored for drug development against type 2 diabetes mellitus. In this context, thiazolidine-2,4-diones (TZDs) have emerged as potential drug candidates for developing newer molecules against α-amylase and α-glucosidase. Nineteen TZD-hybrids were synthesized and evaluated in vitro α-amylase and α-glucosidase inhibitory activity. The compounds 7i, 7k, and 7p have emerged as the best dual inhibitors with IC50 of 10.33 ± 0.11-20.94 ± 0.76 μM and 10.19 ± 0.25-24.07 ± 1.56 μM against α-glucosidase and α-amylase, respectively. The derivatives had good anti-oxidant activity, displaying IC50 = 14.95 ± 0.65-23.27 ± 0.99 μM. The compounds 7k and 7p showed the best inhibition of reactive oxygen species in the PNAC-1 cells. The molecules exhibit good binding within the active site of α-amylase (PDB id: 1B2Y) and α-glucosidase (PDB id: 3W37), displaying binding energies of -7.5 to -10.7 kcal/mol and -7.4 to -10.3 kcal/mol, respectively. Further, the compounds were nontoxic (LD50 = 500-1311 mg/kg) and possessed good GI absorption. The compounds 7i, 7k, and 7p were evaluated in vivo antidiabetic activity in an STZ-induced diabetic model in Wistar rats. The compound 7p emerged as the best compound in the in vivo studies; however, the activity was lesser than that of the standard drug pioglitazone.

Comparative Assessment of In Vitro Xanthine Oxidase and α-Glucosidase Inhibitory Activities of Cultured Cambial Meristematic Cells, Adventitious Roots, and Field-Cultivated Ginseng

Panax ginseng, a traditional Chinese medicine with a history spanning thousands of years, faces overexploitation and challenges related to extended growth periods. Tissue-cultured adventitious roots and stem cells are alternatives to wild and field-cultivated ginseng. In this study, we assessed the in vitro xanthine oxidase and α-glucosidase inhibitory activities of saponin extracts among cultured cambial meristematic cells (CMC), adventitious ginseng roots (AGR), and field-cultivated ginseng roots (CGR). The xanthine oxidase (XO) and α-glucosidase inhibitory activities were determined by uric acid estimation and the p-NPG method, respectively. Spectrophotometry and the Folin-Ciocalteu, aluminum nitrate, and Bradford methods were employed to ascertain the total saponins and phenolic, flavonoid, and protein contents. The calculated IC50 values for total saponin extracts against XO and α-glucosidase were 0.665, 0.844, and >1.6 mg/mL and 0.332, 0.745, and 0.042 mg/mL for AGR, CMC, CGR, respectively. Comparing the total saponin, crude protein, and total phenolic contents revealed that AGR > CMC > CGR. To the best of our knowledge, this study presents the first report on the in vitro comparison of xanthine oxidase and α-glucosidase inhibitory activities among AGR, CMC, and CGR. The findings offer valuable insights into the development of hypoglycemic and antihyperuricemic medicinal, nutraceutical, and functional products utilizing AGR and CMC.

Discovery of N-(phenylsulfonyl)thiazole-2-carboxamides as potent α-glucosidase inhibitors

In a search for novel nonsugar α-glucosidase inhibitors for diabetes treatment, a series of N-(phenylsulfonyl)thiazole-2-carboxamide derivatives were designed and synthesized, the α-glucosidase inhibitory activities were then evaluated. Several compounds with promising α-glucosidase inhibitory effects were identified. Among these, compound W24 which shows low cytotoxicity and good α-glucosidase inhibitory activity with an IC50 value of 53.0 ± 7.7 μM, is more competitive compared with the commercially available drug acarbose (IC50  = 228.3 ± 9.2 μM). W24 was identified as a promising candidate in the development of α-glucosidase inhibitors. Molecular docking studies and molecular dynamics simulation were also performed to reveal the binding pattern of the active compound to α-glucosidase, and the binding free energy of the best compound W24 was 36.3403 ± 3.91 kcal/mol.

Novel Approaches for the Management of Type 2 Diabetes Mellitus: An Update

Diabetes mellitus is an irreversible, chronic metabolic disorder indicated by hyperglycemia. It is now considered a worldwide pandemic. T2DM, a spectrum of diseases initially caused by tissue insulin resistance and slowly developing to a state characterized by absolute loss of secretory action of the β cells of the pancreas, is thought to be caused by reduced insulin secretion, resistance to tissue activities of insulin, or a combination of both. Insulin secretagogues, biguanides, insulin sensitizers, alpha-glucosidase inhibitors, incretin mimetics, amylin antagonists, and sodium-glucose co-transporter-2 (SGLT2) inhibitors are the main medications used to treat T2DM. Several of these medication's traditional dosage forms have some disadvantages, including frequent dosing, a brief half-life, and limited absorption. Hence, attempts have been made to develop new drug delivery systems for oral antidiabetics to ameliorate the difficulties associated with conventional dosage forms. In comparison to traditional treatments, this review examines the utilization of various innovative therapies (such as microparticles, nanoparticles, liposomes, niosomes, phytosomes, and transdermal drug delivery systems) to improve the distribution of various oral hypoglycemic medications. In this review, we have also discussed some new promising candidates that have been approved recently by the US Food and Drug Administration for the treatment of T2DM, like semaglutide, tirzepatide, and ertugliflozin. They are used as a single therapy and also as combination therapy with drugs like metformin and sitagliptin.

Natural Inhibitors of Mammalian α-Amylases as Promising Drugs for the Treatment of Metabolic Diseases

α-Amylase is a generally acknowledged molecular target of a distinct class of antidiabetic drugs named α-glucosidase inhibitors. This class of medications is scarce and rather underutilized, and treatment with current commercial drugs is accompanied by unpleasant adverse effects. However, mammalian α-amylase inhibitors are abundant in nature and form an extensive pool of high-affinity ligands that are available for drug discovery. Individual compounds and natural extracts and preparations are promising therapeutic agents for conditions associated with impaired starch metabolism, e.g., diabetes mellitus, obesity, and other metabolic disorders. This review focuses on the structural diversity and action mechanisms of active natural products with inhibitory activity toward mammalian α-amylases, and emphasizes proteinaceous inhibitors as more effective compounds with significant potential for clinical use.

A high-resolution α-glucosidase inhibition profiling for targeted identification of natural antidiabetic products from Lycopodiella cernua (L.) Pic. Serm and their inhibitory mechanism study

The targeted identification of α-glucosidase inhibitors from the crude ethyl acetate of Lycopodiella cernua (L.) Pic. Serm (L.cernua) was guided by high-resolution inhibition profiling. The α-glucosidase inhibition profiling and HPLC-QTOF-MS showed tannins and serratenes were the corresponding antidiabetic constituents. Two new serratenes named 3β, 21β-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (4), 3β, 21α-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (7), together with two known compounds (5 and 6) were isolated. Their structures were elucidated by HR-ESI-MS and NMR. Compounds 5-7 inhibited the α-glucosidase activity in a non-competitive manner with Ki values ranging from 1.29 to 12.9 µM. The molecular docking result unveiled that 4-7 bound to the residues at the channel site, which enabled to block the substrate access. In addition, the molecular dynamics (MD) simulation of the most active compound 7 and α-glucosidase indicated the 4'-methoxy-5'-hydroxybenzoate group formed the stable hydrogen bonds and pi-pi T-shaped interactions with Arg312, Gln350 and Phe300 residues, while the rings D and E were stabilized by hydrophobic interaction.

Identification of Potential Mechanisms of Rk1 Combination with Rg5 in the Treatment of Type II Diabetes Mellitus by Integrating Network Pharmacology and Experimental Validation

In this study, we aimed to explore the potential targets and functional mechanisms of Rk1 combined with Rg5 (Rk1+Rg5) against type II diabetes mellitus (T2DM). Network pharmacology and molecular docking were used to predict and verify the targets and signaling pathways of Rk1+Rg5 against T2DM. The results were further confirmed by a db/db mouse model and a model using PA-induced L6 cells. According to network pharmacology, a total of 250 core targets of Rk1+Rg5 towards T2DM were identified; the insulin resistance signaling pathways were enriched by KEGG. Results of molecular docking indicated good binding affinity of Rk1 and Rg5 to Akt1. In vivo and in vitro studies further showed that Rk1+Rg5 is an inhibitor of skeletal muscle insulin resistance. The results showed that Rk1+Rg5 significantly improved the hyperglycemic state of db/db mice, alleviated dyslipidemia, and promoted skeletal muscle glucose uptake. This phenomenon was closely related to the alleviation of the insulin resistance in skeletal muscles. Finally, the combination activated the Akt signaling pathway and promoted GLUT4 translocation to the cell membrane for glucose uptake. Altogether, our findings, for the first time, demonstrate that the combination of Rk1 and Rg5 could be beneficial for anti-T2DM, possibly involving ameliorated insulin resistance.

Supplementary Effects of Allium hookeri Extract on Glucose Tolerance in Prediabetic Subjects and C57BL/KsJ-db/db Mice

Allium hookeri (AH) has been used as a nutritional and medicinal food in Asia for many years. Our previous studies have described its anti-diabetic, anti-obesity, and anti-inflammatory activities in animal models and prediabetes. This study investigated whether AH could improve glycemia by modulating insulin secretion in prediabetic subjects through an in-depth study. Eighty prediabetic subjects (100 ≤ fasting plasma glucose < 140 mg/dL) were randomly assigned to a placebo (n = 40) group or an ethanol AH extract (500 mg/day, n = 40) group for 12 weeks. Dietary intake and physical activity, blood glucose (an oral glucose tolerance test for 120 min), insulin (insulin response to oral glucose for 120 min), area under the curve (AUC) of glucose or insulin after oral glucose intake, insulin sensitivity markers, C-peptide, adiponectin, glycated hemoglobin A1c (HbA1c) levels, hematological tests (WBC, RBC, hemoglobin, hematocrit, and platelet count), blood biochemical parameters (ALP, AST, total bilirubin, total protein, albumin, gamma-GT, BUN, creatinine, LD, CK, and hs-CRP), and urine parameters (specific gravity and pH) were examined at both baseline and 12 weeks after supplementation with placebo or AH capsules. Fifty-eight participants (placebo group: 20 men and 10 women; AH group: 13 men and 15 women) completed the study. AH supplementation moderately reduced postprandial blood glucose at 60 min (-6.14 mg/dL, p = 0.061), postprandial insulin levels at 90 min (-16.69 µU/mL, p = 0.017), the glucose AUC at 90 min (-412.52 mg*min/dL, p = 0.021), as well as the insulin AUC at 90 min (-978.77 µU*min/mL, p = 0.021) and 120 min (-1426.41 µU*min/mL, p = 0.015) when compared with the placebo group. However, there were no effects of AH on dietary intake and physical activity; HOMA index; HbAlc; C-peptide; or adiponectin, hematological-, blood biochemical-, and urinary markers. To confirm the effects of AH extract on blood glucose insulin sensitivity, C57BL/6J or C57BL/KsJ-db/db mice were used (n = 8/group). Body weight, fasting plasma glucose level, lipid profiles, liver and renal function, pancreatic histology, and insulin immunoreactivity were assessed. In the diabetic db/db mice, hyperglycemia, which was accompanied by an increase in insulin secretion in diabetic mice, was significantly reduced by AH treatment, resulting in the alleviation of β-cell overcompensation and insulin resistance. We confirmed that AH supplementation can effectively control blood glucose and insulin levels by improving insulin sensitivity and may be a potential agent for glycemic control in subjects with prediabetes and type 2 diabetes mellitus.

Xanthones as potential α-glucosidase non-competition inhibitors: Synthesis, inhibitory activities, and in silico studies

α-glucosidase inhibitors (AGIs) were commonly used in clinical for the treatment of type 2 diabetes. Xanthones were naturally occurring antioxidants, and they may also be potential AGIs. In this study, eleven 1,6- and 1,3-substituted xanthone compounds were designed and synthesized, of which four were new compounds. Their α-glucosidase inhibitory activities in vitro and in silico were evaluated. Five xanthone compounds with higher activity than acarbose were screened out, and the xanthones substituted at the 1,6-positions were more likely to be potential α-glucosidase non-competitive inhibitors. The binding mode of xanthones with α-glucosidase was further studied by molecular docking method, and the results showed that the inhibitory effect of non-competitive inhibitors on site 1 of α-glucosidase may be related to the hydrogen bonds formed by the compounds with amino acid residues ASN165, HIS209, TRY207, ASP243, and SER104. This study provided a theoretical basis of the rapid discovery and structural modification of non-competitive xanthone inhibitors of α-glucosidase.

Anti-Diabetic Activity of Glycyrrhetinic Acid Derivatives FC-114 and FC-122: Scale-Up, In Silico, In Vitro, and In Vivo Studies

Type 2 diabetes (T2D) is one of the most common diseases and the 8th leading cause of death worldwide. Individuals with T2D are at risk for several health complications that reduce their life expectancy and quality of life. Although several drugs for treating T2D are currently available, many of them have reported side effects ranging from mild to severe. In this work, we present the synthesis in a gram-scale as well as the in silico and in vitro activity of two semisynthetic glycyrrhetinic acid (GA) derivatives (namely FC-114 and FC-122) against Protein Tyrosine Phosphatase 1B (PTP1B) and α-glucosidase enzymes. Furthermore, the in vitro cytotoxicity assay on Human Foreskin fibroblast and the in vivo acute oral toxicity was also conducted. The anti-diabetic activity was determined in streptozotocin-induced diabetic rats after oral administration with FC-114 or FC-122. Results showed that both GA derivatives have potent PTP1B inhibitory activity being FC-122, a dual PTP1B/α-glucosidase inhibitor that could increase insulin sensitivity and reduce intestinal glucose absorption. Molecular docking, molecular dynamics, and enzymatic kinetics studies revealed the inhibition mechanism of FC-122 against α-glucosidase. Both GA derivatives were safe and showed better anti-diabetic activity in vivo than the reference drug acarbose. Moreover, FC-114 improves insulin levels while decreasing LDL and total cholesterol levels without decreasing HDL cholesterol.

Chromone Containing Hybrid Analogs: Synthesis and Applications in Medicinal Chemistry

The use of privileged scaffolds has proven beneficial for generating novel bioactive scaffolds in drug discovery program. Chromone is one such privileged scaffold that has been exploited for designing pharmacologically active analogs. The molecular hybridization technique combines the pharmacophoric features of two or more bioactive compounds to avail a better pharmacological activity in the resultant hybrid analogs. The current review summarizes the rationale and techniques involved in developing hybrid analogs of chromone, which show potential in fields of obesity, diabetes, cancer, Alzheimer's disease and microbial infections. Here the molecular hybrids of chromone with various pharmacologically active analogs or fragments (donepezil, tacrine, pyrimidines, azoles, furanchalcones, hydrazones, quinolines, etc.) are discussed with their structure-activity relationship against above-mentioned diseases. Detailed methodologies for the synthesis of corresponding hybrid analogs have also been described, with suitable synthetic schemes. The current review will shed light on various strategies utilized for the design of hybrid analogs in the field of drug discovery. The importance of hybrid analogs in various disease conditions is also illustrated.

Reactive hypoglycemia owing to an intrahepatic congenital portosystemic shunt in an older patient

An 85-year-old woman was admitted to our hospital because of hypoglycemia and impairment of consciousness several hours after breakfast. Because the hypoglycemia predominantly occurred 2-4 h after meals, we diagnosed reactive hypoglycemia. An oral glucose tolerance test showed prolonged hyperinsulinemia following the postprandial hyperglycemia, with a subsequent rapid decrease in blood glucose concentration. The post-stimulus plasma C-peptide concentration was relatively low compared to the plasma insulin concentration. Abdominal computed tomography revealed an intrahepatic congenital portosystemic shunt (CPSS). On the basis of these findings, we concluded that the reactive hypoglycemia was induced by the CPSS, via a reduction in hepatic insulin extraction. Treatment with an alpha-glucosidase inhibitor resolved the reactive hypoglycemia. CPSS comprises anomalous vascular connections between the portal vein and the systemic venous circulation, and reactive hypoglycemia is a rare complication of this malformation, which has most frequently been reported in children, with only a few cases reported in adults. However, this case indicates that even in adult patients, imaging studies should be conducted to rule out CPSS as the cause of the reactive hyperglycemia.

Effect of mulberry fruit extract on glucose fluxes after a wheat porridge meal: a dual isotope study in healthy human subjects

BACKGROUND

Previous research has shown the efficacy of mulberry extracts for lowering post-prandial glucose (PPG) responses. The postulated mechanism is slowing of glucose absorption, but effects on glucose disposal or endogenous production are also possible. This research assessed the effect of a specified mulberry fruit extract (MFE) on these three glucose flux parameters.

METHODS

The study used a double-blind, randomized, controlled, full cross-over design. In 3 counter-balanced treatments, 12 healthy adult male subjects, mean (SD) age 24.9 (2.50) years and body mass index 22.5 (1.57) kg/m2, consumed porridge prepared from 13C-labelled wheat, with or without addition of 0.75 g MFE, or a solution of 13C-glucose in water. A co-administered 2H-glucose venous infusion allowed for assessment of glucose disposal. Glucose flux parameters, cumulative absorption (time to 50% absorption, T50%abs), and PPG positive incremental area under the curve from 0 to 120 min (+iAUC0-120) were determined from total and isotopically labelled glucose in plasma. As this exploratory study was not powered for formal inferential statistical tests, results are reported as the mean percent difference (or minutes for T50%abs) between treatments with 95% CI.

RESULTS

MFE increased mean T50%abs by 10.2 min, (95% CI 3.9-16.5 min), and reduced mean 2 h post-meal rate of glucose appearance by 8.4% (95% CI -14.9 to -1.4%) and PPG + iAUC0-120 by 11% (95% CI -26.3 to -7.3%), with no significant changes in glucose disposal or endogenous production.

CONCLUSIONS

The PPG-lowering effect of MFE is primarily mediated by a reduced rate of glucose uptake.

New Halogenated Flavonoids from Adenosma bracteosum and Vitex negundo and Their α-Glucosidase Inhibition

Adenosma bracteosum and Vitex negundo are natural sources of methoxylated flavonoids. Little is known about the α-glucosidase inhibition of multi-methoxylated flavonoid derivatives. Eighteen natural flavonoids were isolated from A. bracteosum and V. negundo. Seven halogenated derivatives were synthesized. Their chemical structures were elucidated by extensive NMR analysis and high-resolution mass spectroscopy as well as comparisons in literature. All compounds were evaluated for their α-glucosidase inhibition. Most compounds showed good activity with IC50 values ranging from 16.7 to 421.8 μM. 6,8-Dibromocatechin was the most active compound with an IC50 value of 16.7 μM. A molecular docking study was conducted, indicating that those compounds are potent α-glucosidase inhibitors.

In-vitro high-throughput library screening-Kinetics and molecular docking studies of potent inhibitors of α-glucosidase

High throughput screening of synthetic compounds against vital enzymes is the way forward for the determination of potent enzyme inhibitors. In-vitro high throughput library screening of 258 synthetic compounds (comp. 1-258), was performed against α-glucosidase. The active compounds out of this library were investigated for their mode of inhibition and binding affinities towards α-glucosidase through kinetics as well as molecular docking studies. Out of all the compounds selected for this study, 63 compounds were found active within the IC50 range of 3.2 μM to 50.0 μM. The most potent inhibitor of α-glucosidase out of this library was the derivative of an oxadiazole (comp. 25). It showed the IC50 value of 3.23 ± 0.8 μM. Other highly active compounds were the derivatives of ethyl-thio benzimidazolyl acetohydrazide with IC50 values of 6.1 ± 0.5 μM (comp. 228), 6.84 ± 1.3 μM (comp. 212), 7.34 ± 0.3 μM (comp. 230) and 8.93 ± 1.0 μM (comp. 210). For comparison, the standard (acarbose) showed IC50 = 378.2 ± 0.12 μM. Kinetic studies of oxadiazole (comp. 25) and ethylthio benzimidazolyl acetohydrazide (comp. 228) derivatives indicated that Vmax and Km, both change with changing concentrations of inhibitors which suggests an un-competitive mode of inhibition. Molecular docking studies of these derivatives with the active site of α-glucosidase (PDB ID:1XSK), revealed that these compounds mostly interact with acidic or basic amino acid residues through conventional hydrogen bonds along with other hydrophobic interactions. The binding energy values of compounds 25, 228, and 212 were -5.6, -8.7 and -5.4 kcal.mol-1 whereas RMSD values were 0.6, 2.0, and 1.7 Å, respectively. For comparison, the co-crystallized ligand showed a binding energy value of -6.6 kcal.mol-1 along with an RMSD value of 1.1 Å. Our study predicted several series of compounds as active inhibitors of α-glucosidase including some highly potent inhibitors.