Chemistry and Biochemistry of Type 2 Diabetes

Health-Related Composition and Bioactivity of an Agave Sap/Prickly Pear Juice Beverage

In this study, a beverage made from a combination of Agave sap (AS) and prickly pear juice (PPJ) was analyzed for its nutrients and bioactive and potentially health-promoting compounds. The beverage was evaluated for its ability to act as an antioxidant, regulate glycemic properties, and undergo gut bacterial fermentation in vitro. The major mono- and oligosaccharides present in the beverage were galacturonic acid (217.74 ± 13.46 mg/100 mL), rhamnose (227.00 ± 1.58 mg/100 mL), and fructose (158.16 ± 8.86 mg/mL). The main phenolic compounds identified were protocatechuic acid (440.31 ± 3.06 mg/100 mL) and catechin (359.72 ± 7.56 mg/100 mL). It was observed that the beverage had a low glycemic index (<40) and could inhibit digestive carbohydrases. The combination of ingredients also helped to reduce gas production during AS fermentation from 56.77 cm3 to 15.67 cm3. The major SCFAs produced during fermentation were butyrate, acetate, and propionate, with valerate being produced only during the late fermentation of the AS. This beverage is rich in bioactive compounds, such as polyphenols and dietary fiber, which will bring health benefits when consumed.

Phloroglucinol derivatives with α-glucosidase inhibitory activities from Syzygium fluviatile

Four new phloroglucinol derivatives (1 - 4) were isolated from the leaves of Syzygium fluviatile. Their structures were elucidated by means of extensive spectroscopic data. Among them, compounds 1 and 3 showed significant inhibitory activity against α-glucosidase with IC50 values of 10.60 and 5.07 µM, respectively. The structure-activity relationship was also discussed briefly.

DFT calculations, molecular docking, in vitro antimicrobial and antidiabetic studies of green synthesized Schiff bases: as Covid-19 inhibitor

In this investigation, we synthesized Schiff bases 2-(2-methoxyphenoxy)-N-(4-methylbenzylidene)ethanamine, N-(4-methoxybenzylidene)-2-(2-methoxyphenoxy)ethanamine and 2-(2-methoxyphenoxy)-N-(4-nitrobenzylidene)ethanamine from 2-(2-methoxyphenoxy)ethanamine and various aromatic aldehydes by the environmentally friendly sonication method. The B3LYP method with a 6-311++G (d, p) basis set was used in the DFT calculation to obtain the optimized structure of the Schiff base MPEA-NIT. The compounds were tested in vitro for inhibition of bacterial growth (disc well method) and inhibition of α-amylase (starch-iodine method). The compounds tested showed inhibitory activities. In addition, they were subjected to PASS analysis, drug likeness, and bioactivity score predictions using online software. To confirm the experimental findings, molecular docking analyses of synthesized compounds on α-amylase (PDB ID: 1SMD), tRNA threonylcarbamoyladenosine (PDB ID: 5MVR), glycosyl transferase (PDB ID: 6D9T), and peptididoglycan D,D-transpeptidase (PDB ID: 6HZQ) were performed. The emergence of a new coronavirus epidemic necessitates the development of antiviral medications (SARS-CoV-2). Docking active site interactions were investigated to predict compounds' activity against COVID-19 by binding with the SARS-CoV-2 (PDB ID: 6Y84).Communicated by Ramaswamy H. Sarma.

Ultrasound-Assisted Deep Eutectic Solvent Extraction of Polysaccharides from Anji White Tea: Characterization and Comparison with the Conventional Method

Deep eutectic solvent as a new green and safe solvent system has attracted more and more attention in recent years. In this study, three deep eutectic solvents (DES) were combined with ultrasound irradiation to extract tea polysaccharides (TPs) from Anji white tea, which was compared with conventional hot water extraction (HW). The physicochemical, structural, and biological properties of TPs extracted by ultrasound-assisted DES and hot water (HWP) were further investigated. Results showed that the DES system composed of choline chloride and 1,6-hexanediol (CH) with the molar ratio of 1:2 exhibited the optimal extraction yield (19.18%) and in vitro antioxidant activities for TPs (CHP). Furthermore, compared to the HWP, the CHP had a higher extraction yield and total carbohydrate content and a lower molecular weight. Monosaccharide composition analysis displayed that the molecular structure of CHP exhibited more arabinose but less glucose, mannose, galacturonic acid, and glucuronic acid than HWP. Little difference was observed in the preliminary structural characteristics between HWP and CHP from Fourier transform infrared analysis. Besides, CHP possessed better α-glucosidase inhibitory and hypoglycemic activity in L6 cells than HWP. Therefore, the ultrasound-assisted DES extraction method can be a promising strategy for extracting TPs with excellent bioactivities for future applications in functional foods.

Novel hybrids of thiazolidinedione-1,3,4-oxadiazole derivatives: synthesis, molecular docking, MD simulations, ADMET study, in vitro, and in vivo anti-diabetic assessment

As compared to standard medicinal compounds, hybrid molecules that contain multiple biologically active functional groups have greater affinity and efficiency. Hence based on this concept, we predicted that a combination of thiazolidinediones and 1,3,4-oxadiazoles may enhance α-amylase and α-glucosidase inhibition activity. A series of novel 3-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)thiazolidine-2,5-dione derivatives (5a-5j) were synthesized and characterized using different spectroscopic techniques i.e., FTIR, 1H-NMR, 13C-NMR and MS. To evaluate in silico, molecular docking, MMGBSA, and MD simulations were carried out which were further evaluated via in vitro inhibition of α-amylase and α-glycosidase enzyme inhibition assays. In addition, the in vivo study was performed on a genetic model of Drosophila melanogaster to assess the antihyperglycemic effects. The compounds (5a-5j) demonstrated α-amylase and α-glucosidase inhibitory activity in the range of IC50 values 18.42 ± 0.21-55.43 ± 0.66 μM and 17.21 ± 0.22-51.28 ± 0.88 μM respectively when compared to standard acarbose. Based on the in vitro studies, compounds 5a, 5b, and 5j were found to be potent against both enzymes. In vivo studies have shown that compounds 5a, 5b, and 5j lower glucose levels in Drosophila. These compounds could be further developed in the future to produce a new class of antidiabetic agents.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Circular RNA ITCH: An Emerging Multifunctional Regulator

In the last decade, numerous circRNAs were discovered by virtue of the RNA-Seq technique. With the deepening of experimental research, circRNAs have brought to light the key biological functions and progression of human diseases. CircRNA ITCH has been demonstrated to be a tumor suppressor in numerous cancers, and recently it was found to play an important role in bone diseases, diabetes mellitus, and cardiovascular diseases. However, the functions of circ-ITCH have not been completely understood. In this review, we comprehensively provide a conceptual framework to elucidate circ-ITCH biological functions of cell proliferation, apoptosis and differentiation, and the pathological mechanisms of inflammation, drug resistance/toxicity, and tumorigenesis. Finally, we summarize its clinical applications in various diseases. This research aimed at clarifying the role of circ-ITCH, which could be a promising therapeutic target.

Functionalized quinoxalinones as privileged structures with broad-ranging pharmacological activities

Quinoxalinones are a class of heterocyclic compounds which attract extensive attention owing to their potential in the field of organic synthesis and medicinal chemistry. During the past few decades, many new synthetic strategies toward the functionalization of quinoxalinone based scaffolds have been witnessed. Regrettably, there are only a few reports on the pharmacological activities of quinoxalinone scaffolds from a medicinal chemistry perspective. Therefore, herein we intend to outline the applications of multifunctional quinoxalinones as privileged structures possessing various biological activities, including anticancer, neuroprotective, antibacterial, antiviral, antiparasitic, anti-inflammatory, antiallergic, anti-cardiovascular, anti-diabetes, antioxidation, etc. We hope that this review will facilitate the development of quinoxalinone derivatives in medicinal chemistry.

Heart failure in diabetes

Heart failure and cardiovascular disorders represent the leading cause of death in diabetic patients. Here we present a systematic review of the main mechanisms underlying the development of diabetic cardiomyopathy. We also provide an excursus on the relative contribution of cardiomyocytes, fibroblasts, endothelial and smooth muscle cells to the pathophysiology of heart failure in diabetes. After having described the preclinical tools currently available to dissect the mechanisms of this complex disease, we conclude with a section on the most recent updates of the literature on clinical management.

Purification, identification and molecular mechanism of dipeptidyl peptidase IV inhibitory peptides from discarded shrimp (Penaeus vannamei) head

DPP-IV plays a key role for regulation of glucose metabolism in the body. The object of this study was to obtain DPP-IV inhibitors from discarded but protein-rich Penaeus vannamei (P. vannamei) head, and to explore the potential mechanism between DPP-IV and its inhibitors. P. vannamei head protein was hydrolyzed by five food grade proteases, respectively. The animal protease hydrolysate showed the highest inhibitory active. Then the hydrolysate was sequentially separated by ultrafiltration, gel filtration chromatography and reversed phase high-performance liquid chromatography (RP-HPLC), the peptides sequences were identified by LC-MS/MS and four potential peptides YPGE, VPW, HPLY, YATP showed superior DPP-IV inhibitory activity. Meanwhile, molecular docking effectively explored their mechanism through formed hydrogen bonds and hydrophobic regions. The four peptides showed better DPP-IV inhibitory activity stability with heating treatment, pH (1-10) treatment, and in vitro gastrointestinal digestion. Our results demonstrated that the protein hydrolysate from discarded P. vannamei head can be considered as a promising natural source of DPP-IV inhibitor for helping to improve glycaemic control in Type 2 diabetes.

Novel tetrahydrobenzo[b]thiophen-2-yl)urea derivatives as novel α-glucosidase inhibitors: Synthesis, kinetics study, molecular docking, and in vivo anti-hyperglycemic evaluation

α-Glucosidase inhibitors, which can inhibit the digestion of carbohydrates into glucose, are one of important groups of anti-type 2 diabetic drugs. In the present study, we report our effort on the discovery and optimization of α-glucosidase inhibitors with tetrahydrobenzo[b]thiophen-2-yl)urea core. Screening of an in-house library revealed a moderated α-glucosidase inhibitors, 5a, and then the following structural optimization was performed to obtain more efficient derivatives. Most of these derivatives showed increased inhibitory activity against α-glucosidase than the parental compound 5a (IC₅₀ of 26.71 ± 1.80 μM) and the positive control acarbose (IC₅₀ of 258.53 ± 1.27 μM). Among them, compounds 8r (IC₅₀ = 0.59 ± 0.02 μM) and 8s (IC₅₀ = 0.65 ± 0.03 μM) were the most potent inhibitors, and showed selectivity over α-amylase. The direct binding of both compounds with α-glucosidase was confirmed by fluorescence quenching experiments. Kinetics study revealed that these compounds were non-competitive inhibitors, which was consistent with the molecular docking results that compounds 8r and 8s showed high preference to bind to the allosteric site instead of the active site of α-glucosidase. In addition, compounds 8r and 8s were not toxic (IC₅₀ > 100 μM) towards LO2 and HepG2 cells. Finally, the in vivo anti-hyperglycaemic activity assay results indicated that compounds 8r could significantly decrease the level of plasma glucose and improve glucose tolerance in SD rats treated with sucrose. The present study provided the tetrahydrobenzo[b]thiophen-2-yl)urea chemotype for developing novel α-glucosidase inhibitors against type 2 diabetes.

Direct epitaxial growth of nickel phosphide nanosheets on nickel foam as self-support electrode for efficient non-enzymatic glucose sensing

Design and develop of cost-effective non-enzymatic electrode materials is of great importance for next generation of glucose sensors. In this work, we report a high-performance self-supporting electrode fabricated via direct epitaxial growth of nickel phosphide on Ni foam (Ni₂P/NF) for nonenzymatic glucose sensors in alkaline solution. Under the optimal conditions, the uniform Ni₂P nanosheets could be obtained with an average thickness of 80 nm, which provides sufficient active sites for glucose molecules. As a consequence, the Ni₂P/NF electrode displays superior electrochemistry performances with a high sensitivity of 6375.1μA mM^-1cm^-2, a quick response about 1 s, a low detection limit of 0.14μM (S/N = 3), and good selectivity and specificity. Benefit from the strong interaction between Ni₂P and NF, the Ni₂P/NF electrode is also highly stable for long-term applications. Furthermore, the Ni₂P/NF electrode is capable of analyzing glucose in human blood serum with satisfactory results, indicating that the Ni₂P/NF is a potential candidate for glucose sensing in real life.

Novel carbohydrate-triazole derivatives as potential α-glucosidase inhibitors

A series of novel pyrano[2, 3-d]trizaole compounds were synthesized and their α-glucosidase inhibitory activities were evaluated by in vitro enzyme assay. The experimental data demonstrated that compound 10f showed up to 10-fold higher inhibition (IC₅₀74.0 ± 1.3 μmol·L^-1) than acarbose. The molecular docking revealed that compound 10f could bind to α-glucosidase via the hydrophobic, π-π stacking, and hydrogen bonding interactions. The results may benefit further structural modifications to find new and potent α-glucosidase inhibitors.

Isolation, Structural Characterization and Antidiabetic Activity of New Diketopiperazine Alkaloids from Mangrove Endophytic Fungus Aspergillus sp. 16-5c

Six new DIKETOPIPERAZINE alkaloids aspergiamides A-F (1-6), together with ten known alkaloids (7-16), were isolated from the mangrove endophytic fungus Aspergillus sp. 16-5c. The structures of the new compounds were elucidated based on 1D/2D NMR spectroscopic and HR-ESIMS data analyses. The absolute configurations of aspergiamides A-F were established based on the experimental and calculated ECD data. All the compounds were evaluated for the antidiabetic activity against α-glucosidase and PTP1B enzyme. The bioassay results disclosed compounds 1 and 9 exhibited significant α-glucosidase inhibitory with IC₅₀ values of 18.2 and 7.6 μM, respectively; compounds 3, 10, 11, and 15 exhibited moderate α-glucosidase inhibition with IC₅₀ values ranging from 40.7 to 83.9 μM; while no compounds showed obvious PTP1B enzyme inhibition activity.

The impact of chemical engineering and technological advances on managing diabetes: present and future concepts

Monitoring blood glucose levels for diabetic patients is critical to achieve tight glycaemic control. As none of the current antidiabetic treatments restore lost functional β-cell mass in diabetic patients, insulin injections and the use of insulin pumps are most widely used in the management of glycaemia. The use of advanced and intelligent chemical engineering, together with the incorporation of micro- and nanotechnological-based processes have lately revolutionized diabetic management. The start of this concept goes back to 1974 with the description of an electrode that repeatedly measures the level of blood glucose and triggers insulin release from an infusion pump to enter the blood stream from a small reservoir upon need. Next to the insulin pumps, other drug delivery routes, including nasal, transdermal and buccal, are currently investigated. These processes necessitate competences from chemists, engineers-alike and innovative views of pharmacologists and diabetologists. Engineered micro and nanostructures hold a unique potential when it comes to drug delivery applications required for the treatment of diabetic patients. As the technical aspects of chemistry, biology and informatics on medicine are expanding fast, time has come to step back and to evaluate the impact of technology-driven chemistry on diabetics and how the bridges from research laboratories to market products are established. In this review, the large variety of therapeutic approaches proposed in the last five years for diabetic patients are discussed in an applied context. A survey of the state of the art of closed-loop insulin delivery strategies in response to blood glucose level fluctuation is provided together with insights into the emerging key technologies for diagnosis and drug development. Chemical engineering strategies centered on preserving and regenerating functional pancreatic β-cell mass are evoked in addition as they represent a permanent solution for diabetic patients.

Mechanochemical Synthesis and Reactivity of 1,2,3-Triazole Carbohydrate Derivatives as Glycogen Phosphorylase Inhibitors

AIMS

We have developed this work to recommend an original route for the preparation of triazole derivatives.

BACKGROUND

Carbohydrates containing 1,2,3-triazole derivatives have various biological activities. Due to their advantageous and biological property, they are eye-catching synthetic targets in the arsenal of organic chemistry. Thus, finding green and efficient methods, as well as using the ball milling procedure for the synthesis of these heterocycles, is of interest to organic chemistry researchers.

OBJECTIVE

The objective of this study was to synthesize carbohydrate-derived triazoles under high-speed vibration milling conditions and investigate their properties.

MATERIALS AND METHODS

A mixture of glycoside azide derivatives (1 mmol) and prop-2-yn-1-ol (1.5 mmol) in the presence of copper (I) was vigorously shaken under vibration milling conditions at 650 rpm with three balls for 15 min. The deprotection of the resulting triazole derivatives was affected by treatment with 4M hydrochloric acid in methanol under reflux.

RESULTS AND DISCUSSION

A short and convenient route to synthesize carbohydrate-derived triazoles, based on a ball-mill via 1,3-dipolar cycloaddition reactions to prop-2-yn-1-ol, was developed. Cleavage of the isopropylidene protecting group provided water-soluble triazoles, evaluated as glycogen phosphorylase inhibitors. 1-[6- (4-Hydroxymethyl-[1,2,3]triazol-1-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-yl]-ethane-1,2-diol was the best inhibitor of rabbit muscle glycogen phosphorylase b (IC50 = 60 μM).

CONCLUSION

In summary, we developed new, short and convenient routes to glucose-derived 1,2,3-triazole based on 1,3-dipolar cycloaddition reactions flowed by ball milling. The use of isopropylidene protective groups gave access to the analogous deprotected water-soluble motifs, analogous to known inhibitors of glycogen phosphorylase.

Surface Selenylation Engineering for Construction of a Hierarchical NiSe2/Carbon Nanorod: A High-Performance Nonenzymatic Glucose Sensor

As glucose (Glu) is an essential substance for metabolism as well as a symbol to diagnose diabetes, the demand of Glu sensors has increased significantly in recent decades. In this work, a hierarchical Ni-based electrochemical enzyme-free Glu sensor, namely, NiSe₂/CNR (carbon nanorod), was engineered through a facile thermal treatment using dimethylglyoxime dinickel salt with selenium (Se) powder. The prepared NiSe₂/CNR not only subtly introduces a hierarchical structure with rod-like carbon nanorods and rock-like NiSe₂ nanoparticles, which are extremely helpful in offering a greater catalytic activity area and more catalytic active sites, but also incorporates the Se element to increase the inherent activity. The fabricated NiSe₂/CNR exhibits distinguished performance for Glu detection in alkaline electrolytes with linear ranges of 0.5-411 μM and 411 μM to 6.311 mM, high sensitivities of 3636 μA mM^-1 cm^-2 at low concentrations, and 2121 μA mM^-1 cm^-2 at high concentrations, as well as a low detection limit of 380 nM (S/N = 3). It also possesses favorable reproducibility, stability, and long-term storage capacity. The practical feasibility of NiSe₂/CNR was also validated by detecting Glu in human serum. Moreover, the prepared hierarchical NiSe₂/CNR is of general interest for the construction of hierarchical Ni-based sensors.

Synthesis, in vitro inhibitory activity, kinetic study and molecular docking of novel N-alkyl-deoxynojirimycin derivatives as potential α-glucosidase inhibitors

A series of novel N-alkyl-1-deoxynojirimycin derivatives 25 ∼ 44 were synthesised and evaluated for their in vitro α-glucosidase inhibitory activity to develop α-glucosidase inhibitors with high activity. All twenty compounds exhibited α-glucosidase inhibitory activity with IC₅₀ values ranging from 30.0 ± 0.6 µM to 2000 µM as compared to standard acarbose (IC₅₀ = 822.0 ± 1.5 µM). The most active compound 43 was ∼27-fold more active than acarbose. Kinetic study revealed that compounds 43, 40, and 34 were all competitive inhibitors on α-glucosidase with K_iof 10 µM, 52 µM, and 150 µM, respectively. Molecular docking demonstrated that the high active inhibitors interacted with α-glucosidase by four types of interactions, including hydrogen bonds, π–π stacking interactions, hydrophobic interactions, and electrostatic interaction. Among all the interactions, the π–π stacking interaction and hydrogen bond played a significant role in a various range of activities of the compounds.

Dual-Target Compounds against Type 2 Diabetes Mellitus: Proof of Concept for Sodium Dependent Glucose Transporter (SGLT) and Glycogen Phosphorylase (GP) Inhibitors

A current trend in the quest for new therapies for complex, multifactorial diseases, such as diabetes mellitus (DM), is to find dual or even multi-target inhibitors. In DM, the sodium dependent glucose cotransporter 2 (SGLT2) in the kidneys and the glycogen phosphorylase (GP) in the liver are validated targets. Several (β-D-glucopyranosylaryl)methyl (het)arene type compounds, called gliflozins, are marketed drugs that target SGLT2. For GP, low nanomolar glucose analogue inhibitors exist. The purpose of this study was to identify dual acting compounds which inhibit both SGLTs and GP. To this end, we have extended the structure-activity relationships of SGLT2 and GP inhibitors to scarcely known (C-β-D-glucopyranosylhetaryl)methyl arene type compounds and studied several (C-β-D-glucopyranosylhetaryl)arene type GP inhibitors against SGLT. New compounds, such as 5-arylmethyl-3-(β-D-glucopyranosyl)-1,2,4-oxadiazoles, 5-arylmethyl-2-(β-D-glucopyranosyl)-1,3,4-oxadiazoles, 4-arylmethyl-2-(β-D-glucopyranosyl)pyrimidines and 4(5)-benzyl-2-(β-D-glucopyranosyl)imidazole were prepared by adapting our previous synthetic methods. None of the studied compounds exhibited cytotoxicity and all of them were assayed for their SGLT1 and 2 inhibitory potentials in a SGLT-overexpressing TSA201 cell system. GP inhibition was also determined by known methods. Several newly synthesized (C-β-D-glucopyranosylhetaryl)methyl arene derivatives had low micromolar SGLT2 inhibitory activity; however, none of these compounds inhibited GP. On the other hand, several (C-β-D-glucopyranosylhetaryl)arene type GP inhibitor compounds with low micromolar efficacy against SGLT2 were identified. The best dual inhibitor, 2-(β-D-glucopyranosyl)-4(5)-(2-naphthyl)-imidazole, had a K_i of 31 nM for GP and IC₅₀ of 3.5 μM for SGLT2. This first example of an SGLT-GP dual inhibitor can prospectively be developed into even more efficient dual-target compounds with potential applications in future antidiabetic therapy.

An online target and rapid screening method for α-glucosidase inhibitors based on capillary electrophoresis

Screening enzymatic active compounds is one of the important fields in drug research. α-Glucosidase can hydrolyze carbohydrates to monosaccharides after meals and lead to the rise of blood glucose levels in human body. Thus, the inhibition of α-glucosidase activity is an effective approach for the diabetes treatment. In this work, we developed a new method to simultaneously screen multiple bioactive compounds within a single CE running. The affect factors on the method performance, including injection, mixing, incubation, separation and detection, were carefully analyzed and discussed. Under the optimum, the mixture consisting of two internal standards (DMSO and 4-nitrophenol) and five compounds (lyoniresinol, hydroxytyrosol, rutin, kaempferol, and quercetin) was simultaneously screened, and kaempferol and quercetin showed stronger activity and this conclusion was also supported by offline assay. Furthermore, molecular docking was employed for investigating its interaction mechanism. Eventually, the established method has been applied to screen potential α-glucosidase inhibitors from an extract of Lycium barbarum and the peak area of rutin, taxifolin, quercetin, and chlorogenic acid in L. barbarum samples changed before and after the enzymatic reaction, confirming that these four compounds had potential inhibitory activities, which was consistent with the literature data. The present work provides a promising method for the target and rapid discovery of bioactive compounds from a plant extract or mixture.

2,5-Disubstituted furan derivatives containing 1,3,4-thiadiazole moiety as potent α-glucosidase and E. coli β-glucuronidase inhibitors

In this paper, the 2,5-disubstituted furan derivatives containing 1,3,4-thiadiazole were synthesized and screened for their inhibitory activity against α-glucosidase and β-glucuronidases to obtain potent α-glucosidase inhibitor 9 (IC₅₀ = 0.186 μM) and E. coli β-glucuronidase inhibitor 26 (IC₅₀ = 0.082 μM), respectively. The mechanisms of the compounds were studied. The kinetic study revealed that compound 9 is a competitive inhibitor against α-glucosidase (Ki = 0.05 ± 0.003 μM) and molecular docking simulation showed several key interactions between 9 and the target including hydrogen bond and p-π stacking interaction. Derivative 26 (Ki = 0.06 ± 0.005 μM) displayed uncompetitive inhibition behavior against EcGUS. Furthermore, the result of docking revealed the furan ring of 26 may be a key moiety in obstructing the active domain of EcGUS. In addition, compound 15 exhibited significant inhibitory activity against these two enzymes, with potential therapeutic effects against diabetes and against CPT-11-induced diarrhea. At the same time, their low toxicity against normal liver tissue LO2 cells lays the foundation for in vivo studies and the development of bifunctional drug.

Schiff Bases of Pioglitazone Provide Better Antidiabetic and Potent Antioxidant Effect in a Streptozotocin-Nicotinamide-Induced Diabetic Rodent Model

Pioglitazone is a Food and Drug Administration-approved thiazolidinedione (TZD) derivative and peroxisome proliferator-activated receptor gamma (PPARγ) agonist and used for the treatment of diabetes mellitus (DM). However, this drug is still associated with many adverse effects. In the present study, four new Schiff bases of pioglitazone (P1-P4) were synthesized and characterized using FTIR, ¹HNMR, ¹³CNMR, mass spectrometry, and elemental analysis. For preliminary screening, the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and in vitro alpha-amylase antidiabetic inhibitory assay were performed. Further, P3 was used to investigate in vivo antioxidant and in vivo antidiabetic effects in a streptozotocin-nicotinamide-induced diabetic rat model. Diabetic rats were administered with an i.p dose of pioglitazone 10 mg/kg body weight for 21 days. Moreover, biochemical parameters and antioxidants were quantified from liver and kidney tissues of rodents. In the DPPH assay, compound P3 showed superior antioxidant effects. Using the in vitro α-amylase inhibitory assay, P3 exhibited potent effects as compared to other groups, that is, 93% inhibition, while pioglitazone showed 81% inhibition. Enzymatic and nonenzymatic antioxidants showed significant changes in P3 (10 mg/kg)-treated groups (p < 0.001). Similarly, compound P3 produced significant and better results in comparison to pioglitazone in the rodent model. This study confirmed potent antidiabetic and superior antioxidant potential of the newly synthesized Schiff base (P3), which could ultimately account for insulin sensitization and for cellular protection and hence provide a potential clue for dual therapeutics.

In silico study of garlic (Allium sativum L.)-derived compounds molecular interactions with α-glucosidase

Diabetes mellitus is a metabolic syndrome characterized by elevated blood glucose. The α-glucosidase enzyme is responsible for the hydrolysis of carbohydrates. This in silico study aimed to evaluate the inhibitory effects of the isolated compounds from Allium sativum L. on α-glucosidase. At first, sulfur and phenolic compounds of A. sativum L. were obtained from PubChem database, and α-glucosidase enzyme structure was obtained from Protein Data Bank. Toxicity class of compounds and the Lipinski parameter were predicted by Toxtree and Protox II and the Swiss ADME tools, respectively. Finally, the molecular interaction analysis between α-glucosidase and compounds from A. sativum L. was performed by AutoDock 4.2.6. Molecular interactions were investigated using Discovery Studio Visulizer and Ligplot 2.1 program. All of the selected sulfur and phenolic compounds from A. sativum L. followed the Lipinski's rules, had an acceptable binding energy, and lacked toxicity; therefore, they were appropriate candidates for α-glucosidase inhibition. Among these compounds, methionol and caffeic acid showed the lowest binding energy, and the highest inhibitory effect on α-glucosidase enzyme with - 3.9 and - 4.8 kcal/mol, respectively. These compounds also indicated the lower binding energy than the standard inhibitor (miglitol). Among the sulfur and phenolic compounds in A. sativum L., methionol and caffeic acid were predicted to be the powerful inhibitors, due to having more hydrogen binds and hydrophobic interactions with the active site of α-glucosidase.

Generating Ins2+/-/miR-133aTg Mice to Model miRNA-Driven Cardioprotection of Human Diabetic Heart

Diabetes mellitus (DM) is caused either due to insulin deficiency (T1DM) or insulin resistance (T2DM). DM increases the risk of heart failure by diabetic cardiomyopathy (DMCM), a cardiac muscle disorder that leads to a progressive decline in diastolic function, and ultimately systolic dysfunction. Mouse models of T1DM and T2DM exhibit clinical signs of DMCM. Growing evidence implicates microRNA (miRNA), an endogenous, non-coding, regulatory RNA, in the pathogenesis and signaling of DMCM. Therefore, inhibiting deleterious miRNAs and mimicking cardioprotective miRNAs could provide a potential therapeutic intervention for DMCM. miRNA-133a (miR-133a) is a highly abundant miRNA in the human heart. It is a cardioprotective miRNA, which is downregulated in the DM heart. It has anti-hypertrophic and anti-fibrotic effects. miR-133a mimic treatment after the onset of early DMCM can reverse histological and clinical signs of the disease in mice. We hypothesized that overexpression of cardiac-specific miR-133a in Ins2^+/- Akita (T1DM) mice can prevent progression of DMCM. Here, we describe a method to create and validate cardiac-specific Ins2^+/-/miR-133aTg mice to determine whether cardiac-specific miR-133a overexpression prevents development of DMCM. These strategies demonstrate the value of genetic modeling of human disease such as DMCM and evaluate the potential of miRNA as a therapeutic intervention.

Probing blood plasma samples for the detection of diabetes using SERS aided by PCA and LDA multivariate data analyses

Fabrication of a SERS-active substrate using Langmuir–Blodgett and self-assembly techniques for the detection of diabetes from blood plasma samples.

Metronidazole-conjugates: A comprehensive review of recent developments towards synthesis and medicinal perspective

Nitroimidazoles based compounds remain a hot topic of research in medicinal chemistry due to their numerous biological activities. Moreover, many clinical candidates based on this chemical core have been reported to be valuable in the treatment of human diseases. Metronidazole (MTZ) derived conjugates demonstrated a potential application in medicinal chemistry research over the last decade. In this review, we summarize the synthesis, key structure-activity-relationship (SAR) and associated biological activities such as antimicrobial, anticancer, antidiabetic, anti-inflammatory, anti-HIV and anti-parasitic (Anti-trichomonas, antileishmanial, antiamoebic and anti-giardial) of explored MTZ-conjugates. The molecular docking analysis is also presented simultaneously, which will assist in developing an understanding towards designing of new MTZ-conjugates for target-based drug discovery against multiple disease areas.

Erica multiflora extract rich in quercetin-3-O-glucoside and kaempferol-3-O-glucoside alleviates high fat and fructose diet-induced fatty liver disease by modulating metabolic and inflammatory pathways in Wistar rats

The wide morbidity of obesity has heightened interest in providing natural and safe compounds to maintain optimal health. The present study was designed to determine the chemical constituents and the effects of methanol leaf extract from Erica multiflora (M-EML) on mitigating high-fat and high-fructose diet (HFFD)-induced metabolic syndrome (MS). LC-MS/MS characterization of M-EML allowed the identification of 14 secondary metabolites and showed that quercetin-3-O-glucoside and kaempferol-3-O-glucoside were the main compounds of our extract. In the in vivo study, the oral administration of M-EML (250 mg/kg) during the last 4 weeks of the experimentation alleviated HFFD-induced obesity, insulin resistance (IR) and cardiovascular diseases. Thus, M-EML treatment significantly normalized body and liver weight, allowed to a sharp decline in plasma levels of TC, TG and LDL-c by 32%, 35% and 66%, respectively. Moreover, hepatic enzymes, total and direct bilirubin, lipase and uric acid levels have been diminished in treated group. Histopathology of the liver confirmed the changes induced by HFFD and the hepatoprotective effect of M-EML. The supply of M-EML reduced NO production and cellular lysosomal enzyme activity by 44% and 60%, respectively compared to HFFD. Besides, M-EML showed decreased pro-inflammatory cytokines levels (259.5±47.35 pg/ml and 56.08±1.56 pg/ml) of TNF-α and IL-6, respectively. In addition, M-EML reduced liver malondialdehyde (MDA) content and enhanced superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities. In contrast, these enzymatic activities have been disrupted in HFFD rats. Overall, M-EML prevented obesity through the modulation of metabolic syndrome, reducing inflammation and promoting antioxidant enzymes activities.

A Library of Thiazolidin-4-one Derivatives as Protein Tyrosine Phosphatase 1B (PTP1B) Inhibitors: An Attempt To Discover Novel Antidiabetic Agents

Protein tyrosine phosphatase 1B (PTP1B) is an important target for the treatment of diabetes. A series of thiazolidin-4-one derivatives 8-22 was designed, synthesized and investigated as PTP1B inhibitors. The new molecules inhibited PTP1B with IC₅₀ values in the micromolar range. 5-(Furan-2-ylmethylene)-2-(4-nitrophenylimino)thiazolidin-4-one (17) exhibited potency with a competitive type of enzyme inhibition. structure-activity relationship studies revealed various structural facets important for the potency of these analogues. The findings revealed a requirement for a nitro group-including hydrophobic heteroaryl ring for PTP1B inhibition. Molecular docking studies afforded good correlation with experimental results. H-bonding and π-π interactions were responsible for optimal binding and effective stabilization of virtual protein-ligand complexes. Furthermore, in-silico pharmacokinetic properties of test compounds predicted their drug-like characteristics for potential oral use as antidiabetic agents.Additionally, a binding site model demonstrating crucial pharmacophoric characteristics influencing potency and binding affinity of inhibitors has been proposed, which can be employed in the design of future potential PTP1B inhibitors.

Evaluation of Antidiabetic Effect of Ethanolic Leaves Extract of Becium grandiflorum Lam. (Lamiaceae) in Streptozotocin-Induced Diabetic Mice

BACKGROUND

Becium grandiflorum has been used traditionally for treatment of different ailments including diabetes mellitus although it lacks scientific evidence. Thus, the present study was aimed at evaluating the antidiabetic effect of Becium grandiflorum in streptozotocin (STZ)-induced diabetic mice.

METHODS

The antidiabetic activity of hydro-ethanolic (30:70) leaf extract of Becium grandiflorum was evaluated in STZ (45 mg/kg)-induced diabetic and normal mice. Antihyperglycemic, hypoglycemic, oral glucose tolerance and body weight change effects of the extract were assessed after administering three doses of the extract (200, 400 and 600 mg/kg), glibenclamide 5 mg/kg (reference drug) and 2% Tween 80 (vehicle). One-way analysis of variance and Tukey's post hoc test were used for data analysis.

RESULTS

All doses of the extract (200 mg/kg (p<0.05), 400 mg/kg (p<0.05) and 600 mg/kg (p<0.01)) and glibenclamide 5 mg/kg (p<0.001) showed statistically significant blood glucose level reduction in normal mice as compared to Tween 80. The hydroalcoholic extract at a dose of 200 mg/kg (p<0.05), 400 mg/kg (p<0.01) and 600 mg/kg (p<0.001) showed better blood glucose tolerance after 60, 120 and 180-minute treatment duration in normal mice as compared to negative control. In diabetic mice, Becium grandiflorum doses and the reference drug caused maximum reduction in blood glucose level at the end of the 15th day of treatment by 17.61%, 22.52%, 24.62% and 34.12%, respectively. The extract's doses and the standard drug showed significant (p<0.05) improvement in body weight while the diabetic control continued to lose their body weight.

CONCLUSION

Thus, Becium grandiflorum exhibits antihyperglycemic activity in STZ-induced diabetic mice, and shows improvement in oral glucose tolerance and body weight, which justifies the claimed use of the plant in ameliorating diabetes mellitus in Ethiopian folk medicine.

The anti-diabetic effect of eightLagerstroemia speciosaleaf extracts based on the contents of ellagitannins and ellagic acid derivatives

Anti-diabetic effects of eight extracts from leaves ofL. speciosausing different manufacturing processes based on the contents of active ellagitannins and inhibitory ellagic acid derivatives.

Variation in the metabolites and α-glucosidase inhibitory activity of Cosmos caudatus at different growth stages

BACKGROUND

Cosmos caudatus is an annual plant known for its medicinal value in treating several health conditions, such as high blood pressure, arthritis, and diabetes mellitus. The α-glucosidase inhibitory activity and total phenolic content of the leaf aqueous ethanolic extracts of the plant at different growth stages (6, 8. 10, 12 and 14 weeks) were determined in an effort to ascertain the best time to harvest the plant for maximum medicinal quality with respect to its glucose-lowering effects.

METHODS

The aqueous ethanolic leaf extracts of C. caudatus were characterized by NMR and LC-MS/MS. The total phenolic content and α-glucosidase inhibitory activity were evaluated by the Folin-Ciocalteu method and α-glucosidase inhibitory assay, respectively. The statistical significance of the results was evaluated using one-way ANOVA with Duncan's post hoc test, and correlation among the different activities was performed by Pearson's correlation test. NMR spectroscopy along with multivariate data analysis was used to identify the metabolites correlated with total phenolic content and α-glucosidase inhibitory activity of the C. caudatus leaf extracts.

RESULTS

It was found that the α-glucosidase inhibitory activity and total phenolic content of the optimized ethanol:water (80:20) leaf extract of the plant increased significantly as the plant matured, reaching a maximum at the 10th week. The IC50 value for α-glucosidase inhibitory activity (39.18 μg mL- 1) at the 10th week showed greater potency than the positive standard, quercetin (110.50 μg mL- 1). Through an 1H NMR-based metabolomics approach, the 10-week-old samples were shown to be correlated with a high total phenolic content and α-glucosidase inhibitory activity. From the partial least squares biplot, rutin and flavonoid glycosides, consisting of quercetin 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, and quercetin 3-O-xyloside, were identified as the major bioactive metabolites. The metabolites were identified by NMR spectroscopy (J-resolve, HSQC and HMBC experiments) and further supported by dereplication via LC-MS/MS.

CONCLUSION

For high phytomedicinal quality, the 10th week is recommended as the best time to harvest C. caudatus leaves with respect to its glucose lowering potential.

Gadofullerene Nanoparticles Reverse Dysfunctions of Pancreas and Improve Hepatic Insulin Resistance for Type 2 Diabetes Mellitus Treatment

Type 2 diabetes mellitus (T2DM) has been one of the most prevalent metabolic disorders. Nonetheless, the commonly used anti-T2DM drugs failed to substant to treat T2DM when anti-T2DM was withdrawn. Here we put forward a superior and sustainable anti-diabetic strategy using intraperitoneal administration of amino-acid-functionalized gadofullerene nanoparticles (GFNPs) in db/db diabetic mice. Highly accumulated in the pancreas and liver, GFNPs could prominently decrease hyperglycemia, along with permanently maintaining normal blood sugar levels in T2DM mice and even stopping administration. Importantly, GFNPs reversed the pancreas islets dysfunctions by reducing oxidative stress and inflammation responses and fundamentally normalized the insulin secretory function of the pancreas islets. Mechanistically, GFNPs improved hepatic insulin resistance by regulating glucose and lipid metabolism through the activation of IRS2/PI3K/AKT signal pathways, resulting in inhibiting gluconeogenesis and increasing glycogenesis in the liver. Additionally, GFNPs relieved hepatic steatosis in the liver, ultimately maintaining systemic glucose and lipid metabolic homeostasis without obvious toxicity. Together, GFNPs reverse the dysfunctions of the pancreas and improve hepatic insulin resistance, providing a promising approach for T2DM treatment.

Discovery and Biological Evaluation of Potent and Orally Active Human 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors for the Treatment of Type 2 Diabetes Mellitus

We synthesized and evaluated novel 5-[2-(thiophen-2-yl)propan-2-yl]-4H-1,2,4-triazole derivatives as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors. Optimization of the thiophene ring and the substituents on the 1,2,4-triazole ring produced 3,4-dicyclopropyl-5-{2-[3-fluoro-5-(trifluoromethyl)thiophen-2-yl]propan-2-yl}-4H-1,2,4-triazole monohydrochloride (9a), which showed potent and selective inhibitory activity against human 11β-HSD1. Compound 9a was also metabolically stable against human and mouse liver microsomes. Oral administration of 9a to diabetic ob/ob mice lowered corticosterone levels in adipose tissue, and thereby reduced plasma glucose and insulin levels in a dose-dependent manner.

Nanotechnology Advanced Strategies for the Management of Diabetes Mellitus

Background:

Medications currently available for the management of diabetes mellitus are inconvenient and have some limitations. Thus, investigations for novel approaches are needed to deliver and target antidiabetics safely to the site of action.

Objective:

The present review emphasizes the limitations of conventional antidiabetics and provides the recent progresses of nanotechnology in the treatment of diabetes mellitus with a special highlight on the novel nanocarriers methodologies employed as antidiabetic drug delivery systems.

Methods:

The potential nanocarriers employed for the treatment of diabetes comprise liposomes, niosomes, self-nanoemulsifying drug delivery systems, polymeric nanoparticles, gold nanoparticles, dendrimers and micelles. Herbal nanomedicine has also emerged to be a promising way for adequate delivery of herbal compounds. Other nanotechnology approaches involve the usage of oral insulin, inhalable insulin, artificial pancreas, and nanopump.

Results:

Nanocarriers have proved to lead a successful delivery of antidiabetic medications, aiming at drug targeting for enhanced efficacy and safety.

Conclusion:

These innovative generations of drug delivery systems have important benefits over conventionally existing ones. The future of nanotechnology in the management of diabetes is still open with several prospects and will be of pronounced significance.

In vitro (anti-alpha-glucosidase) activity and in vivo anti-diabetic activity of Androsace foliosa (common rock jasmine) in alloxan-induced diabetic BALB/c mice

Androsace foliosa syn. Androsace sarmentosa (botanical name of common rock jasmine) ( Primulaceae) is used in the treatment various disorders. The aim of this study is to evaluate in vitro anti-diabetic activity of crude methanolic extract of leaves and roots of A. foliosa by anti -alpha-glucosidase (α-Glc) and in vivo anti-diabetic activity of n-hexane fraction on alloxan-induced diabetic mice. Results of in vitro anti-diabetic (α-Glc) activity showed that n-hexane leaves fraction was most potent among all the fractions and showed IC50 (half maximal inhibitory concentration) value of 64.91 ± 0.16 µg and % inhibition of 89.35 ± 0.45, comparable to that of standard acarbose. In vivo n-hexane leaves fraction decreases blood glucose level and reduces body weight similar to that of standard drug glibenclamide. Based on the conclusion of both in vitro and in vivo activities, it can be accomplished that the plant A. foliosa acquires noteworthy anti-diabetic action and can be used to treat diabetes mellitus type II and to reduce body weight.

In the Search of Glycoside-Based Molecules as Antidiabetic Agents

This review is an effort to summarize recent developments in synthesis of O-glycosides and N-, C-glycosyl molecules with promising antidiabetic potential. Articles published after 2000 are included. First, the O-glycosides used in the treatment of diabetes are presented, followed by the N-glycosides and finally the C-glycosides constituting the largest group of antidiabetic drugs are described. Within each group of glycosides, we presented how the structure of compounds representing potential drugs changes and when discussing chemical compounds of a similar structure, achievements are presented in the chronological order. C-Glycosyl compounds mimicking O-glycosides structure, exhibit the best features in terms of pharmacodynamics and pharmacokinetics. Therefore, the largest part of the article is concerned with the description of the synthesis and biological studies of various C-glycosides. Also N-glycosides such as N-(β-d-glucopyranosyl)-amides, N-(β-d-glucopyranosyl)-ureas, and 1,2,3-triazolyl derivatives belong to the most potent classes of antidiabetic agents. In order to indicate which of the compounds presented in the given sections have the best inhibitory properties, a list of the best inhibitors is presented at the end of each section. In summary, the best inhibitors were selected from each of the summarizing figures and the results of the ranking were placed. In this way, the reader can learn about the structure of the compounds having the best antidiabetic activity. The compounds, whose synthesis was described in the article but did not appear on the figures presenting the structures of the most active inhibitors, did not show proper activity as inhibitors. Thus, the article also presents studies that have not yielded the desired results and show directions of research that should not be followed. In order to show the directions of the latest research, articles from 2018 to 2019 are described in a separate Sect. 5. In Sect. 6, biological mechanisms of action of the glycosides and patents of marketed drugs are described.

The Effect of Clinacanthus nutans (Burm.f.) Lindau Water Fraction Addition on Hypoglycemia

This research aimed to investigate the effect of administering water fraction of Clinacanthus nutans [Burm.F.] Lindau (the local name of daun dandang gendis) in different doses on hypoglycemia. The research method was using the test of dandang gendis leaves (Clinacanthus nutans (Burm.f.) Lindau) water fraction on wistar rats using pre and post test method randomized control group design. The induction using a high-fat diet consisting of pork oil: duck egg (3:1) and fructose 1.8 g/kgBW for 30 days was applied. Rats were divided into 6 groups: normal control (aquadest), negative control (carboxyl methyl cellulose/CMC), positive control (metformin), dose I 15,89 mg/kgBW (water fraction of Clinacanthus nutans [Burm.F.] Lindau), dose II 31,78 mg / kgBW, and dose III 47,67 mg / kgBW. The result showed that a dose of 15,89 mg/kg BW was an effective dose to reduce blood glucose level. of wistar male rats induced by fructose and high-fat feed.

Anthraquinone-type inhibitor of α-glucosidase enhances glucose uptake by activating an insulin-like signaling pathway in C2C12 myotubes

This study assesses the ability of anthraquinone derivative, 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone (MTAQ) to decrease postprandial hyperglycemia or enhance glucose uptake and to elucidate the underlying molecular mechanism. We investigated α-glucosidase inhibition, glucose uptake, and translocation of glucose transporter 4 (GLUT4) in C2C12 myotubes. The data indicate that MTAQ strongly inhibited α-glucosidase activity in a concentration-dependent manner, with an IC₅₀ value of 6.49 ± 1.31 μM, and functioned as a reversible competitive inhibitor, with a dissociation constant of 41.88 μM. Moreover, MTAQ significantly augmented basal and insulin-stimulated glucose uptake as well as translocation of GLUT4 to the plasma membrane. It also stimulated the phosphorylation of insulin receptor β isoform, insulin receptor substrate-1,3-phosphoinositide-dependent protein kinase 1, and protein kinase B (AKT). A pretreatment with an AKT inhibitor, LY294002, attenuated the ability of MTAQ to activate an insulin-like signaling pathway and to enhance basal and insulin-stimulated glucose uptake and stimulate GLUT4 translocation to the plasma membrane. These findings reveal the fact that MTAQ may have potential for the development of new antidiabetic drugs to manage blood glucose levels.