Antidiabetic agents: past, present and future

Design, synthesis, computational molecular docking studies of novel heterocyclics bearing 1,2,4-triazole, 1,3,4-oxadiazole conjugates as potent antibacterial and antitubercular agents

Herein, we report the synthesis, and characterization of a new series of 1,3,4-oxadiazole and 1,2,4-triazole derivatives based on azaindole acetamides and assigned as potential antibacterial and antitubercular substances. The structures of these compounds were established by 1H NMR, 13C NMR, and HRMS spectral analysis. In preliminary antibacterial studies, analogues 6b, 6d, and 6e were found to be most effective against S. aureus with MIC of 12.5, 6.25, and 12.5 μg/mL, whereas 8d displayed excellent activity against S. aureus, B. subtilis, E. coli bacterial strains with zones of inhibition 12.5, 25, and 12.5 μg/mL respectively. Particularly, the prepared scaffolds 8c, 8d, and 8e showed remarkable antifungal activity with MIC value 12.5, 12.5, and 6.25 μg/mL against A. flavus and 6d, 6c producing an increase in the activity against C. Albicans with zones of inhibition 12.5 and 12.5 μg/mL respectively. Also, through the antitubercular studies, we found that compounds 6e and 8b have a strong activity with M. tuberculosis H37Rv with MICs 3.26, and 6.48 μg/mL, respectively. The protein stability, fluctuations of APO-Protein, and protein-ligand complexes were investigated through Molecular Dynamics (MD) simulations studies using Desmond Maestro 11.3, and potential lead molecules were identified. Our findings were further confirmed using molecular docking, revealing that azaindole based ligand 6e, 6f, and 8a has strong hydrophobic Tyr179, Trp183, Ile177, Ile445, and H-bondings interactions Arg151 and Arg454 through molecular dynamics simulation studies, making it potential biological compound. These compounds were further evaluated for their ADMET and physicochemical properties by using SwissADME.Communicated by Ramaswamy H. Sarma.

Synthesis of Thiazole-Chalcone Hybrid Molecules: Antioxidant, Alpha(α)-Amylase Inhibition and Docking Studies

The molecular hybrid approach is very significant to combat various drug-resistant disorders. A simple, convenient, and cost-effective synthesis of thiazole-based chalcones is accomplished, using a molecular hybrid approach, in two steps. The compound 1-(2-phenylthiazol-4-yl)ethanone (3) was used as the main intermediate for the synthesis of 3-(arylidene)-1-(2-phenylthiazol-4-yl)prop-2-en-1-ones (4a-f). Thin layer chromatography was used to testify the formation and purity of all synthesized compounds. Further structural confirmation of all compounds was achieved via different spectroscopic techniques (UV, FT-IR, ¹ H- and ¹³ C-NMR) and elemental analysis. All synthesized compounds were tested for their α-amylase inhibition and antioxidant potential. The cytotoxic property of compounds was also tested with in vitro haemolytic assay. All tested compounds showed moderate to excellent α-amylase inhibition and antioxidant activity. All tested compounds are found safe to use due to their less toxicity when compared to the standard Triton X. The molecular docking simulation study of all synthesized compounds was also conducted to examine the best binding interactions with human pancreatic α-amylase (pdb: 4 W93) using AutodockVina. The molecular docking results authenticated the in vitro amylase inhibition results, i.e., 3-(3-Methoxyphenyl)-1-(2-phenylthiazol-4-yl)prop-2-en-1-one (4e) exhibited lowest IC₅₀ value 54.09±0.11  μM with a binding energy of -7.898 kcal/mol.

Carbon nanomaterials: A growing tool for the diagnosis and treatment of diabetes mellitus

Diabetes mellitus is a growing disease that affects people of different ages due to deficiencies in insulin action and secretion. Diabetes causing long-term hyperglycemia damages, destroys, and fails essential organs, including kidneys, eyes, hearts, nerves, and blood vessels. The involvement of pathogenic factors makes diabetes mellitus a severe disease. The autoimmune process results in insulin deficiency by destroying the beta-cells in the pancreas. This leads to insulin resistance. As a result of defects and abnormalities in fat, carbohydrate, and protein synthesis, insulin does not work as it should on the target tissues. As diabetes mellitus becomes, more severe, long-term and effective treatment becomes necessary. A wide range of nanomaterials can be used to treat diabetes mellitus in patients. In addition to being potential imaging, diagnostic, and treatment agents for diabetes mellitus, carbon nanomaterials (CNMs) are another group of nanoparticles that exhibit potential interest. The CNMs acts as implantable nanosensor to track and detect blood glucose level in patients with diabetes. CNMS are possible drug carriers that can treat diabetes mellitus selectively, precisely, and effectively. Diabetes mellitus can be diagnosed and treated with CNMs due to their structural specificity and high drug-loading efficiency. The present review explores CNMs for their types, synthesis, and anti-diabetic properties. This review aims to provide a detailed view of the new technology that can be used to decipher the mechanism of CNMs in diabetes mellitus.

A Comprehensive Approach to Derivatization: Elemental Composition, Biochemical, and In Silico Studies of Metformin Derivatives Containing Copper and Zinc Complexes

The current study was designed to synthesize, characterize, and screen the molecular and biological activities of different metformin derivatives that possess potent antidiabetic potential with minimal side-effects. Metformin-based derivatives containing the metal complexes Cu II (MCu1-MCu9) and Zn II (MZn1-MZn9) were generated using aromatic aldehydes and ketones in a template process. The novel metal complexes were characterized through elemental analysis, physical state, melting point, physical appearance, Fourier-transform infrared (FTIR) spectroscopy, UV/visible (UV/Vis) spectroscopy, ¹H nuclear magnetic resonance (NMR) spectroscopy, and ¹³C-NMR spectroscopy. Screening for inhibitory activity against the enzymes α-amylase and α-glucosidase, and molecular simulations performed in Schrödinger were used to assess the synthesized derivatives' biological potential. Met1, Met2, Met3, and Met8 all displayed activities that were on par with the reference in an enzymatic inhibition assay (amylase and glucosidase). The enzyme inhibition assay was corroborated by molecular simulation studies, which also revealed a competitive docking score compared to the gold standard. The Swiss ADME online web server was utilized to compute ADME properties of metformin analogues. Lipinski's rule of five held true across all derivatives, making it possible to determine the percentage of absorption. Metformin derivatives showed significant antidiabetic activities against both targeted enzymes, and the results of this work suggest that these compounds could serve as lead molecules for future study and development.

Synthesis, characterization, and in vitro antibacterial activity of some new pyridinone and pyrazole derivatives with some in silico ADME and molecular modeling study

A new series of pyridine-2-one and pyrazole derivatives were designed and synthesized based on cyanoacrylamide derivatives containing 2,4-dichlro aniline and 6-methyl 2-amino pyridine as an aryl group. Condensation of cyanoacrylamide derivatives 3a–d with different active methylene (malononitrile, ethyl cyanoacetate cyanoacetamide, and ethyl acetoacetate) in the presence of piperidine as basic catalyst afforded the corresponding pyridinone derivatives 4a–c, 5, 9, and 13. Furthermore, the reaction of cyanoacrylamide derivatives 3a–d with bi-nucleophile as hydrazine hydrate and thiosemicarbazide afforded the corresponding pyrazole derivatives 14a,b and 16. The newly designed derivatives were confirmed and established based on the elemental analysis and spectra data (IR, 1H NMR, 13C NMR, and mass). The in vitro antibacterial activity was evaluated against four bacterial strains with weak to good antibacterial activity. Moreover, the results indicated that the most active derivatives 3a, 4a, 4b, 9, and 16 might lead to antibacterial agents, especially against B. subtilis and P. vulgaris. The DFT calculations were performed to estimate its geometric structure and electronic properties. In addition, the most active pyridinone and pyrazole derivatives were further evaluated for in silico physicochemical, drug-likeness, and toxicity prediction. These derivatives obeyed all Lipinski’s and Veber’s rules without any violation and displayed non-immunotoxin, non-mutagenic, and non-cytotoxic. Molecular docking simulation was performed inside the active site of Topoisomerase IV (PDB:3FV5). It displayed binding energy ranging from -14.97 kcal/mol to -18.86 kcal/mol with hydrogen bonding and arene–cation interaction. Therefore, these derivatives were suggested to be good antibacterial agents via topoisomerase IV inhibitor.

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Oat β Glucan Ameliorates Renal Function and Gut Microbiota in Diabetic Rats

Diabetic nephropathy is a severe complication of diabetes and the leading cause of end-stage renal disease and death. Therefore, we must find effective prevention and treatment approaches to the problem. Oat has a long history of use for its nutritional and medicinal properties, such as maintaining physiological blood glucose levels. Oat β glucan is one of the major bioactive substances produced by oat. However, the protective effects of oat β glucan on diabetic nephropathy are still unclear. This study generated a rat model of diabetic nephropathy to explore the potent therapeutic ability and mechanism of oat β glucan in renal function by 16S rRNA genes sequencing. Diabetic nephropathy model was established in forty rats by left nephrectomy and single intraperitoneal injection of streptozotocin. These rats were randomly divided into the model group and three oat β glucan intervention groups. Twenty rats underwent sham operation and were randomly divided into normal control group and oat β glucan control group. Animals were treated by oral gavage for 8 consecutive weeks. The results showed that oat β glucan reduced blood glucose level and improved renal function (P < 0.05). Oat β glucan significantly improved serum inflammatory levels (P < 0.05). The diversity of intestinal microflora in diabetic nephropathy rats decreased with time prolongation, while oat β-glucan reversed the result. Compared with the model group at week 8, the abundances of Eubacterium, Butyricicoccus, and Ruminococcus were elevated significantly after oat β glucan intervention (P < 0.05). Correlation analysis indicated that abundances of Eubacterium, Butyricicoccus, and Ruminococcus were significantly negatively correlated with the levels of renal impairment markers. In summary, the findings of this study showed that oat β glucan can increase the diversity of intestinal flora, regulate the composition of intestinal flora, modulate intestinal flora metabolism, alleviate the inflammatory response, and further delay the development of diabetic nephropathy. Therefore, oat β glucan has the potential to be developed into the novel and safe drug for diabetic nephropathy.

Intestinal Microbiota Play an Important Role in the Treatment of Type I Diabetes in Mice With BefA Protein

More and more studies have shown that the intestinal microbiota is the main factor in the pathogenesis of type 1 diabetes mellitus (T1DM). Beta cell expansion factor A (BefA) is a protein expressed by intestinal microorganisms. It has been proven to promote the proliferation of β-cells and has broad application prospects. However, as an intestinal protein, there have not been studies and reports on its application in diabetes and its mechanism of action. In this study, a T1DM model induced by multiple low-dose STZ (MLD-STZ) injections was established, and BefA protein was administered to explore its therapeutic effect in T1DM and the potential mechanism of intestinal microbiota. BefA protein significantly reduced the blood glucose, maintained the body weight, and improved the glucose tolerance of the mice. At the same time, the BefA protein significantly increased the expression of ZO-1, Occludin, and significantly reduced the expression of TLR-4, Myd88, and p-p65/p65. BefA protein significantly reduced the relative expression of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α. In addition, our high-throughput sequencing shows for the first time that the good hypoglycemic effect of BefA protein is strongly related to the increase in the abundance of the beneficial gut bacteria Lactobacillus, Bifidobacterium and Oscillospria and the decrease in the abundance of the opportunistic pathogen Acinetobacter. Our group used animal models to verify the hypoglycemic effect of BefA protein, and first explored the potential mechanism of intestinal microbiota in BefA protein treatment.

Biguanides drugs: Past success stories and promising future for drug discovery

Biguanides have attracted much attention a century ago and showed resurgent interest in recent years after a long period of dormancy. They constitute an important class of therapeutic agents suitable for the treatment of a wide spectrum of diseases. Therapeutic indications of biguanides include antidiabetic, antimalarial, antiviral, antiplaque, and bactericidal applications. This review presents an extensive overview of the biological activity of biguanides and different mechanisms of action of currently marketed biguanide-containing drugs, as well as their pharmacological properties when applicable. We highlight the recent developments in research on biguanide compounds, with a primary focus on studies on metformin in the field of oncology. We aim to provide a critical overview of all main bioactive biguanide compounds and discuss future perspectives for the design of new drugs based on the biguanide fragment.

Natural Antidiabetic Agents: Molecular Docking Study using the Extra Precision Method

Background:

Diabetes mellitus (DM) is the most severe, chronic metabolic disorder with abnormally elevated concentration of plasma glucose levels, leading to significant complications, such as diabetic neuropathy, retinopathy, and cardiovascular illnesses.

Objective:

Synthetic drugs have some disadvantages and limitations. Therefore, there is a continuous global and insisting need for new and better treatment options for Diabetes Mellitus.

Methods:

In this study, 42 natural anti-diabetic constituents like alkaloids, glycosides, and flavonoids were selected on the basis of mechanism of action on various molecular targets such as Glucokinase activator, Dipeptidyl peptidase 4 (DPP-4), peroxisome proliferator-activated receptors (PPARγ), and α-glucosidase inhibitor. To investigate the potential molecular targets for natural antidiabetcs agents, molecular docking study was carried out using the Glide module of Schrodinger Suit.

Results:

Interactions of specific amino acid of the targets with the atoms of the chemical constituents and their Gscore indicate the proper binding of chemical constituents with target. The results revealed that Myricetin, Quercetin ae interacts with active sites of the target chosen and can be used for the designing of novel compounds as anti-dibetics.

Conclusion:

Calculated GScore could be used as a preliminary tool for screening of anti-diabetic drugs before performing experimental activity.

Chagas Disease: Perspectives on the Past and Present and Challenges in Drug Discovery

Chagas disease still has no effective treatment option for all of its phases despite being discovered more than 100 years ago. The development of commercial drugs has been stagnating since the 1960s, a fact that sheds light on the question of how drug discovery research has progressed and taken advantage of technological advances. Could it be that technological advances have not yet been sufficient to resolve this issue or is there a lack of protocol, validation and standardization of the data generated by different research teams? This work presents an overview of commercial drugs and those that have been evaluated in studies and clinical trials so far. A brief review is made of recent target-based and phenotypic studies based on the search for molecules with anti-Trypanosoma cruzi action. It also discusses how proteochemometric (PCM) modeling and microcrystal electron diffraction (MicroED) can help in the case of the lack of a 3D protein structure; more specifically, Trypanosoma cruzi carbonic anhydrase.

Blood pressure control in type 2 diabetes mellitus with arterial hypertension. The important ancillary role of SGLT2-inhibitors and GLP1-receptor agonists

Type 2 diabetes mellitus and arterial hypertension are major cardiovascular risks factors which shares metabolic and haemodynamic abnormalities as well as pathophysiological mechanisms. The simultaneous presence of diabetes and arterial hypertension increases the risk of left ventricular hypertrophy, congestive heart failure, and stroke, as compared to either condition alone. A number of guidelines recommend lifestyle measures such as salt restriction, weight reduction and ideal body weight mainteinance, regular physical activity and smoking cessation, together with moderation of alcohol consumption and high intake of vegetables and fruits, as the basis for reduction of blood pressure and prevention of CV diseases. Despite the availability of multiple drugs effective for hypertension, BP targets are reached in only 50 % of patients, with even fewer individuals with T2DM-achieving goals. It is established that new emerging classes of type 2 diabetes mellitus treatment, SGLT2 inhibitors and GLP1-receptor agonists, are efficacious on glucose control, and safe in reducing HbA1c significantly, without increasing hypoglycemic episodes. Furthermore, in recent years, many CVOT trials have demonstrated, using GLP1-RA or SGLT2-inihibitors compared to placebo (in combination with the usual diabetes medications) important benefits on reducing MACE (cardio-cerebral vascular events) in the diabetic population. In this hypothesis-driven review, we have examined the anti-hypertensive effects of these novel molecules of the two different classes, in the diabetic population, and suggest that they could have an interesting ancillary role in controlling blood pressure in type 2 diabetic patients.

Nitrothiadiazolo[3,2-a]pyrimidines as promising antiglycating agents

Managing the advanced glycation end-products (AGEs) concentration is a reliable approach to achieve control over the pathogenesis of diabetic vascular complications. Inhibition of dipeptidyl peptidase-4 (DPP-4) is also an attractive way to tackle type 2 diabetes mellitus (T2DM). We showed previously that azoloazine heterocycles have the potential to prevent the formation of AGEs and in this work, we conducted docking studies with DPP-4 of 5-alkylamino-6-nitro-1,3,4-thiadiazolo[3,2-a]pyrimidines. Consequently, we have developed a synthetic approach to these structures by chlorodeoxygenation and amination reactions. Antidiabetic properties of obtained compounds were studied by evaluating DPP-4 (ex vivo/in vitro) and AGEs formation inhibition (in vitro). It was shown that the nitrothiadiazolopyrimidines exhibit a higher antiglycation activity than reference compound aminoguanidine, but only moderate inhibition of DPP-4. The most active DPP-4 inhibitor 1l had IC₅₀ of 55.87 μM and showed the ability to inhibit serum DPP-4 activity in rats after 10 mg/kg oral administration but with the less and shorter effect than vildagliptin. At the same time, 1l was the most active antiglycating compound in the series (IC₅₀ 134.4 μM). Copper chelation properties of synthesized compounds were also investigated since the formation of AGEs is catalyzed by the transition metal cations. A noticeable correlation between antiglycation activity and metal chelation was revealed. Both activities (antiglycation and copper chelation) correlated with quantum-chemical properties (calculated with ab initio) of the tested compounds. These findings will allow us to predict both activities in the future, without the need to model multiple steps of glycation reaction.

α-Glucosidase inhibitory activity and cytotoxic effects of some cyclic urea and carbamate derivatives

The inhibitory activities of selected cyclic urea and carbamate derivatives (1-13) toward α-glucosidase (α-Gls) in in vitro assay were examined in this study. All examined compounds showed higher inhibitory activity (IC₅₀) against α-Gls compared to standard antidiabetic drug acarbose. The most potent was benzyl (3,4,5-trimethoxyphenyl)carbamate (12) with IC₅₀ = 49.85 ± 0.10 µM. In vitro cytotoxicity of the investigated compounds was tested on three human cancer cell lines HeLa, A549 and MDA-MB-453 using MTT assay. The best antitumour activity was achieved with compound 2 (trans-5-phenethyl-1-phenylhexahydro-1H-imidazo[4,5-c]pyridin-2(3H)-one) against MDA-MB-453 human breast cancer cell line (IC₅₀ = 83.41 ± 1.60 µM). Cyclic ureas and carbamates showed promising anti-α-glucosidase activity and should be further tested as potential antidiabetic drugs. The PLS model of preliminary QSAR study indicated that, in planing the future synthesis of more potent compounds, the newly designed should have the substituents capable of polar interactions with receptor sites in various positions, while avoiding the increase of their lipophilicity.

Clinical pharmacology of dipeptidyl peptidase 4 inhibitors indicated for the treatment of type 2 diabetes mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic drugs that improve glycaemic control without causing weight gain or increasing hypoglycaemic risk in patients with type 2 diabetes mellitus (T2DM). The eight available DPP-4 inhibitors, including alogliptin, anagliptin, gemigliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, and vildagliptin, are small molecules used orally with identical mechanism of action and similar safety profiles in patients with T2DM. DPP-4 inhibitors may be used as monotherapy or in double or triple combination with other oral glucose-lowering agents such as metformin, thiazolidinediones, or sulfonylureas. Although DPP-4 inhibitors have the same mode of action, they differ by some important pharmacokinetic and pharmacodynamic properties that may be clinically relevant in some patients. The main differences between the eight gliptins include: potency, target selectivity, oral bioavailability, elimination half-life, binding to plasma proteins, metabolic pathways, formation of active metabolite(s), main excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug-drug interactions. The off-target inhibition of selective DPP-4 inhibitors is responsible for multiorgan toxicities such as immune dysfunction, impaired healing, and skin reactions. As a drug class, the DPP-4 inhibitors have become accepted in clinical practice due to their excellent tolerability profile, with a low risk of hypoglycaemia, a neutral effect on body weight, and once-daily dosing. It is unknown if DPP-4 inhibitors can prevent disease progression. More clinical studies are needed to validate the optimal regimens of DPP-4 inhibitors for the management of T2DM when their potential toxicities are closely monitored.

Managing diabetes with nanomedicine: challenges and opportunities

Nanotechnology-based approaches hold substantial potential for improving the care of patients with diabetes. Nanoparticles are being developed as imaging contrast agents to assist in the early diagnosis of type 1 diabetes. Glucose nanosensors are being incorporated in implantable devices that enable more accurate and patient-friendly real-time tracking of blood glucose levels, and are also providing the basis for glucose-responsive nanoparticles that better mimic the body's physiological needs for insulin. Finally, nanotechnology is being used in non-invasive approaches to insulin delivery and to engineer more effective vaccine, cell and gene therapies for type 1 diabetes. Here, we analyse the current state of these approaches and discuss key issues for their translation to clinical practice.

Relieving the cardiometabolic disease burden: a perspective on phytometabolite functional and chemical annotation for diabetes management

Type 2 diabetes (T2D) is both a complex, multifactorial disease state and an unsolved, intensifying public-health problem. To help reduce disease burden, some T2D patients have embraced plant-derived substances for use with - if not in place of - prescription medicines, a trend based mainly upon historical precedent and anecdotal observations of human health benefit. Preclinical research has emphasized phytometabolite interactions with purported T2D pathogenic targets and the effects of botanical preparations on experimental T2D symptomology as induced in laboratory animals. More holistic, systems-oriented profiling of phytochemicals with functional-biology, omics, and chemical-fingerprinting tools now appears necessary to increase our appreciation of phytometabolite actions potentially beneficial to the T2D patient. The resultant, multidimensional view of phytometabolite pharmacology should help provide a more rational basis for evaluating the potential of natural plant products as T2D pharmacotherapy. Such information may also help substantiate and legitimize (pre)clinical demonstrations of phytochemical health benefits, advance our understanding of T2D pathogenesis, and offer scope for better T2D medicines. Public-private partnerships are invoked for conducting this research with the ultimate aim of improving the global cardiometabolic profile.

Loss of the anorexic response to systemic 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside administration despite reducing hypothalamic AMP-activated protein kinase phosphorylation in insulin-deficient rats

This study tested whether chronic systemic administration of 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) could attenuate hyperphagia, reduce lean and fat mass losses, and improve whole-body energy homeostasis in insulin-deficient rats. Male Wistar rats were first rendered diabetic through streptozotocin (STZ) administration and then intraperitoneally injected with AICAR for 7 consecutive days. Food and water intake, ambulatory activity, and energy expenditure were assessed at the end of the AICAR-treatment period. Blood was collected for circulating leptin measurement and the hypothalami were extracted for the determination of suppressor of cytokine signaling 3 (SOCS3) content, as well as the content and phosphorylation of AMP-kinase (AMPK), acetyl-CoA carboxylase (ACC), and the signal transducer and activator of transcription 3 (STAT3). Rats were thoroughly dissected for adiposity and lean body mass (LBM) determinations. In non-diabetic rats, despite reducing adiposity, AICAR increased (∼1.7-fold) circulating leptin and reduced hypothalamic SOCS3 content and food intake by 67% and 25%, respectively. The anorexic effect of AICAR was lost in diabetic rats, even though hypothalamic AMPK and ACC phosphorylation markedly decreased in these animals. Importantly, hypothalamic SOCS3 and STAT3 levels remained elevated and reduced, respectively, after treatment of insulin-deficient rats with AICAR. Diabetic rats were lethargic and displayed marked losses of fat and LBM. AICAR treatment increased ambulatory activity and whole-body energy expenditure while also attenuating diabetes-induced fat and LBM losses. In conclusion, AICAR did not reverse hyperphagia, but it promoted anti-catabolic effects on skeletal muscle and fat, enhanced spontaneous physical activity, and improved the ability of rats to cope with the diabetes-induced dysfunctional alterations in glucose metabolism and whole-body energy homeostasis.