Drug repurposing: In-vitro anti-glycation properties of 18 common drugs

Monosaccharide-Mediated Glycoxidation of Bovine Serum Albumin and Its Prevention by Nigella sativa

The substantial rise in metabolic illnesses that has occurred in both developed and developing countries over the last three decades has been linked to an increase in sugar-added foods and sweetened beverage intake. The significance of advanced glycation end products (AGEs) in the pathophysiology of metabolic diseases related to modern nutrition is an emerging issue. Spices and herbs can potentially be potent AGE production inhibitors due to their high polyphenol content. The inhibitory activity of an aqueous extract of Nigella sativa seeds (NS) on glucose- and fructose-mediated glycation of bovine serum albumin (BSA) was investigated. The glycation of proteins and its prevention using NS were assessed using spectrophotometry, spectrofluorometrics, and electrophoretic techniques. Additionally, the NBT assay, DNPH assay, Ellman assay, and thioflavin T assay were used to observe the biochemical alterations caused by glycated BSA. Molecular docking was employed to dock the BSA active site residues with inhibitors. Our data showed that NS protects against glucose- and fructose-mediated glycation and aggregation in vitro by inhibiting the formation of fructosamine, protein carbonyl content, free sulfhydryl groups, and fluorescent AGEs. Furthermore, NS also inhibited the production of β-cross-amyloid aggregates in proteins. It was interesting to note that the inhibition was found to be significantly higher in the Glu-BSA system, although the glycation product formed in the Fru-BSA system was higher compared to the Glu-induced protein system. It can be concluded that, by inhibiting AGE production, oxidation, and aggregation of the protein, NS may be an effective antiglycation drug for the prevention of diabetes complications.

Exploring anti-diabetic potential of compounds from roots of Dendrobium polyanthum Wall. ex Lindl. through inhibition of carbohydrate-digesting enzymes and glycation inhibitory activity

Eight compounds, including one anthraquinone, two bibenzyls, one phenanthrene, three dihydrophenanthrenes, and one flavonoid, were isolated from the roots of Dendrobium polyanthum Wall. ex Lindl. Among these, six compounds were investigated for inhibitory activities against alpha-glucosidase, alpha-amylase, and advanced glycation end products (AGEs) production. Additionally, molecular docking was conducted to analyze the interactions of the test compounds with alpha-glucosidase. Moscatin, the only isolated phenanthrene, displayed the strongest anti-alpha-glucosidase activity with an IC50 of 32.45 ± 1.04 μM, approximately 10-fold smaller than that of acarbose. Furthermore, moscatilin most strongly inhibited alpha-amylase and AGEs production with IC50 values of 256.94 ± 9.87 and 67.89 ± 9.42 μM, respectively. Molecular docking analysis revealed the effective binding of all substances to alpha-glucosidase with smaller lowest binding energy values than acarbose. Moscatin was selected for kinetics studies, and it was identified as a non-competitive inhibitor with approximately 9-fold greater inhibitory capability than acarbose. This study represents the first report on the phytochemical constituents and antidiabetic potential of compounds derived from the roots of D. polyanthum Wall. ex Lindl.

The inhibitory effects of endophytic metabolites on glycated proteins under non-communicable disease conditions: A review

Protein glycation in human body is closely linked to the onset/progression of diabetes associated complications. These glycated proteins are commonly known as advanced glycation end products (AGEs). Recent literature has also highlighted the involvement of AGEs in other non-communicable diseases (NCDs) such as cardiovascular, cancer, and Alzheimer's diseases and explored the impact of plant metabolites on AGEs formation. However, the significance of endophytic metabolites against AGEs has recently garnered attention but has not been thoroughly summarized thus far. Therefore, the objective of this review is to provide a comprehensive overview of the importance of endophytic metabolites in combating AGEs under NCDs conditions. Additionally, this review aims to elucidate the processes of AGEs formation, absorption, metabolism, and their harmful effects. Collectively, endophytic metabolites play a crucial role in modulating signaling pathways and enhancing the digestibility properties of gut microbiota (GM) by targeting on AGEs/RAGE (receptor for AGEs) axis. Furthermore, these metabolites exhibit anti-AGEs activities similar to those derived from host plants, but at a lower cost and higher production rate. The use of endophytes as a source of such metabolites offers a risk-free and sustainable approach that holds substantial potential for the treatment and management of NCDs.

Drug repurposing for metabolic disorders: Scientific, technological and economic issues

Obesity, diabetes, and other metabolic disorders place a huge burden on both the physical health and financial well-being of the community. While the need for effective treatment of metabolic disorders remains urgent and the reality is that traditional drug development involves high costs and a very long time with many pre-clinical and clinical trials, the need for drug repurposing has emerged as a potential alternative. Scientific evidence has shown the anti-diabetic and anti-obesity effects of old drugs, which were initially utilized for the treatment of inflammation, depression, infections, and even cancers. The drug library used modern technological methods to conduct drug screening. Computational molecular docking, genome-wide association studies, or omics data mining are advantageous and unavoidable methods for drug repurposing. Drug repurposing offers a promising avenue for economic efficiency in healthcare, especially for less common metabolic diseases, despite the need for rigorous research and validation. In this chapter, we aim to explore the scientific, technological, and economic issues surrounding drug repurposing for metabolic disorders. We hope to shed light on the potential of this approach and the challenges that need to be addressed to make it a viable option in the treatment of metabolic disorders, especially in the future fight against metabolic disorders.

Mentha piperita silver nanoparticle-loaded hydrocolloid film for enhanced diabetic wound healing in rats

OBJECTIVE

To investigate the role of Mentha piperita silver nanoparticle-loaded carbopol gel for enhanced wound healing in a diabetic rat model. This research further aims to explore bioactive compounds derived from Mentha piperita obtained from high altitude.

METHOD

Methanolic extracts of Mentha piperita (MP), Mentha spicata (MS) and Mentha longifolia (ML) were used to synthesise silver nanoparticles (AgNP). AgNP synthesis was confirmed by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antioxidant activity was assessed by 2, 2-diphenyl-1-picrylhydrazyl (DDPH) assay. Antiglycation potential was determined by measuring the fluorescent advanced glycation end products. The bioactive compound identified in the Mentha piperita methanolic (MPM) fraction through electrospray ionisation tandem mass spectrometric analysis (ESI-MS) was responsible for the highest antiglycation. The effects of MPM and MPM.AgNP-loaded Carbopol (Sanare Lab, India) on wound healing were compared in male, alloxan-induced, diabetic albino rats (200-250g), divided into control and treated groups. Effects on wound healing were assessed via histopathology.

RESULTS

UV-Vis and FTIR confirmed NP synthesis with peaks for flavonoids and polyphenols. SEM and XRD explored the cubical, 30-63nm crystalline NP. The maximum antioxidant and antiglycation potential was observed in order of; MP.AgNP>MS.AgNP>ML.AgNP. The highest antioxidant activity was observed by methanolic and aqueous MP.AgNPs (88.55% and 83.63%, respectively) at 2mg.ml-1, and (75.16% and 69.73%, respectively) at 1mg.ml-1, compared to ascorbic acid (acting as a positive control, 90.01%). MPM.AgNPs demonstrated the best antiglycation potential of 75.2% and 83.3% at 1mg.ml-1 and 2mg.ml-1, respectively, comparable to positive control (rutin: 88.1%) at 14 days post-incubation. A similar trend was observed for antimicrobial activity against Bacillus subtilis, Micrococcus luteus and Escherichia coli with an inhibition zone of 21mm, 21.6mm and 24.6mm. Rosmarinic acid was the active compound present in Mentha piperita, as identified by ESI-MS. MPM.AgNP-loaded Carbopol resulted in 100% wound closure compared with control at 20 days post-wounding. In the treatment group, re-epithelialisation was achieved by day 18, compared with 25 days for the positive control group.

CONCLUSION

MPM.AgNP-loaded Carbopol demonstrated safer and more effective biological properties, hence accelerating the diabetic excision wound healing process in alloxan-induced diabetic rats.

Antiglycation potential of metal ions and polyphenolic extract of chickpea on thiol-protease inhibitor: A management for diabetic complications

Glycation is the non-enzymatic adduct formation between reducing sugars or dicarbonyls with proteins and is a crucial molecular event under hyperglycaemic conditions of diabetes. The accumulation of advanced glycation end products (AGEs) due to glycation of proteins has been implicated in several diseases associated with ageing and diabetes. Thus, investigating the antiglycation potential of some trace metal ions (Manganese; Mn2+, and Zinc; Zn2+) and polyphenolic extract of chickpea seeds (PEC) on the methylglyoxal (MGO) induced glycation of a phytocystatin isolated from chickpea was taken up to find an inexpensive and non-toxic therapeutic means of medicating protein glycation and associated diabetic complications. The current study focused on the comparative analyses of these micronutrients and herbal extracts in inhibiting protein glycation and AGEs formation in a quest to develop nutraceuticals for managing diabetes. The effect of metals (Mn2+, Zn2+) and PEC on protein glycation was assessed by different techniques, i.e., glycation-specific AGE fluorescence and absorbance, thiol protease inhibitory activity assay, and conformational alterations by spectroscopic assays. This study revealed the significant anti-glycation potencies of Mn2+, Zn2+, and PEC against the MGO-induced glycation of CPC, which might pave the way for resolving pathological complications of diabetes by combining higher levels of efficacy, selectivity, and safety in humans. Moreover, characterization and identification of different AGEs formed during the glycation process in diabetics was done to apply the same for determining the onset of glycation at the early stage so that appropriate steps be taken to address the menace of diabetic complications.

Methylglyoxal in Cardiometabolic Disorders: Routes Leading to Pathology Counterbalanced by Treatment Strategies

Methylglyoxal (MGO) is the major compound belonging to reactive carbonyl species (RCS) responsible for the generation of advanced glycation end products (AGEs). Its upregulation, followed by deleterious effects at the cellular and systemic levels, is associated with metabolic disturbances (hyperglycemia/hyperinsulinemia/insulin resistance/hyperlipidemia/inflammatory processes/carbonyl stress/oxidative stress/hypoxia). Therefore, it is implicated in a variety of disorders, including metabolic syndrome, diabetes mellitus, and cardiovascular diseases. In this review, an interplay between pathways leading to MGO generation and scavenging is addressed in regard to this system's impairment in pathology. The issues associated with mechanistic MGO involvement in pathological processes, as well as the discussion on its possible causative role in cardiometabolic diseases, are enclosed. Finally, the main strategies aimed at MGO and its AGEs downregulation with respect to cardiometabolic disorders treatment are addressed. Potential glycation inhibitors and MGO scavengers are discussed, as well as the mechanisms of their action.

Potential inhibitory effect of fish, maize, and whey protein hydrolysates on advanced glycation end-products (AGEs)

Advanced glycation end-products (AGEs) are produced in the final stage of the Maillard reaction. AGEs formation may be inhibited by natural hydrolysates derived from plant or animal sources. The present study aimed to investigate the antiglycation potential of fish, maize, and whey protein hydrolysates. It was carried out in four model systems, Bovine serum albumin (BSA)-Glucose, BSA-Fructose, BSA-Sorbitol, and BSA-HFCS (high fructose corn syrup), by evaluation of fluorescent intensity of AGEs after seven days of reaction at 37°C. The results showed that the highest inhibitory effect belonged to 0.16% of FPH (fish protein hydrolysate, percent inhibition ~99.0%), whereas maize protein hydrolysate (MPH) had lower antiglycation activity in comparison with FPH. Among all hydrolysates, whey protein hydrolysate with the lowest degree of hydrolysis showed the weakest inhibitory activity. Overall, our results indicated that the investigated hydrolysates, particularly FPH, have promising antiglycation potential and can be recommended for the production of functional foods.

TLR7 and IgM: Dangerous Partners in Autoimmunity

The B cell antigen receptor (BCR)-repertoire is capable of recognizing a nearly unlimited number of antigens. Inevitably, the random nature of antibody gene segment rearrangement, needed in order to provide mature B cells, will generate autoreactive specificities. Once tolerance mechanisms fail to block the activation and differentiation of autoreactive B cells, harmful autoantibodies may get secreted establishing autoimmune diseases. Besides the hallmark of autoimmunity, namely IgG autoantibodies, IgM autoantibodies are also found in many autoimmune diseases. In addition to pathogenic functions of secreted IgM the IgM-BCR expressing B cell might be the initial check-point where, in conjunction with innate receptor signals, B cell mediated autoimmunity starts it fateful course. Recently, pentameric IgM autoantibodies have been shown to contribute significantly to the pathogenesis of various autoimmune diseases, such as rheumatoid arthritis (RA), autoimmune hemolytic anemia (AIHA), pemphigus or autoimmune neuropathy. Further, recent studies suggest differences in the recognition of autoantigen by IgG and IgM autoantibodies, or propose a central role of anti-ACE2-IgM autoantibodies in severe COVID-19. However, exact mechanisms still remain to be uncovered in detail. This article focuses on summarizing recent findings regarding the importance of autoreactive IgM in establishing autoimmune diseases.

In Vitro and In Vivo Evaluation of the Antidiabetic Activity of Solidago virgaurea Extracts

Background

Solidago virgaurea (Asteraceae) has been used for more than 700 years for treating cystitis, chronic nephritis, urolithiasis, rheumatism, and inflammatory diseases. However, the antidiabetic activity of Solidago virgaurea has been rarely studied.

Methods

Three extracts of Solidago virgaurea were prepared, and their antidiabetic potentials were evaluated by various cell-free, cell-based, and in vivo studies.

Results

We found that the Solidago virgaurea contained multiple bioactive phytochemicals based on the GC-MS analysis. The Solidago virgaurea extracts effectively inhibited the functions of the carbohydrate digestive enzyme (α-glucosidase) and protein tyrosine phosphatase 1B (PTP1B), as well as decreased the amount of advanced glycation end products (AGEs). In the L6 myotubes, the Solidago virgaurea methanolic extract remarkably enhanced the glucose uptake via the upregulation of glucose transporter type 4 (GLUT4). The extract also significantly downregulated the expression of PTP1B. In the streptozotocin-nicotinamide induced diabetic mice, the daily intraperitoneal injection of 100 mg/kg Solidago virgaurea methanolic extract for 24 days, substantially lowered the postprandial blood glucose level with no obvious toxicity. The extract's anti-hyperglycemic effect was comparable to that of the glibenclamide treatment.

Conclusion

Our findings suggested that the Solidago virgaurea extract might have great potential in the prevention and treatment of diabetes.

Evaluation and molecular modelling of bis-Schiff base derivatives as potential leads for management of diabetes mellitus

Developing a medication to cure and manage diabetes mellitus complications is of interest in medicinal chemistry. Toward this end, six bis-biphenyl-salicylaldehyde Schiff base derivatives have been evaluated for their α-glucosidase inhibition, antiglycation and anti-inflammation potentials. Four compounds (compounds 2-5) showed an excellent α-glucosidase inhibitory effect superior to that produced by acarbose. Additionally, the docking study revealed that these compounds are anchored within the binding pocket of α-glucosidase via hydrogen bonding, π-stacking and hydrophobic interactions, comparable to a high number of hydrogen bonding involved in anchoring acarbose. Interestingly, all tested compounds showed varying degrees of antiglycation activity with superior activity for two of them (compound 1 and compound 6) compared to the standard rutin. Moreover, the results indicated an outstanding anti-inflammatory activity for two compounds (compounds 1 and 6) compared to ibuprofen.

Glycation-induced age-related illnesses, antiglycation and drug delivery strategies

OBJECTIVES

Ageing is a major cause of multiple age-related diseases. Several mechanisms have been reported to contribute to these abnormalities including glycation, oxidative stress, the polyol pathway and osmotic stress. Glycation, unlike glycosylation, is an irregular biochemical reaction to the formation of active advanced glycation end-products (AGEs), which are considered to be one of the causes of these chronic diseases. This study provides a recent and comprehensive review on the possible causes, mechanisms, types, analytical techniques, diseases and treatments of the toxic glycation end products.

KEY FINDINGS

Several mechanisms have been found to play a role in generating hyperglycaemia-induced oxidative stress including an increase in the levels of reactive oxygen species (ROS), increase in the levels of AGEs, binding of AGEs and their receptors (RAGE) and the polyol pathway and thus have been investigated as promising novel targets.

SUMMARY

This review focuses on the key mechanisms attributed to cumulative increases of glycation and pathological RAGE expression as a significant cause of multiple age-related diseases, and reporting on different aspects of antiglycation therapy as a novel approach to managing/treating age-related diseases. Additionally, historical, current and possible future antiglycation approaches will be presented focussing on novel drug delivery methods.

Novel Organic Salts Based on Mefloquine: Synthesis, Solubility, Permeability, and In Vitro Activity against Mycobacterium tuberculosis

The development of novel pharmaceutical tools to efficiently tackle tuberculosis is the order of the day due to the rapid development of resistant strains of Mycobacterium tuberculosis. Herein, we report novel potential formulations of a repurposed drug, the antimalarial mefloquine (MFL), which was combined with organic anions as chemical adjuvants. Eight mefloquine organic salts were obtained by ion metathesis reaction between mefloquine hydrochloride ([MFLH][Cl]) and several organic acid sodium salts in high yields. One of the salts, mefloquine mesylate ([MFLH][MsO]), presented increased water solubility in comparison with [MFLH][Cl]. Moreover, all salts with the exception of mefloquine docusate ([MFLH][AOT]) showed improved permeability and diffusion through synthetic membranes. Finally, in vitro activity studies against Mycobacterium tuberculosis revealed that these ionic formulations exhibited up to 1.5-times lower MIC values when compared with [MFLH][Cl], particularly mefloquine camphorsulfonates ([MFLH][(1R)-CSA], [MFLH][(1S)-CSA]) and mefloquine HEPES ([MFLH][HEPES]).

Systematic optimization of host-directed therapeutic targets and preclinical validation of repositioned antiviral drugs

Inhibition of host protein functions using established drugs produces a promising antiviral effect with excellent safety profiles, decreased incidence of resistant variants and favorable balance of costs and risks. Genomic methods have produced a large number of robust host factors, providing candidates for identification of antiviral drug targets. However, there is a lack of global perspectives and systematic prioritization of known virus-targeted host proteins (VTHPs) and drug targets. There is also a need for host-directed repositioned antivirals. Here, we integrated 6140 VTHPs and grouped viral infection modes from a new perspective of enriched pathways of VTHPs. Clarifying the superiority of nonessential membrane and hub VTHPs as potential ideal targets for repositioned antivirals, we proposed 543 candidate VTHPs. We then presented a large-scale drug-virus network (DVN) based on matching these VTHPs and drug targets. We predicted possible indications for 703 approved drugs against 35 viruses and explored their potential as broad-spectrum antivirals. In vitro and in vivo tests validated the efficacy of bosutinib, maraviroc and dextromethorphan against human herpesvirus 1 (HHV-1), hepatitis B virus (HBV) and influenza A virus (IAV). Their drug synergy with clinically used antivirals was evaluated and confirmed. The results proved that low-dose dextromethorphan is better than high-dose in both single and combined treatments. This study provides a comprehensive landscape and optimization strategy for druggable VTHPs, constructing an innovative and potent pipeline to discover novel antiviral host proteins and repositioned drugs, which may facilitate their delivery to clinical application in translational medicine to combat fatal and spreading viral infections.

Anti-glycation properties of Illicium verum Hook. f. fruit in-vitro and in a diabetic rat model

Background

Chronic hyperglycemic triggers the non-enzymatic glycation of biomolecules, resulting in the production of advanced glycation endproducts, that lead to several micro- and macrovascular complications. Therefore, the discovery of new, effective, and safe anti-glycation agents is an important need. One of the best choices for the management of diabetes is to use complementary and alternative medicinal therapies. Therefore, the present study was designed to evaluate the anti-glycation activity of ethanolic extract of Illicium verum Hook. f. (Star anise, a frequently used spice and medicinally important herb).

Methods

The anti-glycation activity of ethanolic extract of Illicium verum Hook. f. was determined by using both in-vitro and in-vivo assays. HSA-fructose glycation model was employed to assess the in-vitro inhibition of protein glycation, additionally cross-linked AGEs (formed by incubating lysozyme with fructose) were assessed by SDS polyacrylamide gel electrophoresis. Dual inhibitory mechanisms, i.e., antioxidant and metal chelating activities, were also evaluated by using DPPH, ABTS, and Fe (II)-chelation assays. Acute toxicity of I. verum extract was also performed (by administrating different doses i.e. 2,000, 1,500, 1,000, and 500 mg/kg of body weight). Finally, in-vivo anti-glycation potential was evaluated by 7 weeks of administration of I. verum extract in streptozotocin-induced diabetic rats.

Results

In HSA-fructose glycation model, extract of I. verum showed a good inhibitory activity with IC₅₀ value of 0.11±0.001 mg/mL, as compared to the standard inhibitor, rutin (IC₅₀ = 0.02±0.01 mg/mL). Extract of I. verum showed inhibitory activity in DPPH, and ABTS radical scavenging assays with IC₅₀ values of 130±1.0, and 57±2.0 μg/mL, respectively, while it was found to be inactive in the Fe⁺²-chelation assay. The extract was found to be non-toxic, and reduce the elevated blood glucose, urea, lipid, liver function parameters, and renal AGEs levels in streptozotocin-induced diabetic rats.

Conclusions

These results suggest that I. verum supplementation might help to reduce the burden of AGEs, and may have potential in preventing diabetes-associated complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03550-z.

Drug repurposing for Chagas disease: In vitro assessment of nimesulide against Trypanosoma cruzi and insights on its mechanisms of action

Chagas disease is a neglected illness caused by Trypanosoma cruzi and its treatment is done only with two drugs, nifurtimox and benznidazole. However, both drugs are ineffective in the chronic phase, in addition to causing serious side effects. This context of therapeutic limitation justifies the continuous research for alternative drugs. Here, we study the in vitro trypanocidal effects of the non-steroidal anti-inflammatory drug nimesulide, a molecule that has in its chemical structure a toxicophoric nitroaromatic group (NO2). The set of results obtained in this work highlights the potential for repurposing nimesulide in the treatment of this disease that affects millions of people around the world.

New nimesulide derivatives with amide/sulfonamide moieties: Selective COX-2 inhibition and antitumor effects

Seventeen new amide/sulfonamide containing nimesulide derivatives were synthesized and characterized by several spectroscopic techniques and primarily investigated for their inhibitory potential on COX enzymes and other pro-inflammatory factors. Experimental analyses showed that among seventeen compounds, N8 and N10 have remarkable potency and selectivity for the COX-2 enzyme over COX-1 at very low doses as compared to nimesulide. Moreover, both N8 and N10 selectively reduced the Lipopolysaccharide (LPS)-stimulated COX-2 mRNA expression level while the COX-1 level remained stable. Both PGE₂ release and nitric oxide production in macrophage cells were significantly suppressed by the N8 and N10 treatment groups. In silico ADME/Tox, molecular docking and molecular dynamics (MD) simulations were also conducted. Additionally, all compounds were also screened in a panel of cancer cell lines for their antiproliferative properties by MTT and SRB assays. Compound N17 exhibited a considerable antiproliferative effect on the colon (IC₅₀: 9.24 μM) and breast (IC₅₀: 11.35 μM) cancer cell lines. N17 exposure for 48 h decreased expression of anti-apoptotic protein BCL-2 and increased the expression of apoptogenic BAX. Besides, the BAX/BCL-2 ratio was increased with visible ultrastructural changes and apoptotic bodies under scanning electron microscopy. In order to investigate the structural and dynamical properties of selected hits on the target structures, multiscale molecular modeling studies are also conducted. Our combined in silico and in vitro results suggest that N8 and N10 could be further developed as potential nonsteroidal anti-inflammatory drugs (NSAIDs), while cytotoxic N17 might be studied as a potential lead compound that could be developed as an anticancer agent.

LINCS gene expression signature analysis revealed bosutinib as a radiosensitizer of breast cancer cells by targeting eIF4G1

Radioresistance is the predominant cause for radiotherapy failure and disease progression, resulting in increased breast cancer‑associated mortality. Using gene expression signature analysis of the Library of Integrated Network‑Based Cellular Signatures (LINCS) and Gene Expression Omnibus (GEO), the aim of the present study was to systematically identify potential candidate radiosensitizers from known drugs. The similarity of integrated gene expression signatures between irradiated eukaryotic translation initiation factor 4 γ 1 (eIF4G1)‑silenced breast cancer cells and known drugs was measured using enrichment scores (ES). Drugs with positive ES were selected as potential radiosensitizers. The radiosensitizing effects of the candidate drugs were analyzed in breast cancer cell lines (MCF‑7, MX‑1 and MDA‑MB‑231) using CCK‑8 and colony formation assays following exposure to ionizing radiation. Cell apoptosis was measured using flow cytometry. The expression levels of eIF4G1 and DNA damage response (DDR) proteins were analyzed by western blotting. Bosutinib was identified as a promising radiosensitizer, as its administration markedly reduced the dosage required both for the drug and for ionizing radiation, which may be associated with fewer treatment‑associated adverse reactions. Moreover, combined treatment of ionizing radiation and bosutinib significantly increased cell killing in all three cell lines, compared with ionizing radiation or bosutinib alone. Among the three cell lines, MX‑1 cells were identified as the most sensitive to both ionizing radiation and bosutinib. Bosutinib markedly downregulated the expression of eIF4G1 in a dose‑dependent manner and also reduced the expression of DDR proteins (including ATM, XRCC4, ATRIP, and GADD45A). Moreover, eIF4G1 was identified as a key target of bosutinib that may regulate DNA damage induced by ionizing radiation. Thus, bosutinib may serve as a potential candidate radiosensitizer for breast cancer therapy.

Inhibitory Effect of Multimodal Nanoassemblies against Glycative and Oxidative Stress in Cancer and Glycation Animal Models

In recent years, there has been a progress in the study of glycation reaction which is one the possible reason for multiple metabolic disorders. Glycation is a nonenzymatic reaction between nucleic acids, lipids, and proteins resulting into the formation of early glycation products that may further lead to the accumulation of advanced glycation end products (AGEs). The precipitation of AGEs in various cells, tissues, and organs is one of the factors for the initiation and progression of various metabolic derangements including the cancer. The AGE interaction with its receptor "RAGE" activates the inflammatory pathway; yet, the downregulation of RAGE and its role in these pathways are not clear. We explore the effect of anticancer novel nanoassemblies on AGEs to determine its role in the regulation of the expression of RAGE, NFƙB, TNF-α, and IFN-γ. This paper is based on the in vivo and in vitro study in glycation and lung cancer model systems. Upon the treatment of nanoassemblies in both the model systems, we observed a protective effect of nanoassemblies over the inhibition of glycative and oxidative stress via mRNA expression analysis. The mRNA expression results corroborated with the reactive oxygen species (ROS), carboxy-methyl-lysine (CML), and fluorescence studies. In this study, we found that the presence of common factors for glycation and lung cancer is oxidative and glycative stress. This oxidation and glycation might be responsible for the initiation of inflammation which may further lead to uncontrolled growth of cells leading to cancer. This can be a strong association between lung cancer and glycation reaction. The intervention of the anticancer and antiglycation effects of multimodal nanoassemblies throughout the study promises a new pathway for cancer research.

Vitexin Inhibits Protein Glycation through Structural Protection, Methylglyoxal Trapping, and Alteration of Glycation Site

In this study, the antiglycation potential and mechanisms of vitexin were explored in vitro by multispectroscopy, microscope imaging, high-resolution mass spectrometry, and computational simulations. Vitexin was found to show much stronger antiglycation effects than aminoguanidine. The inhibition against the fluorescent advanced glycation end products was more than 80% at 500 μM vitexin in both bovine serum albumin (BSA)-fructose and BSA-methylglyoxal (MGO) models. Treated with 100 and 200 μM vitexin for 24 h, the contents of MGO were reduced to 4.97 and 0.2%, respectively, and only one vitexin-mono-MGO adduct was formed. LC-Orbitrap-MS/MS analysis showed that vitexin altered the glycated sites and reduced the glycation degree of some sites. The mechanisms of vitexin against protein glycation were mainly through BSA structural protection, MGO trapping, and alteration of glycation sites induced by interaction with BSA. These findings provided valuable information about the functional development of vitexin as a potential antiglycation agent.

Mefloquine synergism with anti-tuberculosis drugs and correlation to membrane effects: Biologic, spectroscopic and molecular dynamics simulations studies

Studies displaying the combination of mefloquine (MFL) with anti-tuberculosis (TB) substances are limited in the literature. In this work, the effect of MFL-association with two first-line anti-TB drugs and six fluoroquinolones was evaluated against Mycobacterium tuberculosis drug resistant strains. MFL showed synergistic interaction with isoniazid, pyrazinamide, and several fluoroquinolones, reaching fractional inhibitory concentration indexes (FICIs) ranging from 0.03 to 0.5. In order to better understand the observed results, two approaches have been explored: (i) spectroscopic responses attributed to the effect of MFL on physicochemical properties related to a liposomal membrane model composed by soybean asolectin; (ii) molecular dynamics (MD) simulation data regarding MFL interaction with a membrane model based on PIM₂, a lipid constituent of the mycobacterial cell wall. FTIR and NMR data showed that MFL affects expressively the region between the phosphate and the first methylene groups of soybean asolectin membranes, disordering these regions. MD simulations results detected high MFL density in the glycolipid interface and showed that the drug increases the membrane lateral diffusion, enhancing its permeability. The obtained results suggest that synergistic activities related to MFL are attributed to its effect of lipid disorder and membrane permeability enhancement.

'BhAVI-23'-A spice-herb based dietary infusion possessing in-vitro anti-viral potential

Background

Viruses cause many life threatening human diseases. Recently, COVID-19 pandemic has challenged the health care systems worldwide. As a disease preventive approach and to bring relief to the severity of the symptoms, a infusion termed as Bhabha Anti-Viral Infusion-23 (‘BhAVI-23’) was conceptualized and formulated which comprised of 23 selected spices and herbals.

Objective

The present study was conducted to assess the in vitro antiviral potential of the formulation, BhaAVI-23.

Material and methods

The in-vitro anti-viral potential of BhAVI-23 was assessed through inhibition of HIV1 reverse transcriptase (RT) as well as through a novel P1 (virulent) bacteriphage based screening assay system. Anti-diabetic potential was assessed by non-enzymatic glycosylation of haemoglobin and the bioactive volatile components were detected through headspace gas chromatography followed by molecular docking analysis.

Results

The infusion displayed prominent anti-viral activity as evident from significant (57%) inhibition of the HIV1-RT as well as through reduction in the infectivity of P1 (virulent) bacteriophage. The infusion also exerted profound protection (∼64%) to non-enzymatic glycosylation of haemoglobin. Headspace gas chromatography and mass spectrometric analysis confirmed the presence of at least 47 major compounds. Docking analysis indicated possible interaction of α-pinene and eugenol with SARS-CoV spike protein.

Conclusion

This ‘BhAVI-23’ infusion displayed prominent in-vitro anti-viral and anti-diabetic potential in different model systems. These attributes have relevance as diabetic patients are more prone to COVID-19 morbidity. ‘BhAVI-23’ opens the avenue for its potential inclusion as a supportive health care system upon due regulatory approval during the current pandemic.

An Electrochemical Chip to Monitor In Vitro Glycation of Proteins and Screening of Antiglycation Potential of Drugs

Hyperglycemia and the production of advanced glycation end products (AGEs) are the primary factors for the development of chronic complications in diabetes. The level of protein glycation is proportional to the glucose concentration and represents mean glycemia. In this study, we present an electrochemical chip-based method for in vitro glycation monitoring and the efficacy evaluation of an antiglycation compound. An electrochemical chip consisting of five microchambers and embedded microelectrodes was designed for parallel measurements of capacitance signals from multiple solutions at different concentrations. The feasibility of glycation monitoring was then investigated by measuring the capacitance signal at 0.13 MHz with bovine serum albumin and gelatin samples in the presence of various glucose concentrations over 28 days. A significant change in the capacitance due to protein glycation was observed through measurements conducted within 30 s and 21 days of incubation. Finally, we demonstrated that the chip-based capacitance measurement can be utilized for the selection of an antiglycation compound by supplementing the protein solution and hyperglycemic concentration of glucose with an inhibitory concentration of the standard antiglycation agent aspirin. The lack of a significant change in the capacitance over 28 days proved that aspirin is capable of inhibiting protein glycation. Thus, a strong relationship exists between glycation and capacitance, suggesting the application of an electrochemical chip for evaluating glycation and novel antiglycation agents.

Annona cherimola Miller Fruit as a Promising Candidate against Diabetic Complications: An In Vitro Study and Preliminary Clinical Results

Diabetes is a chronic metabolic disease with a strong social impact worldwide. Under chronic hyperglycemia, protein glycation strongly contributes to diabetes-related complications onset. Anti-glycation agents and inhibitors of α-glucosidase are often therapeutically used to control postprandial glycemia in order to prevent development of long-term diabetic complications. Given drug resistance and adverse effects of conventional antidiabetic therapies, the discovery of new effective and non-toxic naturally occurring compounds is needed to prevent and/or to manage life-threatening diabetic complications. Annona cherimola Miller fruit has been used in Mexican traditional medicine as natural remedy against diabetes. In this work, the in vitro anti-glycation and anti-α-glucosidase roles of Annona cherimola Miller pulp extract (CE) were investigated. Moreover, healthy and diabetic subjects were enrolled in a cross-over design intervention study aimed at investigating the effects of pulp intake on postprandial glycemia. This work shows that CE was able to inhibit albumin glycation in vitro and to inhibit α-glucosidase enzyme. Furthermore, the pulp intake did not contribute to an increase in postprandial glycemia, making it a suitable source of health-promoting phytonutrients and a potential functional food in diabetics and pre-diabetics diet.

In vitro anti-glycation activity of the marine plant Posidonia oceanica (L.) Delile

ETHNOPHARMACOLOGICAL RELEVANCE

The marine plant Posidonia oceanica (L.) Delile is traditionally used by villagers of the west coast of Anatolia as a remedy for diabetes and hypertension.

AIM OF THE STUDY

The aim of this study was to explore the role of the P. oceanica hydroalcoholic leaves extract (POE) against human serum albumin glycation.

MATERIAL AND METHODS

Advanced glycation end products (AGEs) were obtained with the albumin-glucose in vitro assay. The AGEs intrinsic fluorescence intensity and the electrophoretic migration under native conditions allowed us to verify the effective glycation of albumin. The presence of POE during glycation process was intended to evaluate its anti-glycation role.

RESULTS

POE exhibited a strong in vitro anti-glycation ability which occurred independently from its known antioxidant property.

CONCLUSIONS

Overall, the antidiabetic, antioxidant, anti-inflammatory and anti-glycation properties of POE could be exploited as an effective tool against diabetes and related complications.

Antioxidant and antiglycation activities of traditional plants and identification of bioactive compounds from extracts of Hordeum vulgare by LC-MS and GC-MS

Glycation has been involved in Schiff base reaction lead to hyperglycemia at cellular level. The current study aimed to identify the bioactive compounds from selected folkloric plants for their antiglycation and antioxidant potential. Methanol extracts demonstrated the highest activities, therefore, it was further fractionated using n-hexane, dichloromethane, ethyl acetate, and methanol solvents to isolate the nonpolar compounds from the Hordeum vulgare. Moreover, n-hexane and dichloromethane fractions of H. vulgare demonstrated the best antioxidant (61.58% and 62.89%) and antiglycation activities (72.52% and 61.52%) at 2 mg/ml, respectively. Analytical techniques of LC-MS and GC-MS were employed for identification of bioactive compounds; Biochanin A in dichloromethane (DCM) and Vitamin E in n-hexane fractions. There was a strong correlation between antioxidant and antiglycation activities (r = 0.97 and r = 0.96) of DCM & n-hexane fractions of H. vulgare. Findings of this study established the role of Biochanin A and Vit E from H. vulgare as potent antiglycation agents. PRACTICAL APPLICATIONS: The results of this study confirmed the potential role of Black Barley has involved in the inhibition of protein glycation, which can be the potential treatment to reduce the complications of Diabetic Patients. The Black Barley has a rich source of identified compounds Biochanin A and Vitamin E. We can use this plant as a staple food in curing the severity of diabetes. The other practical approach is to use this plant as an ingredient of different food products. The extraction of identified bioactive compounds from the plant will be a good and cheap source of the treatment.

Medicinal Thiols: Current Status and New Perspectives

The thiol (-SH) functional group is found in a number of drug compounds and confers a unique combination of useful properties. Thiol-containing drugs can reduce radicals and other toxic electrophiles, restore cellular thiol pools, and form stable complexes with heavy metals such as lead, arsenic, and copper. Thus, thiols can treat a variety of conditions by serving as radical scavengers, GSH prodrugs, or metal chelators. Many of the compounds discussed here have been in use for decades, yet continued exploration of their properties has yielded new understanding in recent years, which can be used to optimize their clinical application and provide insights into the development of new treatments. The purpose of this narrative review is to highlight the biochemistry of currently used thiol drugs within the context of developments reported in the last five years. More specifically, this review focuses on thiol drugs that represent the standard of care for their associated conditions, including N-acetylcysteine, 2,3-meso-dimercaptosuccinic acid, British anti-Lewisite, D-penicillamine, amifostine, and others. Reports of novel dosing regimens, delivery strategies, and clinical applications for these compounds were examined with an eye toward emerging approaches to address a wide range of medical conditions in the future.

Protein Glycation: An Old Villain is Shedding Secrets

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The glycation of proteins is non-physiological post-translational incorporation of carbohydrates onto the free amines or guanidines of proteins and some lipids. Although the existence of glycated proteins has been known for forty years, a full understanding of their pathogenic nature has been slow in accruing. In recent years, however, glycation has gained widespread acceptance as a contributing factor in numerous metabolic, autoimmune, and neurological disorders, tying together several confounding aspects of disease etiology. From diabetes, arthritis, and lupus, to multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer’s, and Parkinson’s diseases, an emerging glycation/inflammation paradigm now offers significant new insight into a physiologically important toxicological phenomenon. It exposes novel drug targets and treatment options, and may even lay foundations for long-awaited breakthroughs.

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This ‘current frontier’ article briefly profiles current knowledge regarding the underlying causes of glycation, the structural biology implications of such modifications, and their pathological consequences. Although several emerging therapeutic strategies for addressing glycation pathologies are introduced, the primary purpose of this mini-review is to raise awareness of the challenges and opportunities inherent in this emerging new medicinal target area.

In silico study of chikungunya polymerase, a potential target for inhibitors

Non-structural protein 4 (nsP4) polymerase of chikungunya virus (CHIKV) has a crucial role in genome replication and hence could act as a promising target for novel therapeutics. Though, nsP4 is important in viral life cycle, but it is less explored as therapeutic target. The catalytic core of nsP4 Polymerase includes conserved GDD motif which is present not only across different CHIKV strains but also across other Alphaviruses. This emphasizes the uniqueness and importance of this motif in the functioning of nsP4 polymerase and hence, we focused on GDD motif for docking of drug molecules. Herein, a model of nsP4 polymerase was developed using Swiss Model, validated by Ramachandran plot and molecular dynamic simulation. Molecular docking was performed using LeadIT FlexX flexible docking module with FDA approved drug molecule library. On the basis of flexX score, top 5 leads with flexX scores - 33.7588, - 30.2555, - 29.6043, - 28.916 and - 28.5042 were selected. The bonding pattern of these leads were analysed in discovery studio and were further screened on the basis of molecular dynamic simulation studies. Simulation analysis revealed that only the top lead, Mitoxantrone Hydrochloride which is an anticancer drug and is currently indicated in leukemias and lymphomas interacted favourably and stably with nsP4. Our findings suggest that Mitoxantrone Hydrochloride can be a potential novel inhibitor of CHIKV polymerase and should be further validated by in vitro assays.

The relatively selective cyclooxygenase-2 inhibitor nimesulide: What's going on?

Nimesulide is a relatively selective cyclooxygenase (COX)-2 inhibitor, non-steroidal anti-inflammatory drug; it has been discovered in 1971 and firstly commercialized in Italy in 1985. There is much evidence that the pharmacological profile of nimesulide is peculiar and not shared with the other COX-2 selective inhibitors, suggesting that other molecular mechanisms besides inhibition of COX-2 derived prostaglandins are involved. Similarly, experimental data suggest that the gastrointestinal safety of nimesulide cannot be ascribed only to a COX-1 sparing effect. On the inflammatory process, the efficacy of nimesulide is dependent upon a wide spectrum of actions, due to the combination of effects on immune and non-immune cells. Early data demonstrated a central role for cyclic AMP (cAMP) in the anti-inflammatory effect of nimesulide; more recently, we have shown the involvement of the pathway ecto-5'-nucleotidase/adenosine A_2A receptor. To date, the molecular mechanism(s) that confers uniqueness to nimesulide have not yet been defined. To go inside the mechanism of action of an existing drug, such as nimesulide, would be helpful to refine its therapeutic use but also to identify new targets for novel therapeutic anti-inflammatory approach. Here, we focus on accumulated evidence for a peculiar pharmacological profile of nimesulide.

Phenolics from Eugenia jambolana seeds with advanced glycation endproduct formation and alpha-glucosidase inhibitory activities

Published data suggest that dietary-derived phenolics exert beneficial effects against hyperglycemia-mediated diseases, such as diabetes, through inhibiting the formation of advanced glycation endproducts (AGEs) and carbohydrate hydrolyzing enzyme activities. In the course of our investigation on the edible berry, Eugenia jambolana (known as Jamun), 21 phenolics (1-21) were isolated and identified from its seeds. Among these, one compound (1) is new and eleven compounds (3, 6, 9-13, 17, and 19-21) are being reported from E. jambolana for the first time. The anti-AGE activities of thirteen pure isolates (2-7, 9-12, 14, 15, and 20) were either comparable or superior to the synthetic anti-glycation agent, aminoguanidine, at three test concentrations (20, 50, and 100 μM) in the BSA-fructose assay. Most of these phenolics with anti-AGE activity exhibited potent free radical scavenging activity in the DPPH assay, and attenuated intracellular levels of LPS-induced reactive oxygen species in RAW264.7 macrophage. In addition, compounds 2-6, and 14 showed superior α-glucosidase inhibitory activity (IC50 = 5.0-21.2 μM) compared to the clinical α-glucosidase inhibitor, acarbose (IC50 = 289.9 μM). This is the first report of the anti-AGE effects of compounds 2-6 and 9-12, and α-glucosidase inhibitory activities of compounds 3-6, 9, 11 and 14. The current study supports the role of phenolics in the antidiabetic properties attributed to this edible berry, and warrants further animal studies to evaluate their potential as dietary agents for the prevention and/or therapy of hyperglycemia-mediated diseases.