Synthesis of Pyrazolo[3,4-b]pyridine Derivatives and Their In-Vitro and In-Silico Antidiabetic Activities.

In the current study, new pyrazolo[3,4-b]pyridine esters, hydrazides, and Schiff bases have been synthesized starting from 3-methyl-1-phenyl-1H-pyrazol-5-amine. The first step involved solvent-free synthesis of pyrazolo[3,4-b]pyridine-6-carboxylate derivatives (2a-d) with 55%-70% yield in the minimum time frame compared with the conventional refluxing method, which was followed by the synthesis of corresponding hydrazides (3a-d) and hydrazones (4a-e). The structures of the synthesized derivatives were confirmed using element analysis, FT-IR, 1H NMR, 13C NMR, and LC-MS techniques. Synthesized hydrazides (3a-d) and hydrazones (4a-e) were also tested for their in-vitro antidiabetic activity and found that all the compounds exhibited significant antidiabetic activity, while 3c (IC50 = 9.6 ± 0.5 µM) among the hydrazides and 4c (IC50 = 13.9 ± 0.7 µM) among the hydrazones were found to be more active in comparison to other synthesized derivatives. These in-vitro results were further validated via docking studies against the α-amylase enzyme using the reference drug acarbose (200.1 ± 10.0 µM). The results were greatly in agreement with their in-vitro studies and these derivatives can be encouraging candidates for further in-vivo studies in mice models.

Synthesis, biochemical screening and in-silico investigations of arylsulfonamides bearing linear and cyclic tails.

A small series of arylsulfonamide derivatives was designed and synthesized to study linear and cyclic inhibitors targeting human Carbonic Anhydrases (hCAs EC 4.2.1.1) as essential enzymes regulating (patho)-physiological processes. Particularly, the synthesis of these ten compounds was inspired to the well-known arylsulfonamides having flexible or constrained linkers able to maintain the two crucial moieties, anchoring zinc group and hydrophobic tail, in the optimized orientation within CA cavities of tumor-expressed isoforms hCA IX and hCA XII. The synthesized imine derivatives and related cyclic 1,3-thiazin-4-ones were screened in a stopped-flow carbon dioxide hydrase assay and proved to be effective inhibitors against hCA IX and hCA XII isoforms with Ki values ranging of 3.7-215.7 nM and 5.7-415.0 nM, respectively. Molecular docking studies of both series of arylsulfonamides were conducted to propose their binding mode within hCA IX and hCA XII active sites thus highlighting their distinct ability to occupy the two catalytic cavities. Moreover, the 4-[(3-cyanophenyl)methylidene]aminobenzene-1-sulfonamide 7 proved to reduce the cell viability of breast carcinoma (MCF-7) and colon rectal carcinoma (HCT-116) human cell lines under the fixed doses of 10 µM. These results encouraged us to continue our efforts in developing potent and efficient arylsulfonamides targeting hCA IX and hCA XII isoforms.

Synthesis, molecular docking and biological evaluation of 1,2,4-oxadiazole based novel non-steroidal derivatives against prostate cancer.

Prostate cancer is one of the most prevalent cancers in men leading to second most death causing cancer in men. Despite the availability of multiple treatment still the prevalence is high for prostate cancer. Steroidal antagonists associated with poor bioavailability, side effects while non-steroidal antagonists show serious side effects like gynecomastia. Therefore, there is a need of potential candidate for the treatment of prostate cancer with better bioavailability, good therapeutic effect and minimal side effects. In the same context, we have designed the series, SP1-SP25 based 3-phenyl-5-styryl-1,2,4-oxadiazole as the core structure. We successfully synthesized all 25 molecules in this series and characterized them using 1H, 13C NMR, and mass spectroscopy. Subsequently, we conducted MTT assays using PC-3 cells and observed that all the compounds exhibited a dose-dependent decrease in cell viability. Notably, compounds SP04, SP16, and SP19 demonstrated a significant decrease in cell viability and exhibited potent activity compared to the other synthesized molecules and standard drug bicalutamide. Among them, SP04 emerged as the one of the most potent compounds with an IC50 value of 238.13 nM and an 89.99 % inhibition of PC-3 cells, compared to synthesized molecules and standard drug bicalutamide. Furthermore, we conducted ROS assays and androgen receptor inhibition assays using the potent compound SP04 and bicalutamide. The results indicated that SP04 increased ROS production and decreased androgen receptor expression dose-dependent manner. Additionally, we conducted a docking study to analyse the interaction patterns within the active site of the androgen receptor. ADMET analysis revealed that all the compounds exhibited favorable physicochemical properties and manageable toxicity profiles.

Insights into nucleoside hydrolase from Leishmania donovani inhibition: A new bioaffinity chromatography-based screening assay and docking studies.

Leishmaniasis, a group of neglected infectious diseases, encompasses a serious health concern, particularly with visceral leishmaniasis exhibiting potentially fatal outcomes. Nucleoside hydrolase (NH) has a fundamental role in the purine salvage pathway, crucial for Leishmania donovani survival, and presents a promising target for developing new drugs for visceral leishmaniasis treatment. In this study, LdNH was immobilized into fused silica capillaries, resulting in immobilized enzyme reactors (IMERs). The LdNH-IMER activity was monitored on-flow in a multidimensional liquid chromatography system, with the IMER in the first dimension. A C18 analytical column in the second dimension furnished the rapid separation of the substrate (inosine) and product (hypoxanthine), enabling direct enzyme activity monitoring through product quantification. LdNH-IMER exhibited high stability and was characterized by determining the Michaelis-Menten constant. A known inhibitor (1-(ß-d-Ribofuranosyl)-4-quinolone derivative) was used as a model to validate the established method in inhibitor recognition. Screening of three additional derivatives of 1-(ß-d-Ribofuranosyl)-4-quinolone led to the discovery of novel inhibitors, with compound 2a exhibiting superior inhibitory activity (Ki = 23.37 ± 3.64 µmol/L) compared to the employed model inhibitor. Docking and Molecular Dynamics studies provided crucial insights into inhibitor interactions at the enzyme active site, offering valuable information for developing new LdNH inhibitors. Therefore, this study presents a novel screening assay and contributes to the development of potent LdNH inhibitors.

Synthesis and anti-ureolitic activity of Biginelli adducts derived from formylphenyl boronic acids.

Urease is a metalloenzyme that contains two Ni(II) ions in its active site and catalyzes the hydrolysis of urea into ammonia and carbon dioxide. The development of effective urease inhibitors is crucial not only for mitigating nitrogen losses in agriculture but also for offering an alternative treatment against infections caused by resistant pathogens that utilize urease as a virulence factor. This study focuses on synthesizing and investigating the urease inhibition potential of Biginelli Adducts bearing a boric acid group. An unsubstituted or hydroxy-substituted boronic group in the Biginelli adducts structure enhances the urease inhibitory activity. Biophysical and kinetics studies revealed that the best Biginelli adduct (4e; IC50 = 132 ± 12 µmol/L) is a mixed inhibitor with higher affinity to the urease active site over an allosteric one. Docking studies confirm the interactions of 4e with residues essential for urease activity and demonstrate its potential to coordinate with the nickel atoms through the oxygen atoms of carbonyl or boronic acid groups. Overall, the Biginelli adduct 4e shows great potential as an additive for developing enhanced efficiency fertilizers and/or for medical applications.

New Smoothened ligands based on the purine scaffold as potential agents for treating pancreatic cancer.

Aberrant activation of the Hedgehog (Hh) signalling pathway has been associated with the development and progression of pancreatic cancer. For this reason, blockade of Hh pathway by inhibitors targeting the G protein-coupled receptor Smoothened (SMO) has been considered as a therapeutic target for the treatment of this cancer. In our previous work, we obtained a new SMO ligand based on a purine scaffold (compound I), which showed interesting antitumor activity in several cancer cell lines. In this work, we report the design and synthesis of 17 new purine derivatives, some of which showed high cytotoxic effect on Mia-PaCa-2 (Hh-dependent pancreatic cancer cell lines) and low toxicity on non-neoplastic HEK-293 cells compared with gemcitabine, such as 8f, 8g and 8h (IC50 = 4.56, 4.11 and 3.08 µM, respectively). Two of these purines also showed their ability to bind to SMO through NanoBRET assays (pKi = 5.17 for 8f and 5.01 for 8h), with higher affinities to compound I (pKi = 1.51). In addition, docking studies provided insight the purine substitution pattern is related to the affinity on SMO. Finally, studies of Hh inhibition for selected purines, using a transcriptional functional assay based on luciferase activity in NIH3T3 Shh-Light II cells, demonstrated that 8g reduced GLI activity with a IC50 = 6.4 µM as well as diminished the expression of Hh target genes in two specific Hh-dependent cell models, Med1 cells and Ptch1-/- mouse embryonic fibroblasts. Therefore, our results provide a platform for the design of SMO ligands that could be potential selective cytotoxic agents for the treatment of pancreatic cancer.

Virtual screening, molecular dynamics simulations, and in vitro validation of EGFR inhibitors as breast cancer therapeutics.

A high abundance of Epidermal Growth Factor Receptor (EGFR) in malignant cells makes them a prospective therapeutic target for basal breast tumors. Although EGFR inhibitors are in development as anticancer therapeutics, there exists limitations due to the dose-limiting cytotoxicity that limits their clinical utilization, thereby necessitating the advancement of effective inhibitors. In the present study, we have developed common pharmacophore hypotheses using 30 known EGFR inhibitors. The best pharmacophore hypothesis DHRRR_1 was utilized for virtual screening (VS) of the Phase database containing 4.3 × 106 fully prepared compounds. The top 1000 hits were further subjected to ADME filtration followed by structure-based VS and Molecular Dynamics (MD) simulation investigations. Based on pharmacophore hypothesis matching, XP glide score, interactions between ligands and active site residues, ADME properties, and MD simulations, the five best hits (SN-01 through SN-05) were preferred for in-vitro cytotoxicity studies. All the molecules except SN-02 exhibited cytotoxicity in Triple Negative Breast Cancer (TNBC) cells. These potential EGFR inhibitors effectively downregulated the EGF-induced proliferation, migration, in-vitro tumorigenic capability, and EGFR activation (pEGFR) in the TNBCs. Additionally, in combination with doxorubicin, the identified EGFR inhibitors significantly decreased the EGF-induced proliferation. SN-04, and SN-05 in the presence of a lower concentration of doxorubicin markedly increased the apoptotic markers expression in the TNBCs, an effect which was comparable to a higher concentration of doxorubicin treatment, alone. These observations suggest that both SN-04 and/or SN-05 can improve the efficacy of chemotherapeutic drug, doxorubicin at a lower concentration to avert the higher dose of chemotherapeutic-induced side effects during breast cancer treatment.

Fluoroquinolones tackling antimicrobial resistance: Rational design, mechanistic insights and comparative analysis of norfloxacin vs ciprofloxacin derivatives.

Antimicrobial resistance poses a global health concern and develops a need to discover novel antimicrobial agents or targets to tackle this problem. Fluoroquinolone (FN), a DNA gyrase and topoisomerase IV inhibitor, has helped to conquer antimicrobial resistance as it provides flexibility to researchers to rationally modify its structure to increase potency and efficacy. This review provides insights into the rational modification of FNs, the causes of resistance to FNs, and the mechanism of action of FNs. Herein, we have explored the latest advancements in antimicrobial activities of FN analogues and the effect of various substitutions with a focus on utilizing the FN nucleus to search for novel potential antimicrobial candidates. Moreover, this review also provides a comparative analysis of two widely prescribed FNs that are ciprofloxacin and norfloxacin, explaining their rationale for their design, structure-activity relationships (SAR), causes of resistance, and mechanistic studies. These insights will prove advantageous for new researchers by aiding them in designing novel and effective FN-based compounds to combat antimicrobial resistance.

Pyrazoline Spiro-oxindole tethered 1,2,3-triazole hybrids: Design, synthesis, antimicrobial efficacy and molecular modelling studies.

Inspired from the important applications of spirocyclic compounds in medicinal chemistry, a new series of pyrazoline Spiro-oxindole tethered 1,2,3-triazole hybrids was reported via Cu(I)-catalyzed click reaction from isatin-pyrazoline linked terminal alkynes with in situ derived benzyl azides. Antimicrobial evaluation data showed that all hybrids exhibited promising efficacy towards the tested microbial strains. Antimicrobial screening as well as docking studies suggested that hybrid 6a was found to be most potent towards Aspergillus niger (MIC = 0.0122 µmol/mL) and Escherichia coli (MIC = 0.0061 µmol/mL). Molecular docking studies of 6a within the binding pockets of antibacterial and antifungal targets revealed good interactions with the binding energies of - 144.544 kcal/mol and - 154.364 kcal/mol against 1KZN (E. coli) and 3D3Z (A. niger), respectively. Further, MD simulations were performed to study the stability of the complexes formed at 300 K. Based on the RMSD trajectories, it is evident that 3D3Z-6a complex exhibits minimal deviation, whereas the 1KZN-6a complex displayed little more deviation compared to the protein but, both are in acceptable range. Moreover, 3D3Z-6a and 1KZN-6a showed maximum number of hydrogen bonds at 50 ns and 70 ns, respectively, thereby complementing the stability of these complexes.

Design, synthesis, in vitro, and in silico study of benzothiazole-based compounds as a potent anti-Alzheimer agent.

Alzheimer's disease (AD) is a multifactorial neurological disorder that involves multiple enzymes in the process of developing. Conventional monotherapies provide relief, necessitating alternative multi-targeting approaches to address AD complexity. Therefore, we synthesize N-(benzo[d]thiazol-2-yl) benzamide-based compounds and tested against monoamine oxidases (MAO-A and MAO-B). In the in vitro experimental evaluation of MAO, all the compounds displayed remarkable potency, having IC50 values in the lower micromolar range. The most potent MAO-A inhibitor was (3e) with an IC50 value of 0.92 ± 0.09 µM, whereas, (3d) was the most potent inhibitor of MAO-B with an IC50 value of 0.48 ± 0.04 µM. Moreover, Enzyme kinetics studies revealed that the potent inhibitors of MAO-A and MAO-B showed competitive mode of inhibition. Furthermore, molecular docking studies were also performed to confirm the mode of inhibition and obtain an intuitive picture of potent inhibitors. It also revealed several important interactions, particularly hydrogen bonding interaction. All the newly synthesized compounds showed good ADME pharmacokinetic profile and followed Lipinski rule; these compounds represent promising hits for the development of promising lead compounds for AD treatment.

Evaluation of Anti-Hyperlipidemic Activity of the Seeds Extracts of Ficus carica: In Vitro and In Silico Approaches.

Obesity and hyperlipidemia have become major disorders predominantly causing prevailing cardiovascular diseases and ultimately death. The prolonged use of anti-obesity drugs and statins for reducing obesity and blood lipid levels is leading toward adverse effects of kidneys and muscles, specifically rhabdomyolysis. The objective of this study is to evaluate potential of seeds of Ficus carica against hyperlipidemia. Various extracts and isolated compounds from fig seeds were analyzed and evaluated for their anti-hyperlipidemic potential. Methanol extract and its ethyl acetate fraction showed maximum pancreatic lipase inhibition of 61.93% and 86.45% in comparison to reference drug Orlistat. Four compounds isolated by HPLC-PDA technique were determined as Gallic acid, Catechin, Epicatechin, and Quercetin also showed strong potential to inhibit enzyme pancreatic lipase comparable to Orlistat. These isolated compounds were further analyzed for molecular docking and MM-GBSA studies. Three ligands, namely Quercetin, Epicatechin, and Catechin were found more effective against pancreatic lipase as these possessed docking scores (-9.881, -9.741, -9.410) higher to that of the reference ligand Orlistat (-5.273). The binding free energies of these compounds were -55.03, -56.54, and 60.35 kcal/mol, respectively. The results have shown that Quercetin has the highest binding affinity correlating with the highest inhibition of pancreatic lipase enzyme 1LPB. Hence, it is suggested that seeds of F. carica have promising anti-hyperlipidemic potential and foremost in reducing obesity.

Synthesis, carbonic anhydrase inhibition studies and modelling investigations of phthalimide-hydantoin hybrids.

A novel series of hydantoins incorporating phthalimides has been synthesised by condensation of activated phthalimides with 1-aminohydantoin and investigated for their inhibitory activity against a panel of human (h) carbonic anhydrase (CA, EC 4.2.1.1): the cytosolic isoforms hCA I, hCA II, and hCA VII, secreted isoform hCA VI, and the transmembrane hCA IX, by a stopped-flow CO2 hydrase assay. Although all newly developed compounds were totally inactive on hCA I and mainly ineffective towards hCA II, they generally exhibited moderate repressing effects on hCA VI, VII, and IX with KIs values in the submicromolar to micromolar ranges. The salts 3a and 3b, followed by derivative 5, displayed the best inhibitory activity of all the evaluated compounds and their binding mode was proposed in silico. These compounds can also be considered interesting starting points for the development of novel pharmacophores for this class of enzyme inhibitors.

Design, synthesis, and biological evaluation of piperazine derivatives involved in the 5-HT1AR/BDNF/PKA pathway.

In this study, four series of piperazine derivatives were designed, synthesised and subjected to biological test, and compound 6a with potential antidepressant activity was obtained. An affinity assay of compound 6a with 5-hydroxytryptamine (serotonin, 5-HT)1A receptor (5-HT1AR) was undertaken, and the effects on the 5-HT level in the brains of mice were also tested. The results showed that compound 6a had the best affinity with 5-HT1AR (Ki = 1.28 nM) and significantly increased the 5-HT level. The expression levels of 5-HT1AR, BDNF, and PKA in the hippocampus were analysed by western blot and immunohistochemistry analyses. The results showed that the expression of 5-HT1AR, BDNF, and PKA in the model group was reduced compared to that of the control group, and compound 6a could reverse this phenomenon. Molecular docking was performed to investigate the interactions of the studied compound 6a with 5-HT1AR on the molecular level.

Chemical Constituents, Biological Activities and Molecular Docking Studies of Root and Aerial Part Essential Oils from Erigeron sublyratus Roxb. ex DC. (Asteraceae).

In this study, the volatile components of Erigeron sublyratus essential oils and their anti-inflammatory and cytotoxic activities were investigated for the first time. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that a total of 28 components were identified in the root and aerial part essential oils. Among them, cis-lachnophyllum ester (53.4-64.2%), followed by germacrene D (5.6-8.6%), trans-ß-ocimene (2.6-7.5%), ß-caryophyllene (4.7-6.8%), ß-myrcene (2.0-6.3%), and (E)-ß-famesene (4.8-5.0%) were principal components. The root essential oil significantly inhibited nitric oxide (NO) production on LPS-induced RAW264.7 cells (IC50 = 1.41 ± 0.10 µg/mL) as compared to standard, dexamethasone (IC50 = 5.43 ± 0.54 µg/mL). Besides, both root and aerial part essential oils exhibited cytotoxic activity against MCF-7, SK-LU-1, and HepG2 (IC50 from 1.11 ± 0.04 to 1.70 ± 0.05 µg/mL). Molecular docking simulation results show that (E)-ß-farnesene exhibits the strongest binding energy among the studied compounds with the VEGFR-2 enzyme (ΔG = -7.295 kcal/mol), while δ-cadinene demonstrates the strongest affinity (ΔG = -8.047 kcal/mol) towards the COX-2 enzyme. Furthermore, hydrophobic interactions were indicated to be the main contributors to the binding ability in the studied protein-ligand complex. These findings proposed that E. sublyratus can be exploited for its anti-inflammatory and anti-cytotoxicity potential.

Cytotoxicity Activity of Some meso-Dihydroguaiaretic Acid Derivatives and Mode of Action of the Most Active Compound.

The aim of this study was to screen sixteen meso-1 semi-synthetic derivatives bearing ether, esther, carbamate, phosphate or aminoether functional groups against five cancer cell lines: MCF-7 (breast), A549 (lung), HepG2 (liver), HeLa (cervix), and DU145 (prostate) at 25 µM using the MTT assay. Results from the screening showed that two derivatives had the lowest percentage of cell viability at 25 µM, the aminoether derivative meso-11 and the esther derivative meso-20 against A549 (44.15±0.78 %) and MCF-7 (41.60±0.92 %), respectively. Then, it was determined the IC50 value of each compound against their most sensitive cancer cell line. Results showed that aminoether derivative meso-11 showed potent cytotoxicity against A549 (IC50 =17.11±2.11 µM), whereas it resulted more cytotoxic against the LL-47 lung normal cell line (IC50 =9.49±1.19 µM) having a Selective Index (SI) of 0.55. On the other hand, the esther derivative meso-20 exhibited potent activity against MCF-7 (IC50 =18.20±1.98 µM), whereas it displayed moderate cytotoxicity against the MCF-10 breast normal cell line (IC50 =41.22±2.17 µM) with a SI of 2.2. Finally, studies on the mechanism of action of meso-20 indicated disruption of MCF-7 plasma membrane in vitro and the AMPK activation in silico.

Triazole derivatives as potential xanthine oxidase inhibitors: Design, enzyme inhibition potential, and docking studies.

Considerable ingenuity has been shown in the recent years in the discovery of novel xanthine oxidase (XO) inhibitors that fall outside the purine scaffold. The triazole nucleus has been the cornerstone for the development of many enzyme inhibitors for the clinical management of several diseases, where hyperuricemia is one of them. Here, we give a critical overview of significant research on triazole-based XO inhibitors, with respect to their design, synthesis, inhibition potential, toxicity, and docking studies, done till now. Based on these literature findings, we can expect a burst of modifications on triazole-based scaffolds in the near future by targeting XO, which will treat hyperuricemics, that is, painful conditions like gout that at present are hard to deal with.

Benzimidazole-oxindole hybrids: A novel class of selective dual CDK2 and GSK-3ß inhibitors of potent anticancer activity.

A new series of benzimidazole-oxindole hybrids 8a-x was discovered as dual cyclin-dependent kinase (CDK2) and glycogen synthase kinase-3-beta (GSK-3ß) inhibitors with potent anticancer activity. The synthesized hits displayed potent anticancer activity against national cancer institute cancer cell lines in single-dose and five-dose assays. Moreover, the derivatives 8k, 8l, 8n, 8o, and 8p demonstrated potent cytotoxic activity against PANC-1 cells with IC50 = 1.88-2.79 µM. In addition, the hybrids 8l, 8n, 8o, and 8p displayed potent antiproliferative activity on the MG-63 cell line (IC50 = 0.99-1.90 µM). Concurrently, the benzimidazole-oxindole hybrid 8v exhibited potent dual CDK2/GSK-3ß inhibitory activity with IC50 values of 0.04 and 0.021 µM, respectively. In addition, 8v displayed more than 10-fold higher selectivity toward CDK2 and GSK-3 ß over CDK1, CDK5, GSK-3α, vascular endothelial growth factor receptor-2, and B-rapidly accelerated fibrosarcoma. Screening of the effect of 8n and 8v on the cell cycle and apoptosis of PANC-1 and MG-63 cells displayed their ability to arrest their cell cycle at the G2-M phase and to potentiate the apoptosis of both cell lines. In silico docking of the benzimidazole-oxindole hybrid 8v into the catalytic pocket of both CDK2 and GSK-3ß revealed its perfect fitting through the formation of hydrogen bonding and hydrophobic interactions with the key amino acids in the binding sites. In addition, in silico absorption, distribution, metabolism, excretion studies proved that 8a-x exhibit satisfactory drug-likeness properties for drug development.

Molecular Pro-Apoptotic Activities of Flavanone Derivatives in Cyclodextrin Complexes: New Implications for Anticancer Therapy.

This study evaluates the antiproliferative potential of flavanones, chromanones and their spiro-1-pyrazoline derivatives as well as their inclusion complexes. The main goal was to determine the biological basis of molecular pro-apoptotic activities and the participation of reactive oxygen species (ROS) in shaping the cytotoxic properties of the tested conjugates. For this purpose, changes in mitochondrial potential and the necrotic/apoptotic cell fraction were analyzed. Testing with specific fluorescent probes found that ROS generation had a significant contribution to the biological anticancer activity of complexes of flavanone analogues. TT (thrombin time), PT (prothrombin time) and APTT (activated partial tromboplastin time) were used to evaluate the influence of the compounds on the extrinsic and intrinsic coagulation pathway. Hemolysis assays and microscopy studies were conducted to determine the effect of the compounds on RBCs.

Evaluation of anti-glioma effects of benzothiazoles as efficient apoptosis inducers and DNA cleaving agents.

Glioma is the fast-growing, aggressive, and prevalent brain cancer with a great level of morbidity and mortality. Current therapy is usually found insufficient for glioma treatment. In the course of our research attempting to identify effective anti-glioma agents, three benzothiazole derivatives (1-3) were examined on U251 glioma cells. Among these derivatives, compound 3 was found to have the strongest cytotoxic effect on glioma cells with an IC50 value of 9.84 ± 0.64 µM in reference to cisplatin (IC50 = 8.41 ± 1.27 µM). Further mechanism of anti-glioma effects of compound 3 was characterized by the determination of its apoptotic effects in glioma cells and DNA cleaving capacity. Compound 3 caused a significant apoptotic death of U251 cell line. Besides, this compound cleaved DNA with FeSO4, H2O2 and ascorbic acid system. Molecular docking results also showed that compound 3 possessed a significant binding potential to DNA via important π-π stacking interaction with DG-16. Some pharmacokinetic determinants of compound 3 complied with standard limits making it as an efficient bioavailable anti-glioma drug candidate for upcoming exploration.

A multidisciplinary approach disclosing unexplored Aflatoxin B1 roles in severe impairment of vitamin D mechanisms of action.

Aflatoxin B1 (AFB1), produced by fungi of the genus Aspergillus, is the most toxic and carcinogenic mycotoxin among the classes of aflatoxins. Previous research showed that AFB1 affects vitamin D receptor (VDR) expression. In the present study, integrated computational and experimental studies were carried out to investigate how AFB1 can interfere with Vitamin D signalling. A competitive antagonism of AFB1 toward RXRα and VDR was hypothesized by comparing the docked complex of AFB1/RXRα and AFB1/VDR ligand-binding domain (LBD) with the X-ray structures of RXRα and VDR bound to known ligands. Accordingly, we demonstrated that AFB1 can affect vitamin D-mediated transcriptional activation of VDR by impairing the formation of protein complexes containing both VDR-RXRα and RXRα/RAR and affecting the subcellular localization of VDR and RXRα. As a whole, our data indicate that AFB1 can interfere with different molecular pathways triggered by vitamin D with an antagonistic mechanism of action.