New arylated benzo[h]quinolines induce anti-cancer activity by oxidative stress-mediated DNA damage

Role of 4-Thiazolidinone-Pyrazoline/Indoline Hybrids Les-4369 and Les-3467 in BJ and A549 Cell Lines

Cancer is one of the most important problems of modern societies. Recently, studies have reported the anticancer properties of rosiglitazone related to its ability to bind peroxisome proliferator receptor γ (PPARγ), which has various effects on cancer and can inhibit cell proliferation. In this study, we investigated the effect of new 4-thiazolidinone (4-TZD) hybrids Les-4369 and Les-3467 and their effect on reactive oxygen species (ROS) production, metabolic activity, lactate dehydrogenase (LDH) release, caspase-3 activity, and gene and protein expression in human foreskin fibroblast (BJ) cells and lung adenocarcinoma (A549) cells. The ROS production and caspase-3 activity were mainly increased in the micromolar concentrations of the studied compounds in both cell lines. Les-3467 and Les-4369 increased the mRNA expression of PPARG, P53 (tumor protein P53), and ATM (ATM serine/threonine kinase) in the BJ cells, while the mRNA expression of these genes (except PPARG) was mainly decreased in the A549 cells treated with both of the tested compounds. Our results indicate a decrease in the protein expression of AhR, PPARγ, and PARP-1 in the BJ cells exposed to 1 µM Les-3467 and Les-4369. In the A549 cells, the protein expression of AhR, PPARγ, and PARP-1 increased in the treatment with 1 µM Les-3467 and Les-4369. We have also shown the PPARγ modulatory properties of Les-3467 and Les-4369. However, both compounds prove weak anticancer properties evidenced by their action at high concentrations and non-selective effects against BJ and A549 cells.

The Antioxidant Properties of Selected Varieties of Pumpkin Fortified with Iodine in the Form of Potassium Iodide and Potassium Iodate

This study aimed to investigate the use of selected pumpkin varieties as carriers of potassium iodide (KI) and potassium iodate (KIO₃) at different concentrations (2.3, 0.23, and 0.023 mg/100 g). It was hypothesized that the concentrations and form of iodine fortification in pumpkins affect the antioxidant activity of pumpkins. The results showed a high recovery of the introduced iodine in all pumpkin varieties after drying, as well as high iodine stability during storage, especially for KIO₃. However, statistical analysis confirmed a relationship between the forms and concentration of iodine and the ABTS cation radical and the DPPH radical test results. In the systems with iodine concentration at 0.023 and 0.23 mg/100 g, the antioxidant activity did not change. However, for all pumpkin varieties fortified with a KIO₃ concentration at 3.9 mg/100 g (2.3 mg/100 g of iodine), a statistically significant decrease in free-radical scavenging was confirmed. Therefore, for maximum effectiveness in pumpkin's free-radical scavenging indices, it is suggested to introduce iodine in the form of KI and KIO₃, but in controlled concentrations. However, KIO₃ should be added at a maximum amount of 0.39 mg/100 g.

Synthesis, Antimicrobial, and Antibiofilm Activities of Some Novel 7-Methoxyquinoline Derivatives Bearing Sulfonamide Moiety against Urinary Tract Infection-Causing Pathogenic Microbes

A new series of 4-((7-methoxyquinolin-4-yl) amino)-N-(substituted) benzenesulfonamide 3(a-s) was synthesized via the reaction of 4-chloro-7-methoxyquinoline 1 with various sulfa drugs. The structural elucidation was verified based on spectroscopic data analysis. All the target compounds were screened for their antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, and unicellular fungi. The results revealed that compound 3l has the highest effect on most tested bacterial and unicellular fungal strains. The highest effect of compound 3l was observed against E. coli and C. albicans with MIC = 7.812 and 31.125 µg/mL, respectively. Compounds 3c and 3d showed broad-spectrum antimicrobial activity, but the activity was lower than that of 3l. The antibiofilm activity of compound 3l was measured against different pathogenic microbes isolated from the urinary tract. Compound 3l could achieve biofilm extension at its adhesion strength. After adding 10.0 µg/mL of compound 3l, the highest percentage was 94.60% for E. coli, 91.74% for P. aeruginosa, and 98.03% for C. neoformans. Moreover, in the protein leakage assay, the quantity of cellular protein discharged from E. coli was 180.25 µg/mL after treatment with 1.0 mg/mL of compound 3l, which explains the creation of holes in the cell membrane of E. coli and proves compound 3l's antibacterial and antibiofilm properties. Additionally, in silico ADME prediction analyses of compounds 3c, 3d, and 3l revealed promising results, indicating the presence of drug-like properties.

Topoisomerase II inhibitors design: Early studies and new perspectives

The DNA topoisomerase enzymes are widely distributed throughout all spheres of life and are necessary for cell function. Numerous antibacterial and cancer chemotherapeutic drugs target the various topoisomerase enzymes because of their roles in maintaining DNA topology during DNA replication and transcription. Agents derived from natural products, like anthracyclines, epipodophyllotoxins and quinolones, have been widely used to treat a variety of cancers. A very active field of fundamental and clinical research is the selective targeting of topoisomerase II enzymes for cancer treatment. This thematic review summarizes the recent advances in the anticancer activity of the most potent topoisomerase II inhibitors (anthracyclines, epipodophyllotoxins and fluoroquinolones) their modes of action, and structure-activity relationships (SARs) organized chronologically in the last ten years from 2013 to 2023. The review also highlights the mechanism of action and SARs of promising new topoisomerase II inhibitors.

Naturally occurring Anaplasma marginale infection in cattle: Molecular prevalence and associated risk factors, haemato-biochemical alterations, oxidant/antioxidant status and serum trace mineral levels

The present investigation was undertaken to map the distribution of Anapalsma species infection in cattle from the Aizawl region of Mizoram, India, in relation to various risk factors, and to study the haemato-biochemical alterations, oxidant/antioxidant status and serum trace mineral levels in cattle with naturally occurring Anapalsma marginale infection. The study was carried out over 31 months from June 2019 to December 2021. A total of 401 cattle blood samples were collected and screened for the presence of Anaplasma spp. by microscopic examination and polymerase chain reaction (PCR). Non-infected clinically healthy cattle (n = 21) served as control. Blood samples were collected to study the haemogram and serum samples were used for the evaluation of biochemical parameters, oxidative stress indices and trace minerals. During the study period, an overall prevalence of 15.71% was recorded for A. marginale infection in cattle. The prevalence of A. marginale infection was highly associated with age, sex, breed and tick infestation status of animals, floor system and management of farms, and season. The mean values of total erythrocyte count (TEC), haemoglobin (Hb), packed cell volume (PCV), total platelet count, total protein, albumin, superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (TAC), copper (Cu) and zinc (Zn) were significantly (P < 0.05) lower, whereas the mean values of mean corpuscular volume (MCV), aspartate aminotransferase (AST), total bilirubin, indirect bilirubin, blood urea nitrogen (BUN), creatinine and lipid hydroperoxide (LPO) were significantly (P < 0.05) higher in cattle infected with A. marginale. A negative correlation of TEC with LPO, and a positive correlation with SOD, GSH, TAC, Cu and Zn suggest a possible link between oxidative stress and the haemolytic crisis noticed in bovine anaplasmosis. Incorporation of antioxidants and organ protective drugs as an adjunct therapy may result in better prognosis.

Quinoline-based thiazolidinone derivatives as potent cytotoxic and apoptosis-inducing agents through EGFR inhibition

Quinoline-based thiazolidinone heterocycles exhibited potent activity in the field of cancer therapy. Hence, ten quinoline-based thiazolidinone derivatives were evaluated for their anticancer activity through cytotoxic activity, epidermal growth factor receptor (EGFR) inhibition pathway, apoptosis investigation through flow cytometric analyses, RT-PCR gene expression, in vivo solid-Ehrlich carcinoma model, and finally in silico approach for highlighting the interaction pose. Results revealed that compound 7 exhibited cytotoxic activity against HCT-116 cells with an IC₅₀ value of 7.43 µM compared to 5-FU (IC₅₀  = 11.36 µM) with moderate cytotoxic activity against the FHC (IC₅₀  = 35.27 µM), and it exhibited remarkable inhibition activity of EGFR with IC₅₀ value of 96.43 nM compared to Erlotinib (IC₅₀  = 78.65 nM). Moreover, it significantly stimulated apoptotic colon cancer cell death with 171.58-fold arresting cell cycle at G2 and S-phases. Additionally, it ameliorated both biochemical and histochemical structures near normal with tumor inhibition ratio of 52.92% compared to 5-FU of 57.16%, with immunohistochemical examinations of EGFR inhibition in the treated group compared to control. Finally, molecular docking study highlighted its good binding affinity through good interactive binding pose inside the EGFR protein. In conclusion, the potent EGFR inhibitory activity of compound 7 was investigated using three integrated approaches in vitro, in vivo, and in silico, so it worth be validated and developed as a chemotherapeutic anticancer agent.

Optimization of Ultrasound-Assisted Extraction of Bioactive Compounds from Acacia Seyal Gum Using Response Surface Methodology and Their Chemical Content Identification by Raman, FTIR, and GC-TOFMS

Acacia Seyal gum (ASG), also known as gum Arabic, is an antioxidant-rich soluble fiber. ASG has been reported to have many biological activities, including anticancer, antidiabetic, antiulcer, and immunomodulatory activity. Extraction of bioactive compounds from ASG is commonly performed using conventional extraction methods. However, these techniques have certain limitation in terms of extraction time, energy, and solvent requirements. Ultrasound-assisted extraction (UAE) could be used as an alternative technique to extract bioactive compounds in less time, at low temperature, and with less energy and solvent requirements. In this study, the UAE extraction of ASG was optimized using response surface methodology (RSM). A face-centered central composite design (FCCCD) was used to monitor the effect of different independent factors of ultrasound operation (sonication time, temperature, and solvent ratio) on ASG extraction yield. In addition, screening and characterization of phytochemicals in 60% ethanol ASG extract was carried out using Raman microscopy, Fourier transform infrared spectroscopy (FTIR), and gas chromatography time-of-flight mass spectroscopy (GC-TOFMS) analysis. The results indicated that, under optimal conditions (extraction time 45 min, extraction temperature 40 °C, and solid–liquid ratio of 1:25 g/mL), the yield of ASG was 75.87% ± 0.10. This yield was reasonably close to the predicted yield of 75.39% suggested by the design of experiment. The ANOVA revealed that the model was highly significant due to the low probability value (p < 0.0001). Raman spectrum fingerprint detected polysaccharides, such as galactose and glucose, and protein like lysine and proline, while FTIR spectrum revealed the presence of functional groups peaks value of alkanes, aldehydes, aliphatic amines, and phenol. GC-TOFMS spectroscopic detected the presence of strong d-galactopyranose, carotenoid, and lycopene antioxidant compounds. In conclusion, this study demonstrated that the UAE technique is an efficient method to achieve a high yield of ASG extracts. The selected model is adequate to optimize the extraction of several chemical compounds reported in this study.

Drug resistance reversal potential of multifunctional thieno[3,2-c]pyran via potentiation of antibiotics in MDR P. aeruginosa

We explored the antibacterial potential (alone and combination) against multidrug resistant (MDR) Pseudomonas aeruginosa isolates KG-P2 using synthesized thieno[3,2-c]pyran-2-ones in combination with different antibiotics. Out of 14 compounds, two compounds (3g and 3l) abridged the MIC of tetracycline (TET) by 16 folds. Compounds was killing the KG-P2 cells, in time dependent manner, lengthened post-antibiotic effect (PAE) of TET and found decreased the mutant prevention concentration (MPC) of TET. In ethidium bromide efflux experiment, two compounds repressed the drug transporter (efflux pumps) which is further supported by molecular docking of these compounds with efflux complex MexAB-OprM. In another study, these compounds inhibited the synthesis of biofilm.

Discovery of a novel series of substituted quinolines acting as anticancer agents and selective EGFR blocker: Molecular docking study

A Ta₂O₅-anchored-piperidine-4-carboxylic acid (PPCA) nanoparticle has been synthesized and characterized. It was then used as a highly effective nanocatalyst for the synthesis of quinolin-2(1H)-one derivatives through CO bond functionalization. The special advantage of this heterogeneous solid catalyst is the reusability of the catalyst for up to five cycles without any noticeable reduction in product yields. In comparison, healthy reaction profiles, wide substrate scope, excellent yields and easy workup conditions are the notable highlights of this approach. All the compounds were tested for their anticancer activity against MCF-7 (human breast), HepG2 (human liver), HCT116 (human colorectal), and PC-3 (human prostate) cancer cell lines with the MTT assay. All the compounds were shown to have moderate to good inhibitory effects on tested cancer cell lines. Besides, compounds 5b, 5c and 5d showed good selectivity against epidermal growth factor receptor-tyrosine kinase (EGFR-TK). Molecular docking results showed that active compounds showed a good affinity towards EGFR kinase (PDB ID: 6V6O) by forming two hydrogen bonds with Cys-797 and Tyr-801. All the compounds were screened for computational ADMET and Lipinski analysis.

Synthesis of Michael Adducts as Key Building Blocks for Potential Analgesic Drugs: In vitro, in vivo and in silico Explorations

Background

Organocatalytic asymmetric Michael addition is a strong approach for C-C bond formation. The objective of the study is to design molecules by exploiting the efficiency of Michael Adducts. We proceeded with the synthesis of Michael adducts by tailoring the substitution pattern on maleimide and trans-β-nitro styrene as Michael acceptors. The synthesized compounds were evaluated for dual cyclooxygenases (COX) and lipoxygenase (LOX) inhibition.

Methods

The compounds (4, 9–11) were synthesized through Michael additions. The cyclooxygenases (COX-1 and 2) and lipoxygenase (5-LOX) assays were used for in vitro evaluations of compounds. After the acute toxicity studies, the in vivo analgesic potential was determined with acetic acid induced writhing, tail immersion, and formalin tests. Furthermore, the possible roles of adrenergic and dopaminergic receptors were also studied. Extensive computational studies were performed to get a better understanding regarding the binding of this compound with protein target.

Results

Four Michael adducts (4, 9–11) were synthesized. Compound 4 was obtained in enantio- and diastereopure form. The stereopure compound 4 showed encouraging COX-1 and-2 inhibitions with IC₅₀ values of 128 and 65 μM with SI of 1.94. Benzyl derivative 11 showed excellent COX-2 inhibition with the IC₅₀ value of 5.79 μM and SI value 7.96. Compounds 4 and 11 showed good results in in vivo models of analgesia like acetic acid test, tail immersion, and formalin tests. Our compounds were not active in dopaminergic and adrenergic pathways and so were acting centrally. Through extensive computational studies, we computed binding energies, and pharmacokinetic predictions.

Conclusion

Our findings conclude that our synthesized Michael products (pyrrolidinedione 4 and nitroalkane 11) can be potent centrally acting analgesics. Our in silico predictions suggested that the compounds have excellent pharmacokinetic properties. It is concluded here that dual inhibition of COX/LOX pathways provides a convincing step towards the discovery of safe lead analgesic molecules.

Synthesis, antibacterial, and cytotoxicity evaluation of oleanolic acid-4-aminoquinoline based hybrid compounds

AIM

To prepare a class of oleanolic-based compounds.

BACKGROUND

Conventional drugs used to treat infectious diseases suffer from limitations such as drug toxicity and drug resistance. The resistance of microbes to antimicrobial agents is a significant challenge in treating microbial infections. Combining two or more drugs with different modes of action to treat microbial infections results in a delay in developing drug resistance by the microbes. However, it is challenging to select the appropriate choice of drugs for combination therapy due to the differences in stability and pharmacokinetic profile of the drugs.Therefore, developing hybrid compounds using the existing drugs is a promising approach to design effective antimicrobial agents.

OBJECTIVES

To prepare oleanolic-based hybrid compounds followed by characterization, in vitro antibacterial, and cytotoxicity evaluation.

METHODS

Oleanolic acid-4-aminoquinoline-based hybrid compounds weresynthesized via esterification and amidation. The compounds werecharacterized using FTIR, NMR, and UHPLC-HRMS. Oleanolic acid was isolated from the flower buds of Syszygium aromaticum (L.) Merr. & L.M.Perry, a specie from Kingdom Plantae, order Mytales in Myrtaceae family. Their antibacterial and cytotoxicity activity was determined against selected strains of bacteria assessed using the microdilution assay and sulforhodamine B assay against selected cancer cell lines.

RESULTS

The synthesized hybrid compounds exhibited significant antibacterial activity against the Gram-positive bacteria Enterococcus faecalis (ATCC13047), Bacillus subtilis (ATCC19659), Staphylococcus aureus as well as Gram-negative bacteria,Klebsiella oxytoca (ATCC8724), Escherischia coli (ATCC25922), and Proteus vulgaris (ATCC6380)with minimum inhibitory concentrations of 1.25 mg/mLcompared to oleanolic acid (2.5 mg/mL). Compounds 13 and 14 displayed significant cytotoxic effectsin vitro against the cancer cell lines (MCF-7 and DU 145) compared to the oleanolic acid (IC50 ˃ 200 µM).

CONCLUSION

The present study revealed that the modification of C28 of OA enhanced its biological properties.

In Silico Docking, ADMET and QSAR Study of few Antimalarial Phytoconstituents as Inhibitors of Plasmepsin II of P. falciparum Against Malaria

Background:

Malaria is endemic in various parts of India particularly in the North- Eastern states with Plasmodium falciparum-the most prevalent human malaria parasite. Plantderived compounds have always received tremendous importance in the area of drug discovery and development and scientific study of traditional medicinal plants are of great importance to mankind.

Objective:

The present work deals with the computational study of some antimalarial compounds obtained from a few medicinal plants used by the tribal inhabitants of the North-Eastern region of India for treating malaria.

Methods:

In silico methodologies were performed to study the ligand-receptor interactions. Target was identified based on the pharmacophore mapping approach. A total of 18 plant-derived compounds were investigated in order to estimate the binding energies of the compounds with their drug target through molecular docking using Autodock 4.2. ADMET filtering for determining the pharmacokinetic properties of the compounds was done using Mobyle@RPBS server. Subsequent Quantitative-Structure Activity Relationship analysis for bioactivity prediction (IC50) of the compounds was done using Easy QSAR 1.0.

Results:

The docking result identified Salannin to be the most potent Plasmepsin II inhibitor while the QSAR analysis identified Lupeol to have the least IC50 value. Most of the compounds have passed the ADME/Tox filtration.

Conclusion:

Salannin and Lupeol were found to be the most potent antimalarial compounds that can act as successful inhibitors against Plasmepsin II of P. falciparum. The compounds Salannin and Lupeol are found in Azadirachta indica and Swertia chirata plants respectively, abundantly available in the North-Eastern region of India and used by many inhabiting tribes for the treatment of malaria and its symptoms.

Oxidative stress mitigation by antioxidants - An overview on their chemistry and influences on health status

The present review paper focuses on the chemistry of oxidative stress mitigation by antioxidants. Oxidative stress is understood as a lack of balance between the pro-oxidant and the antioxidant species. Reactive oxygen species in limited amounts are necessary for cell homeostasis and redox signaling. Excessive reactive oxygenated/nitrogenated species production, which counteracts the organism's defense systems, is known as oxidative stress. Sustained attack of endogenous and exogenous ROS results in conformational and oxidative alterations in key biomolecules. Chronic oxidative stress is associated with oxidative modifications occurring in key biomolecules: lipid peroxidation, protein carbonylation, carbonyl (aldehyde/ketone) adduct formation, nitration, sulfoxidation, DNA impairment such strand breaks or nucleobase oxidation. Oxidative stress is tightly linked to the development of cancer, diabetes, neurodegeneration, cardiovascular diseases, rheumatoid arthritis, kidney disease, eye disease. The deleterious action of reactive oxygenated species and their role in the onset and progression of pathologies are discussed. The results of oxidative attack become themselves sources of oxidative stress, becoming part of a vicious cycle that amplifies oxidative impairment. The term antioxidant refers to a compound that is able to impede or retard oxidation, acting at a lower concentration compared to that of the protected substrate. Antioxidant intervention against the radicalic lipid peroxidation can involve different mechanisms. Chain breaking antioxidants are called primary antioxidants, acting by scavenging radical species, converting them into more stable radicals or non-radical species. Secondary antioxidants quench singlet oxygen, decompose peroxides, chelate prooxidative metal ions, inhibit oxidative enzymes. Moreover, four reactivity-based lines of defense have been identified: preventative antioxidants, radical scavengers, repair antioxidants, and those relying on adaptation mechanisms. The specific mechanism of a series of endogenous and exogenous antioxidants in particular aspects of oxidative stress, is detailed. The final section resumes critical conclusions regarding antioxidant supplementation.

Pharmacoinformatics approaches to identify potential hits against tetraacyldisaccharide 4'-kinase (LpxK) of Pseudomonas aeruginosa

Pseudomonas aeruginosa infection can cause pneumonia and urinary tract infection and the management of Pseudomonas aeruginosa infection is critical in multidrug resistance, hospital-acquired bacteremia and ventilator-associated pneumonia. The key enzymes of lipid A biosynthesis in Pseudomonas aeruginosa are promising drug targets. However, the enzyme tetraacyldisaccharide 4'-kinase (LpxK) has not been explored as a drug target so far. Several pharmacoinformatics tools such as comparative metabolic pathway analysis (Metacyc), data mining from a database of essential genes (DEG), homology modeling, molecular docking, pharmacophore based virtual screening, ADMET prediction and molecular dynamics simulation were used in identifying novel lead compounds against this target. The top virtual hits STOCK6S-33288, 43621, 39892, 37164 and 35740 may serve as the templates for the design and synthesis of potent LpxK inhibitors in the management of serious Pseudomonas aeruginosa infection.

Potential Metabolite Nymphayol Isolated from Water Lily (Nymphaea stellata) Flower Inhibits MCF-7 Human Breast Cancer Cell Growth via Upregulation of Cdkn2a, pRb2, p53 and Downregulation of PCNA mRNA Expressions

Controlled production of cyclin dependent kinases (CDK) and stabilization of tumor suppressor genes are the most important factors involved in preventing carcinogenesis. The present study aimed to explore the cyclin dependent apoptotic effect of nymphayol on breast cancer MCF-7 cells. In our previous study, we isolated the crystal from a chloroform extract of Nymphaea stellata flower petals and it was confirmed as nymphayol (17-(hexan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-3-ol) using x-ray diffraction (XRD), Fourier transform infrared (FTIR), and mass spectroscopy (MS) methods. The cytotoxic effect of nymphayol on MCF-7 cells were analyzed using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The cellular and nuclear damage was determined using propidium iodide (PI) and acridine orange/ethidium bromide (AO/ErBr) staining. Tumor suppressor and apoptosis related mRNA transcript levels were determined using real-time polymerase chain reaction (RT-PCR). Nymphayol potentially inhibits MCF-7 cell viability up to 78%, and the IC₅₀ value was observed as 2.8 µM in 24 h and 1.4 µM in 48 h. Treatment with nymphayol significantly increased reactive oxygen species (ROS) level and the tunnel assay confirmed DNA damage. We found characteristically 76% apoptotic cells and 9% necrotic cells in PI and AO/ErBr staining after 48 h treatment with 2.8 µM of nymphayol. Gene expression analysis confirmed significantly (p ≤ 0.001) increased mRNA levels of cyclin dependent kinase inhibitor 2A (Cdkn2a), retinoblastoma protein 2 (pRb2), p53, nuclear factor erythroid 2-factor 2 (Nrf2), caspase-3, and decreased B-cell lymphoma 2 (Bcl-2), murine double minute 2 (mdm2), and proliferating cell nuclear antigen (PCNA) expression after 48 h. Nymphayol effectively inhibited breast cancer cell viability, and is associated with early expression of Cdkn2a, pRb2, and activation of p53 and caspases.

Dextran-coated iron oxide nanoparticle-induced nanotoxicity in neuron cultures

Recent technological advances have introduced diverse engineered nanoparticles (ENPs) into our air, water, medicine, cosmetics, clothing, and food. However, the health and environmental effects of these increasingly common ENPs are still not well understood. In particular, potential neurological effects are one of the most poorly understood areas of nanoparticle toxicology (nanotoxicology), in that low-to-moderate neurotoxicity can be subtle and difficult to measure. Culturing primary neuron explants on planar microelectrode arrays (MEAs) has emerged as one of the most promising in vitro techniques with which to study neuro-nanotoxicology, as MEAs enable the fluorescent tracking of nanoparticles together with neuronal electrical activity recording at the submillisecond time scale, enabling the resolution of individual action potentials. Here we examine the dose-dependent neurotoxicity of dextran-coated iron oxide nanoparticles (dIONPs), a common type of functionalized ENP used in biomedical applications, on cultured primary neurons harvested from postnatal day 0-1 mouse brains. A range of dIONP concentrations (5-40 µg/ml) were added to neuron cultures, and cells were plated either onto well plates for live cell, fluorescent reactive oxidative species (ROS) and viability observations, or onto planar microelectrode arrays (MEAs) for electrophysiological measurements. Below 10 µg/ml, there were no dose-dependent cellular ROS increases or effects in MEA bursting behavior at sub-lethal dosages. However, above 20 µg/ml, cell death was obvious and widespread. Our findings demonstrate a significant dIONP toxicity in cultured neurons at concentrations previously reported to be safe for stem cells and other non-neuronal cell types.

Computational Modeling on Aquaporin-3 as Skin Cancer Target: A Virtual Screening Study

Aquaporin-3 (AQP3) is one of the aquaglyceroporins, which is expressed in the basolateral layer of the skin membrane. Studies have reported that human skin squamous cell carcinoma overexpresses AQP3 and inhibition of its function may alleviate skin tumorigenesis. In the present study, we have applied a virtual screening method that encompasses filters for physicochemical properties and molecular docking to select potential hit compounds that bind to the Aquaporin-3 protein. Based on molecular docking results, the top 20 hit compounds were analyzed for stability in the binding pocket using unconstrained molecular dynamics simulations and further evaluated for binding free energy. Furthermore, examined the ligand-unbinding pathway of the inhibitor from its bound form to explore possible routes for inhibitor approach to the ligand-binding site. With a good docking score, stability in the binding pocket, and free energy of binding, these hit compounds can be developed as Aquaporin-3 inhibitors in the near future.

Cold atmospheric plasma generated reactive species aided inhibitory effects on human melanoma cells: an in vitro and in silico study

Malignant melanoma is considered to be a heterogeneous disease that arises from altered genes and transformed melanocytes. In this study, special softjet cold atmospheric plasma was used to treat three different human melanoma cells using air and N₂ gases to check the anti-melanoma activity. The physical effects by plasma revealed an increase in the temperature with the gradual reduction in pH at 60 sec, 180 sec and 300 sec air and N₂ plasma treatment. Cellular toxicity revealed a decreased in cell survival (~50% cell survival using air gas and <~60% cell survival using N₂ gas at 60 sec plasma treatment in G-361 cells). Gene analysis by q-PCR revealed that 3 min and 5 min air and N₂ plasma treatment activated apoptotic pathways by triggering apoptotic genes in all three melanoma cell lines. The apoptosis was confirmed by DAPI staining and its related pathways were further explored according to protein-protein docking, and their probable activation mechanism was revealed. The pathways highlighted that activation of apoptosis which leads to cellular cascades and hence stimulation ASK1 (docking method) revealed that softjet plasma can be an effective modality for human melanoma treatment.

Molecular interaction of tea catechin with bovine β-lactoglobulin: A spectroscopic and in silico studies

Polyphenols has attained pronounced attention due to their beneficial values of health and found to prevent several chronic diseases. Here, we elucidated binding mechanism between frequently consumed polyphenol “tea catechin” and milk protein bovine beta-lactoglobulin (β-Lg). We investigated the conformational changes of β-Lg due to interaction with catechin using spectroscopic and in silico studies. Fluorescence quenching data (Stern-Volmer quenching constant) revealed that β-Lg interacted with catechin via dynamic quenching. Thermodynamic data revealed that the interaction between β-Lg and catechin is endothermic and spontaneously interacted mainly through hydrophobic interactions. The UV-Vis absorption and far-UV circular dichroism (CD) spectroscopy exhibited that the tertiary as well as secondary structure of β-Lg distorted after interaction with catechin. Molecular docking and simulation studies also confirm that catechin binds at the central cavity of β-Lg with high affinity (~10⁵ M⁻¹) and hydrophobic interactions play significant role in the formation of a stable β-Lg-catechin complex.

Evaluation of oxidative/nitrosative stress biomarkers and DNA damage in buffaloes naturally infected with Theileria annulata

Previously, we evaluated serum sialic acid (SA) levels in buffaloes naturally infected with T. annulata. In the current paper, we conducted a further study on oxidative/nitrosative stress biomarkers in erythrocyte lysate samples of the same buffaloes. DNA damage also was assessed. Additionally, we tested whether, there is any correlation between SA and the aforementioned indicators or not. To achieve these aims, several biomarkers including the activities of key antioxidant enzymes, superoxide dismutase, glutathione peroxidase and catalase, as well as malondialdehyde (MDA), protein carbonyl (PCO), nitric oxide contents (NO), total antioxidant capacity (TAC) and DNA damage levels were measured. The obtained results showed that the activities of the antioxidant enzymes and TAC levels decreased significantly as the percentage of parasitemia increased accordingly. Also, a significant increase in the levels of PCO, MDA, NO and DNA damage were recorded, depending on the degree of parasitemia. There was a significant correlation between oxidative/nitrosative stress indicators and SA. Conclusively, T. annulata infection in buffaloes is associated with a parasitic burden-dependent oxidative/nitrosative damages to erythrocytes and SA plays a crucial role in pathogenesis of the disease, as it is tightly correlated with oxidative/nitrosative indicators.

Surfen-mediated blockade of extratumoral chondroitin sulfate glycosaminoglycans inhibits glioblastoma invasion

Invasive spread of glioblastoma (GBM) is linked to changes in chondroitin sulfate (CS) proteoglycan (CSPG)-associated sulfated glycosaminoglycans (GAGs) that are selectively up-regulated in the tumor microenvironment (TME). We hypothesized that inhibiting CS-GAG signaling in the TME would stem GBM invasion. Rat F98 GBM cells demonstrated enhanced preferential cell invasion into oversulfated 3-dimensional composite of CS-A and CS-E [4- and 4,6-sulfated CS-GAG (COMP)] matrices compared with monosulfated (4-sulfated) and unsulfated hyaluronic acid matrices in microfluidics-based choice assays, which is likely influenced by differential GAG receptor binding specificities. Both F98 and human patient-derived glioma stem cells (GSCs) demonstrated a high degree of colocalization of the GSC marker CD133 and CSPGs. The small molecule sulfated GAG antagonist bis-2-methyl-4-amino-quinolyl-6-carbamide (surfen) reduced invasion and focal adhesions in F98 cells encapsulated in COMP matrices and blocked CD133 and antichondroitin sulfate antibody (CS-56) detection of respective antigens in F98 cells and human GSCs. Surfen-treated F98 cells down-regulated CSPG-binding receptor transcripts and protein, as well as total and activated ERK and protein kinase B. Lastly, rats induced with frontal lobe tumors and treated with a single intratumoral dose of surfen demonstrated reduced tumor burden and spread compared with untreated controls. These results present a first demonstration of surfen as an inhibitor of sulfated GAG signaling to stem GBM invasion.-Logun, M. T., Wynens, K. E., Simchick, G., Zhao, W., Mao, L., Zhao, Q., Mukherjee, S., Brat, D. J., Karumbaiah, L. Surfen-mediated blockade of extratumoral chondroitin sulfate glycosaminoglycans inhibits glioblastoma invasion.

Comparative Drug Resistance Reversal Potential of Natural Glycosides: Potential of Synergy Niaziridin & Niazirin

Background:

Due to the limited availability of antibiotics, Gram-negative bacteria (GNB) acquire different levels of drug resistance. It raised an urgent need to identify such agents, which can reverse the phenomenon of drug resistance.

Objective:

To understand the mechanism of drug resistance reversal of glycosides; niaziridin and niazirin isolated from the pods of Moringa oleifera and ouabain (control) against the clinical isolates of multidrug-resistant Escherichia coli.

Methods:

The MICs were determined following the CLSI guidelines for broth micro-dilution. In-vitro combination studies were performed by broth checkerboard method followed by Time-Kill studies, the efflux pump inhibition assay, ATPase inhibitory activity, mutation prevention concentration and in-silico studies.

Results:

The results showed that both glycosides did not possess antibacterial activity of their own, but in combination, they reduced the MIC of tetracycline up to 16 folds. Both were found to inhibit efflux pumps, but niaziridin was the best. In real time expression pattern analysis, niaziridin was also found responsible for the down expression of the two important efflux pump acrB & yojI genes alone as well as in combination. Niaziridin was also able to over express the porin forming genes (ompA & ompX). These glycosides decreased the mutation prevention concentration of tetracycline.

Conclusion:

This is the first ever report on glycosides, niazirin and niaziridin acting as drug resistance reversal agent through efflux pump inhibition and modulation of expression pattern drug resistant genes. This study may be helpful in preparing an effective antibacterial combination against the drug-resistant GNB from a widely growing Moringa oleifera.

Synthesis and X-ray study of dispiro 8-nitroquinolone analogues and their cytotoxic properties against human cervical cancer HeLa cells

A series of unique dispiro analogues containing an oxindole pyrrolidine 8-nitroquinolone hybrid has been obtained through a one-pot three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the condensation of isatins and benzylamine with (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolones. The structures of the newly synthesized compounds were characterized by using different spectroscopic techniques and by X-ray diffraction studies of their regio- and stereochemistry. All the synthesized compounds were screened for in vitro cytotoxic activity against the human cervical cancer cell line HeLa. The compounds have exhibited potent inhibition against human cervical cancer cells and insignificant toxicity to normal cells. The compounds 6d, 6a, 6h, 6b, and 6e induced apoptosis of HeLa cells, through ROS influx. The expression levels of proteins involved in the mitochondrion-related pathways were detected, and Western blot analysis showed that apoptosis occurred via activation of caspase-3.

Molecular docking, pharmacophore based virtual screening and molecular dynamics studies towards the identification of potential leads for the management of H. pylori

The enzyme pantothenate synthetase panC is one of the potential new antimicrobial drug targets, but it is poorly characterized in H. pylori. H. pylori infection can cause gastric cancer and the management of H. pylori infection is crucial in various gastric ulcers and gastric cancer. The current study describes the use of innovative drug discovery and design approaches like comparative metabolic pathway analysis (Metacyc), exploration of database of essential genes (DEG), homology modelling, pharmacophore based virtual screening, ADMET studies and molecular dynamics simulations in identifying potential lead compounds for the H. pylori specific panC. The top ranked virtual hits STOCK1N-60270, STOCK1N-63040, STOCK1N-44424 and STOCK1N-63231 can act as templates for synthesis of new H. pylori inhibitors and they hold a promise in the management of gastric cancers caused by H. pylori.

Computational approaches such as pharmacophore modeling, virtual screening and MD simulations were explored to find the potential hits as H. pylori specific panC inhibitors for the management of gastric ulcers and gastric cancers.

Quinoline-triazole hybrids inhibit falcipain-2 and arrest the development ofPlasmodium falciparumat the trophozoite stage

The present study involves development of novel quinoline triazole-containing cysteine protease inhibitors which arrest the development ofP. falciparumat the trophozoite stage.

Discovery of Aporphine Analogues as Potential Antiplatelet and Antioxidant Agents: Design, Synthesis, Structure-Activity Relationships, Biological Evaluations, and in silico Molecular Docking Studies

To explore the potential of aporphine alkaloids, a novel series of functionalized aporphine analogues with alkoxy (OCH₃ , OC₂ H₅ , OC₃ H₇ ) functional groups at C1/C2 of ring A and an acyl (COCH₃ and COPh) or phenylsulfonyl (SO₂ Ph and SO₂ C₆ H₄ -3-CH₃ ) functionality at the N6 position of ring B of the aporphine scaffold were synthesized and evaluated for their arachidonic acid (AA)-induced antiplatelet aggregation inhibitory activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging antioxidant activity, with acetylsalicylic acid and ascorbic acid as standard references, respectively. The preliminary structure-activity relationship related to AA-induced platelet aggregation inhibitory activity results showed that the aporphine analogues 1-[1,2,9,10-tetramethoxy-6a,7-dihydro-4H-dibenzo[de,g]quinolin-6(5H)-yl]ethanone and 1-[2-(benzyloxy)-1,9,10-trimethoxy-6a,7-dihydro-4H-dibenzo[de,g]quinolin-6(5H)-yl]ethanone to be the best compounds of the series. Moreover, the DPPH free-radical-scavenging antioxidant activity results demonstrated that the aporphine analogues 1,2,9,10-tetramethoxy-6-(methylsulfonyl)-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline, 2-ethoxy-1,9,10-trimethoxy-6-(methylsulfonyl)-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline, 1-ethoxy-2,9,10-trimethoxy-6-(methylsulfonyl)-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline, 2,9,10-trimethoxy-6-(methylsulfonyl)-1-propoxy-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline, and 1-(benzyloxy)-2,9,10-trimethoxy-6-(methylsulfonyl)-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline were the best compounds of the series. Moreover, in silico molecular docking simulation studies of the active analogues were also performed.

New amyloid beta-disaggregating agents: synthesis, pharmacological evaluation, crystal structure and molecular docking of N-(4-((7-chloroquinolin-4-yl)oxy)-3-ethoxybenzyl)amines

In the journey towards the development of potent multi-targeted ligands for the treatment of Alzheimer's disease, a series of Aβ aggregation inhibitors having quinoline scaffold were designed utilizing computational biology tools, synthesized and characterized by various spectral techniques including single-crystal X-ray crystallography. Organic syntheses relying upon convergent synthetic routes were employed. Investigations via ThT fluorescence assay, electron microscopy and transmission electron microscopy revealed the synthesized derivatives to exhibit Aβ self-aggregation inhibition. Molecules 5g and 5a showed the highest inhibitory potential, 53.73% and 53.63% at 50 μM respectively; higher than the standard Aβ disaggregating agent, curcumin. Molecules 5g and 5a disaggregated AChE-induced (58.26%, 47.36%) Aβ aggregation more than two fold more than the standard drug-donepezil (23.66%) and inhibited Cu²⁺-induced Aβ aggregation. A docking study significantly showed their interaction with key residues of Aβ and the results were in accordance with the study. Besides, these compounds also exhibited potential antioxidant activity (5a, 2.7240 Trolox equivalent by ORAC assay) and metal chelating property. Furthermore, the stoichiometric ratio of Cu (ii)-5a and Cu(ii)-5g complexes were found by Job's method (0.5 : 1 for 5a and 0.8 : 1 for 5g). In silico ADMET profiling showed these derivatives to have drug like properties with very low toxicity effects in the pharmacokinetic study. Overall, these results displayed a multi-activity profile with promising Aβ aggregation inhibition and antioxidation and metal chelation activity that could be helpful for developing new multifunctional agents against Alzheimer's disease.

Synthesis, docking and anticancer activity of azo-linked hybrids of 1,3,4-thia-/oxadiazoles with cyclic imides

A series of novel analogues based on a diazole-imide pharmacophore were synthesized by diazotizing substituted 1,3,4-thia-/oxadiazol-2-amines and subsequently coupling the resulting diazonium salts with N-substituted cyclic imides. The resulting compounds C1 to C28 were characterized by various spectral methods, viz. IR, NMR and mass spectroscopy. All the synthesized compounds were tested against two human cancer cell lines: human breast adenocarcinoma cell line MCF-7 and colorectal adenocarcinoma cell line HT-29. Among the synthesized compounds, C14 (2-(4-chloro-3-((5-(4-nitrophenyl)-1,3,4-thiadiazol-2-yl)diazenyl)phenyl)-4,5,6,7-tetrahydro-1H-isoindole-1,3(2H)-dione) emerged as a potential candidate against both MCF-7 and HT-29 with [Formula: see text] values of 0.09 ± 0.02 [Formula: see text]M and 0.11 ± 0.03 [Formula: see text]M, respectively. Similarly, compound C16 displayed highest anticancer activity against MCF-7 cell line with [Formula: see text] = 0.07 ± 0.02 [Formula: see text]M. Target fishing (inverse docking) using ChemMapper server identified EGFR tyrosine and CDK2 kinases as high priority targets for this pharmacophore. Computational docking (AutoDock 4.2) was used to analyse the interactions between the target proteins and active compounds.

Molecular Insights into the Interaction of RONS and Thieno[3,2-c]pyran Analogs with SIRT6/COX-2: A Molecular Dynamics Study

SIRT6 and COX-2 are oncogenes target that promote the expression of proinflammatory and pro-survival proteins through a signaling pathway, which leads to increased survival and proliferation of tumor cells. However, COX-2 also suppresses skin tumorigenesis and their relationship with SIRT6, making it an interesting target for the discovery of drugs with anti-inflammatory and anti-cancer properties. Herein, we studied the interaction of thieno[3,2-c]pyran analogs and RONS species with SIRT6 and COX-2 through the use of molecular docking and molecular dynamic simulations. Molecular docking studies revealed the importance of hydrophobic and hydrophilic amino acid residues for the stability. The molecular dynamics study examined conformational changes in the enzymes caused by the binding of the substrates and how those changes affected the stability of the protein-drug complex. The average RMSD values of the backbone atoms in compounds 6 and 10 were calculated from 1000 ps to 10000 ps and were found to be 0.13 nm for both compounds. Similarly, the radius of gyration values for compounds 6 and 10 were found to be 1.87 ± 0.03 nm and 1.86 ± 0.02 nm, respectively. The work presented here, will be of great help in lead identification and optimization for early drug discovery.

Computer-Aided Drug Design in Epigenetics

Epigenetic dysfunction has been widely implicated in several diseases especially cancers thus highlights the therapeutic potential for chemical interventions in this field. With rapid development of computational methodologies and high-performance computational resources, computer-aided drug design has emerged as a promising strategy to speed up epigenetic drug discovery. Herein, we make a brief overview of major computational methods reported in the literature including druggability prediction, virtual screening, homology modeling, scaffold hopping, pharmacophore modeling, molecular dynamics simulations, quantum chemistry calculation, and 3D quantitative structure activity relationship that have been successfully applied in the design and discovery of epi-drugs and epi-probes. Finally, we discuss about major limitations of current virtual drug design strategies in epigenetics drug discovery and future directions in this field.

Alginate oligosaccharide indirectly affects toll-like receptor signaling via the inhibition of microRNA-29b in aneurysm patients after endovascular aortic repair

Endovascular aortic repair (EVAR) is often followed by aneurysm recurrence. Alginate oligosaccharide (AOS) has potential antitumor properties as a natural product while the related mechanisms remain unclear. Toll-like receptor (TLR) signaling is associated with inflammatory activity of aneurysm and may be affected by miR-29b. Thus, inhibitory function of AOS on aneurysms was explored by measuring the important molecules in TLR4 signaling. After EVAR, a total of 248 aortic aneurysm patients were recruited and randomly assigned into two groups: AOS group (AG, oral administration 10-mg AOS daily) and control group (CG, placebo daily). The size of residual aneurysms, aneurysm recurrence, and side effects were investigated. Aneurysm recurrence was determined by Kaplan-Meier analysis. After 2 years, eight and two patients died in the CG and AG, respectively. The sizes of residual aneurysms were significantly larger in the CG than in the AG (P<0.05). The incidence of aneurysm recurrence was also significantly higher in the CG than in the AG (P<0.05). AOS treatment reduced the levels of miR-29b, TLR4, mitogen-activated protein kinase (MAPK), nuclear factor kappa B (NF-kappa B), interleukin 1 (IL-1) beta, and interleukin 6 (IL-6). Overexpression and silence of miR-29b increased and reduced the level of TLR4, phospho-p65 NF-kappa B, phospho-p38 MAPK, IL-1 beta, and IL-6. Spearman's rank correlation analysis shows that the level of miR-29b is positively related to the levels of TLR4, NF-kappa B, IL-1 beta, and IL-6 (P<0.05). Thus, AOS represses aneurysm recurrence by indirectly affecting TLR signaling via miR-29b.

Novel Gomisin B analogues as potential cytotoxic agents: Design, synthesis, biological evaluation and docking studies

As part of pharmacological-phytochemical integrated studies on medicinal flora, Gomisin B (1) was isolated as major phytochemical lead from schisandra grandiflora, a plant traditionally used in different Asian systems of medicine. A series of 1,2,3-triazoles derivatives were synthesized at the C-7' position of the gomisin B core through diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5q) were well characterized using modern spectroscopic techniques and evaluated for their anti-cancer activity against a panel of five human cancerous cell-lines. Among them, compound 5b exhibited the best cytotoxicity against SIHA cell (IC₅₀ 0.24 μM) which was more than the standard drug doxorubicin, while the other derivatives were exhibited moderate to low activities in tested cell lines. The cell cycle analysis indicated that compound 5b stalled HeLa cells at G2/M phase. 5b promoted tubulin polymerization and this was supported by the docking studies, wherein 5b showed significant binding affinity at the colchicine binding pocket of tubulin. Overall, we identified a novel small molecule that demonstrated anticancer activity by promoting in vitro tubulin assembly.

Molecular docking, QSAR and ADMET studies of withanolide analogs against breast cancer

Withanolides are a group of pharmacologically active compounds present in most prodigal amounts in roots and leaves of Withania somnifera (Indian ginseng), one of the most important medicinal plants of Indian traditional practice of medicine. Withanolides are steroidal lactones (highly oxygenated C-28 phytochemicals) and have been reported to exhibit immunomodulatory, anticancer and other activities. In the present study, a quantitative structure activity relationship (QSAR) model was developed by a forward stepwise multiple linear regression method to predict the activity of withanolide analogs against human breast cancer. The most effective QSAR model for anticancer activity against the SK-Br-3 cell showed the best correlation with activity (r²=0.93 and rCV² =0.90). Similarly, cross-validation regression coefficient (rCV²=0.85) of the best QSAR model against the MCF7/BUS cells showed a high correlation (r²=0.91). In particular, compounds CID_73621, CID_435144, CID_301751 and CID_3372729 have a marked antiproliferative activity against the MCF7/BUS cells, while 2,3-dihydrowithaferin A-3-beta-O-sulfate, withanolide 5, withanolide A, withaferin A, CID_10413139, CID_11294368, CID_53477765, CID_135887, CID_301751 and CID_3372729 have a high activity against the Sk-Br-3 cells compared to standard drugs 5-fluorouracil (5-FU) and camptothecin. Molecular docking was performed to study the binding conformations and different bonding behaviors, in order to reveal the plausible mechanism of action behind higher accumulation of active withanolide analogs with β-tubulin. The results of the present study may help in the designing of lead compound with improved activity.

Monitoring ZEO apoptotic potential in 2D and 3D cell cultures and associated spectroscopic evidence on mode of interaction with DNA

Recognizing new anticancer compounds to improve Breast cancer treatment seems crucial. Essential oil of Zataria Multiflora (ZEO) is a secondary metabolite with some biological properties, yet underlying cellular and molecular anticancer properties of ZEO is unclear. GC/MS analysis revealed that carvacrol is the major ingredient of the essential oil. ZEO increasingly suppressed viability in MDA-MB-231, MCF-7 and T47D Breast cancer cells while nontoxic to L929 normal cells in monolayer cell cultures (2D), whereas MDA-MB-231 multicellular spheroids (3D) were more resistant to inhibition. ZEO significantly induced cell apoptosis confirmed by fluorescent staining, flow cytometry analysis and DNA fragmentation in MDA-MB-231 2D and 3D cell cultures. ZEO increased ROS generation and subsequent loss of ΔΨm, caspase 3 activation and DNA damage which consequently caused G1 and G2/M cell cycle arrest in a dose- and time-dependent manner in 2D. S phase arrest occurred in cell spheroids therefore ZEO possible DNA interaction with gDNA was investigated and revealed ZEO binds DNA via intercalation. Altogether, these data corroborate anticancer properties of ZEO and suggest that cell culture format (2D monolayer vs. 3D spheroid) plays a critical role in drug response and provides new insights into the mechanisms underlying ZEO cytotoxicity effect on Breast cancer cells.