Synthesis of novel benzodioxane midst piperazine moiety decorated chitosan silver nanoparticle against biohazard pathogens and as potential anti-inflammatory candidate: A molecular docking studies

A facile method for monitoring sphingomyelin synthase activity in HeLa cells using liquid chromatography/mass spectrometry

Sphingomyelin synthase (SMS) is a sphingolipid-metabolizing enzyme involved in the de novo synthesis of sphingomyelin (SM) from ceramide (Cer). Recent studies have indicated that SMS is a key therapeutic target for metabolic diseases such as fatty liver, type 2 diabetes, atherosclerosis, and colorectal cancer. However, very few SMS inhibitors have been identified because of the limited sensitivity and selectivity of the current fluorescence-based screening assay. In this study, we developed a simple cell-based assay coupled with liquid chromatography/tandem mass spectrometry (LC-MS/MS) to screen for SMS inhibitors. HeLa cells stably expressing SMS1 or SMS2 were used for the screening. A non-fluorescent unnatural C6-Cer was used as a substrate for SMS to produce C6-SM. C6-Cer and C6-SM levels in the cells were monitored and quantified using LC-MS/MS. The activity of ginkgolic acid C15:1 (GA), a known SMS inhibitor, was measured. GA had half-maximal inhibitory concentrations of 5.5 μM and 3.6 μM for SMS1 and SMS2, respectively. To validate these findings, hSMS1 and hSMS2 proteins were optimized for molecular docking studies. In silico analyses were conducted to assess the interaction of GA with SMS1 and SMS2, and its binding affinity. This study offers an analytical approach for screening novel SMS inhibitors and provides in silico support for the experimental findings.

Design, synthesis and molecular docking of novel D-ring substituted steroidal 4,5-dihydropyrazole thiazole derivatives that act as iNOS/COX-2 inhibitors with potent anti-inflammatory activity against LPS-induced RAW264.7 macrophage cells

Inflammation, an important biological protective response to tissue damage or microbial invasion, is considered to be an alarming signal for the progress of varied biological complications. Based on the previous reports in the literature that proved the noticeable efficacy of pyrazole and thiazole scaffold as well as nitrogen heterocyclic based compounds against acute and chronic inflammatory disease, a new set of novel D-ring substituted steroidal 4,5-dihydropyrazole thiazole derivatives were synthesized and evaluated their anti-inflammatory activities in vitro. Preliminary structure-activity relationship (SAR) analysis was conducted by their inhibitory activities against nitric oxide (NO) release in lipopolysaccharide (LPS)-induced RAW 264.7 cells, and the optimal compound 12b [3β-hydroxy-pregn-5-en-17β-yl-5'- (o- chlorophenyl)- 1'-(4''- phenyl -[1'', 3'']- thiazol-2''- yl) - 4',5'-dihydro - 1'H-pyrazol - 3'- yl] exhibited more potent anti-inflammatory activity than the positive control treatment methylprednisolone (MPS), with an IC50 value of 2.59 μM on NO production and low cytotoxicity against RAW 264.7 cells. In further mechanism study, our results showed that compound 12b significantly suppressed the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and inhibited the expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) through blocking NF-κB p65 nuclear translocation and phosphorylation of IκBα. Compound 12b also attenuated LPS-induced activation of c-Jun amino-terminal kinase (JNK) and p38 phosphorylation in RAW 264.7 cells. Molecular docking study revealed the strong binding affinity of compound 12b to the active site of the COX-2 proteins, which confirmed that compound 12b acted as an anti-inflammatory mediator. These results indicate that steroidal derivatives bearing 4,5-dihydropyrazole thiazole structure might be considered for further research and scaffold optimization in designing anti-inflammatory drugs and compound 12b might be a promising therapeutic anti-inflammatory drug candidate.

Nanodelivery of antiretroviral drugs to nervous tissues

Despite the development of effective combined antiretroviral therapy (cART), the neurocognitive impairments associated with human immunodeficiency virus (HIV) remain challenging. The presence of the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCFB) impedes the adequate penetration of certain antiretroviral drugs into the brain. In addition, reports have shown that some antiretroviral drugs cause neurotoxicity resulting from their interaction with nervous tissues due to long-term systemic exposure. Therefore, the research into the effective therapeutic modality that would cater for the HIV-associated neurocognitive disorders (HAND) and ART toxicity is now receiving broad research attention. Thus, this review explores the latest information in managing HAND using a nanoparticle drug delivery system (NDDS). We discussed the neurotoxicity profile of various approved ART. Also, we explained the applications of silver nanoparticles (AgNPs) in medicine, their different synthesis methods and their interaction with nervous tissues. Lastly, while proposing AgNPs as useful nanoparticles in properly delivering ART to enhance effectiveness and minimize neurocognitive disorders, we hypothesize that the perceived toxicity of AgNPs could be minimized by taking appropriate precautions. One such precaution is using appropriate reducing and stabilizing agents such as trisodium citrate to reduce silver ion Ag + to ground state Ag0 during the synthesis. Also, the usage of medium-sized, spherical-shaped AgNPs is encouraged in AgNPs-based drug delivery to the brain due to their ability to deliver therapeutic agents across BBB. In addition, characterization and functionalization of the synthesized AgNPs are required during the drug delivery approach. Putting all these factors in place would minimize toxicity and enhance the usage of AgNPs in delivering therapeutic agents across the BBB to the targeted brain tissue and could cater for the HIV-associated neurocognitive disorders and neurotoxic effects of antiretroviral drugs (ARDs).

Chitosan/calcium nanoparticles as advanced antimicrobial coating for paper documents

Preservation of paper-based historical artifacts against deterioration due to the presence of bacteria and fungi colonies has been one of the major issues for the importance of protecting the cultural heritage of humankind. Advances in nanotechnology have enabled the implementation of nanomaterials for this purpose. In this work, calcium/chitosan nanoparticles (Ca/CS NPs) were prepared and well-characterized to investigate their potential as a novel approach for preserving paper-based documents. Following the fundamental characterizations, it was found that Ca/CS NPs are spherical nanoparticles with ~65 nm average size and homogenous dispersion (PdI: 0.2). Besides, minimum inhibition concentration results revealed that Ca/CS NPs show a superior antimicrobial effect against specific bacteria and fungi strains commonly found on paper documents compared to the effect of bare chitosan nanoparticles (CS NPs). After the deposition of Ca/CS NPs onto the paper the pH level was increased and stabilized, and only a limited amount of microbial colony formation was observed for up to 20 days. Moreover, molecular docking analysis provided a better insight into the antibacterial and antifungal activities of these nanoparticles. The antimicrobial activity of CS NPs and Ca/CS NPs was investigated through their interactions with E. coli DNA gyrase B and C. albicans dihydrofolate reductase. The binding modes and all possible interactions of active sites were confirmed by in silico molecular docking method. Collectively, our findings revealed that the formulated Ca/CS NPs are promising candidates for preserving paper documents.

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

The biogenic synthesis of silver nanoparticles (AgNPs) has a wide range of applications in the pharmaceutical industry. Here, we synthesized AgNPs using the aqueous flower extract of Bauhinia tomentosa Linn. Formation of AgNPs was observed using ultraviolet-visible light spectrophotometry at different time intervals. Maximum absorption was observed after 4 h at 420 nm due to the reduction of Ag⁺ to Ag⁰. The stabilizing activity of functional groups was identified by Fourier-transform infrared spectroscopy. Size and surface morphology were also analyzed using scanning electron microscopy. The present study revealed the AgNPs were spherical in form with a diameter of 32 nm. The face-centered cubic structure of AgNPs was indexed using X-ray powder diffraction with peaks at 2θ = 37°, 49°, 63°, and 76° (corresponding to the planes of silver 111, 200, 220, 311), respectively. Energy-dispersive X-ray spectroscopy revealed that pure reduced silver (Ag⁰) was the major constituent (59.08%). Antimicrobial analyses showed that the biosynthesized AgNPs possess increased antibacterial activity (against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), with larger zone formation against S. aureus (9.25 mm) compared with that of E. coli (6.75 mm)) and antifungal activity (against Aspergillus flavus and Candida albican (with superior inhibition against A. flavus (zone of inhibition: 7 mm) compared with C. albicans (zone of inhibition: 5.75 mm)). Inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found to be dose-dependent with half-maximal inhibitory concentration (IC₅₀) values of 56.77 μg/mL and 43.03 μg/mL for AgNPs and ascorbic acid (control), respectively, thus confirming that silver nanoparticles have greater antioxidant activity than ascorbic acid. Molecular docking was used to determine the mode of antimicrobial interaction of our biosynthesized B. tomentosa Linn flower-powder extract-derived AgNPs. The biogenic AgNPs preferred hydrophobic contacts to inhibit bacterial and fungal sustainability with reducing antioxidant properties, suggesting that biogenic AgNPs can serve as effective medicinal agents.

Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.

An Overview of the Antimicrobial Activity of Polymeric Nanoparticles Against Enterobacteriaceae

Bacterial resistance is considered one of the most important public health problems of the century, due to the ability of bacteria to rapidly develop resistance mechanisms, which makes it difficult to treat infections, leading to a high rate of morbidity and mortality. Based on this, several options are being sought as an alternative to currently available treatments, with a particular focus on nanotechnology. Nanomaterials have important potential for use in medical interventions aimed at preventing, diagnosing and treating numerous diseases by directing the delivery of drugs. This review presents data on the use of polymeric nanoparticles having in vitro and in vivo activity against bacteria belonging to the Enterobacteriaceae family.

Design and synthesis of methoxyphenyl- and coumarin-based chalcone derivatives as anti-inflammatory agents by inhibition of NO production and down-regulation of NF-κB in LPS-induced RAW264.7 macrophage cells

Exaggerated inflammatory responses may cause serious and debilitating diseases such as acute lung injury and rheumatoid arthritis. Two series of chalcone derivatives were prepared as anti-inflammatory agents. Methoxylated phenyl-based chalcones 2a-l and coumarin-based chalcones 3a-f were synthesized and compared for their inhibition of COX-2 enzyme and nitric oxide production suppression. Methoxylated phenyl-based chalcones showed better inhibition to COX-2 enzyme and nitric oxide suppression than the coumarin-based chalcones. Among the 18 synthesized chalcone derivatives, compound 2f exhibited the highest anti-inflammatory activity by inhibition of nitric oxide concentration in LPS-induced RAW264.7 macrophages (IC₅₀ = 11.2 μM). The tested compound 2f showed suppression of iNOS and COX-2 enzymes. Moreover, compound 2f decreases in the expression of NF-κB and phosphorylated IκB in LPS-stimulated macrophages. Finally, docking studies suggested the inhibition of IKKβ as a mechanism of action and highlighted the importance of 2f hydrophobic interactions.

Exploring the properties and potential biomedical applications of NSAID-capped peptide hydrogels

The development of strategies to minimise the adverse side-effects of non-steroidal anti-inflammatory drugs (NSAIDs) remains a challenge for medicinal chemists. One such strategy is the development of NSAID-peptide prodrug conjugates and this conjugation to a peptide often confers the additional property of hydrogelation. This review summarises the work published by our research group, alongside other research groups, on supramolecular hydrogels consisting of short peptides conjugated to NSAIDs. Generally, supramolecular low molecular weight hydrogels (LMWHs) are composed of amphiteric molecules, usually consisting of short peptides attached to an aromatic capping group. When the aromatic capping group is switched for an NSAID to afford hybrid gelators, some conjugates exhibit retained or improved anti-inflammatory properties of the parent drug, and sometimes new and unexpected biological activities are observed. Conjugation to peptides often provides selective COX-2 inhibition over COX-1 inhibtion, which is key to retaining the anti-inflammatory benefits of NSAIDs whilst minimising gastric side-effects. Naproxen is the most commonly employed NSAID capping group, partly due to its similarity in structure to commonly employed naphthalene capping groups. Biomimetic approaches, where canonical amino acids are switched for non-natural amino acids such as d-amino acids or dehydroamino acids, are often employed, to tune the stability. The future direction for this area of research is discussed.

New indole-7-aldehyde derivatives as melatonin analogues; synthesis and screening their antioxidant and anticancer potential

Over the last decade, there has been substantial interest in the use of melatonin (MLT) and MLT-like compounds in the treatment of several diseases. MLT can scavenge different reactive oxygen species and can also stimulate the synthesis of antioxidant enzymes. Our ongoing study relies on changing the groups in the different modifiable sites of the indole ring to increase the antioxidant activity. In this study a new approach for substitution of indole ring as indole based MLT analogue was proposed. We report the synthesis and characterization of a series of new indole-7-aldehyde hydrazide/hydrazone derivatives as indole-based MLT analogues. Anticancer potential of the compounds were evaluated both by their antioxidant and CYP1 inhibitory activities. In vitro antioxidant capacity of the compounds was investigated both in a cell-based (DCFH assay) and a cell-free (DPPH assay) assay. Potential inhibitory effects of the compounds on CYP1 catalytic activity were investigated via EROD assay. Cytotoxic activity of the compounds was further evaluated by the MTT assay in CHO-K1 cells. MLT analogues having an o-halogenated aromatic moiety exhibited effective antioxidant properties without having any cytotoxic effect. In conclusion, MLT derivatives represent promising scaffolds for discovery of effective antioxidant agents.

Synthesis, docking and evaluation of in vitro anti-inflammatory activity of novel morpholine capped β-lactam derivatives

This study reports the synthesis and biological investigation of three series of novel monocyclic β-lactam derivatives bearing a morpholine ring substituent on the nitrogen. The resulting β-lactam adducts were synthesized via Staudinger's [2 + 2]-ketene-imine cycloaddition reaction. New synthesized products were fully characterized by spectral data and elemental analyses, and then evaluated for anti-inflammatory activity toward human inducible nitric oxide synthase (iNOS) and cytotoxicity toward HepG2 cell line. The compounds 3e, 3h, 3k, 5c, 5f, 6c, 6d and 6f showed higher activity with anti-inflammatory ratio values of 38, 62, 51, 72, 51, 35, 55 and 99, respectively, in comparison to the reference compound dexamethasone having an anti-inflammatory ratio value of 32. Hence, these compounds can be considered as potent iNOS inhibitors. They also exhibited IC50 values of 0.48 ± 0.04 mM, 0.51 ± 0.01 mM, 0.22 ± 0.02 mM, 0.12 ± 0.00 mM, 0.25 ± 0.05 mM, 0.82 ± 0.07 mM, 0.44 ± 0.04 mM and 0.60 ± 0.04 mM, respectively, in comparison with doxorubicin (IC50 < 0.01 mM) against HepG2 cells, biocompatibility and nontoxic behavior. In silico prediction of drug-likeness characteristic indicated that the compounds are compliant with the Lipinski and Veber rules. Molecular docking experiments showed a good correlation between the experimental activity and the calculated binding affinity to human inducible nitric oxide synthase, the enzymatic target for the anti-inflammatory response.

1,4-Benzodioxane, an evergreen, versatile scaffold in medicinal chemistry: A review of its recent applications in drug design

1,4-Benzodioxane has long been a versatile template widely employed to design molecules endowed with diverse bioactivities. Its use spans the last decades of medicinal chemistry until today concerning many strategies of drug discovery, not excluding the most advanced ones. Here, more than fifty benzodioxane-related lead compounds, selected from recent literature, are presented showing the different approaches with which they have been developed. Agonists and antagonists at neuronal nicotinic, α₁ adrenergic and serotoninergic receptor subtypes and antitumor and antibacterial agents form the most representative classes, but a variety of other biological targets are addressed by benzodioxane-containing compounds.

In situ construction of hybrid MnO2@GO heterostructures for enhanced visible light photocatalytic, anti-inflammatory and anti-oxidant activity

Hybrid MnO₂@GO heterostructure nano-composites with enhanced visible light photocatalytic, anti-oxidant and anti-inflammatory activity.

New ibuprofen derivatives as H2S and NO donors as safer anti-inflammatory agents

Aim: Nonsteroidal anti-inflammatory drugs are expansively used worldwide. However, their prolonged administration is associated with serious side effects, especially gastrointestinal ulceration. Materials & methods: New ibuprofen derivatives hybridized with H₂S- or NO-donating moieties were synthesized and evaluated for their anti-inflammatory activity and ulcerogenic effect. COX-1/COX-2 isozymes selectivity test for the most promising derivatives was performed. Molecular docking studies were performed. Results: Most of the compounds showed promising anti-inflammatory activity comparable to that of ibuprofen (% edema inhibition = 76.6 and ulcer index = 21.26) with much better gastrointestinal tract tolerance (ulcer indices ranging from 0 to 14.67), especially compound 2 -H₂S donor- (% edema inhibition = 75.5 and ulcer index = 11.75) and compound 16 -NO donor- (% edema inhibition = 65.4 and ulcer index = 8.66).

A novel copper (II) PAmPiCaT complex (cPAmPiCaTc) as a biologically potent candidate: A contraption evidence against methicillin-resistant Staphylococcus aureus (MRSA) and a molecular docking proof

Increasing in the alarm against the resistant bacteria due to the failure of antibiotics, thereby the need of more efficiency/potent molecule to treat infections. In the present investigation, series of piperazine derivatives 5(a-l) compounds were synthesized and they were characterised by different spectral techniques such as ¹H NMR, ¹³C NMR, IR and LCMS. A novel copper complex (cPAmPiCaTc) was developed for the first time by using potent analog 5e and characterized by IR and LCMS. The cPAmPiCaTc evaluated for antibacterial activity and showed excellent antimicrobial effect (12 ± 0.08 mm, ZOI) at MIC 20 µg/mL against MRSA compared to standard antibiotics streptomycin and bacitracin at MIC 10 µg/mL. The results show promising anti-staphylococcal action against MRSA which confirmed by membrane damage, bioelectrochemistry, gene regulation (SarA and DHFR), and in silico molecular docking studies. Further, the cPAmPiCaTc also showed excellent blood compatibility and this result pave the way for interesting metallodrug therapeutics in future against MRSA infections.

Biological properties of modified bioactive glass on dental pulp cells

Dental caries is a bacteria-caused condition classified among the most common chronic diseases worldwide. Treatment of dental caries implies the use of materials having regenerative and anti-bacterial properties, and controlling inflammation is critical for successful endodontic regeneration.

OBJECTIVES

The aim of this study was to fabricate and characterize a novel composite incorporating sol-gel derived silver-doped bioactive glass (BG) in a chitosan (CS) hydrogel at a 1:1 wt ratio(Ag-BG/CS).

METHODS

The effect of Ag-BG/CS on dental pulp cells (DPCs) proliferation was analyzed by CCK-8 assay, whereas the adhesion of DPCs was evaluated by confocal microscopy. The physical morphology of Ag-BG/CS was analyzed by scanning electron microscope. The anti-inflammatory effect of Ag-BG/CS was investigated by quantitative polymerase chain reaction (qPCR). Moreover, the effect of Ag-BG/CS on odontogenic differentiation of DPCs was studied by immunochemical staining, tissue-nonspecific alkaline phosphatase staining, qPCR, and western blot analyses. The antibacterial activity against dental caries key pathogenic bacteria was also evaluated.

RESULTS

The results of this study showed that Ag-BG/CS did not affect the proliferation of DPCs, it down-regulated the inflammatory-associated markers (IL-1β, IL-6, IL-8, TNF-α) of DPCs treated with Escherichia coli lipopolysaccharide (LPS) by inhibiting NF-κB pathway, and enhanced the in vitro odontogenic differentiation potential of DPCs. Furthermore, Ag-BG/CS strongly inhibited Streptococcus mutans and Lactobacillus casei growth.

CONCLUSIONS

This novel biomaterial possessed antibacterial and anti-inflammatory activity, also enhanced the odontogenic differentiation potential of LPS-induced inflammatory-reacted dental pulp cells. The material introduced in this study may thus represent a suitable dental pulp-capping material for future clinical applications.

Biomedical Applications of Silver Nanoparticles: An Up-to-Date Overview

During the past few years, silver nanoparticles (AgNPs) became one of the most investigated and explored nanotechnology-derived nanostructures, given the fact that nanosilver-based materials proved to have interesting, challenging, and promising characteristics suitable for various biomedical applications. Among modern biomedical potential of AgNPs, tremendous interest is oriented toward the therapeutically enhanced personalized healthcare practice. AgNPs proved to have genuine features and impressive potential for the development of novel antimicrobial agents, drug-delivery formulations, detection and diagnosis platforms, biomaterial and medical device coatings, tissue restoration and regeneration materials, complex healthcare condition strategies, and performance-enhanced therapeutic alternatives. Given the impressive biomedical-related potential applications of AgNPs, impressive efforts were undertaken on understanding the intricate mechanisms of their biological interactions and possible toxic effects. Within this review, we focused on the latest data regarding the biomedical use of AgNP-based nanostructures, including aspects related to their potential toxicity, unique physiochemical properties, and biofunctional behaviors, discussing herein the intrinsic anti-inflammatory, antibacterial, antiviral, and antifungal activities of silver-based nanostructures.

Development of piperazine-1-carbothioamide chitosan silver nanoparticles (P1C-Tit*CAgNPs) as a promising anti-inflammatory candidate: a molecular docking validation

Natural products are important leads in drug discovery. The search for effective plant-derived agents or their synthetic analogues has continued to be of interest to biologists and chemists for a long time. Herein, we have synthesized a novel compound, P1C, and P1C-Tit*CAgNPs from chitosan; P1C is a precursor and an anti-inflammatory candidate, which has been validated by molecular docking studies. The synthesized P1C-Tit*CAgNPs showed monodisperse, spherical, and cationic nature and antioxidant properties, protecting destabilization of the erythrocyte membrane by the azo compound 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH); the involvement of NPs as a protective agent for biomolecules, such as DNA and protein, followed by the treatment of NPs with AAPH was confirmed. The inhibition of cellular damage and leakage of cellular inflammatory agents was confirmed by AFM, SEM, TEM, SDS-PAGE, LDH, and PLA2 enzyme inhibition via in vitro studies. The anti-inflammatory property of P1C was further validated by in silico molecular docking studies and showed that, the P1C best pose aligned to PLA2 compared to standard drug. The significant anticancer property of P1C-Tit*CAgNPs was confirmed against MCF7, U373, and C6 cancer cell lines. Thus, the present study highlights the synthesized P1C in P1C-Tit*CAgNPs as a target PLA2-specific anti-inflammatory candidate, and further tuning of small and development-functionalized nanoparticles has a great future in medicine; hence, their clinical applications are warranted.