Design and synthesis of ibuprofen-quinoline conjugates as potential anti-inflammatory and analgesic drug candidates

Indole Compounds in Oncology: Therapeutic Potential and Mechanistic Insights

Cancer remains a formidable global health challenge, with current treatment modalities such as chemotherapy, radiotherapy, surgery, and targeted therapy often hindered by low efficacy and adverse side effects. The indole scaffold, a prominent heterocyclic structure, has emerged as a promising candidate in the fight against cancer. This review consolidates recent advancements in developing natural and synthetic indolyl analogs, highlighting their antiproliferative activities against various cancer types over the past five years. These analogs are categorized based on their efficacy against common cancer types, supported by biochemical assays demonstrating their antiproliferative properties. In this review, emphasis is placed on elucidating the mechanisms of action of these compounds. Given the limitations of conventional cancer therapies, developing targeted therapeutics with enhanced selectivity and reduced side effects remains a critical focus in oncological research.

Fenamates and ibuprofen as foundational components in the synthesis of innovative, targeted COX-2 anti-inflammatory drugs, undergoing thorough biopharmacological assessments and in-silico computational studies

Cyclooxygenase-2 plays a vital role in inflammation by catalyzing arachidonic acid conversion toward prostaglandins, making it a prime therapeutic objective. Selective COX-2 inhibitors represent significant progress in anti-inflammatory therapy, offering improved efficacy and fewer side effects. This study describes the synthesis of novel anti-inflammatory compounds from established pharmaceutically marketed agents like fenamates III-V and ibuprofen VI. Through rigorous in vitro testing, compounds 7b-c, and 12a-b demonstrated substantial in vitro selective inhibition, with IC50 values of 0.07 to 0.09 μM, indicating potent pharmacological activity. In vivo assessment, particularly focusing on compound 7c, revealed significant anti-inflammatory effects. Markedly, it demonstrated the highest inhibition of paw thickness (58.62 %) at the 5-hr mark compared to the carrageenan group, indicating its potency in mitigating inflammation. Furthermore, it exhibited a rapid onset of action, with a 54.88 % inhibition observed at the 1-hr mark. Subsequent comprehensive evaluations encompassing analgesic efficacy, histological characteristics, and toxicological properties indicated that compound 7c did not induce gastric ulcers, in contrast to the ulcerogenic tendency associated with mefenamic acid. Moreover, compound 7c underwent additional investigations through in silico methodologies such as molecular modelling, field alignment, and density functional theory. These analyses underscored the therapeutic potential and safety profile of this novel compound, warranting further exploration and development in the realm of pharmaceutical research.

Experimental and Machine-Learning-Assisted Design of Pharmaceutically Acceptable Deep Eutectic Solvents for the Solubility Improvement of Non-Selective COX Inhibitors Ibuprofen and Ketoprofen

Deep eutectic solvents (DESs) are commonly used in pharmaceutical applications as excellent solubilizers of active substances. This study investigated the tuning of ibuprofen and ketoprofen solubility utilizing DESs containing choline chloride or betaine as hydrogen bond acceptors and various polyols (ethylene glycol, diethylene glycol, triethylene glycol, glycerol, 1,2-propanediol, 1,3-butanediol) as hydrogen bond donors. Experimental solubility data were collected for all DES systems. A machine learning model was developed using COSMO-RS molecular descriptors to predict solubility. All studied DESs exhibited a cosolvency effect, increasing drug solubility at modest concentrations of water. The model accurately predicted solubility for ibuprofen, ketoprofen, and related analogs (flurbiprofen, felbinac, phenylacetic acid, diphenylacetic acid). A machine learning approach utilizing COSMO-RS descriptors enables the rational design and solubility prediction of DES formulations for improved pharmaceutical applications.

Harnessing molecular hybridization approach to discover novel quinoline EGFR-TK inhibitors for cancer treatment

Aim: Using molecular hybridization approach, novel 18 quinoline derivatives (6a-11) were designed and synthesized as EGFR-TK inhibitors. Materials & methods: The antiproliferative activity was assessed against breast (MCF-7), leukemia (HL-60) and lung (A549) cancer cell lines. Moreover, the most active quinoline derivatives (6d and 8b) were further investigated for their potential as EGFR-TK inhibitors. In addition, cell cycle analysis and apoptosis induction activity were conducted. Results: A considerable cytotoxic activity was attained with IC50 values spanning from 0.06 to 1.12 μM. Besides, the quinoline derivatives 6d and 8b displayed potent inhibitory activity against EFGR with IC50 values of 0.18 and 0.08 μM, respectively. Conclusion: Accordingly, the afforded quinoline derivatives can be used as promising lead anticancer candidates for future optimization.

Quinoline-sulfonamides as a multi-targeting neurotherapeutic for cognitive decline: in vitro, in silico studies and ADME evaluation of monoamine oxidases and cholinesterases inhibitors

Alzheimer's disease (AD) is a multifactorial irreversible neurological disorder with multiple enzymes involved. In the treatment of AD, multifunctional agents targeting cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors have shown promising results. Herein, a series of novel quinoline-sulfonamides (a1-18) were designed and synthesized as a dual inhibitor of MAOs and ChEs. The in vitro results showed that compounds a5, a12, a11, and a6 exhibited the most potent compounds against specific enzymes. They had IC50 value 0.59 ± 0.04 for MAO-A, 0.47 ± 0.03 for MAO-B, 0.58 ± 0.05 for BChE and 1.10 ± 0.77 for AChE μM respectively. Furthermore, kinetic studies revealed that these compounds are competitive. Molecular docking studies enhanced the understanding of the in silico component, unveiling critical interactions, specifically the hydrogen bonding interaction, π-π, π-alkyl, π-amid and π-sulfur interactions between the ligand and enzymes. These findings suggest that compounds a5, a6, a11, a12, a15, and a18 may be potent multifunctional candidates for AD treatment.

Antineoplastic indole-containing compounds with potential VEGFR inhibitory properties

Cancer is one of the most significant health challenges worldwide. Various techniques, tools and therapeutics/materials have been developed in the last few decades for the treatment of cancer, together with great interest, funding and efforts from the scientific society. However, all the reported studies and efforts seem insufficient to combat the various types of cancer, especially the advanced ones. The overexpression of tyrosine kinases is associated with cancer proliferation and/or metastasis. VEGF, an important category of tyrosine kinases, and its receptors (VEGFR) are hyper-activated in different cancers. Accordingly, they are known as important factors in the angiogenesis of different tumors and are considered in the development of effective therapeutic approaches for controlling many types of cancer. In this case, targeted therapeutic approaches are preferable to the traditional non-selective approaches to minimize the side effects and drawbacks associated with treatment. Several indole-containing compounds have been identified as effective agents against VEGFR. Herein, we present a summary of the recent indolyl analogs reported within the last decade (2012-2023) with potential antineoplastic and VEGFR inhibitory properties. The most important drugs, natural products, synthesized potent compounds and promising hits/leads are highlighted. Indoles functionalized and conjugated with various heterocycles beside spiroindoles are also considered.

Synthesis and In vitro and In silico Anti-inflammatory Activity of New Thiazolidinedione-quinoline Derivatives

BACKGROUND

Inflammation is a series of complex defense-related reactions. The inflammation cascade produces various pro-inflammatory mediators. Unregulated production of these pro-inflammatory mediators can lead to a wide range of diseases, including rheumatoid arthritis, sepsis, and inflammatory bowel disease. In the literature, the anti-inflammatory action of quinoline and thiazolidinedione nuclei are well established, alone, and associated with other nuclei. The synthesis of hybrid molecules is a strategy for obtaining more efficient molecules due to the union of pharmacophoric nuclei known to be related to pharmacological activity.

OBJECTIVES

Based on this, this work presents the synthesis of thiazolidinedione-quinoline molecular hybrids and their involvement in the modulation of cytokines involved in the inflammatory reaction cascade.

METHODS

After synthesis and characterization, the compounds were submitted to cell viability test (MTT), ELISA IFN-γ and TNF-α, adipogenic differentiation, and molecular docking assay with PPARy and COX-2 targets.

RESULTS

LPSF/ZKD2 and LPSF/ZKD7 showed a significant decrease in the concentration of IFN- γ and TNF-α, with a dose-dependent behavior. LPSF/ZKD4 at a concentration of 50 μM significantly reduced IL-6 expression. LPSF/ZKD4 demonstrates lipid accumulation with significant differences between the untreated and negative control groups, indicating a relevant agonist action on the PPARγ receptor. Molecular docking showed that all synthesized compounds have good affinity with PPARγ e COX-2, with binding energy close to -10,000 Kcal/mol.

CONCLUSION

These results demonstrate that the synthesis of quinoline-thiazolidinedione hybrids may be a useful strategy for obtaining promising candidates for new anti-inflammatory agents.

Molecular Hybridization of Alkaloids Using 1,2,3-Triazole-Based Click Chemistry

Alkaloids found in multiple species, known as 'driver species', are more likely to be included in early-stage drug development due to their high biodiversity compared to rare alkaloids. Many synthetic approaches have been employed to hybridize the natural alkaloids in drug development. Click chemistry is a highly efficient and versatile reaction targeting specific areas, making it a valuable tool for creating complex natural products and diverse molecular structures. It has been used to create hybrid alkaloids that address their limitations and serve as potential drugs that mimic natural products. In this review, we highlight the recent advancements made in modifying alkaloids using click chemistry and their potential medicinal applications. We discuss the significance, current trends, and prospects of click chemistry in natural product-based medicine. Furthermore, we have employed computational methods to evaluate the ADMET properties and drug-like qualities of hybrid molecules.

2-Oxoquinoline-based-thiosemicarbazones as multitargeting neurotherapeutics against Alzheimer's disease: In vitro and in silico studies of MAO and ChE inhibitors

Alzheimer's disease (AD) presents a multifactorial neurological disorder with multiple enzyme involvement in its onset. Conventional monotherapies fall short in providing long-term relief, necessitating the exploration of alternative multitargeting approaches to address the complexity of AD. Therefore, the design, synthesis, and in vitro and in silico evaluation of 2-oxoquinoline-based thiosemicarbazones 9a-r as multipotent analogs, able to simultaneously inhibit the cholinesterase (ChE) and monoamine oxidase (MAO) enzymes for the potential treatment of AD, are reported. In the in vitro experimental evaluation of MAO and ChE inhibition, all tested compounds demonstrated remarkable potency exhibiting nonselective inhibition of both MAO-A and MAO-B, and selective inhibition of acetylcholinesterase (AChE) over butyrylcholinesterase (BChE), with 9d, 9j, and 9m evolving as lead compounds for MAO-A, MAO-B, and AChE, displaying IC50 values of 0.35 ± 0.92, 0.50 ± 0.02, and 0.25 ± 0.13 μM, respectively. Moreover, the kinetic studies revealed that all tested compounds inhibited all three enzymes through a competitive mode of inhibition. Furthermore, the molecular docking studies of the most active compounds revealed several crucial interactions, particularly hydrogen bonding interactions. These interactions were observed between the nitrogen and sulfur atoms of thiosemicarbazone and the nitrogen and oxygen atoms of the quinoline ring with various amino acids, suggesting the strong interactions of these compounds with the enzymes.

Indole-Based Compounds as Potential Drug Candidates for SARS-CoV-2

The COVID-19 pandemic has posed a significant threat to society in recent times, endangering human health, life, and economic well-being. The disease quickly spreads due to the highly infectious SARS-CoV-2 virus, which has undergone numerous mutations. Despite intense research efforts by the scientific community since its emergence in 2019, no effective therapeutics have been discovered yet. While some repurposed drugs have been used to control the global outbreak and save lives, none have proven universally effective, particularly for severely infected patients. Although the spread of the disease is generally under control, anti-SARS-CoV-2 agents are still needed to combat current and future infections. This study reviews some of the most promising repurposed drugs containing indolyl heterocycle, which is an essential scaffold of many alkaloids with diverse bio-properties in various biological fields. The study also discusses natural and synthetic indole-containing compounds with anti-SARS-CoV-2 properties and computer-aided drug design (in silico studies) for optimizing anti-SARS-CoV-2 hits/leads.

Anxiolytic and anticonvulsant effect of Ibuprofen derivative through GABAergic neuromodulation in adult Zebrafish

Anxiety and epilepsy affect millions of people worldwide, and the treatment of these pathologies involves the use of Benzodiazepines, drugs that have serious adverse effects such as dependence and sedation, so the discovery of new anxiolytic and antiepileptic drugs are necessary. Many routes for synthesizing ibuprofen derivatives have been developed, and these derivatives have shown promising pharmacological effects. Therefore, this study aims to evaluate its anxiolytic and anticonvulsant effect against the adult Zebrafish animal model of Ibuprofen (IBUACT) and its interaction with the GABAergic receptor through in silico studies. The light/dark preference test (Scototaxis test) was used to evaluate the anxiolytic behavior of adult Zebrafish acutely treated with IBUACT and Diazepam, and their anticonvulsant effects were investigated through the pentylenetetrazol (PTZ)-induced seizure model. Animals treated with IBUACT showed anxiolytic behavior similar to Diazepam, and pretreatment with flumazenil reversed this behavior. PTZ-induced seizures were delayed by IBUACT in all three stages and were shown to bind strongly in the Diazepam region of GABAA. In addition, this work presents evidence of new pharmacological applications of ibuprofen derivative in pathologies of the central nervous system (CNS), opening the horizon for new studies.Communicated by Ramaswamy H. Sarma.

Recent advances in functionalized quinoline scaffolds and hybrids-Exceptional pharmacophore in therapeutic medicine

Quinoline is one of the most common nitrogen-containing heterocycles owing to its fascinating pharmacological properties and synthetic value in organic and pharmaceutical chemistry. Functionalization of this moiety at different positions has allowed for varying pharmacological activities of its derivative. Several publications over the last few decades have specified various methods of synthesis. This includes classical methods of synthesizing the primary quinoline derivatives and efficient methods that reduce reaction time with increased yield employing procedures that fulfill one of the twelve green chemistry principles, "safer solvent". The metal nanoparticle-catalyzed reaction also serves as a potent and effective technique for the synthesis of quinoline with excellent atom efficiency. The primary focus of this review is to highlight the routes to synthesizing functionalized quinoline derivatives, including hybrids that have moieties with predetermined activities bound to the quinoline moiety which are of interest in synthesizing drug candidates with dual modes of action, overcoming toxicity, and resistance amongst others. This was achieved using updated literature, stating the biological activities and mechanisms through which these compounds administer relief. The ADMET studies and Structure-Activity Relationship (SAR) of novel derivatives were also highlighted to explore the drug-likeness of the quinoline-hybrids and the influence of substituent characteristics and position on the biological activity of the compounds.

Synthesis of Potential Antiviral Agents for SARS-CoV-2 Using Molecular Hybridization Approach

We synthesized a set of small molecules using a molecular hybridization approach with good yields. The antiviral properties of the synthesized conjugates against the SAR-CoV-2 virus were investigated and their cytotoxicity was also determined. Among all the synthesized conjugates, compound 9f showed potential against SARS-CoV-2 and low cytotoxicity. The conjugates’ selectivity indexes (SIs) were determined to correlate the antiviral properties and cytotoxicity. The observed biological data were further validated using computational studies.

Synthesis, biological evaluation and molecular docking studies of novel diosgenin derivatives as anti-inflammatory agents

Thirty-two novel DG F-spiroacetal ring-opening derivatives, including 24 acetylated derivatives and 8 nitrogenous derivatives, were designed and synthesized from diosgenin (DG). The cytotoxicity of the novel derivatives was evaluated by MTT assay, except for compounds 4a, 4e, 4i, 4 l, 5a and 5 h, which were potentially cytotoxic to RAW264.7 cells, all the other derivatives had no significant cytotoxicity. The NO release inhibitory activities of novel derivatives were screened by Griess method. The results showed that the anti-inflammatory activity of the DG acetylated derivatives was stronger than the nitrogenous derivatives, and 4a-4 m containing acetyl groups at the 3-position may have better anti-inflammatory effects than 5a-5 k containing free hydroxyl groups. In ELISA assay, compound 4 m exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by LPS with IC₅₀ values 0.449 ± 0.050 μM. The results of docking experiments showed that 4 m has a good affinity for p65 protein.

Synthesis of New 1,2,3,4-Tetrahydroquinoline Hybrid of Ibuprofen and Its Biological Evaluation

Herein we report the obtaining of 1-(3,4-dihydroquinolin-1(2H)-yl)-2- (4-isobutylphenyl)propan-1-one and its characterization. The newly obtained hybrid and its derivatives (hybrids of ibuprofen with 1,2,3,4-tetrahydroisoquinoline, and piperidine) were screened for their in vitro antioxidant, antitryptic, and inhibition of albumin denaturation activity. The lipophilicity was established using both reversed-phase thin layer chromatography and in silico calculations.

Cytoprotective potentialities of carvacrol and its nanoemulsion against cisplatin-induced nephrotoxicity in rats: development of nano-encasulation form

Cisplatin (Cisp) is a widely distributed chemotherapeutic drug for cancers. Nephrotoxicity is one of the most common side effects of the use of this drug. Carvacrol (CV) is a common natural compound in essential oils and extracts of medicinal plants with potent in vivo and in vitro bioactivities. The work was extended to achieve the target of investigation of the protective potentialities of CV and its nanoemulsion as a cytoprotective drug against Cisp-induced nephrotoxicity in albino rats. CV-nanoemulsion was prepared by a hydrophilic surfactant polysorbate 80 (Tween 80) and deionized water. The TEM image of the particle distribution prepared nanoemulsion is mainly spherical in shape with particle size varying between 14 and 30 nm. Additionally, the Cisp administration caused the increasing of the levels of urea and creatinine in the blood and serum. These increasing of urea and creatinine levels caused consequently the turbulence of the oxidative stress as well as the rising of hs-CRP, IL-6, and TNF-α levels in the serum. Also, histopathological changes of the kidney tissue were observed. These changes back to normal by treatment with CV-nanoemulsion. Expression levels of nephrotoxicity-related genes including LGALS3, VEGF, and CAV1 in kidney tissue using qRT-PCR were measured. The results revealed that the expression of LGALS3, VEGF and CAV1 genes was highly significantly increased in only Cisp treated group when compared with other treated groups. While, these genes expressions were significantly decreased in Cisp + CV treated group when compared with Cisp treated rats (P < 0.001). In addition, there were no significant differences between Cisp + nano-CV treated group and both negative control and nanoemulsion alone groups but it was not significant. In addition, the Western blot of protein analysis results showed that the LGALS3 and CAV1 are highly expressed only in Cisp + CV treated group compared with other groups. There was no significant difference between Cisp + nano-CV treated animals and negative control for both mRNA and protein expression. Based on these results, CV was combined with calcium alginate; a more stable capsule is formed, allowing for the formation of a double wall in the microcapsule. These results supported the therapeutic effect of CV and its nano-emulsion as cytoprotective agents against Cisp nephrotoxicity.

Synthesis, Antibacterial Evaluation, and Computational Studies of a Diverse Set of Linezolid Conjugates

The development of new antibiotics to treat multidrug-resistant (MDR) bacteria or possess broad-spectrum activity is one of the challenging tasks. Unfortunately, there are not many new antibiotics in clinical trials. So, the molecular hybridization approach could be an effective strategy to develop potential drug candidates using the known scaffolds. We synthesized a total of 31 diverse linezolid conjugates 3, 5, 7, 9, 11, 13, and 15 using our established benzotriazole chemistry with good yield and purity. Some of the synthesized conjugates exhibited promising antibacterial properties against different strains of bacteria. Among all the synthesized compounds, 5d is the most promising antibacterial agent with MIC 4.5 µM against S. aureus and 2.25 µM against B. subtilis. Using our experimental data pool, we developed a robust QSAR (R2 = 0.926, 0.935; R2cvOO = 0.898, 0.915; R2cvMO = 0.903, 0.916 for the S. aureus and B. subtilis models, respectively) and 3D-pharmacophore models. We have also determined the drug-like properties of the synthesized conjugates using computational tools. Our findings provide valuable insight into the possible linezolid-based antibiotic drug candidates.