Ligand-Based Design on the Dog-Bone-Shaped BIBR1532 Pharmacophoric Features and Synthesis of Novel Analogues as Promising Telomerase Inhibitors with In Vitro and In Vivo Evaluations

Pharmacophore-based, rationale design, and efficient synthesis of novel tetrahydrobenzo[b]thiophene candidates as potential dual Topo I/II inhibitors and DNA intercalators

A series of tetrahydrobenzo[b]thiophene derivatives was designed and synthesized as dual topoisomerase (Topo) I/II inhibitors implicating potential DNA intercalation. Ethyl-2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-4-carboxylate (1) was prepared by modification of the Gewald reaction procedure using a Fe2O3 nanocatalyst and then it was used as a building block for the synthesis of tetrahydrobenzo[b]thiophene candidates (2-14). Interestingly, compound 14 showed the best cytotoxic potential against hepatocellular, colorectal, and breast cancer cell lines (IC50 = 7.79, 8.10, and 3.53 µM), respectively, surpassing doxorubicin at breast cancer (IC50 = 4.17 µM). Meanwhile, the Topo I and II inhibition assay displayed that compound 3 could exhibit the best inhibitory potential among the investigated candidates (IC50 = 25.26 and 10.01 nM), respectively, in comparison to camptothecin (IC50 = 28.34 nM) and doxorubicin (IC50 = 11.01 nM), as reference standards. In addition, the DNA intercalation assay showed that compound 14 could display the best binding affinity with an IC50 value of 77.82 µM in comparison to doxorubicin (IC50 = 58.03 µM). Furthermore, cell cycle and apoptosis analyses described that compound 3 prompts the G1 phase arrest in michigan cancer foundation-7 cancer cells and increases the apoptosis ratio by 29.31% with respect to untreated cells (2.25%). Additionally, the conducted molecular docking assured the promising binding of the investigated members toward Topo I and II with potential DNA intercalation. Accordingly, the synthesized compounds could be treated as promising anticancer candidates for future optimization.

Recent contributions of pyridazine as a privileged scaffold of anticancer agents in medicinal chemistry: An updated review

Pyridazine, as a privileged scaffold, has been extensively utilized in drug development due to its multiple biological activities. Especially around its distinctive anticancer property, a massive number of pyridazine-containing compounds have been synthesized and evaluated that target a diverse array of biological processes involved in cancer onset and progression. These include glutaminase 1 (GLS1) inhibitors, tropomyosin receptor kinase (TRK) inhibitors, and bromodomain containing protein (BRD) inhibitors, targeting aberrant tumor metabolism, cell signal transduction and epigenetic modifications, respectively. Pyridazine moieties functioned as either core frameworks or warheads in the above agents, exhibiting promising potential in cancer treatment. Therefore, the review aims to summarize the recent contributions of pyridazine derivatives as potent anticancer agents between 2020 and 2024, focusing mainly on their structure-activity relationships (SARs) and development strategies, with a view to show that the application of the pyridazine scaffold by different medicinal chemists provides new insights into the rational design of anticancer drugs.

Discovery of telomerase inhibitors: existing strategies and emerging innovations

Telomerase, crucial for maintaining telomere length, is an attractive target for cancer therapy due to its role in cellular immortality. Despite three decades of research efforts, no small-molecule telomerase inhibitors have been clinically approved, highlighting the extensive challenges in developing effective telomerase-based therapeutics. This review examines conventional and emerging methods to measure telomerase activity and discusses existing inhibitors, including oligonucleotides and small molecules. Furthermore, this review highlights recent breakthroughs in structural studies of telomerase using cryo-electron microscopy, which can facilitate improved structure-based drug design. Altogether, advancements in structural methodologies and high-throughput screening offer promising prospects for telomerase-based cancer therapeutic development.

A new framework for novel analogues of pazopanib as potent and selective human carbonic anhydrase inhibitors: Design, repurposing rational, synthesis, crystallographic, in vivo and in vitro biological assessments

Herein, we describe the design and synthesis of novel aryl pyrimidine benzenesulfonamides APBSs 5a-n, 6a-c, 7a-b, and 8 as pazopanib analogues to explore new potent and selective inhibitors for the CA IX. All APBSs were examined in vitro for their promising inhibition activity against a small panel of hCAs (isoforms I, II, IX, and XII). The X-ray crystal structure of CA I in adduct with a representative APBS analogue was solved. APBS-5m, endowed with the best hCA IX inhibitory efficacy and selectivity, was evaluated for antiproliferative activity against a small panel of different cancer cell lines, SK-MEL-173, MDA-MB-231, A549, HCT-116, and HeLa, and it demonstrated one-digit IC50 values range from 2.93 μM (MDA-MB-231) to 5.86 μM (A549). Furthermore, compound APBS-5m was evaluated for its influence on hypoxia-inducible factor (HIF-1α) production, apoptosis induction, and colony formation in MDA-MB-231 cancer cells. The in vivo efficacy of APBS-5m as an antitumor agent was additionally investigated in an animal model of Solid Ehrlich Carcinoma (SEC). In order to offer perceptions into the conveyed hCA IX inhibitory efficacy and selectivity in silico, a molecular docking investigation was also carried out.

Rationale design of novel substituted 1,3,5-triazine candidates as dual IDH1(R132H)/ IDH2(R140Q) inhibitors with high selectivity against acute myeloid leukemia: In vitro and in vivo preclinical investigations

In this study, novel substituted 1,3,5-triazine candidates (4a-d, 5a-j, and 6a-d) were designed as second-generation small molecules to act as dual IDH1 and IDH2 inhibitors according to the pharmacophoric features of both vorasidenib and enasidenib. Compounds 6a and 6b for leukemia cell lines showed from low to sub-micromolar GI50. Moreover, compounds 4c, 5f, and 6b described the frontier antitumor activity against THP1 and Kasumi Leukemia cancer cells with IC50 values of (10 and 12), (10.5 and 7), and (6.2 and 5.9) µg/mL, which were superior to those of cisplatin (25 and 28) µg/mL, respectively. Interestingly, compounds 4c, 6b, and 6d represented the best dual IDH1(R132H)/IDH2(R140Q) inhibitory potentials with IC50 values of (0.72 and 1.22), (0.12 and 0.93), and (0.50 and 1.28) µg/mL, respectively, compared to vorasidenib (0.02 and 0.08) µg/mL and enasidenib (0.33 and 1.80) µg/mL. Furthermore, the most active candidate (6b) has very promising inhibitory potentials towards HIF-1α, VEGF, and SDH, besides, a marked increase of ROS was observed as well. Besides, compound 6b induced the upregulation of P53, BAX, Caspases 3, 6, 8, and 9 proteins by 3.70, 1.99, 2.06, 1.73, 1.75, and 1.85-fold changes, respectively, and the downregulation for the BCL-2 protein by 0.55-fold change compared to the control. Besides, the in vivo behavior of compound 6b as an antitumor agent was evaluated in female mice bearing solid Ehrlich carcinoma tumors. Notably, compound 6b administration resulted in a prominent decrease in the weight and volume of the tumors, accompanied by improvements in biochemical, hematological, and histological parameters.

Marein Alleviates Doxorubicin-Induced Cardiotoxicity through FAK/AKT Pathway Modulation while Potentiating its Anticancer Activity

Doxorubicin (DOX) is an effective anticancer agent, yet its clinical utility is hampered by dose-dependent cardiotoxicity. This study explores the cardioprotective potential of Marein (Mar) against DOX-induced cardiac injury and elucidates underlying molecular mechanisms. Neonatal rat cardiomyocytes (NRCMs) and murine models were employed to assess the impact of Mar on DOX-induced cardiotoxicity (DIC). In vitro, cell viability, oxidative stress were evaluated. In vivo, a chronic injection method was employed to induce a DIC mouse model, followed by eight weeks of Mar treatment. Cardiac function, histopathology, and markers of cardiotoxicity were assessed. In vitro, Mar treatment demonstrated significant cardioprotective effects in vivo, as evidenced by improved cardiac function and reduced indicators of cardiac damage. Mechanistically, Mar reduced inflammation, oxidative stress, and apoptosis in cardiomyocytes, potentially via activation of the Focal Adhesion Kinase (FAK)/AKT pathway. Mar also exhibited an anti-ferroptosis effect. Interestingly, Mar did not compromise DOX's efficacy in cancer cells, suggesting a dual benefit in onco-cardiology. Molecular docking studies suggested a potential interaction between Mar and FAK. This study demonstrates Mar's potential as a mitigator of DOX-induced cardiotoxicity, offering a translational perspective on its clinical application. By activating the FAK/AKT pathway, Mar exerts protective effects against DOX-induced cardiomyocyte damage, highlighting its promise in onco-cardiology. Further research is warranted to validate these findings and advance Mar as a potential adjunctive therapy in cancer treatment.

LKB1 inhibits telomerase activity resulting in cellular senescence through histone lactylation in lung adenocarcinoma

Despite the confirmed role of LKB1 in suppressing lung cancer progression, its precise effect on cellular senescence is unknown. The aim of this research was to clarify the role and mechanism of LKB1 in restraining telomerase activity in lung adenocarcinoma. The results showed that LKB1 induced cellular senescence and apoptosis either in vitro or in vivo. Overexpression of LKB1 in LKB1-deficient A549 cells led to the inhibition of telomerase activity and the induction of telomere dysfunction by regulating telomerase reverse transcriptase (TERT) expression in terms of transcription. As a transcription factor, Sp1 mediated TERT inhibition after LKB1 overexpression. LKB1 induced lactate production and inhibited histone H4 (Lys8) and H4 (Lys16) lactylation, which further altered Sp1-related transcriptional activity. The telomerase inhibitor BIBR1532 was beneficial for achieving the optimum curative effect of traditional chemotherapeutic drugs accompanied by the glycolysis inhibitor 2DG. These data reveal a new mechanism by which LKB1 regulates telomerase activity through lactylation-dependent transcriptional inhibition, and therefore, provide new insights into the effects of LKB1-mediated senescence in lung adenocarcinoma. Our research has opened up new possibilities for the creation of new cancer treatments.

Discovery of new 1,3-diphenylurea appended aryl pyridine derivatives as apoptosis inducers through c-MET and VEGFR-2 inhibition: design, synthesis, in vivo and in silico studies

Interest has been generated in VEGFR-2 and c-MET as potential receptors for the treatment of different malignancies. Using aryl pyridine derivatives with 1,3-diphenylurea attached, a number of promising dual VEGFR-2 and c-MET inhibitors were developed and synthesized. Regarding the molecular target, compounds 2d, 2f, 2j, 2k, and 2n had potent IC50 values of 65, 24, 150, 170, and 18 nM against c-MET, respectively. Additionally, they had potent IC50 values of 310, 35, 290, 320, and 24 nM against VEGFR-2, respectively. Regarding cytotoxicity, compounds 2d, 2f, 2j, 2k and 2n exhibited potent cytotoxicity against MCF-7 with IC50 values in the range 0.76-21.5 μM, and they showed promising cytotoxic activity against PC-3 with IC50 values in the range 1.85-3.42 μM compared to cabozantinib (IC50 = 1.06 μM against MCF-7 and 2.01 μM against PC-3). Regarding cell death, compound 2n caused cell death in MCF-7 cells by 87.34-fold; it induced total apoptosis by 33.19% (8.04% for late apoptosis, 25.15% for early apoptosis), stopping their growth in the G2/M phase, affecting the expression of apoptosis-related genes P53, Bax, caspases 3 and 9 and the anti-apoptotic gene, Bcl-2. In vivo study illustrated the anticancer activity of compound 2n by reduction of tumor mass and volume, and the tumor inhibition ratio reached 56.1% with an improvement of hematological parameters. Accordingly, compound 2n can be further developed as a selective target-oriented chemotherapeutic against breast cancer.

Telomere-related DNA damage response pathways in cancer therapy: prospective targets

Maintaining the structural integrity of genomic chromosomal DNA is an essential role of cellular life and requires two important biological mechanisms: the DNA damage response (DDR) mechanism and telomere protection mechanism at chromosome ends. Because abnormalities in telomeres and cellular DDR regulation are strongly associated with human aging and cancer, there is a reciprocal regulation of telomeres and cellular DDR. Moreover, several drug treatments for DDR are currently available. This paper reviews the progress in research on the interaction between telomeres and cellular DNA damage repair pathways. The research on the crosstalk between telomere damage and DDR is important for improving the efficacy of tumor treatment. However, further studies are required to confirm this hypothesis.

Repurposed organoselenium tethered amidic acids as apoptosis inducers in melanoma cancer via P53, BAX, caspases-3, 6, 8, 9, BCL-2, MMP2, and MMP9 modulations

Organoselenium (OSe) agents hold promise for preventing cancer due to their potential ability to fight cancer development and protect cells from oxidative damage. Herein, OSe-based maleanilic and succinanilic acids were tested to estimate their antitumor activities against fifteen cancer cell lines. Besides, their potential safety and selectivity were further investigated against two normal cell lines, namely, human skin fibroblasts (HSF) and olfactory ensheathing cell line (OEC) using the growth inhibition percentage (GI%) assay. Moreover, the apoptotic potential of the superior anticancer candidates (8, 9, 10, and 11) was evaluated against P53, BAX, Caspase-3, Caspase-6, Caspase-8, Caspase-9, BCL-2, MMP2, and MMP9 apoptotic markers. Additionally, to enhance our understanding and predict the inhibitory potential of the examined compounds as potential anticancer agents, a thorough structure-activity relationship (SAR) analysis was conducted. On the other hand, molecular docking and ADMET studies were performed for the examined candidates as well. Overall, our findings point to significant anticancer activities of the organoselenium tethered amidic acids, suggesting their promising cytotoxic potential as effective anticancer drugs.

Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the β-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

Discovery and Mechanistic Studies of Dual-Target Hits for Carbonic Anhydrase IX and VEGFR-2 as Potential Agents for Solid Tumors: X-ray, In Vitro, In Vivo, and In Silico Investigations of Coumarin-Based Thiazoles

A dual-targeting approach is predicted to yield better cancer therapy outcomes. Consequently, a series of coumarin-based thiazoles (5a-h, 6, and 7a-e) were designed and constructed as potential carbonic anhydrase (CA) and VEGFR-2 suppressors. The inhibitory actions of the target compounds were assessed against CA isoforms IX and VEGFR-2. The assay results showed that coumarin-based thiazoles 5a, 5d, and 5e can effectively inhibit both targets. 5a, 5d, and 5e cytotoxic effects were tested on pancreatic, breast, and prostate cancer cells (PANC1, MCF7, and PC3). Further mechanistic investigation disclosed the ability of 5e to interrupt the PANC1 cell progression in the S stage by triggering the apoptotic cascade, as seen by increased levels of caspases 3, 9, and BAX, alongside the Bcl-2 decline. Moreover, the in vivo efficacy of compound 5e as an antitumor agent was evaluated. Also, molecular docking and dynamics displayed distinctive interactions between 5e and CA IX and VEGFR-2 binding pockets.

Multi-target rational design and synthesis of novel diphenyl-tethered pyrazolopyrimidines targeting EGFR and topoisomerase II with potential DNA intercalation and apoptosis induction

Herein, we envisioned the design and synthesis of novel pyrazolopyrimidines (confirmed by elemental analysis, 1H and 13C NMR, and mass spectra) as multitarget-directed drug candidates acting as EGFR/TOPO II inhibitors, DNA intercalators, and apoptosis inducers. The target diphenyl-tethered pyrazolopyrimidines were synthesized starting from the reaction of phenyl hydrazine and ethoxymethylenemalononitrile to give aminopyrazole-carbonitrile 2. The latter hydrolysis with NaOH and subsequent reaction with 4-chlorobenzaldhyde afforded the corresponding pyrazolo[3,4-d]pyrimidin-4-ol 4. Chlorination of 4 with POCl3 and sequential reaction with different amines afforded the target compounds in good yields (up to 73 %). The growth inhibition % of the new derivatives (6a-m) was investigated against different cancer and normal cells and the IC50 values of the most promising candidates were estimated for HNO97, MDA-MB-468, FaDu, and HeLa cancer cells. The frontier derivatives (6a, 6i, 6k, 6l, and 6m) were pursued for their EGFR inhibitory activity. Compound 6l decreased EGFR protein concentration by a 6.10-fold change, compared to imatinib as a reference standard. On the other side, compounds (6a, 6i, 6k, 6l, and 6m) underwent topoisomerase II (TOPO II) inhibitory assay. In particular, compounds 6a and 6l exhibited IC50s of 17.89 and 19.39 μM, respectively, surpassing etoposide with IC50 of 20.82 μM. Besides, the DNA fragmentation images described the great potential of both candidates 6a and 6l in inducing DNA degradation at lower concentrations compared to etoposide and doxorubicin. Moreover, compound 6l, with the most promising EGFR/TOPO II inhibition and DNA intercalation, was selected for further investigation for its apoptosis induction ability by measuring caspases 3, 7, 8, and 9, Bax, p53, MMP2, MMP9, and BCL-2 proteins. Additionally, molecular docking was used to explain the SAR results based on the differences in the molecular features of the investigated congeners and the target receptors' topology.

Design and synthesis of novel chloropyridazine hybrids as promising anticancer agents acting by apoptosis induction and PARP-1 inhibition through a molecular hybridization strategy

Guided by the molecular hybridization principle, a novel series of 4-chloropyridazinoxyphenyl conjugates (3a-h, 4a-e, and 5) was designed and synthesized as proposed apoptotic inducers and PARP-1 inhibitors. The growth inhibition % of the designed hybrids was investigated in eleven cancer cell lines, where the anticancer activities were found to be in the following order: 4-chloropyridazinoxyphenyl-aromatic ketones hybrids (3a-h) > 4-chloropyridazinoxyphenyl-benzyloxyphenylethan-1-one hybrids (4a-e) > 4-chloropyridazinoxyphenyl-thiazolidine-2,4-dione hybrid (5). Further, the most sensitive three cancer cell lines (HNO97, FaDu, and MDA-MB-468) were selected to measure the IC50 values of the new hybrids. Moreover, the frontier three members (3c, 3e, and 4b) were selected for the measurements of apoptotic protein markers (p53, BAX, caspase 3, caspase 6, BCL-2, and CK 18). Besides, the impact of compounds 3a-e and 4b on the activity of PARP-1 was investigated, where 3c, 3d, and 3e demonstrated comparable efficiencies to olaparib. Furthermore, γ-H2Ax, a well-established marker for double-strand DNA breaks, was examined and the occurrence of DNA damage was observed. In addition, a significant inhibition of cell proliferation and a remarkable 15 to 50-fold reduction in the number of colonies compared to the control group were recorded. Finally, the PARP-1 inhibitory potential of the novel hybrids was compared to the co-crystal of the target receptor (PDB ID: 6NTU) using molecular docking.

Development of new thieno[2,3-d]pyrimidines as dual EGFR and STAT3 inhibitors endowed with anticancer and pro-apoptotic activities

In part due to the resilience of cellular feedback pathways that develop therapeutic resistance to targeting the EGFR alone, using EGFR inhibitors alone was demonstrated to be unsuccessful in clinical trials. The over-activation of the signal transducer/activator of transcription 3 (STAT3) during the administration of an EGFR inhibitor is expected to play a substantial part in the failure and resistance of EGFR inhibitor treatment. Therein, we proposed a hypothesis that induced STAT3-mediated resistance to EGFR inhibition therapy could be addressed by a dual inhibition of EGFR and STAT3 method. To this end, we tried to discover new thieno[2,3-d]pyrimidine derivatives "5a-o". Results from the screening on A549 and MCF7 cancer cell lines revealed that compounds 5j and 5k showed two-digit nanomolar with appropriate safety towards the WI-38 cell line. The best molecules, 5j and 5k, were subjected to γ-radiation, and their cytotoxic efficacy didn't change after irradiation, demonstrating that not having to use it avoided its side effects. Compounds 5j and 5k demonstrated the highest inhibition when their potency was tested as dual inhibitors on EGFR 67 and 41 nM, respectively, and STAT3 5.52 and 3.34 nM, respectively, proved with in silico molecular docking and dynamic simulation. In light of the results presented above, the capacity of both powerful compounds to alter the cell cycle and initiate the apoptotic process in breast cancer MCF7 cells was investigated. Caspase-8, Bcl-2, Bax and Caspase-9 apoptotic indicators were studied.

The regulations of telomerase reverse transcriptase (TERT) in cancer

Abnormal activation of telomerase occurs in most cancer types, which facilitates escaping from cell senescence. As the key component of telomerase, telomerase reverse transcriptase (TERT) is regulated by various regulation pathways. TERT gene changing in its promoter and phosphorylation respectively leads to TERT ectopic expression at the transcription and protein levels. The co-interacting factors play an important role in the regulation of TERT in different cancer types. In this review, we focus on the regulators of TERT and these downstream functions in cancer regulation. Determining the specific regulatory mechanism will help to facilitate the development of a cancer treatment strategy that targets telomerase and cancer cell senescence. As the most important catalytic subunit component of telomerase, TERT is rapidly regulated by transcriptional factors and PTM-related activation. These changes directly influence TERT-related telomere maintenance by regulating telomerase activity in telomerase-positive cancer cells, telomerase assembly with telomere-binding proteins, and recruiting telomerase to the telomere. Besides, there are also non-canonical functions that are influenced by TERT, including the basic biological functions of cancer cells, such as proliferation, apoptosis, cell cycle regulation, initiating cell formation, EMT, and cell invasion. Other downstream effects are the results of the influence of transcriptional factors by TERT. Currently, some small molecular inhibitors of TERT and TERT vaccine are under research as a clinical therapeutic target. Purposeful work is in progress.

Discovery of Novel Pyridazine-Tethered Sulfonamides as Carbonic Anhydrase II Inhibitors for the Management of Glaucoma

As a progressive neuropathic condition, glaucoma can cause lifelong blindness if left untreated. Novel phenylpyridazine-tethered sulfonamides were designed as selective inhibitors for carbonic anhydrase (CA) isoform II to find effective therapeutic agents for glaucoma. Subsequently, the target inhibitors were synthesized and assessed for their inhibitory action against cytosolic CA I and II. Interestingly, the synthesized molecules poorly inhibited CA I while exhibiting low subnanomolar potency against CA II. Compound 7c disclosed the most potent activity (IC50 = 0.63 nM) with high selectivity against CA II (605-fold than acetazolamide selectivity). Moreover, compound 7c also showed significant in vivo IOP-reducing properties in the in vivo model of glaucoma. Furthermore, the binding of compound 7c to CA II was assessed at the molecular level, exploiting the molecular docking approach.

Lead Optimization of BIBR1591 To Improve Its Telomerase Inhibitory Activity: Design and Synthesis of Novel Four Chemical Series with In Silico, In Vitro, and In Vivo Preclinical Assessments

Herein, modifications to the previously reported BIBR1591 were conducted to obtain bioisosteric candidates with improved activities. The % inhibition of the newly afforded candidates against the telomerase target was investigated. Notably, 6f achieved superior telomerase inhibition (63.14%) compared to BIBR1532 and BIBR1591 (69.64 and 51.58%, respectively). In addition, 8a and 8b showed comparable promising telomerase inhibition with 58.65 and 55.57%, respectively, which were recorded to be frontier to that of BIBR1591. 6f, 8a, and 8b were tested against five cancer cell lines related to the lung and liver subtypes. Moreover, 6f was examined on both cell cycle progression and apoptosis induction in HuH7 cancer cells. Furthermore, the in vivo antitumor activity of 6f was further assessed in female mice with solid Ehrlich carcinoma. In addition, molecular docking and molecular dynamics simulations were carried out. Collectively, 6f, 8a, and 8b could be considered potential new telomerase inhibitors to be subjected to further investigation and/or optimization.

Rational design and eco-friendly one-pot multicomponent synthesis of novel ethylidenehydrazineylthiazol-4(5H)-ones as potential apoptotic inducers targeting wild and mutant EGFR-TK in triple negative breast cancer

A novel series of ethylidenehydrazineylthiazol-4(5H)-ones were synthesized using various eco-friendly one-pot multicomponent synthetic techniques. The anticancer activity of compounds (4a-m) was tested against 11 cancer cell lines. While the IC50 of all compounds was evaluated against the most sensitive cell lines (MDA-MB-468 and FaDu). Our SAR study pinpointed that compound 4a, having a phenyl substituent, exhibited a significant growth inhibition % against all cancer cell lines. The frontier anticancer candidates against the MDA-MB-468 were also examined against the wild EGFR (EGFR-WT) and mutant EGFR (EGFR-T790M) receptors. Most of the synthesized compounds exhibited a higher inhibitory potential against EGFR-T790M than the wild type of EGFR. Remarkably, compound 4k exhibited the highest inhibitory activity against both EGFR-WT and EGFR-T790M with IC50 values (0.051 and 0.021 µM), respectively. The pro-apoptotic protein markers (p53, BAX, caspase 3, caspase 6, caspase 8, and caspase 9) and the anti-apoptotic key marker (BCL-2) were also measured to propose a mechanism of action for the compound 4k as an apoptotic inducer for MDA-MB-468. Investigation of the cell cycle arrest potential of compound 4k was also conducted on MDA-MB-468 cancer cells. We also evaluated the inhibitory activities of compounds (4a-m) against both EGFR-WT and EGFR-T790M using two different molecular docking processes.

Diverse Pharmacological Potential of Pyridazine Analogs against Various Diseases

Pyridazinone analogs possess diverse types of pharmacological activities, such as anticancer, antimicrobial, anticonvulsant, analgesic, anti-inflammatory, antioxidant, antihypertensive, antisecretory, antiulcer, and other useful pharmacological activities. They also possess cyclooxygenase (COX) inhibitors, dipeptidyl peptidase inhibitors, phosphodiesterase inhibitors, glutamate transporter activators, adenosine receptor antagonists, serotonin receptors antagonists, lipooxygenase, cholinesterase, vasodilator, and anesthetics. Pyridazine rings are the essential structure for some marketed drugs, such as pimobendan, levosimendan as a cardiotonic drug, and emorfozan as an analgesic and anti-inflammatory (Non-steroidal anti-inflammatory drug) agent. So, researchers all over the world have paid attention to synthesizing various pyridazinone compounds mainly due to the ease of design and synthesis of different analogs and variables in the pharmacological responses. This review article focuses on the pharmacological activities of different pyridazine analogs.

Investigating the potential anticancer activities of antibiotics as topoisomerase II inhibitors and DNA intercalators: in vitro, molecular docking, molecular dynamics, and SAR studies

Topoisomerase II (TOP-2) is a promising molecular target for cancer therapy. Numerous antibiotics could interact with biologically relevant macromolecules and provoke antitumor potential. Herein, molecular docking studies were used to investigate the binding interactions of 138 antibiotics against the human topoisomerase II-DNA complex. Followed by the MD simulations for 200 ns and MM-GBSA calculations. On the other hand, the antitumor activities of the most promising candidates were investigated against three cancer cell lines using doxorubicin (DOX) as a reference drug. Notably, spiramycin (SP) and clarithromycin (CL) showed promising anticancer potentials on the MCF-7 cell line. Moreover, azithromycin (AZ) and CL exhibited good anticancer potentials against the HCT-116 cell line. Finally, the TOP-2 enzyme inhibition assay was carried out to confirm the proposed rationale. Briefly, potent TOP-2 inhibitory potentials were recorded for erythromycin (ER) and roxithromycin (RO). Additionally, a SAR study opened eyes to promising anticancer pharmacophores encountered by these antibiotics.HighlightsMolecular docking studies of 139 antibiotics against the topoisomerase II-DNA complex.SP, RO, AZ, CL, and ER were the most promising and commercially available candidates.Molecular dynamics simulations for 200 ns for the most promising five complexes.MM-GBSA calculations for the frontier five complexes.SP and CL showed promising anticancer potentials on the MCF-7 cell line, besides, AZ and CL exhibited good anticancer potentials against the HCT-116 cell line.Potent TOP-2 inhibitory potentials were recorded for ER and RO.

Novel 4-(2-arylidenehydrazineyl)thienopyrimidine derivatives as anticancer EGFR inhibitors: Design, synthesis, biological evaluation, kinome selectivity and in silico insights

The current study discovered fifteen new thieno[2,3-d]pyrimidine derivatives with potential anticancer action, including 5a-l, 6, and 7a-b. Results from the NCI screening revealed that compounds 5f-i and 7a significantly inhibited the proliferation of MDA-MB-468 cells at mean GI% and GI50 levels. Compared to staurosporine, these compounds (5f-i and 7a) demonstrated better safety towards typical WI-38 cells. Compounds 5g and 7a demonstrated the highest inhibition (two-digit nanomolar) when compared to erlotinib when their potency was tested on EGFR kinase. Considering the outcomes above, 5g was examined for its ability to disrupt the cell cycle with trigger apoptosis in breast cancer MDA-MB-468 cell lines. The apoptosis markers Bax, Bcl-2, Caspase-8, and Caspase-9, were detected. In silico molecular docking and dynamic simulation were used to explainthe biological activities of the most potent compound.

Design and synthesis of novel pyrazolopyrimidine candidates as promising EGFR-T790M inhibitors and apoptosis inducers

Aim: Our objective was to design and synthesize a new range of pyrazolopyrimidines while maintaining the key pharmacophoric features of EGFR tyrosine kinase inhibitors. Materials & methods: Percentage inhibition in 14 human cancer cell lines and IC50 values were recorded. Compounds 6c, 7e and 7f were examined against both wild and mutant (T790M) EGFR subtypes. Apoptosis markers, cell cycle arrest, apoptosis assay and molecular docking were performed. Results: Compounds 6c, 7e and 7f demonstrated superior inhibitory potentials against wild and mutant (T790M) EGFR subtypes. A molecular docking study showed that compounds 6c and 7e had the best fit. Conclusion: The designed candidates demonstrated superior inhibitory potential as promising EGFR-T790M inhibitors that agrees with the proposed rationale.

A Comparative GC/MS Analysis of Citrus Essential Oils: Unveiling the Potential Benefits of Herb-Drug Interactions in Preventing Paracetamol-Induced Hepatotoxicity

Our study aimed to test the potential of Citrus oils in protecting against paracetamol (PAR)-induced hepatotoxicity. The essential oils of Pineapple sweet orange (OO), Murcott mandarin (MO), Red grapefruit (GO), and Oval kumquat (KO) were investigated using gas chromatography coupled with mass spectrometry (GC/MS). Twenty-seven compounds were identified, with monoterpene hydrocarbons being abundant class. d-Limonene had the highest percentage (92.98 %, 92.82 %, 89.75 %, and 94.46 % in OO, MO, GO, and KO, respectively). Hierarchical cluster analysis (HCA) and principal components analysis (PCA) revealed that octanal, linalool, germacrene D, and d-limonene were the principal discriminatory metabolites that segregated the samples into three distinct clusters. In vitro antioxidant capacities were ranged from 1.2-12.27, 1.79-5.91, and 235.05-585.28 μM Trolox eq/mg oil for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic (ABTS), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC), respectively. In vivo, citrus oils exhibited a significant reduction in alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and nitric oxide (NO). Additionally, there was an increase in glutathione reductase (GSH), and the liver architecture was nearly normal. Molecular docking revealed that d-limonene exhibited a good inhibitory interaction with cytochrome P450 (CYP450) isoforms 1A2, 3A4, and 2E1, with binding energies of -6.17, -4.51, and -5.61 kcal/mol, respectively.

Design and synthesis of new spirooxindole candidates and their selenium nanoparticles as potential dual Topo I/II inhibitors, DNA intercalators, and apoptotic inducers

A new wave of dual Topo I/II inhibitors was designed and synthesised via the hybridisation of spirooxindoles and pyrimidines. In situ selenium nanoparticles (SeNPs) for some derivatives were synthesised. The targets and the SeNP derivatives were examined for their cytotoxicity towards five cancer cell lines. The inhibitory potencies of the best members against Topo I and Topo II were also assayed besides their DNA intercalation abilities. Compound 7d NPs exhibited the best inhibition against Topo I and Topo II enzymes with IC50 of 0.042 and 1.172 μM, respectively. The ability of compound 7d NPs to arrest the cell cycle and induce apoptosis was investigated. It arrested the cell cycle in the A549 cell at the S phase and prompted apoptosis by 41.02% vs. 23.81% in the control. In silico studies were then performed to study the possible binding interactions between the designed members and the target proteins.

Design and synthesis of novel uracil-linked Schiff bases as dual histone deacetylase type II/topoisomerase type I inhibitors with apoptotic potential

Aim: The previously reported dual histone deacetylase type II (HDAC II) / topoisomerase type I (Topo I) inhibitors suffer pharmacokinetic limitations because of their huge molecular weights. Materials & methods: We report the design and synthesis of a smarter novel set of uracil-linked Schiff bases (19-30) as dual HDAC II/Topo I inhibitors keeping the essential pharmacophoric features. Cytotoxicity of all compounds was assessed against three cancer cell lines. Studies of their effects on the apoptotic BAX and antiapoptotic BCL2 genes, molecular docking studies, and absorption, distribution, metabolism and excretion studies were conducted. Results: Compounds 22, 25 and 30 exhibited significant activities. The bromophenyl derivative 22 displayed the best selectivity index, with IC50 values against HDAC II and Topo I of 1.12 and 13.44 μM, respectively. Conclusion: Compound 22 could be considered a lead HDAC II/Topo I inhibitor.

Novel 4-thiophenyl-pyrazole, pyridine, and pyrimidine derivatives as potential antitumor candidates targeting both EGFR and VEGFR-2; design, synthesis, biological evaluations, and in silico studies

In this article, we continued our previous effort to develop new selective anticancer candidates based on the basic pharmacophoric requirements of both EGFR and VEGFR-2 inhibitors. Therefore, twenty-two novel 4-thiophenyl-pyrazole, pyridine, and pyrimidine derivatives were designed and examined as dual EGFR/VEGFR-2 inhibitors. Besides, the previously reported antimicrobial activities of the aforementioned nuclei motivated us to screen their antibacterial and antifungal activities as well. First, the antitumor activities of the newly synthesized derivatives were evaluated against two cancer cell lines (HepG-2 and MCF-7). Notably, compounds 2a, 6a, 7a, 10b, 15a, and 18a exhibited superior anticancer activities against both HepG-2 and MCF-7 cancer cell lines. These candidates were selected to further evaluate their anti-EGFR and anti-VEGFR-2 potentialities which were found to be very promising compared to erlotinib and sorafenib, respectively. Both 10b and 2a derivatives achieved better dual EGFR/VEGFR-2 inhibition with IC₅₀ values of 0.161 and 0.141 μM and 0.209 and 0.195 μM, respectively. Moreover, the most active 10b was selected to evaluate the exact phase of cell cycle arrest and to investigate the exact mechanism of cancer cell death whether it be due to apoptosis or necrosis. On the other hand, all the synthesized compounds were tested against Gram-positive bacteria such as S. aureus and B. subtilis as well as Gram-negative bacteria such as E. coli and P. aeuroginosa. Also, the antifungal activity was investigated against C. albicans and A. flavus strains. The findings of the antimicrobial tests revealed that most of the investigated compounds exhibited strong to moderate antibacterial and antifungal effects. Furthermore, to understand the pattern by which the investigated compounds bound to the active site, all the newly synthesized candidates were subjected to two different docking processes into the EGFR and VEGFR-2 binding sites. Besides, we tried to correlate compound 10b and the reference drugs (erlotinib and sorafenib) through DFT calculations. Finally, following the biological data of the new pyrazole, pyridine, and pyrimidine derivatives as anticancer and antimicrobial candidates, we concluded a very interesting SAR for further optimization.

Papaverinol-N-Oxide: A Microbial Biotransformation Product of Papaverine with Potential Antidiabetic and Antiobesity Activity Unveiled with In Silico Screening

Bioconversion of biosynthetic heterocyclic compounds has been utilized to produce new semisynthetic pharmaceuticals and study the metabolites of bioactive drugs used systemically. In this investigation, the biotransformation of natural heterocyclic alkaloid papaverine via filamentous fungi was explored. Molecular docking simulations, using protein tyrosine phosphatase 1B (PTP1B), α-glucosidase and pancreatic lipase (PL) as target enzymes, were performed to investigate the antidiabetic potential of papaverine and its metabolites in silico. The metabolites were isolated from biotransformation of papaverine with Cunninghamella elegans NRRL 2310, Rhodotorula rubra NRRL y1592, Penicillium chrysogeneum ATCC 10002 and Cunninghamella blackesleeana NRRL 1369 via reduction, demethylation, N-oxidation, oxidation and hydroxylation reactions. Seven metabolites were isolated: namely, 3,4-dihydropapaverine (metabolite 1), papaveroline (metabolite 2), 7-demethyl papaverine (metabolite 3), 6,4'-didemethyl papaverine (metabolite 4), papaverine-3-ol (metabolite 5), papaverinol (metabolite 6) and papaverinol N-oxide (metabolite 7). The structural elucidation of the metabolites was investigated with 1D and 2D NMR and mass spectroscopy (EI and ESI). The molecular docking studies showed that metabolite 7 exhibited better binding interactions with the target enzymes PTP1B, α-glucosidase and PL than did papaverine. Furthermore, papaverinol-N-oxide (7) also displayed inhibition of α-glucosidase and lipase enzymes comparable to that of their ligands (acarbose and orlistat, respectively), as unveiled with an in silico ADMET profile, molecular docking and molecular dynamics studies. In conclusion, this study provides evidence for enhanced inhibition of PTP1B, α-glucosidase and PL via some papaverine fungal transformation products and, therefore, potentially better antidiabetic and antiobesity effects than those of papaverine and other known therapeutic agents.