Novel 2-[thio]acetamide linked quinazoline/1,2,4-triazole/chalcone hybrids: Design, synthesis, and anticancer activity as EGFR inhibitors and apoptotic inducers

Novel triazoloquinazolines carrying the 2-[thio]acetamide entity (4 and 5a-d) and triazoloquinazoline/chalcone hybrids incorporating the 2-[thio]acetamide linker (8a-b and 9a-f) were developed as anticancer candidates. NCI screening of the synthesized compounds at 10 μM concentration displayed growth inhibition not only up to 99.74% as observed for 9a but also a lethal effect could be achieved as stated for compounds 9c (RPMI-8226 and HCT-116) and 8b, 9a, and 9e on the HCT-116 cell line. The antiproliferative activity was determined for the chalcone series on three cell lines: RPMI-8226, HCT-116, and MCF-7. Compounds 8b, 9a, 9b, and 9f were the most active ones. To understand the mechanistic study, the inhibitory effect on the epidermal growth factor receptor (EGFR) kinase was evaluated. The results stated that the activity of compound 8b (IC50 = 0.07 μM) was near that of the reference drug erlotinib (IC50 = 0.052 μM) whereas compound 9b (IC50 = 0.045 μM) was found to be more potent than erlotinib. Both compounds 8b and 9b were selected for cell cycle analysis and apoptotic assays. Moreover, molecular docking results of the selected chalcone hybrids showed high binding scores and good binding affinities especially for 8b and 9b, which were consistent with the biological activity (EGFR).

Green chemometric-assisted UV-spectrophotometric methods for the determination of favipiravir, cefixime and moxifloxacin hydrochloride as an effective therapeutic combination for COVID-19; application in pharmaceutical form and spiked human plasma

As pharmaceutical analysis progresses towards environmental sustainability, there is a growing need to enhance the safety and health conditions for analysts. Consequently, the incorporation of chemometrics into environmentally friendly analytical methods represents a promising approach. Favipiravir, cefixime, and moxifloxacin hydrochloride have been currently used in COVID-19 treatment. In this study, we develop spectrophotometric methods depending on chemometric based models to measure the levels of favipiravir, cefixime, and moxifloxacin hydrochloride in pharmaceutical preparations and spiked human plasma. It is challenging to determine favipiravir, cefixime, and moxifloxacin simultaneously because of overlap in their UV absorption spectra. Two advanced chemometric models, partial least square (PLS) and genetic algorithm (GA), have been developed to provide better predictive abilities in spectrophotometric determination of the drugs under study. The described models were created using a five-level, three-factor experimental design. The outcomes of the models have been thoroughly assessed and interpreted, and a statistical comparison with recognized values has been taken into consideration. The analytical eco-scale and the green analytical procedure index (GAPI) evaluation methods were also utilized to determine how environmentally friendly the mentioned models were. The outcomes demonstrated how well the models described complied with the environmental requirements.

Eco-friendly novel deconvoluted synchronous spectrofluorimetric approach for the determination of favipiravir, levodropropizine and moxifloxacin hydrochloride as an effective therapeutic combination for COVID-19; application in laboratory prepared mixtures and spiked human plasma

In this work, a green, fast, and simple synchronous spectrofluorimetric approach has been developed to simultaneously determine favipiravir, levodropropizine, and moxifloxacin hydrochloride as co-administered medications for COVID-19 treatment in pure form and spiked human plasma. The synchronous fluorescence spectroscopy technique to analyze the studied drugs at Δλ = 110 nm enabled the determination of levodropropizine at 360 nm. Then, applying Fourier Self-Deconvolution to each spectra to measure favipiravir and moxifloxacin hydrochloride at peak amplitudes of 431 nm and 479 nm, respectively, without any interference. Favipiravir, levodropropizine, and moxifloxacin hydrochloride could be sensitively determined using the described approach over concentration ranges of 20-300 ng/mL, 10-600 ng/mL, and 50-500 ng/mL, respectively. The method's validation was carried out effectively in accordance with guidelines recommended by the ICH. Finally, the Eco-scale and Green Analytical Procedure Index (GAPI) techniques have been used to evaluate the greenness of the proposed method.

Dual COX-2 and 15-LOX inhibition study of novel 4-arylidine-2-mercapto-1-phenyl-1H-imidazolidin-5(4H)-ones: Design, synthesis, docking, and anti-inflammatory activity

Novel arylidene-5(4H)-imidazolone derivatives 4a-r were designed and evaluated as multidrug-directed ligands, that is, inflammatory, proinflammatory mediators, and reactive oxygen species (ROS) inhibitors. All of the tested compounds showed cyclooxygenase (COX)-1 inhibitory effect more than celecoxib and less than indomethacin and also demonstrated an improved inhibitory activity against 15-lipoxygenase (15-LOX). Compounds 4f, 4l, and 4p exhibited COX-2 selectivity comparable to that of celecoxib, while 4k was the most selective COX-2 inhibitor. Interestingly, the screened results showed that compound 4k exhibited a superior inhibition effect against 15-LOX and was found to be the most selective COX-2 inhibitor over celecoxib, whereas compound 4f showed promising COX-2 and 15-LOX inhibitory activities besides its inhibitory effect against ROS production and its lowering effect of both tumor necrosis factor-α and interleukin-6 levels by ∼80%. Moreover, compound 4f attenuated the lipopolysaccharide-mediated increase in NF-κB activation in RAW 264.7 macrophages. The preferred binding affinity of these molecules was confirmed by docking studies. We conclude that arylidene-5(4H)-imidazolone scaffolds provide promising hits for developing new synthons with anti-inflammatory and antioxidant activities.

Triple targeting of mutant EGFRL858R/T790M, COX-2, and 15-LOX: design and synthesis of novel quinazolinone tethered phenyl urea derivatives for anti-inflammatory and anticancer evaluation

We designed and synthesised novel quinazolinone tethered phenyl urea derivatives (6a-p) that triple target the double mutant EGFR^L858R/T790M, COX-2, and 15-LOX. Compounds (6e, 6d, 6j, 6m, and 6n) not only had low micromolar IC50 inhibitory activities against the three targets, but they also showed good selectivity for COX-2 over COX-1 and for EGFR^L858R/T790M over wild-type EGFR. Except for 6e and 6n, all of the tested compounds inhibited the NO production significantly more potently than celecoxib, diclofenac, and indomethacin. Compounds 6i and 6k reduced ROS levels more effectively than celecoxib and diclofenac. In terms of inhibiting TNF-α production, 6o-treated cells showed TNF-α level, which is ∼10 times lower than celecoxib. Furthermore, 6e and 6j had the highest anticancer activity against the breast cancer cell line BT-459 with growth inhibition percentages of 67.14 and 70.07%, respectively. Docking studies confirm their favoured binding affinity. The proposed compounds could be promising multi-targeted leads.

GC-MS profiling and evaluation of acute oral toxicity, anti-tumour, antimicrobial and antioxidant activities of Croton socotranus Balf.f. aerial parts: in-vitro, in-vivo and in-silico studies

Croton socotranus Balf.f. shrub is widely used traditionally in Asia as an anti-infective. The study was conducted for metabolite profiling, oral acute toxicity and antioxidant studies, antimicrobial activity and anticancer effect against human hepatoma (HepG2), breast cancer (MCF-7) and rhabdomyosarcoma (RD) cells. Gas chromatography-mass spectrometry analysis revealed the presence of 39 compounds, predominantly comprising fatty acids (57.76%), sesquiterpenes (24.56%) and triterpenes (9.54%). The n-hexane fraction exhibited promising antimicrobial activity and displayed a potent anti-tumour effect against HepG2, MCF-7 and RD cells with IC50 values of 3.4, 6.5 and 7.1 μg/mL, respectively. Histological examination revealed significant morphological changes consistent with the changes observed in the apoptotic mechanism of action. The molecular docking study provided insights into the rational binding modes of the identified compounds with phosphoinositide 3-kinase and poly(ADP-ribose)polymerase-1 enzymes. Our findings suggest the potential of C. socotranus as a valuable source of antimicrobial and anticancer agents.

Magic shotgun approach to anti-inflammatory pharmacotherapy: Synthesis of novel thienopyrimidine monomers/heterodimer as dual COX-2 and 15-LOX inhibitors endowed with potent antioxidant activity

Emerging evidence points to the intertwining framework of inflammation and oxidative stress in various ailments. We speculate on the potential impact of the magic shotgun approach in these ailments as an attempt to mitigate the drawbacks of current NSAIDs. Hence, we rationally designed and synthesized new tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine monomers/heterodimer as dual selective COX-2/15-LOX inhibitors with potent antioxidant activity. The synthesized compounds were challenged with diverse in vitro biological assays. Regarding the monomeric series, compound 5k exerted the highest COX-2 inhibitory activity (IC50 = 0.068 μM, SI = 160.441), while compound 5i showed the highest 15-LOX inhibitory activity (IC50 = 1.97 μM). Surpassing the most active monomeric members, the heterodimer 11 stemmed as the most potent and selective one in the whole study (COX-2 IC50 = 0.065 μM, SI = 173.846, 15-LOX IC50 = 1.86 μM). Heterodimer design was inspired by the cross-talk between the partner monomers of the COX-2 isoform. Moreover, some of our synthesized compounds could significantly reverse the LPS-enhanced production of ROS and proinflammatory cytokines (IL-6, TNF-α, and NO) in RAW 264.7 macrophages. Again, the heterodimer showed the strongest suppressor activity against ROS (IC50 = 18.79 μM) and IL-6 (IC50 = 4.15 μM) production outperforming the two references, celecoxib and diclofenac. Regarding NO suppressor activity, compound 5j (IC50 = 18.62 μM) surpassed the two references. Only compound 5a significantly suppressed TNF-α production (IC50 = 19.68 μM). Finally, molecular modeling simulated the possible binding scenarios of our synthesized thienopyrimidines within the active sites of COX-2 and 15-LOX. These findings suggest that those novel thienopyrimidines are promising leads showing pharmacodynamics synergy against the selected targets.

Evaluation of acute oral toxicity, anti-diabetic and antioxidant effects of Aloe vera flowers extract

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm.f. is widely used in various traditional systems of medicine worldwide. Since over 5000 years ago, several cultures have used A. vera extract medicinally for conditions ranging from diabetes to eczema. It has been shown to reduce the symptoms of diabetes by enhancing insulin secretion and protecting pancreatic islets.

AIM OF THE WORK

This research study aimed to investigate the in-vitro antioxidant effect, the acute oral toxicity, and the possible pharmacological in-vivo anti-diabetic activity with histological examination of the pancreas of the standardized deep red A. vera flowers methanolic extracts (AVFME).

MATERIALS AND METHODS

The liquid-liquid extraction procedure and TLC technique were used to investigate chemical composition. Total phenolics and flavonoids in AVFME were quantified by Folin-Ciocalteu and AlCl₃ colorimetric methods, respectively. The present study involved evaluating the in-vitro antioxidant effect of AVFME using ascorbic acid as the reference standard, an acute oral toxicity study by using thirty-six albino rats and different concentrations of AVFME (200 mg/kg, 2, 4, 8 and 10 g/kg b.w.). Furthermore, the in-vivo anti-diabetic study was performed on alloxan-induced diabetes in rats (120 mg/kg, I.P.) and two doses of AVFME (200 and 500 mg/kg b.w., orally) were used as compared to glibenclamide (5 mg/kg, orally) as a standard hypoglycemic sulfonylurea medication. A histological examination of the pancreas was performed.

RESULTS

AVFME resulted in the highest phenolic content of 150.44 ± 4.62 mg gallic acid equivalent per gram (GAE/g) along with flavonoid content of 70.38 ± 0.97 mg of quercetin equivalent per gram (QE/g). An in-vitro study revealed that the antioxidant effect of AVFME was strong as ascorbic acid. The results of the in-vivo studies showed that the AVFME didn't cause any apparent toxicity signs or death in all groups at different doses which proves the safety of this extract with a wide therapeutic index. The antidiabetic activity of AVFME demonstrated a considerable drop in blood glucose levels as glibenclamide, without severe hypoglycemia or significant weight gain which is considered an advantage of AVFME over glibenclamide use. The histopathological study of pancreatic tissues confirmed the protective effect of AVFME on the pancreatic beta-cells. The extract is proposed to have antidiabetic activity through inhibition of α-amylase, α-glucosidase, and dipeptidyl peptidase IV (DPP-IV). Molecular docking studies were conducted to understand possible molecular interactions with these enzymes.

CONCLUSION

AVFME represents a promising alternative source of active constituents against diabetes mellitus (DM) based on its oral safety, antioxidant, anti-hyperglycemic activities, and pancreatic protective effects. These data revealed the antihyperglycemic activity of AVFME is mediated by pancreatic protective effects while significantly enhancing insulin secretion through increasing functioning beta cells. This suggests that AVFME has the potential as a novel antidiabetic therapy or a dietary supplement for the treatment of type 2 diabetes (T2DM).

Synthesis of new multitarget-directed ligands containing thienopyrimidine nucleus for inhibition of 15-lipoxygenase, cyclooxygenases, and pro-inflammatory cytokines

A new series of thieno[2,3-d]pyrimidine derivatives 4, 5, 6a-o, and 11 was designed and synthesized starting from cyclohexanone under Gewald condition with the aim to develop multitarget-directed ligands (MTDLs) having anti-inflammatory properties against both 15-LOX and COX-2 enzymes. Moreover, the potential of the compounds against the proinflammatory mediators NO, ROS, TNF-α, and IL-6 were tested in LPS-activated RAW 264.7 macrophages. Compound 6o showed the greatest 15-LOX inhibitory effect (IC₅₀ = 1.17 μM) which was superior to that of the reference nordihydroguaiaretic acid (NDGA, IC₅₀ = 1.28 μM); meanwhile, compounds 6h, 6g, 11, and 4 exhibited potent activities (IC₅₀ = 1.29-1.77 μM). The ester 4 (SI = 137.37) and the phenyl-substituted acetohydrazide 11 (SI = 132.26) showed the highest COX-2 selectivity, which was about 28 times more selective than the reference drug diclofenac (SI = 4.73), however, it was lower than that of celecoxib (SI = 219.25). Interestingly, compound 6o, which showed the highest 15-LOX inhibitory activity and 5 times higher COX-2 selectivity than diclofenac, showed a greater poteny in reducing NO (IC₅₀ = 7.77 μM) than both celecoxib (IC₅₀ = 22.89 μM) and diclofenac (IC₅₀ = 25.34), but comparable activity in inhibiting TNF-α (IC₅₀ = 11.27) to diclofenac (IC₅₀ = 10.45 μM). Similarly, compounds 11 and 6h were more potent in reducing TNF-α and IL6 levels than diclofenac, meanwhile, compound 4 reduced ROS, NO, IL6, and TNF-α levels with comparable potency to the reference drugs celecoxib and diclofenac. Furthermore, docking studies for our compounds within 15-LOX and COX-2 active sites revealed good agreement with the biological evaluations. The proposed compounds could be promising multi-targeted anti-inflammatory candidates to treat resistant inflammatory conditions.

Triazolopyrimidine derivatives: An updated review on recent advances in synthesis, biological activities and drug delivery aspects

Molecules containing triazolopyrimidine core showed diverse biological activities, including anti-Alzheimer, antidiabetes, anticancer, antimicrobial, antituberculosis, antiviral, antimalarial, anti-inflammatory, anti-parkinsonism activities, and treatment of glaucoma. Triazolopyrimidines have around 8 isomeric structures including the most stable 1,2,4-triazolo[1,5-a] pyrimidine ones. Triazolopyrimidines were obtained by using various chemical reactions, among them a) 1,2,4-triazole nucleus annulation to pyrimidine, b) pyrimidines annulation to 1,2,4-triazole structure, c) 1,2,4-triazolo[l,5-a] pyrimidines rearrangement, and d) pyrimido-tetrazine rearrangement. This review discusses synthetic methods, recent pharmacological actions and drug delivery perspectives of triazolopyrimidines.

Controlling of Bacterial Virulence: Evaluation of Anti-Virulence Activities of Prazosin against Salmonella enterica

Salmonella enterica is a Gram-negative orofecal transmitted pathogen that causes a wide diversity of local and systemic illnesses. Salmonella enterica utilizes several interplayed systems to regulate its invasion and pathogenesis: namely, quorum sensing (QS) and type three secretion system (T3SS). In addition, S. enterica could sense the adrenergic hormones in the surroundings that enhance its virulence. The current study aimed to evaluate the ability of α-adrenoreceptor antagonist prazosin to mitigate the virulence of S. enterica serovar Typhimurium. The prazosin effect on biofilm formation and the expression of sdiA, qseC, qseE, and T3SS-type II encoding genes was evaluated. Furthermore, the prazosin intracellular replication inside macrophage and anti-virulence activity was evaluated in vivo against S. typhimurium. The current finding showed a marked prazosin ability to compete on SdiA and QseC and downregulate their encoding genes. Prazosin significantly downregulated the virulence factors encoding genes and diminished the biofilm formation, intracellular replication inside macrophages, and in vivo protected mice. To sum up, prazosin showed significant inhibitory activities against QS, T3SS, and bacterial espionage, which documents its considered anti-virulence activities.

"Methylene Bridge" to 5-HT3 Receptor Antagonists: Conformationally Constrained Phenylguanidines

Arylguanidines, depending upon their aromatic substitution pattern, display varying actions at 5-HT₃ receptors (e.g., partial agonist, agonist, superagonist). Here, we demonstrate that conformational constraint of these agents as dihydroquinazolines (such as A6CDQ; 1) results in their conversion to 5-HT₃ receptor antagonists. We examined the structure-activity relationships of 1. Replacement/removal of any of the guanidinium nitrogen atoms of 1 resulted in decreased affinity. All three nitrogen atoms of 1 are necessary for optimal binding affinity at 5-HT₃ receptors. Introduction of substituents as small as an N2-methyl group abolishes affinity. The results are consistent with homology modeling/docking studies and binding data from site-directed mutagenesis studies. Introducing a "methylene bridge" to the arylguanidine structure, regardless of its functional activity, results in a 5-HT₃ receptor antagonist.