SC-560 and mofezolac isosteres as new potent COX-1 selective inhibitors with antiplatelet effect.

Selective cyclooxygenase (COX)-1 inhibitors can be employed as potential cardioprotective drugs. Moreover, COX-1 plays a key role in inflammatory processes and its activity is associated with some types of cancer. In this work, we designed and synthesized a set of compounds that structurally mimic the selective COX-1 inhibitors, SC-560 and mofezolac, the central cores of which were replaced either with triazole or benzene rings. The advantage of this approach is a relatively simple synthesis in comparison with the syntheses of parent compounds. The newly synthesized compounds exhibited remarkable activity and selectivity toward COX-1 in the enzymatic in vitro assay. The most potent compound, 10a (IC50 = 3 nM for COX-1 and 850 nM for COX-2), was as active as SC-560 (IC50  = 2.4 nM for COX-1 and 470 nM for COX-2) toward COX-1 and it was even more selective. The in vitro COX-1 enzymatic activity was further confirmed in the cell-based whole-blood antiplatelet assay, where three out of four selected compounds (10a,c,d, and 3b) exerted outstanding IC50 values in the nanomolar range (9-252 nM). Moreover, docking simulations were performed to reveal key interactions within the COX-1 binding pocket. Furthermore, the toxicity of the selected compounds was tested using the normal human kidney HK-2 cell line.

Prenylated Stilbenoids Affect Inflammation by Inhibiting the NF-κB/AP-1 Signaling Pathway and Cyclooxygenases and Lipoxygenase.

Stilbenoids are important components of foods (e.g., peanuts, grapes, various edible berries), beverages (wine, white tea), and medicinal plants. Many publications have described the anti-inflammatory potential of stilbenoids, including the widely known trans-resveratrol and its analogues. However, comparatively little information is available regarding the activity of their prenylated derivatives. One new prenylated stilbenoid (2) was isolated from Artocarpus altilis and characterized structurally based on 1D and 2D NMR analysis and HRMS. Three other prenylated stilbenoids were prepared synthetically (9-11). Their antiphlogistic potential was determined by testing them together with known natural prenylated stilbenoids from Macaranga siamensis and Artocarpus heterophyllus in both cell-free and cell assays. The inhibition of 5-lipoxygenase (5-LOX) was also shown by simulated molecular docking for the most active stilbenoids in order to elucidate the mode of interaction between these compounds and the enzyme. Their effects on the pro-inflammatory nuclear factor-κB (NF-κB) and the activator protein 1 (AP-1) signaling pathway were also analyzed. The THP1-XBlue-MD2-CD14 cell line was used as a model for determining their anti-inflammatory potential, and lipopolysaccharide (LPS) stimulation of Toll-like receptor 4 induced a signaling cascade leading to the activation of NF-κB/AP-1. The ability of prenylated stilbenoids to attenuate the production of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) was further evaluated using LPS-stimulated THP-1 macrophages.

Transcriptomic response of Arabidopsis thaliana roots to naproxen and praziquantel.

Exposition to pharmaceutical compounds released to the environment is considered as a potential risk for various organisms. We exposed Arabidopsis thaliana plants to naproxen (NAP) and praziquantel (PZQ) in 5 µM concentration for 2 days and recorded transcriptomic response in their roots with the aim to estimate ecotoxicity and to identify gene candidates potentially involved in metabolism of both compounds. Nonsteroidal anti-inflammatory drug NAP up-regulated 105 and down-regulated 29 genes (p-value ≤ 0.1, fold change ≥ 2), while anthelmintic PZQ up-regulated 389 and down-regulated 353 genes with more rigorous p-value ≤ 0.001 (fold change ≥ 2). High number of up-regulated genes coding for heat shock proteins and other genes involved in response to biotic and abiotic stresses as well as down-regulation of genes involved in processes such as cell proliferation, transcription and water transport indicates serious negative effect of PZQ. NAP up-regulated mostly genes involved in various biological processes and signal transduction and down-regulated mainly genes involved in signal transduction and electron transport or energy pathways. Further, two cytochrome P450s (demethylation) and one methyltransferase (methylation of carboxyl group) were identified as candidates for phase I and several glutathione- and glycosyltransferases (conjugation) for phase II of NAP metabolism. Cytochrome P450s, glutathione and glycosyltransferases seem to play role also in metabolism of PZQ. Up-regulation of several ABC and MATE transporters by NAP and PZQ indicated their role in transport of both compounds.

Anti-inflammatory activity of natural stilbenoids: A review.

Resveratrol and other natural stilbenoids, including piceatannol, pterostilbene, and gnetol, are well-known anti-inflammatory compounds with indisputable activity in vitro as well as in vivo. Their molecular targets include inducible nitric oxide synthase, cyclooxygenases, leukotrienes, nuclear factor kappa B, tumor necrosis factor α, interleukins and many more. This anti-inflammatory activity together with their antioxidant activity is believed to stand behind their other positive health effects against cancer, cardiovascular and neurodegenerative diseases or diabetes. Thus, they are nowadays commercially marketed as nutraceuticals. Naturally, they are present in wine, grapes or berries. However, there is a rigorous debate about the real effect of these compounds on human health. It is argued that the concentration of stilbenoids in food and beverages is too low to have any therapeutic potential and this concentration is further reduced by their low bioavailability and extensive metabolism. Therefore, this review focuses on in vitro, in vivo, preclinical as well as clinical data available for various natural stilbenoids and summarizes the anti-inflammatory targets on molecular level, compares the relevance of the experimental studies, discusses the metabolism of stilbenoids and the potential activity of their metabolites and relates this knowledge to human health. Moreover, the ways to augment stilbenoids efficacy are suggested with special focus on multitargeted therapy and nanocarriers.

Transcriptomic Response of Arabidopsis thaliana Exposed to CuO Nanoparticles, Bulk Material, and Ionic Copper.

Engineered nanoparticles (ENPs) exhibit unique properties advantageous in a number of applications, but they also represent potential health and environmental risks. In this study, we investigated the phytotoxic mechanism of CuO ENPs using transcriptomic analysis and compared this response with the response to CuO bulk particles and ionic Cu2+. Ionic Cu2+ at the concentration of 0.16 mg L-1 changed transcription of 2692 genes (p value of <0.001, fold change of ≥2) after 7 days of exposure, whereas CuO ENPs and bulk particles (both in the concentration of 10 mg L-1) altered the expression of 922 and 482 genes in Arabidopsis thaliana roots, respectively. The similarity between transcription profiles of plants exposed to ENPs and ionic Cu2+ indicated that the main factor in phytotoxicity was the release of Cu2+ ions from CuO ENPs after 7 days of exposure. The effect of Cu2+ ions was evident in all treatments, as indicated by the down-regulation of genes involved in metal homeostasis and transport and the up-regulation of oxidative stress response genes. ENPs were more soluble than bulk particles, resulting in the up-regulation of metallochaperone-like genes or the down-regulation of aquaporins and metal transmembrane transporters that was also characteristic for ionic Cu2+ exposure.

Anti-inflammatory Activity of Natural Geranylated Flavonoids: Cyclooxygenase and Lipoxygenase Inhibitory Properties and Proteomic Analysis.

Geranyl flavones have been studied as compounds that potentially can be developed as anti-inflammatory agents. A series of natural geranylated flavanones was isolated from Paulownia tomentosa fruits, and these compounds were studied for their anti-inflammatory activity and possible mechanism of action. Two new compounds were characterized [paulownione C (17) and tomentodiplacone O (20)], and all of the isolated derivatives were assayed for their ability to inhibit cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX). The compounds tested showed variable degrees of activity, with several of them showing activity comparable to or greater than the standards used in COX-1, COX-2, and 5-LOX assays. However, only the compound tomentodiplacone O (20) showed more selectivity against COX-2 versus COX-1 when compared with ibuprofen. The ability of the test compounds to interact with the above-mentioned enzymes was supported by docking studies, which revealed the possible incorporation of selected test substances into the active sites of these enzymes. Furthermore, one of the COX/LOX dual inhibitors, diplacone (14) (a major geranylated flavanone of P. tomentosa), was studied in vitro to obtain a proteomic overview of its effect on inflammation in LPS-treated THP-1 macrophages, supporting its previously observed anti-inflammatory activity and revealing the mechanism of its anti-inflammatory effect.

Transcriptomic response of Arabidopsis thaliana (L.) Heynh. roots to ibuprofen.

Surface waters in urban areas are contaminated by ibuprofen (IBP), a popular and extensively used anti-inflammatory drug. In this study, we investigated the transcriptomic response in Arabidopsis thaliana (L.) Heynh. roots with the aim of revealing genes that are potentially involved in IBP detoxification and elucidating the effect of IBP on plants. IBP upregulated 63 and downregulated 38 transcripts (p-value < 0.1, fold change ≥2) after 2-day exposure to a 5-µM (1.03 mg/L) concentration of IBP under hydroponic conditions. Although the IBP concentration used in the experiment was highly relative to the concentrations found in rivers and wastewater, the number of genes with transcriptional changes was relatively low. The upregulation of cytochrome P450s, glutathione S-transferases, and UDP-glycosyltransferases indicates the occurrence of IBP oxidation in the first phase, followed by conjugation with glutathione and sugar in the second detoxification phase. ABC transporters could be involved in the transport of IBP and its metabolites. The identification of genes potentially involved in IBP detoxification could be useful in an IBP phytoremediation approach.

The Transcriptomic Response of Arabidopsis thaliana to Zinc Oxide: A Comparison of the Impact of Nanoparticle, Bulk, and Ionic Zinc.

The impact of nanosize was evaluated by comparing of the transcriptomic response of Arabidopsis thaliana roots to ZnO nanoparticles (nZnO), bulk ZnO, and ionic Zn(2+). Microarray analyses revealed 416 up- and 961 down-regulated transcripts (expression difference >2-fold, p [FDR] < 0.01) after a seven-day treatment with nZnO (average particle size 20 nm, concentration 4 mg L(-1)). Exposure to bulk ZnO resulted in 816 up- and 2179 down-regulated transcripts. The most dramatic changes (1711 transcripts up- and 3242 down-regulated) were caused by the presence of ionic Zn(2+) (applied as ZnSO4.7H20 at a concentration of 14.14 mg L(-1), corresponding to the amount of Zn contained in 4 mg L(-1) ZnO). Genes involved in stress response (e.g., to salt, osmotic stress or water deprivation) were the most relatively abundant group of gene transcripts up-regulated by all three Zn treatments while genes involved in cell organization and biogenesis (e.g., tubulins, arabinogalactan proteins) and DNA or RNA metabolism (e.g., histones) were the most relatively abundant groups of down-regulated transcripts. The similarity of the transcription profiles and the increasing number of changed transcripts correlating with the increased concentration of Zn(2+) in cultivation medium indicated that released Zn(2+) may substantially contribute to the toxic effect of nZnO because particle size has not demonstrated a decisive role.

Impact of wines and wine constituents on cyclooxygenase-1, cyclooxygenase-2, and 5-lipoxygenase catalytic activity.

Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1) activity in the range of 63-94%, cyclooxygenase-2 (COX-2) activity in the range of 20-44% (tested at a concentration of 5 mL/L), and 5-lipoxygenase (5-LOX) activity in the range of 72-84% (at a concentration of 18.87 mL/L). White wines inhibited 5-LOX in the range of 41-68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 µM) was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 µM), quercetin (IC50 = 3.29 µM), and myricetin (IC50 = 4.02 µM). trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 µM) and COX-2 (IC50 = 3.40 µM). Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway.

In vitro anti-proliferative and anti-inflammatory activity of leaf and fruit extracts from Vaccinium bracteatum Thunb.

The aim of this study was to evaluate in vitro anti-proliferative (tested on MCF-7, MDA-MB-231, and MCF-10A cell lines) and anti-inflammatory (evaluated as inhibition of prostaglandin E2 synthesis catalyzed by cyclooxygenase-2) effect of various extracts from Vaccinium bracteatum leaves and fruits. The highest anti-proliferative effect possessed leaf dichloromethane extract with IC50 values ranging from 93 to 198 µg/mL. In the case of cyclooxygenase-2 inhibition, n-hexane, dichloromethane, and ethanol fruit extracts showed the best activity with IC50 values = 2.0, 5.4, and 12.7 µg/mL, respectively. These results indicate that V. bracteatum leaves and fruits could be useful source of anti-cancer and anti-inflammatory compounds.

Synthetic polyploidization induces enhanced phytochemical profile and biological activities in Thymus vulgaris L. essential oil.

Essential oil from Thymus vulgaris L. has valuable therapeutic potential that is highly desired in pharmaceutical, food, and cosmetic industries. Considering these advantages and the rising market demand, induced polyploids were obtained using oryzalin to enhance essential oil yield. However, their therapeutic values were unexplored. So, this study aims to assess the phytochemical content, and antimicrobial, antioxidant, and anti-inflammatory activities of tetraploid and diploid thyme essential oils. Induced tetraploids had 41.11% higher essential oil yield with enhanced thymol and γ-terpinene content than diploid. Tetraploids exhibited higher antibacterial activity against all tested microorganisms. Similarly, in DPPH radical scavenging assay tetraploid essential oil was more potent with half-maximal inhibitory doses (IC50) of 180.03 µg/mL (40.05 µg TE/mg) than diploid with IC50 > 512 µg/mL (12.68 µg TE/mg). Tetraploids exhibited more effective inhibition of in vitro catalytic activity of pro-inflammatory enzyme cyclooxygenase-2 (COX-2) than diploids at 50 µg/mL concentration. Furthermore, molecular docking revealed higher binding affinity of thymol and γ-terpinene towards tested protein receptors, which explained enhanced bioactivity of tetraploid essential oil. In conclusion, these results suggest that synthetic polyploidization using oryzalin could effectively enhance the quality and quantity of secondary metabolites and can develop more efficient essential oil-based commercial products using this induced genotype.

Evaluation of anti-inflammatory activity of selected legumes from Pakistan: in vitro inhibition of cyclooxygenase-2.

Crude methanolic extracts of selected legumes namely, black gram (Vigna mungo L.), green gram (Vigna radiata (L.) R. Wilczek ), soybean (Glycine max (L.) Merr.) and lentil (Lens culinaris Medik.) were investigated for anti-inflammatory effects, using COX-2 producing PGE(2) inhibitory assay. Percentage inhibition observed was 73.93, 79.84, 92.17 and 74.47 for black gram, green gram, soybean and lentil respectively at 20µg/ml extract concentration. The 100µg/ml concentration showed increase in the percent inhibition except for soybean. This is the first report on COX-2 inhibitory potential of food legumes.

Redox and non-redox mechanism of in vitro cyclooxygenase inhibition by natural quinones.

In this study, ten anthra-, nine naphtho-, and five benzoquinone compounds of natural origin and five synthetic naphthoquinones were assessed, using an enzymatic in vitro assay, for their potential to inhibit cyclooxygenase-1 and -2 (COX-1 and COX-2), the key enzymes of the arachidonic acid cascade. IC50 values comparable with COX reference inhibitor indomethacin were recorded for several quinones (primin, alkannin, diospyrin, juglone, 7-methyljuglone, and shikonin). For some of the compounds, we suggest the redox potential of quinones as the mechanism responsible for in vitro COX inhibition because of the quantitative correlation with their pro-oxidant effect. Structure-relationship activity studies revealed that the substitutions at positions 2 and 5 play the key roles in the COX inhibitory and pro-oxidant actions of naphthoquinones. In contrast, the redox mechanism alone could not explain the activity of primin, embelin, alkannin, and diospyrin. For these four quinones, molecular modeling suggested similar binding modes as for conventional nonsteroidal anti-inflammatory drugs (NSAIDs).

Platelet aggregation and anti-inflammatory effects of garden pea, Desi chickpea and Kabuli chickpea.

Inflammation is the natural body defense mechanism for the removal of injurious agents, necrosed cells and tissues from the body. This study was aimed to evaluate the anti-inflammatory and platelet aggregation effects of three medicinal plants of Pakistan. Methanolic extract of garden pea inhibited arachidonic acid (AA)-induced platelet aggregation (IC50 = 35 microg/mL) and platelet activating factor (PAF)-induced platelet aggregation (IC50 = 38 microg/mL) in a dose dependent fashion. Methanolic extract of Desi chickpea inhibited arachidonic acid (AA) induced platelet aggregation (IC50 value = AA = 46 microg/mL) in dose dependent fashion while was found not active against PAF-induced platelet aggregation. Methanolic extract of Kabuli chickpea was found not active against both arachidonic acid (AA)-induced platelet aggregation and PAF-induced platelet aggregation. The best potential to inhibit in vitro COX-2 activity showed garden pea (Pisum sativum: the synthesis of PGE2 reduced by 92% in comparison with untreated control wells) followed by Desi chickpea (Cicer arietinum var; 87% inhibition) and Kabuli chickpea extracts (Cicer arietinum var: 65% inhibition). All extracts were tested at concentration 20 microg/mL. in COX-2 assay. The results indicate that if the same were happening in vito, Garden pea, Desi chickpea and Kabuli chickpea could be useful as natural antithrombotic anti-inflammatory materials.

Antioxidant and Anti-Inflammatory Activity of Five Medicinal Mushrooms of the Genus Pleurotus.

Within the group of higher fungi, edible medicinal mushrooms have a long history of being used as food and in folk medicine. These species contain biologically active substances with many potential beneficial effects on human health. The Pleurotus genus is representative of medicinal mushrooms because Pleurotus ostreatus is one of the most commonly cultivated culinary mushrooms. In our study, we focused on lesser-known species in the genus Pleurotus and measured their antioxidant and anti-inflammatory activity. We prepared extracts of the mushrooms and analyzed them using HPLC-HRMS, GC-MS, and 1H-NMR. Significant differences in biological activities were found among the Pleurotus spp. extracts. A MeOH extract of P. flabellatus was the most active as a radical scavenger with the highest ORAC, while a chloroform extract had significant anti-inflammatory COX-2 activity. The 80% MeOH extract of P. flabellatus contained the highest amounts of ergosterol, ergothioneine, and mannitol. The 80% MeOH extract of P. ostreatus Florida was the most active in the NF-κB inhibition assay and had the highest content of ß-glucans (43.3% by dry weight). Given the antioxidant and anti-inflammatory properties of P. flabellatus, the potential therapeutic usefulness of this species is worth evaluating through in-depth investigations and confirmation by clinical trials.

Natural compound cudraflavone B shows promising anti-inflammatory properties in vitro.

Cudraflavone B (1) is a prenylated flavonoid found in large amounts in the roots of Morus alba, a plant used as a herbal remedy for its reputed anti-inflammatory properties. The present study shows that this compound causes a significant inhibition of inflammatory mediators in selected in vitro models. Thus, 1 was identified as a potent inhibitor of tumor necrosis factor α (TNFα) gene expression and secretion by blocking the translocation of nuclear factor κB (NF-κB) from the cytoplasm to the nucleus in macrophages derived from a THP-1 human monocyte cell line. The NF-κB activity reduction resulted in the inhibition of cyclooxygenase 2 (COX-2) gene expression. Compound 1 acts as a COX-2 and COX-1 inhibitor with higher selectivity toward COX-2 than indomethacin. Pretreatment of cells by 1 shifted the peak in an regulatory gene zinc-finger protein 36 (ZFP36) expression assay. This natural product has noticeable anti-inflammatory properties, suggesting that 1 potentially could be used for development as a nonsteroidal anti-inflammatory drug lead.

Positive effects of metallic nanoparticles on plants: Overview of involved mechanisms.

Engineered nanoparticles (NPs) are considered as potential agents for agriculture as fertilizers, growth enhancers and pesticides. Therefore, understanding the mechanisms that are responsible for their effects is important. Various studies demonstrated that the application of nontoxic concentrations can promote seed germination, enhance plant growth and increase the yield. Moreover, NPs can be used to protect plants from environmental impacts such as salt or drought stress and diminish accumulation and toxicity of heavy metals. NPs can serve as a source of micronutrients (e.g. ZnO, iron- and manganese-based NPs), thus increasing fitness and helps plants to cope with stress conditions. TiO2 and iron-based NPs are able to delay senescence and speed-up cell division via changes in phytohormonal levels. The application of some NPs can promote the activity of enzymes such as amylase, nitrate reductase, phosphatase, phytase and carbonic anhydrases, which are involved in metabolism and nutrient acquisition. E.g. ZnO and TiO2 NPs can stimulate chlorophyll biosynthesis and photosynthetic activity. Iron-based and CeO2 NPs enhance stomata opening resulting in better gas exchange and CO2 assimilation rate. NPs can also modulate oxidative stress by the stimulation of the antioxidant enzymes such peroxidases and superoxide dismutase. However, the knowledge about the fate, transformation, and accumulation of NPs in the environment and organisms is needed prior to their use in agriculture to avoid negative environmental impacts. Higher or lower toxicity of various NPs was established for microorganisms, plants or animals. In this overview, we focused on the possible mechanisms of Ag, ZnO, TiO2, Fe-based, CeO2, Al2O3, and manganese-based NPs responsible for their positive effects on plants.

Synthesis, Inhibitory Activity, and In Silico Modeling of Selective COX-1 Inhibitors with a Quinazoline Core.

Selective cyclooxygenase-1 (COX-1) inhibition has got into the spotlight with the discovery of COX-1 upregulation in various cancers and the cardioprotective role of COX-1 in control of thrombocyte aggregation. Yet, COX-1-selective inhibitors are poorly explored. Thus, three series of quinazoline derivatives were prepared and tested for their potential inhibitory activity toward COX-1 and COX-2. Of the prepared compounds, 11 exhibited interesting COX-1 selectivity, with 8 compounds being totally COX-1-selective. The IC50 value of the best quinazoline inhibitor was 64 nM. The structural features ensuring COX-1 selectivity were elucidated using in silico modeling.

Transferases and transporters mediate the detoxification and capacity to tolerate trinitrotoluene in Arabidopsis.

The effect of recalcitrant soil and water pollutant 2,4,6-trinitrotoluen (TNT) on gene expression in Arabidopsis thaliana rosettes and roots was studied separately for the first time using microarrays. Seven-day exposure to TNT resulted in 170 up- and 122 down-regulated genes in the rosettes and 61 up- and 51 down-regulated genes in the roots (expression difference > 1.5-fold; p[t test] < 0.05). TNT concentration, 5 µg/ml, was selected according to the dose response analysis and study of TNT uptake from liquid media. Although many TNT induced genes fell into ontology groups annotated as response to biotic and abiotic stresses in rosettes and roots, only a small overlap of TNT effects on transcriptome was observed between rosettes and roots. The rosettes exhibited induction of several genes associated with toxin metabolism, such as UDP-glycosyltransferases and ATP-binding cassette (ABC) family transporters. On the other side, no genes known to be involved in TNT transformation were found to be up-regulated in the roots. The genes coding for enzymes involved in the cell wall modifications were abundantly up-regulated in roots. Microarray data indicated that after a relatively long incubation with TNT (7 days), metabolism of this xenobiotic proceeded mainly in aerial parts, while its translocation into cell walls still took place in the roots. Results obtained by microarray hybridization were validated by quantitative real-time reverse-transcription PCR. Nitrate reductase 1, several glycosyltransferases and ABC transporters, sucrose-proton symporter 2, thioredoxin-dependent peroxidase 2, and gamma-glutamyltransferase are discussed for their potential to enhance detoxification and toleration capability of plants to TNT.

Synthesis, inhibitory activity and in silico docking of dual COX/5-LOX inhibitors with quinone and resorcinol core.

Based on the significant anti-inflammatory activity of natural quinone primin (5a), series of 1,4-benzoquinones, hydroquinones, and related resorcinols were designed, synthesized, characterized and tested for their ability to inhibit the activity of cyclooxygenase (COX-1 and COX-2) and 5-lipoxygenase (5-LOX) enzymes. Structural modifications resulted in the identification of two compounds 5b (2-methoxy-6-undecyl-1,4-benzoquinone) and 6b (2-methoxy-6-undecyl-1,4-hydroquinone) as potent dual COX/5-LOX inhibitors. The IC50 values evaluated in vitro using enzymatic assay were for compound 5b IC50 = 1.07, 0.57, and 0.34 µM and for compound 6b IC50 = 1.07, 0.55, and 0.28 µM for COX-1, COX-2, and 5-LOX enzyme, respectively. In addition, compound 6d was identified as the most potent 5-LOX inhibitor (IC50 = 0.14 µM; reference inhibitor zileuton IC50 = 0.66 µM) from the tested compounds while its inhibitory potential against COX enzymes (IC50 = 2.65 and 2.71 µM for COX-1 and COX-2, respectively) was comparable with the reference inhibitor ibuprofen (IC50 = 4.50 and 2.46 µM, respectively). The most important structural modification leading to increased inhibitory activity towards both COXs and 5-LOX was the elongation of alkyl chain in position 6 from 5 to 11 carbons. Moreover, the monoacetylation in ortho position of bromo-hydroquinone 13 led to the discovery of potent (IC50 = 0.17 µM) 5-LOX inhibitor 17 (2-bromo-6-methoxy-1,4-benzoquinone) while bromination stabilized the hydroquinone form. Docking analysis revealed the interaction of compounds with Tyr355 and Arg120 in the catalytic site of COX enzymes, while the hydrophobic parts of the molecules filled the hydrophobic substrate channel leading up to Tyr385. In the allosteric catalytic site of 5-LOX, compounds bound to Tyr142 and formed aromatic interactions with Arg138. Taken together, we identified optimal alkyl chain length for dual COX/5-LOX inhibition and investigated other structural modifications influencing COX and 5-LOX inhibitory activity.