Exploring of novel oxazolones and imidazolones as anti-inflammatory and analgesic candidates with cyclooxygenase inhibitory action.

Aim: Over the last few decades, therapeutic needs have led to a search for safer COX-2 inhibitors with potential anti-inflammatory and analgesic activity. Materials & methods: A new series of oxazolone and imidazolone derivatives 3a-c and 4a-r were synthesized and evaluated as anti-inflammatory and analgesic agents. COX-1/COX-2 isozyme selectivity testing and molecular docking were performed. Results: All compounds showed good activities comparable to those of the reference, celecoxib. The most active compounds 3a, 4a, 4c, 4e and 4f showed promising gastric tolerability with an ulcer index lower than that of celecoxib. The molecular docking of p-methoxyphenyl derivative 4c showed alkyl interaction with the side pocket His75 of COX-2 and achieved the best anti-inflammatory activity, with a COX-2 selectivity index better than that of celecoxib.

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Management of ulcerative colitis by dichloroacetate: Impact on NFATC1/NLRP3/IL1B signaling based on bioinformatics analysis combined with in vivo experimental verification.

The inflammatory response in ulcerative colitis (UC) could be relieved by the conventional immunomodulatory agents; 5-aminosalicylic acid, corticosteroids, or azathioprine. However, the low remission rates and the intolerance to these agents necessitate investigation of gene expression signature in UC that could influence the therapeutic efficacy of drugs, as well as the interference with persistence genes by novel therapeutic option. Three microarray datasets (GSE66407, GSE38713 and GSE14580) from the NCBI-GEO database were utilized. Differentially expressed genes between samples of patients with UC and healthy ones were analyzed using R software. In addition, in vivo study using oxazolone-induced UC in BALB/c mice was carried out to investigate the proposed therapeutic efficacy of dichloroacetate (DCA). The bioinformatics analysis revealed the persistence of NLRP3, NFATC1, and IL1B in UC despite treatment with common therapeutic agents. DCA administration to oxazolone-treated mice showed remarkable interference with those persistence genes. Western blotting analysis for NLRP3, NFATC1, nuclear/total NF-κB, and cleaved caspase-1 revealed the ability of DCA to reduce the expression levels of these proteins in oxazolone-treated mice. Additionally, the inflammatory cytokines IL-1ß and IL-13 were reduced in colonic tissue by DCA treatment. The therapeutic efficacy of DCA was further confirmed by the apparent reduction in histopathological scoring, disease activity index, and the normalization of colon length. Therefore, DCA could be suggested as a novel and promising therapeutic option in UC based on its ability to interfere with the persistence of NFATC1/NLRP3/IL1B signaling. That merits further safety/toxicological pre-clinical assessment and update of bioavailability/metabolism data prior to clinical investigation.

Distinct Mechanisms of Cytotoxicity in Novel Nitrogenous Heterocycles: Future Directions for a New Anti-Cancer Agent.

Electron-rich, nitrogenous heteroaromatic compounds interact more with biological/cellular components than their non-nitrogenous counterparts. The strong intermolecular interactions with proteins, enzymes, and receptors confer significant biological and therapeutic properties to the imidazole derivatives, giving rise to a well-known and extensively used range of therapeutic drugs used for infections, inflammation, and cancer, to name a few. The current study investigates the anti-cancer properties of fourteen previously synthesized nitrogenous heterocycles, derivatives of imidazole and oxazolone, on a panel of cancer cell lines and, in addition, predicts the molecular interactions, pharmacokinetic and safety profiles of these compounds. METHOD: The MTT and CellTiter-Glo® assays were used to screen the imidazole and oxazolone derivatives on six cancer cell lines: HL60, MDA-MB-321, KAIMRC1, KMIRC2, MCF-10A, and HCT8. Subsequently, in vitro tubulin staining and imaging were performed, and the level of apoptosis was measured using the Promega ApoTox-Glo® triplex assay. Furthermore, several computational tools were utilized to investigate the pharmacokinetics and safety profile, including PASS Online, SEA Search, the QikProp tool, SwissADME, ProTox-II, and an in silico molecular docking study on tubulin to identify the critical molecular interactions. RESULTS: In vitro analysis identified compounds 8 and 9 to possess the most significant potent cytotoxic activity on the HL60 and MDA-MB-231 cell lines, supported by PASS Online anti-cancer predictions with pa scores of 0.413 and 0.434, respectively. In addition, compound 9 induced caspase 3/7 dependent-apoptosis and interfered with tubulin polymerization in the MDA-MB-231 cell line, consistent with in silico docking results, identifying binding similarity to the native ligand colchicine. All the derivatives, including compounds 8 and 9, had acceptable pharmacokinetics; however, the safety profile was suboptimal for all the tested derivates except compound 4. CONCLUSION: The imidazole derivative compound 9 is a promising anti-cancer agent that switches on caspase-dependent apoptotic cell death and modulates microtubule function. Therefore, it could be a lead compound for further drug optimization and development.

Modulating gut dysbiosis and mitochondrial dysfunction in oxazolone-induced ulcerative colitis: the restorative effects of ß-glucan and/or celastrol.

OBJECTIVES: Microbiome-Mitochondria interaction is gaining a significant attention; thus, studying its mechanism emerges as a must to provide restorative lines in managing diseases. The aim is to study the mechanistic effects of ß-Glucan and/or Celastrol in oxazolone-induced ulcerative colitis (UC). METHODS: 75 Wistar rats were allocated into 5 equal groups. Group I: control group. Group II: UC group, Group III: ß-Glucan-treated UC group, Group IV: Celastrol-treated UC group & Group V: mutual treatment group. All groups were subjected to the detection of free fatty acid receptor 2 (FFAR-2) and peroxisome proliferator-activated receptor gamma co-activator1α (PGC-1α) mRNA gene expressions. Citrate synthase (CS) activity, mitochondrial membrane potential (MMP), ATP concentration, reactive oxygen species (ROS) were detected. Trimethylamine N-oxide (TMAO) concentration was measured. RESULTS: After treatment we monitored significant upregulation of FFAR-2 and PGC-1α mRNA expression. Likewise, ATP level and CS activity were significantly increased. On the contrary, there was a significant lessening in ROS and TMAO levels with improvement of MMP. CONCLUSION: Mutual use of ß- Glucan and Celastrol had a greater effect than each alone against UC, which is considered a novel finding highlighting the ameliorative effects of this combined treatment in modulating Microbiome/Mitochondria axis, thus launching promising avenues for UC.

VISTA-Ig ameliorates OXA-induced allergic dermatitis symptoms in mice.

BACKGROUND: Allergic dermatitis (AD) is a chronic inflammatory skin disease that a variety of immune cells are involved in the progression of AD. Among them, T cells are one of major players of AD pathogenesis. The V-domain Ig suppressor of T cell activation (VISTA) has been reported that it has a potential immunomodulatory for T cell response. OBJECTIVE: This study aimed to investigate immunomodulatory of recombinant VISTA-Ig fusion protein in AD mice model. METHODS: The model of AD was built with oxazolone (OXA) in BALB/c mice, then VISTA-Ig was used to treat AD by intraperitoneal (IP) injection. The ear thickness was measured by a digital thickness gauge. The ears tissues were collected and subjected to hematoxylin-eosin (H&E) and toluidine blue (TB) staining. The secretion levels of IL-4 and IgE in the serum were measured by enzyme linked immunosorbent assay (ELISA). The mRNA expression levels of inflammatory cytokines (IL-1ß, IL-6, IL-12, and INF-γ) in ear tissues were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RESULTS: Treatment with VISTA-Ig successfully alleviated the symptoms of AD, such as erythema, horny substance, and swelling. The infiltration of inflammatory cells was significantly reduced following VISTA-Ig therapy. The secretion levels of IL-4 and IgE in the serum were significantly attenuated following treatment with VISTA-Ig. Additionally, VISTA-Ig observably down-regulated inflammatory cytokines expression in ear tissues. CONCLUSIONS & CLINICAL RELEVANCE: Taken together, our results showed that VISTA-Ig possessed the potential to be a novel immunomodulatory candidate drug against AD.

Synthesis and Characterization of Two Novel Oxazol-5-ones Derivatives and Their Multifunctional Properties; pH Sensitivity, Electropolymerizability and Antiproliferative Activity.

The aim of this study is to synthesize oxazol-5-one derivatives, which have multi-functional properties. Nomenclatures of newly synthesized molecules are 4-(4-N,N-diethylaminophenylmethylene)-2-(3-thienyl)oxazol-5-one (4a) and 4-(4-(1,4,7,10-tetraoxa-13-azacyclopentadecyl)phenylmethylene)-2-(3-thienyl)oxazol-5-one (4b). These two novel derivatives contain pH sensitive and polymerizable groups. 3-Thienyl group was attached to position-2 of the oxazol-5-one ring to provide electrochemical polymerization capability. pH sensing properties were provided by attaching p-N,N-diethylaminophenylmethylene and p-aza-15-crown-5-phenylmethylene groups to the arylmethylene moiety at position-4 of the ring. Target molecules were synthesized by classical process known as Erlenmeyer-Plöchl Azlactone Synthesis Erlenmeyer (Justus Liebigs Ann Chem 275:1-12, 1893), Rodrigues et al. (J Chem Educ 92:1543-1546, 2015) . After structural characterization of 4a and 4b, absorption and emission characteristics were determined in solvents that have different polarities. Difference in maximum absorption and emission wavelengths of the molecules related to solvent polarities were observed at around 6-7 nm and 35-36 nm respectively. In pH studies of the target derivatives in PVC polymer matrix, ratiometric changes were observed at isosbestic point around 398 nm. Polymeric depositions of the molecules (4a, 4b) were proved by using cyclic voltammetry, electrochemical impedance spectrometry studies and scanning electron microscope images. MTT assay studies showed significant results like, 4b derivative's strong cytotoxic activity on PC-3 (cancerous cell line) with IC50 value of 12.57 ± 0.41 µg/ml without exhibiting any cytotoxic effect on HEK293 (healthy cell line).

5-(4H)-Oxazolones and Their Benzamides as Potential Bioactive Small Molecules.

The five membered heterocyclic oxazole group plays an important role in drug discovery. Oxazolones present a wide range of biological activities. In this article the synthesis of 4-substituted-2-phenyloxazol-5(4H)-ones from the appropriate substituted aldehydes via an Erlenmeyer-Plochl reaction is reported. Subsequently, the corresponding benzamides were produced via a nucleophilic attack of a secondary amine on the oxazolone ring applying microwave irradiation. The compounds are obtained in good yields up to 94% and their structures were confirmed using IR, 1H-NMR, 13C-NMR and LC/MS data. The in vitro anti-lipid peroxidation activity and inhibitory activity against lipoxygenase and trypsin induced proteolysis of the novel derivatives were studied. Inhibition of carrageenin-induced paw edema (CPE) and nociception was also determined for compounds 4a and 4c. Oxazolones 2a and 2c strongly inhibit lipid peroxidation, followed by oxazolones 2b and 2d with an average inhibition of 86.5%. The most potent lipoxygenase inhibitor was the bisbenzamide derivative 4c, with IC50 41 µΜ. The benzamides 3c, 4a-4e and 5c were strong inhibitors of proteolysis. The replacement of the thienyl moiety by a phenyl group does not favor the protection. Compound 4c inhibited nociception higher than 4a. The replacement of thienyl groups by phenyl ring led to reduced biological activity. Docking studies of the most potent LOX inhibitor highlight interactions through allosteric mechanism. All the potent derivatives present good oral bioavailability.

Effect of a Product Containing Xyloglucan and Pea Protein on a Murine Model of Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory disease of the skin, characterized by dryness and more or less severe itching. The etiology of AD is complex and has not been fully clarified, involving genetic susceptibility, immunological abnormalities, epidermal barrier dysfunction, and environmental factors. Xyloglucan (XG) and pea protein (PP) are two compounds of natural origin characterized by the ability to create a physical barrier that protects mucosae membranes, reducing inflammation. The aim of the present study was to evaluate the potential beneficial effects of XG + PP in both a mouse model of AD and Staphylococcus aureus (S.aureus) infection- associated AD. Mice were topically treated with 200 µL of 0.5% oxazolone on the dorsal skin three times a week for AD induction. Mice received XG and PP by topical administration 1 h before oxazolone treatment. In S. aureus infection-associated AD, to induce a superficial superinfection of the skin, mice were also treated with 5 µL of 108 of a culture of S. aureus for 2 weeks; mice superinfected received XG and PP by topical administration 1 h before oxazolone + S. aureus. Four weeks later, the skin was removed for histological and biochemical analysis. Our results demonstrated the protective barrier effects of XG and PP characterized by a reduction in histological tissue changes, mastocyte degranulation, and tight junction permeability in the skin following oxazolone treatment. Moreover, XG + PP was able to preserve filaggrin expression, a hallmark of AD. Our data also support the effectiveness of XG + PP to reduce the damage by superinfection post AD induced by S. aureus. In conclusion, a future product containing XG and PP could be considered as a potentially interesting approach for the treatment of AD.

Synthesis of 2-Substituted 4-Arylidene-5(4H)-oxazolones as Potential Cytotoxic Agents in the Presence of Lemon Juice as a Biocatalyst.

BACKGROUND: The oxazolone class of compounds is known to exert a profound effect on malignant cell proliferation, tumor angiogenesis and /or on the established neoplastic vasculature. Additionally, these compounds are generally known to have a low tendency to interact with DNA which is not common with most of the conventional cytotoxic agents. Thus, this class of compounds is of particular interest for the discovery and development of patient-friendly anticancer agents. OBJECTIVE: The initial objective of this study was to synthesize and evaluate 2-substituted 4-arylidene- 5(4H)-oxazolones for their potential anticancer properties. METHODS: A simple, mild and non-hazardous synthetic methodology has been developed for the preparation of 2-substituted 4-arylidene-5(4H)-oxazolones. The methodology involved lemon juice mediated condensation of N-acyl glycine derivatives including hippuric acid with arylaldehydes in PEG-400 under ultrasound irradiation. All the synthesized compounds were screened via an MTT assay for their potential cytotoxic properties in vitro using the cancerous cell lines e.g. K562 (human chronic myeloid leukemia), Colo-205 (human colon carcinoma), and A549 (human lung carcinoma) and a non-cancerous HEK293 (human embryonic kidney) cell line. RESULTS: Compounds 3a, 3c and 3i showed promising growth inhibition against A549 cell line but no significant effects on HEK293 cell line, indicating their selectivity towards cancer cells. Moreover, their IC50 values suggested that all these compounds were comparable to the reference drug doxorubicin indicating their potential against lung cancer. CONCLUSION: The 4-arylidene-5(4H)-oxazolone framework presented here could be a new template for the design and discovery of potential anticancer agents especially for lung cancer.

Intravenously administered contact allergens coupled to syngeneic erythrocytes induce in mice tolerance rather than effector immune response.

Constantly increasing prevalence of allergic diseases determines the attempts to elaborate the therapeutic strategies activating immune tolerance to particular allergen. Our current research focuses on the antigen-specific action of CD8+ suppressor T (Ts) lymphocytes induced in mice by intravenous administration of a high dose of haptenated syngeneic erythrocytes. While the regulatory activity of Ts cells mediated by exosome-delivered miRNA-150 is well de ned, the mechanism of their induction remained unclear. Therefore, the current studies investigated the immune e ects induced in mice by intravenous administration of contact allergens coupled to syngeneic erythrocytes. In mouse models of hapten-induced contact hypersensitivity (CHS) and delayed-type hypersensitivity to ovalbumin, we have shown that intravenous administration of hapten-coupled erythrocytes failed to induce CHS effector cells. Moreover, hapten-induced CHS reaction occurred to be suppressed in mice intravenously administered with syngeneic erythrocytes coupled with protein allergen. Finally, we have demonstrated that intravenously administered allergen induces immune tolerance only when bound to syngeneic erythrocytes, proving that intravenously delivered allergens are deprived of their immunizing properties when coupled with membrane of self cells. Altogether, our current studies suggest that alteration of self cell membrane by allergen binding is enough to induce Ts cell-mediated immune tolerance to nonpathogenic agents, which express a great translational potential in such conditions as allergies and hypersensitivity-related autoimmune disorders.

HBOA ameliorates CCl4-incuded liver fibrosis through inhibiting TGF-ß1/Smads, NF-κB and ERK signaling pathways.

An ingredient was isolated from Acanthus ilicifolius and identified as 4-hydroxy-2(3H)-benzoxazolone (HBOA). Its protective effects and underlying mechanism on liver fibrosis were investigated. Briefly, rats were intragastrically administrated with 50% CCl4 twice a week for 12 weeks to induce liver fibrosis. Meanwhile, the animals were treated with various medicines from weeks 8 to 12. Then the histological change, serum biochemical index, inflammatory factors and hepatocyte apoptosis were detected. Moreover, the TGF-ß1/Smads, NF-κB and ERK signaling pathways were also detected to illustrate the underlying mechanism. The results showed that HBOA significantly ameliorated CCl4-induced liver injury and collagen accumulation in rats, as evidenced by the histopathologic improvement. Moreover, HBOA markedly decreased hepatocyte apoptosis by regulating the expression levels of caspase-3, -9 and -12, as well as the Bcl-2 family. The mechanism study showed that HBOA significantly decreased the expressions of α-smooth muscle actin (α-SMA) and collagen and inhibited the generation of excessive extracellular matrix (ECM) components by restoring the balance between matrix metalloproteinases (MMPs) and its inhibitor (TIMPs). HBOA markedly alleviated oxidative stress and inflammatory cytokines through inhibiting the NF-κB pathway. In addition, HBOA significantly down-regulated the levels of TGF-ß1, Smad2/3, Smad4 and up-regulated the level of Smad7, inhibiting the TGF-ß1/Smads signaling pathway. Moreover, HBOA significantly blocked the ERK signaling pathway, leading to the inactivation of hepatic stellate cells. This study suggests that HBOA exerts a protective effect against liver fibrosis via modulating the TGF-ß1/Smads, NF-κB and ERK signaling pathways, which will be developed as a potential agent for the treatment of liver fibrosis.

Transient epidermal barrier deficiency and lowered allergic threshold in filaggrin-hornerin (FlgHrnr-/- ) double-deficient mice.

BACKGROUND: Filaggrin (Flg) and hornerin (Hrnr) share similar structural and functional features. Both proteins have been implicated as essential proteins for skin barrier maintenance. Loss-of-function mutations of these genes constitute a risk factor for atopic dermatitis and eczema-related asthma. Furthermore, both FLG and HRNR protein levels are downregulated in patients with atopic dermatitis. Thus, mice deficient for Flg and Hrnr provide a novel model to study skin barrier impairment and the susceptibility for cutaneous inflammation. METHODS: By using appropriate targeting vectors and breeding strategies, we established a homozygous FlgHrnr double-deficient (FlgHrnr-/- ) mouse model lacking both genes including the intergenomic sequence. RESULTS: Neonates appeared normal, but developed a transient scaly phenotype with overall flaky appearance, but no overt skin phenotype in adulthood, thereby reflecting a subclinical barrier defect seen in humans. Structurally, FlgHrnr-/- mice displayed a markedly reduced granular layer and a condensed cornified layer. Functionally, FlgHrnr-/- mice showed permeability abnormalities and metabolic aberrations regarding the production of natural moisturizing factors (NMFs) in the stratum corneum. Surprisingly, although the immune system revealed no aberrations under steady-state conditions, FlgHrnr-/- mice are predisposed to mount an allergic contact dermatitis, especially at hapten threshold levels eliciting allergic reactions. CONCLUSIONS: Together, our FlgHrnr-/- mouse model nicely reflects the epicutaneous sensitization susceptibilities and inflammatory reactions to environmental insults in humans with impaired skin barrier functions.

Neural Network Modeling of AChE Inhibition by New Carbazole-Bearing Oxazolones.

Acetylcholine esterase (AChE) is one of the targeted enzymes in the therapy of important neurodegenerative diseases such as Alzheimer's disease. Many studies on carbazole- and oxazolone-based compounds have been conducted in the last decade due to the importance of these compounds. New carbazole-bearing oxazolones were synthesized from several carbazole aldehydes and p-nitrobenzoyl glycine as AChE inhibitors by the Erlenmeyer reaction in the present study. The inhibitory effects of three carbazole-bearing oxazolone derivatives on AChE were studied in vitro and the experimental results were modeled using artificial neural network (ANN). The developed ANN provided sufficient correlation between several dependent systems, including enzyme inhibition. The inhibition data for AChE were modeled by a two-layered ANN architecture. High correlation coefficients were observed between the experimental and predicted ANN results. Synthesized carbazole-bearing oxazolone derivatives inhibited AChE under in vitro conditions, and further research involving in vivo studies is recommended. An ANN may be a useful alternative modeling approach for enzyme inhibition.

Anti-Atopic Effect of Acorn Shell Extract on Atopic Dermatitis-Like Lesions in Mice and Its Active Phytochemicals.

To investigate the potential effects of acorn shells on atopic dermatitis (AD), we utilized oxazolone (OX)- or 2,4-dinitrochlorobenzene (DNCB)-induced AD-like lesion mouse models. Our research demonstrates that Acorn shell extract (ASE) improved the progression of AD-like lesions, including swelling, which were induced by oxazolone on Balb/c mouse ears. Additionally, ASE significantly decreased the ear thickness (OX: 0.42 ± 0.01 mm, OX-ASE: 0.32 ± 0.02 mm) and epidermal thickness (OX: 75.3 ± 32.6 µm, OX-ASE: 46.1 ± 13.4 µm). The continuous DNCB-induced AD mouse model in SKH-1 hairless mice demonstrated that ASE improved AD-like symptoms, including the recovery of skin barrier dysfunction, Immunoglobulin E hyperproduction (DNCB: 340.1 ± 66.8 ng/mL, DNCB-ASE: 234.8 ± 32.9 ng/mL) and an increase in epidermal thickness (DNCB: 96.4 ± 21.9 µm, DNCB-ASE: 52.4 ± 16.3 µm). In addition, we found that ASE suppressed the levels of AD-involved cytokines, such as Tumor Necrosis Factor α, IL-1ß, IL-25 and IL-33 in both animal models. Furthermore, gallic acid and ellagic acid isolated from ASE suppressed ß-hexosaminidase release and IL-4 expression in RBL-2H3 cells. The acorn shell and its active phytochemicals have potential as a new remedy for the improvement of atopic dermatitis and other inflammatory diseases.

CD3+CD4+LAP+Foxp3-Regulatory Cells of the Colonic Lamina Propria Limit Disease Extension in Ulcerative Colitis.

Background and Aims: In ulcerative colitis (UC), inflammation begins in the rectum and can extend proximally throughout the entire colon. The extension of inflammation is an important determinant of disease course, and may be limited by the action of regulatory T cells (Tregs). In this cross-sectional study, we evaluated the relationship between UC extension and the proportions of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-Tregs in the colonic lamina propria (LP) of 79 UC patients and 29 controls. The role of these cells in UC extension was also investigated in the murine oxazolone-induced colitis model. Methods: Patients: Disease extension was classified according to the Montreal classification. Where possible, endoscopic biopsies of involved and uninvolved tissue were obtained from UC patients. Mouse model: Colitis was induced by intrarectal oxazolone administration. Lamina propria mononuclear cells were isolated from patient biopsies and mouse colon tissue using enzymatic method and the percentage of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-cells evaluated by immunofluorescence. Confocal microscopy was applied for the visualization and quantification of CD4+LAP+ cells on tissue histological sections. Results: In UC patients with distal colitis the proportion of LP CD3+CD4+Foxp3+ Tregs was significantly higher in inflamed tissue than uninvolved tissue. As opposite, the proportion of LP CD3+CD4+LAP+ Tregs was significantly higher in uninvolved tissue than involved tissue. Both LP CD3+CD4+Foxp3+ and LP CD3+CD4+LAP+ Tregs proportion in involved tissue was significantly higher than in controls irrespective of the extension of inflammation. In mice with oxazolone-induced distal colitis, treatment with LAP-depleting antibody was associated with the development of extensive colitis. Conclusions: Our findings suggest that CD3+CD4+LAP+Foxp3-Tregs limit the extension of inflammatory lesions in UC patients.

Oxazolone-1,2,3-Triazole Hybrids: Design, Synthesis and Antimicrobial Evaluation.

BACKGROUND: Oxazolones and 1,2,3-triazoles are among the extensively studied heterocycles in medicinal chemistry. Both of these moieties are reported to possess a broad spectrum of biological activity including antimicrobial. OBJECTIVE: The objective of the current work is to design, synthesize and antimicrobial evaluation of some new oxazolone-1,2,3-triazole hybrids. METHODS: The designed oxazolone-1,2,3-triazole hybrids were synthesized using copper(I)-catalyzed azide-alkyne cycloaddition. The antimicrobial evaluation was carried out using serial dilution method. RESULTS: Most of the synthesized hybrids showed significant antimicrobial properties. Some of the compounds were found to be possessing better or comparable activity to that of the standards used. The docking simulations results are also in agreement with the antimicrobial activity data. CONCLUSION: Sixteen new hybrids were synthesized and tested in vitro for their antimicrobial activity. Some of the tested compounds exhibited promising antimicrobial activity and could be utilized for the development of the lead compounds for new and more potent antimicrobial drugs.

The tyrosinase inhibitory effects of isoxazolone derivatives with a (Z)-ß-phenyl-α, ß-unsaturated carbonyl scaffold.

Thirteen (Z)-4-(substituted benzylidene)-3-phenylisoxazol-5(4H)-ones were designed to confirm the geometric effect of the double bond of the ß-phenyl-α, ß-unsaturated carbonyl scaffold on tyrosinase inhibitory activity. Compounds 1a-1m, which all possessed the (Z)-ß-phenyl-α, ß-unsaturated carbonyl scaffold, were synthesized using a tandem reaction consisting of an isoxazolone ring formation and a Knoevenagel condensation, and three starting materials, ethyl benzoylacetate, hydroxylamine and benzaldehydes. Some of the compounds showed inhibitory activity against mushroom tyrosinase as potent as compounds containing the "(E)"-ß-phenyl-α, ß-unsaturated carbonyl scaffold. Compounds 1c and 1m showed greater inhibitory activity than kojic acid: IC50 = 32.08 ±â€¯2.25 µM for 1c; IC50 = 14.62 ±â€¯1.38 µM for 1m; and IC50 = 37.86 ±â€¯2.21 µM for kojic acid. A kinetic study indicated that 1m inhibited tyrosinase in a competitive manner and that it probably binds to the enzyme's active site. In silico docking simulation supported binding of 1m (-7.6 kcal/mol) to the active site of tyrosinase with stronger affinity than kojic acid (-5.7 kcal/mol). Similar results were obtained using cell-based assays, and in B16F10 cells, compound 1m dose-dependently inhibited tyrosinase activity and melanogenesis. These results indicate the anti-melanogenic effect of compound 1m is due to the inhibition of tyrosinase and (Z)-isomer of the ß-phenyl-α, ß-unsaturated carbonyl scaffold can, like its congener the (E)-isomer, act as an excellent scaffold for tyrosinase inhibition.

Integration of multi-scale molecular modeling approaches with experiments for the in silico guided design and discovery of novel hERG-Neutral antihypertensive oxazalone and imidazolone derivatives and analysis of their potential restrictive effects on cell proliferation.

AT1 antagonists is the most recent drug class of molecules against hypertension and they mediate their actions through blocking detrimental effects of angiotensin II (A-II) when acts on type I (AT1) A-II receptor. The effects of AT1 antagonists are not limited to cardiovascular diseases. AT1 receptor blockers may be used as potential anti-cancer agents - due to the inhibition of cell proliferation stimulated by A-II. Therefore, AT1 receptors and the A-II biosynthesis mechanisms are targets for the development of new synthetic drugs and therapeutic treatment of various cardiovascular and other diseases. In this work, multi-scale molecular modeling approaches were performed and it is found that oxazolone and imidazolone derivatives reveal similar/better interaction energy profiles compared to the FDA approved sartan molecules at the binding site of the AT1 receptor. In silico-guided designed hit molecules were then synthesized and tested for their binding affinities to human AT1 receptor in radioligand binding studies, using [125I-Sar1-Ile8] AngII. Among the compounds tested, 19d and 9j molecules bound to receptor in a dose response manner and with relatively high affinities. Next, cytotoxicity and wound healing assays were performed for these hit molecules. Since hit molecule 19d led to deceleration of cell motility in all three cell lines (NIH3T3, A549, and H358) tested in this study, this molecule is investigated in further tests. In two cell lines (HUVEC and MCF-7) tested, 19d induced G2/M cell cycle arrest in a concentration dependent manner. Adherent cells detached from the plates and underwent cell death possibly due to apoptosis at 19d concentrations that induced cell cycle arrest.

Design & synthesis of novel oxazolone & triazinone derivatives and their biological evaluation as COX-2 inhibitors.

A new series of oxazolones and triazinones were designed and synthesized and evaluated against both COX-1 and COX-2 enzymes. Full structure elucidation of the new derivatives was performed using microanalyses, IR, 1H NMR, 13C NMR and mass spectra. Most of the derivatives showed good inhibitory activity against COX-2 enzyme specifically compounds IIIc, IIIe, IVd and IVg with IC50 values 0.024, 0.019, 0.011 and 0.014µM compared to celecoxib as reference drug with IC50 value of 0.05µM. Altogether, these results indicate that these derivatives can be effective anti-inflammatory agents.

P2X7 receptor promotes intestinal inflammation in chemically induced colitis and triggers death of mucosal regulatory T cells.

P2X7 receptor activation contributes to inflammation development in different pathologies. We previously reported that the P2X7 receptor is over-expressed in the gut mucosa of patients with inflammatory bowel disease, and that P2X7 inhibition protects against chemically induced colitis. Here, we investigated in detail the role of the P2X7 receptor in inflammatory bowel disease development, by treating P2X7 knockout (KO) and WT mice with two different (and established) colitis inductors. P2X7 KO mice were protected against gut inflammation induced by 2,4,6-trinitrobenzenesulfonic acid or oxazolone, with no weight loss or gut histological alterations after treatment. P2X7 receptor knockout induced regulatory T cell accumulation in the colon, as evaluated by qRT-PCR for FoxP3 expression and immunostaining for CD90/CD45RBlow. Flow cytometry analysis of mesenteric lymph node cells showed that P2X7 activation (by ATP) triggered regulatory T cell death. In addition, such cells from P2X7 KO mice expressed more CD103, suggesting increased migration of regulatory T cells to the colon (relative to the WT). Our results show that the P2X7 has a key role during inflammation development in inflammatory bowel disease, by triggering the death and retention in the mesenteric lymph nodes of regulatory T cells that would otherwise promote immune system tolerance in the gut.