Search Results (78)

This study evaluated the antioxidant capacity of the oxidation products of three flavonols using oxygen radical absorbance capacity—fluorescein assay (ORAC-FL), oxygen radical absorbance capacity—pyrogallol red assay (ORAC-PGR), and the cellular antioxidant activity (CAA) assay in human dermal fibroblast (HFF) cells, with 2,2’-azobis(2-amidinopropane) dihydrochloride (AAPH) as a free radical generator under controlled pH and solvent conditions. At pH 2 in a polar aprotic solvent, BZF-OH (benzofuranone-OH) compounds were formed, while methoxylated analogs were obtained at pH 7 in a polar protic solvent. The products generated at pH 2 exhibited significantly higher antioxidant capacities, demonstrating the influence of the reaction environment on modulating antioxidant properties. The antioxidant activity was observed to reflect the combined action of the flavonol precursor and its oxidation products. This led to the proposal of the Gross Antioxidant Capacity (GAC) concept to integrate the contribution of all generated species. Since chemical assays such as ORAC do not fully capture the complexity of biological systems, they should be complemented with cellular approaches for a more accurate evaluation. Additionally, BZF-OH compounds were analyzed as potential cyclooxygenase-2 (COX-2) inhibitors through docking and molecular dynamics simulations, where BZF-Quer-OH showed binding affinities comparable to celecoxib, a selective COX-2 inhibitor. These findings were complemented by an analysis of COX-2 expression in RAW 264.7 cells treated with lipopolysaccharide (LPS), where treatment with the antioxidants significantly inhibited COX-2 expression. In the case of the oxidation products, only the oxidation product of rhamnetin showed a reduction in COX-2 expression compared to the LPS-treated control. Together, these results highlight that flavonol-derived oxidation products not only retain significant antioxidant capacity but may also possess anti-inflammatory properties, opening new perspectives for the development of innovative therapies targeting oxidative stress and chronic inflammation. Full article

Oxidative stress critically influences the pathophysiology of glioblastoma (GBM), a deadly and aggressive brain tumor. Reactive oxygen species (ROS) regulate cancer cell homeostasis, influencing the treatment response. The transcription factor Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) activates antioxidant defenses, protecting GBM cells from therapy-induced oxidative stress and contributing to Temozolomide (TMZ) resistance. Cyclooxygenase-2 (COX-2) plays a key role in GBM chemoresistance by modulating the tumor microenvironment and supporting a pro-survival phenotype. The impact of COX-2 inhibition by celecoxib (CXB), a selective COX-2 inhibitor, combined with TMZ on oxidative stress modulation linked to resistance was investigated in GBM primary cultures and cell lines. The drug combination CXB+TMZ was tested on TMZ-sensitive and -resistant cells, and ROS levels and Nrf2 activation were evaluated via a DCFH-DA probe and Western blotting, respectively. The oxidative stress marker malondialdehyde and antioxidant enzymes were assayed using standard methods. COX-2 inhibition combined with TMZ significantly increased ROS, while TMZ alone induced a compensatory antioxidant response, sustaining resistance. Drug combination reduced this response, restoring oxidative stress even in TMZ-resistant cells. Prostaglandin E2 reversed these effects, confirming the role of the COX-2/PGE2 axis in redox balance. Drug combination increased ROS, disrupted redox homeostasis and overcame TMZ resistance, supporting COX-2 inhibition as a promising GBM therapy strategy. Full article

Introduction: Inhibiting cyclooxygenase-2 (COX-2) is a potential strategy in inflammation therapy. Thus, developing COX-2 inhibitors plays a pivotal role in efficient inflammation treatment. This study discloses the synthesis of new heterocyclic compounds incorporating pyridine, pyran, and/or pyrazole moieties as COX-2 inhibitors. Methods: In this study, the Claisen–Schmidt reaction of 1-(5-hydroxy-1,3-diphenyl-1H-pyrazol-4-yl)ethan-1-one 1 and p-methoxybenzaldehyde in ethanol containing aqueous sodium hydroxide (10%) led to the formation of 1-(5-hydroxy-1,3-diphenyl-1H-pyrazol-4-yl)-3-(4-methoxyphenyl)prop-2-en-1-one) 2. The latter compound was allowed to react as a key precursor with various nucleophiles such as ethyl cyanoacetate, malononitrile, cyclohexanone, ethyl acetoacetate, hydrazine, cyano acid hydrazide, hydrazide, and/or thiosemicarbazide to yield new heterocyclic derivatives comprising pyridine, pyran, and/or pyrazole moieties 3–15, according to the Michael addition reaction. The newly synthesized compounds were depicted using spectroscopic techniques such as IR, ¹H-NMR, ¹³C-NMR, and MS. Moreover, their anti-inflammatory efficiency was in vitro evaluated by means of protein denaturation inhibition and cell membrane protection assay. Results: The results of 2^−ΔΔct values of COX-2 expression for compounds 6, 11, 12, and 13 were 6.6, 2.9, 25.8, and 10.1, respectively. Therefore, compound 12, followed by 13, 11, and 6, showed potent anti-inflammatory properties by in vitro evaluation. Further, an in silico molecular docking study was performed on the best-docked compounds and reference drug (Diclofenac) to investigate their binding affinities against the active site of the target enzyme. The obtained results from the in silico study aligned with the biological evaluation. Conclusions: The studies open new doors for designing new heterocycles containing pyridine, pyran, and/or pyrazole moieties as potent anti-inflammatory agents. Full article

2-arachnadoyl glycerol (2-AG) is one of the most common endocannabinoid molecules with anti-proliferative, cytotoxic, and pro-proliferative effects on different types of tumors. Typically, it induces cell death via cannabinoid receptor 1/2 (CB1/CB2)-linked ceramide production. In breast cancer, ceramide is counterbalanced by the sphingosine-1-phosphate, and thus the mechanisms of 2-AG influence on proliferation are poorly understood. We evaluated the mechanism of the anti-proliferative action by 2-AG and the influence of lysophaosphatidylinositol (LPI) on it in six human breast cancer cell lines of different tumor degree (MCF-10A, MCF-7, BT-474, BT-20, SK-BR-3, and MDA-MB-231) using resazurin test, inhibitor, blocker, and anti-oxidant analysis, and siRNA interference. To avoid acyl migration in 2-AG, we replaced it with the analog 2-arachidonoyl-1,3-difluoropropanol (2-ADFP) newly synthesized by us. Using a molecular docking approach, we showed that at the CB2 receptor, 2-ADFP and 2-AG were very close to each other. However, 2-ADFP demonstrated a stronger affinity towards CB1 in the antagonist-bound conformation. 2-ADFP was anti-proliferative in all the cell lines tested. The toxicity of 2-ADFP was enhanced by LPI. 2-ADFP activity was reduced or prevented by the CB2 and vanilloid receptor 1 (TRPV1) blockers, inositol triphosphate receptor, CREB, and cyclooxygenase 2 inhibitor, and by anti-oxidant addition. Together with the literature data, these results indicate CB2- and TRPV1-dependent COX-2 induction with concomitant cell death induction by the oxidized molecule’s metabolites. Full article

Farnesoid X receptor (FXR), a nuclear receptor, is expressed in calvaria and bone marrow stromal cells and plays a role in bone homeostasis. However, the mechanism of FXR-activated osteoblast differentiation remains unclear. In this study, we investigated the regulatory mechanism underlying FXR-activated osteoblast differentiation using bone morphogenetic protein-2 (BMP-2)-induced mouse ST-2 mesenchymal stem cells. We also synthesized a novel FXR agonist, FLG390, and compared its biological effects in osteoblast differentiation with a known FXR agonist, chenodeoxycholic acid (CDCA). As an FXR agonist, FLG390 accelerated osteoblast differentiation to a comparable extent with CDCA, enhancing alkaline phosphatase (ALP) activity and the expression of osteoblast differentiated-related genes such as ALP, collagen type 1 α1 chain (COL1A1), and runt-related transcription factor 2 (RUNX2). FXR activation elevated the expression of cyclooxygenase (COX)-2 and the production of prostaglandin (PG) E₂ in the early phase of osteoblast differentiation. A selective COX-2 inhibitor and an antagonist of EP4 receptors, one of PGE₂ receptors, partially suppressed FXR-activated osteoblast differentiation. Moreover, treatment with either inhibitor during the first 6 h after initiating osteoblast differentiation repressed FXR-activated osteoblast differentiation to the same extent as did the treatment for 6 d. Therefore, a novel FXR agonist, FLG390, exhibited potency comparable to CDCA. FXR activation promoted the early phase of osteoblast differentiation via the COX-2-PGE₂-EP4 axis, representing a potential target for control of bone metabolism. Full article

Inflammation and oxidative stress are crucial for osteoarthritis (OA) pathogenesis. Despite the potential of pharmacological pretreatment of chondrocytes in preventing OA, its efficacy in preventing the progression of cartilage damage and promoting its recovery has not been examined. In this study, an H₂O₂-induced human OA-like chondrocyte cell model was created using H1467 primary human chondrocytes to evaluate the efficacy of interleukin (IL)-6 and cyclooxygenase (COX)-2 inhibitors (tocilizumab and celecoxib, respectively) in the prevention and treatment of cartilage damage. H₂O₂ significantly elevated the IL-6, COX-2, and matrix metalloproteinase (MMP)-13 levels. Although monotherapy decreased the levels, nuclear shrinkage and altered cell morphology, similar to those in the H₂O₂ group, were observed. The expression of these factors was significantly lower in the combination therapy group, and the cell morphology was maintained. Moreover, the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was activated, and levels of the antioxidant protein heme oxygenase-1 (HO-1) were increased, especially in the combination group, indicating an anti-inflammatory effect. The treatment groups, particularly the combination group, demonstrated increased cell viability. Overall, the drug combination exhibited superior efficacy in preventing the progression of cartilage damage and promoted its recovery compared with the monotherapy. Given that the drugs herein are already in clinical use, they are suitable candidates for OA treatment. Full article

Premature skin aging, also known as photoaging, refers to the changes in the structure and function of the skin caused by chronic sun exposure. The ultraviolet radiation in sunlight is one of the key factors that cause photoaging. Thus, matrix metalloproteinases (MMPs), transforming growth factor beta-1 (TGFB1), and nuclear factor kappa B (NF-κB) signaling can be an effective therapeutic strategy for ultraviolet B (UVB) exposure. In this study, we used human dermal fibroblast and mouse macrophage cells to identify the mediators of skin photoaging. Quercitrin isolated from ‘Green Ball’ apple peel was treated to UVB-irradiated fibroblast cells and lipopolysaccharide (LPS)-induced macrophages to identify the photoaging prevention effect of quercitrin. Genes that are associated with photoaging were determined by using enzyme-linked immunosorbent assay (ELISA), Western blot, and quantitative polymerase chain reaction (qPCR). Quercitrin increased the collagen biosynthesis in UVB-irradiated fibroblast cells via regulating MMPs, TIMP metallopeptidase inhibitor 1 (TIMP-1), TGFB1, hyaluronan synthase 2 (HAS2), and collagen type I alpha 1 chain (COL1A2). In addition, quercitrin regulated p-65, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), and its mediators (prostaglandin E2 and nitric oxide), in the NF-κB signaling process, and it inhibited the production of cytokines in LPS-induced macrophages. These results indicate that quercitrin can improve photoaging damaged skin by regulating MMPs, TGFB1, and NF-κB signaling pathway modulators. Full article

Background/Objectives: Diabetes mellitus (DM), a widespread endocrine disorder characterized by chronic hyperglycemia, can cause nerve damage and increase the risk of neurodegenerative diseases such as Alzheimer’s disease (AD). Effective blood glucose management is essential, and sitagliptin (SITG), a dipeptidyl peptidase-4 (DPP-4) inhibitor, may offer neuroprotective benefits in type 2 diabetes mellitus (T2DM). Methods: T2DM was induced in rats using nicotinamide (NICO) and streptozotocin (STZ), and biomarkers of AD and DM-linked enzymes, inflammation, oxidative stress, and apoptosis were evaluated in the brain. Computational studies supported the in vivo findings. Results: SITG significantly reduced the brain enzyme levels of acetylcholinesterase (AChE), beta-secretase-1 (BACE-1), DPP-4, and glycogen synthase kinase-3β (GSK-3β) in T2DM-induced rats. It also reduced inflammation by lowering cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB). Additionally, SITG improved oxidative stress markers by reducing malondialdehyde (MDA) and enhancing glutathione (GSH). It increased anti-apoptotic B-cell lymphoma protein-2 (Bcl-2) while reducing pro-apoptotic markers such as Bcl-2-associated X (BAX) and Caspace-3. SITG also lowered blood glucose levels and improved plasma insulin levels. To explore potential molecular level mechanisms, docking was performed on AChE, COX-2, GSK-3β, BACE-1, and Caspace-3. The potential binding affinity of SITG for the above-mentioned target enzymes were 10.8, 8.0, 9.7, 7.7, and 7.9 kcal/mol, respectively, comparable to co-crystallized ligands. Further binding mode analysis of the lowest energy conformation revealed interactions with the critical residues. Conclusions: These findings highlight SITG’s neuroprotective molecular targets in T2DM-associated neurodegeneration and its potential as a therapeutic approach for AD, warranting further clinical investigations. Full article

Polygonum aviculare L. (PAL), commonly known as knotgrass, has been utilized as a traditional folk medicine across Asian, African, Latin American and Middle Eastern countries to treat various inflammatory diseases, including arthritis and airway inflammation. Numerous medicinal herbs exert anti-inflammatory and antioxidative effects that are mediated through the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and the inhibition of nuclear factor kappa B (NF-κB). However, the underlying molecular mechanisms linking the antioxidative and anti-inflammatory effects remain poorly understood. Heme oxygenase-1 (HO-1) is an antioxidant enzyme that catalyzes heme degradation, ultimately leading to the production of carbon monoxide (CO). Elevated levels of CO have been correlated with the decreased level of inducible nitric oxide synthase (iNOS). In this study, we examined whether HO-1 plays a key role in the relationship between the antioxidative and anti-inflammatory properties of PAL. The anti-inflammatory and antioxidative activities of PAL in an in vitro system were evaluated by determining NF-κB activity, antioxidant response element (ARE) activity, pro-inflammatory cytokine and protein levels, as well as antioxidant protein levels. To examine whether HO-1 inhibition interfered with the anti-inflammatory effect of PAL, we measured nitrite, reactive oxygen species, iNOS, and HO-1 levels in RAW 264.7 murine macrophages pre-treated with Tin protoporphyrin (SnPP, an HO-1 inhibitor). Our results demonstrated that PAL increased ARE activity and the Nrf2-regulated HO-1 level, exerting antioxidative activities in RAW 264.7 macrophages. Additionally, PAL reduced cyclooxygenase-2 (COX-2) and iNOS protein levels by inactivating NF-κB in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Further investigation using the HO-1 inhibitor revealed that HO-1 inhibition promoted iNOS expression, subsequently elevating nitric oxide (NO) generation in LPS-activated RAW 264.7 macrophages treated with PAL compared to those in the macrophages without the HO-1 inhibitor. Overall, our findings suggest that HO-1 induction by PAL may exert anti-inflammatory effects through the reduction of the iNOS protein level. Hence, this study paves the way for further investigation to understand molecular mechanisms underlying the antioxidative and anti-inflammatory activities of medicinal herbs. Full article

Cyclooxygenase-2 (COX-2) is overexpressed in many human and animal cancers. Selective COX-2 inhibitors have shown antitumoral effects in tumors with a high expression of COX-2. This study evaluates (1) the expression of COX-2 in rabbit uterine adenocarcinomas, (2) the correlation between immunophenotypic expression and histopathological changes, and (3) the post-surgery response to therapy with COX-2 inhibitors. Forty rabbit uteri were divided into three groups: neoplastic, hyperplastic, and normal endometrium. A histological and immunohistochemical score was applied to investigate the tumor’s grade and the COX-2 expression. By histological evaluation, 30 cases of endometrial adenocarcinoma, 5 cases of endometrial hyperplasia and 5 normal endometria were found. Of the six cases of endometrial adenocarcinoma with follow-up available, four received a post-surgical treatment with meloxicam and two were treated by surgery alone. The survival time of the animals treated with meloxicam was longer than that observed in the untreated animals. A statistically significant difference in COX-2 IHS was observed between non-neoplastic endometrium and adenocarcinoma. The progressive increase in COX-2 expression from normal epithelium to carcinoma suggests that upregulation of COX-2 expression may play a role in tumor initiation and progression. Our findings suggest the possible use of COX-2 inhibitors in treating uterine adenocarcinoma in rabbits. Further study will be needed to confirm this hypothesis. Full article

The regio- and stereoselectivity and the molecular mechanisms of the [3 + 2] cycloaddition reactions between Syn-propanethial S-oxide and selected conjugated nitroalkenes were explored theoretically in the framework of the Molecular Electron Density Theory. It was found that cycloadditions with the participation of nitroethene as well as its methyl- and chloro-substituted analogs can be realized via a single-step mechanism. On the other hand, [3 + 2] cycloaddition reactions between Syn-propanethial S-oxide and 1,1-dinitroethene can proceed according to a stepwise mechanism with a zwitterionic intermediate. Finally, we evaluated the affinity of model reaction products for several target proteins: cytochrome P450 14α-sterol demethylase CYP51 (RSCB Database PDB ID: 1EA1), metalloproteinase gelatinase B (MMP-9; PDB ID: 4XCT), and the inhibitors of cyclooxygenase COX-1 (PDB:3KK6) and COX-2 (PDB:5KIR). Full article

Background: The intestinal wound healing process is a complex event of three overlapping phases: exudative, proliferative, and remodeling. Although some mechanisms have been extensively described, the intestinal healing process is still not fully understood. There are some similarities but also some differences compared to other tissues. The aim of this systematic review was to summarize all studies with knockout (KO) experimental models in bowel anastomoses, underline any recent knowledge, and clarify further the cellular and molecular mechanisms of the intestinal healing process. A systematic review protocol was performed. Materials and methods: Medline, EMBASE, and Scopus were comprehensively searched. Results: a total of eight studies were included. The silenced genes included interleukin-10, the four-and-one-half LIM domain-containing protein 2 (FHL2), cyclooxygenase-2 (COX-2), annexin A1 (ANXA-1), thrombin-activatable fibrinolysis inhibitor (TAFI), and heparin-binding epidermal growth factor (HB-EGF) gene. Surgically, an end-to-end bowel anastomosis was performed in the majority of the studies. Increased inflammatory cell infiltration in the anastomotic site was found in IL-10-, annexin-A1-, and TAFI-deficient mice compared to controls. COX-1 deficiency showed decreased angiogenesis at the anastomotic site. Administration of prostaglandin E2 in COX-2-deficient mice partially improved anastomotic leak rates, while treatment of ANXA1 KO mice with Ac2-26 nanoparticles reduced colitis activity and increased weight recovery following surgery. Conclusions: our findings provide new insights into improving intestinal wound healing by amplifying the aforementioned genes using appropriate gene therapies. Further research is required to clarify further the cellular and micromolecular mechanisms of intestinal healing. Full article

(1) Background: National health system databases represent an important source of information about the epidemiology of adverse drug reactions including drug-induced allergy and anaphylaxis. Analysis of such databases may enhance the knowledge of healthcare professionals regarding the problem of drug-induced anaphylaxis. (2) Methods: A retrospective descriptive analysis was carried out of spontaneous reports (SRs) with data on drug-induced anaphylaxis (SRsAs) extracted from the Russian National Pharmacovigilance database (analyzed period 2 April 2019–21 June 2023). The percentage of SRsAs among SRs of drug-induced allergy (SRsDIAs) was calculated, as well as of pediatric, elderly, and fatal SrsAs. Drugs involved in anaphylaxis were assessed among total SRsAs, pediatric, and elderly SRsAs, and among fatal SRsAs. Demographic parameters of patients were assessed. (3) Results: SRsAs were reported in 8.3% of SRsDIAs (2304/27,727), the mean age of patients was 48.2 ± 15.8 years, and females accounted for 53.2% of cases. The main causative groups of drugs were antibacterials (ABs) for systemic use (44.6%), local anesthetics (20.0%), and cyclooxygenase (COX) inhibitors (10.1%). Fatal SRsAs were reported in 9.5% (218/2304) of cases, the mean age of patients was 48.0 ± 16.7 years, and females accounted for 56.4% of cases. Pediatric SRsAs accounted for 3.9% of pediatric SRsDIAs and 5.8% of all SRsAs, with a mean age of 11.8 ± 4.5 years, and females acccounted for 51.9% of cases. Elderly SRsAs accounted for 2% of elderly SRsDIAs and 2.8% of all SRsAs, and the mean age was 73.0 ± 5.3 years, and females accounted for 43.5% of cases. ABs caused 40% of SRsAs in the elderly, 42.9% in children, and 50% of fatal SRsAs. (4) Conclusions: Our study revealed a relatively high proportion of anaphylaxis among SRs of drug-induced allergy. ABs were the most prevalent causative agents, especially in fatal SRsAs. Full article

Molecular hybridization has emerged as a promising approach in the treatment of diseases exhibiting multifactorial etiology. With regard to this, dual cyclooxygenase-2/lipoxygenase (COX-2/LOX) inhibitors could be considered a safe alternative to traditional non-steroidal anti-inflammatory drugs (tNSAIDs) and selective COX-2 inhibitors (coxibs) for the treatment of inflammatory conditions. Taking this into account, six novel pyrrole derivatives and pyrrole–cinnamate hybrids were developed as potential COX-2 and soybean LOX (sLOX) inhibitors with antioxidant activity. In silico calculations were performed to predict their ADMET (absorption, distribution, metabolism, excretion, toxicity) properties and drug-likeness, while lipophilicity was experimentally determined as R_M values. All synthesized compounds (1–4, 5–8) could be described as drug-like. The results from the docking studies on COX-2 were in accordance with the in vitro studies. According to molecular docking studies on soybean LOX, the compounds displayed allosteric interactions with the enzyme. Pyrrole 2 appeared to be the most potent s-LOX inhibitor (IC₅₀ = 7.5 μM). Hybrids 5 and 6 presented a promising combination of in vitro LOX (IC₅₀ for 5 = 30 μM, IC₅₀ for 6 = 27.5 μM) and COX-2 (IC₅₀ for 5 = 0.55 μM, IC₅₀ for 6 = 7.0 μM) inhibitory activities, and therefore could be used as the lead compounds for the synthesis of more effective multi-target agents. Full article

Etoricoxib is a non-steroidal anti-inflammatory drug with high selectivity for cyclooxygenase 2 (COX-2), exerting a pronounced anti-inflammatory effect with fewer adverse events when compared to COX-1 inhibitors. The present study aimed to evaluate the bioequivalence between two etoricoxib-coated tablet formulations to meet regulatory requirements for a branded generic product registration in Brazil. A crossover study with an open-label, randomized design and a single-dose regimen with two treatments and two periods was conducted on healthy Brazilians of both genders. Subjects randomly received a single dose of a 90 mg etoricoxib coated tablet of test product Xumer^® 90 mg (Adium S.A.) and the reference product Arcoxia^® 90 mg (Merck Sharp & Dohme Farmacêutica Ltda.) under fasting conditions separated by a 14-day period. Blood samples were collected sequentially for up to 96 h following drug administration, and the concentrations of etoricoxib in plasma were determined using a validated UPLC-MS/MS method. Pharmacokinetic parameters were computed utilizing non-compartmental analysis methods. A total of 32 healthy subjects were enrolled, and 25 subjects completed the study. Geometric mean ratios (90% confidence intervals) for C_max, AUC_0-t, and AUC_0-inf were 103.98% (95.63–113.06), 96.82% (91.82–102.09), and 95.79% (90.70–101.16), respectively. In accordance with regulatory standards, the test formulation (Xumer^® 90 mg) has been deemed bioequivalent to the reference product (Arcoxia^® 90 mg). As a result, these formulations can be considered interchangeable in clinical practice, with both proving to be safe and well-tolerated. The need for in vivo testing for the Xumer^® 60 mg strength was waived due to the proportional similarity of the formulations and the similar in vitro dissolution profiles observed across the various strengths. Full article