Search Results (401)

Kynurenic acid (KYNA), a tryptophan metabolite, possesses immunomodulatory properties, although the molecular mechanism of this action has not yet been resolved. In the present study, the effects of KYNA on the secretion of selected cytokines and chemokines by macrophages derived from the human THP-1 cell line are investigated. Furthermore, the involvement of the aryl hydrocarbon receptor (AhR) and the G protein-coupled receptor 35 (GPR35) in mediating the effects of KYNA was examined. In lipopolysaccharide (LPS)-stimulated THP-1-derived macrophages, KYNA significantly reduced IL-6 and CCL-2, but increased IL-10 and M-CSF levels. AhR antagonist CH-223191 reduced the KYNA influence on IL-6, CCL-2, and M-CSF production, while the GPR35 antagonist, ML-145, blocked KYNA-induced IL-10 production. Furthermore, it was shown that THP-1 derived macrophages were capable of synthesizing and releasing KYNA and that its production was increased in the presence of LPS. These findings suggest that THP-1-derived macrophages are a source of KYNA and that KYNA modulates inflammatory responses predominantly through AhR and GPR35 receptors. Our study provides further evidence for the involvement of macrophages in immunomodulatory processes that are dependent on AhR and GPR35 receptors, as well as the potential role of KYNA in these phenomena. Full article

Plant flowers are recognized as a rich source of bioactive phenolic compounds. In this study, for the first time, the recovery of antioxidant phenolic compounds from Cytisus striatus flowers (CF) was optimized using microwave-assisted extraction (MAE). The variables (% of ethanol, temperature, and time) were studied using a response surface methodology (RSM). Extraction efficiency was assessed by total phenol content, total flavonoid content, and the antioxidant capacity through DPPH, ABTS, FRAP, and CUPRAC assays. Additionally, cytotoxicity and anti-inflammatory properties were evaluated in different cell lines. The optimal extraction conditions (87.6% ethanol, 160.8 °C and 8.76 min) yielded extracts rich in phenolics (85.9 mg GAE/g CF) and flavonoids (120.3 mg RE/g CF), with strong antioxidant capacity. LC-MS/MS analysis identified 27 phenolic compounds, including chrysin, apigenin, and quercetin derivatives. Cytotoxicity tests showed that CF extract maintained high viability (>80%) in human embryonic kidney (HEK293T) and human lung adenocarcinoma (A549) cells up to 2000 µg/mL, indicating low cytotoxicity. The anti-inflammatory potential was evidenced by a decrease in IL-1β levels and an increase in IL-10 cytokine production in LPS-stimulated macrophages. These results highlight the great potential of CF as a promising bioresource to obtain value-added compounds for the development of functional foods, nutraceuticals, and cosmetic products. Full article

Clinacanthus nutans (Burm.f.) Lindau is a Southeast Asian medicinal plant traditionally used for treating skin inflammation and infections. This study evaluated its wound-healing potential through anti-inflammatory, cytoprotective, and antiviral mechanisms. HPLC-DAD analysis identified schaftoside as the major flavonoid in the 95% ethanolic leaf extract. In the lipopolysaccharide (LPS)-stimulated murine macrophage cell line (RAW 264.7), both C. nutans extract (5 and 50 μg/mL) and its flavonoid schaftoside (5 and 20 μg/mL) significantly downregulated the expression of pro-inflammatory genes, including cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and prostaglandin E₂ (PGE₂), under both pre-treatment and post-treatment conditions. ELISA confirmed dose-dependent inhibition of human COX-2 enzymatic activity, reaching up to 99.3% with the extract and 86.9% with schaftoside. In the endothelial cell models (CCL-209), the extract exhibited low cytotoxicity and effectively protected cells from LPS-induced apoptosis, preserving vascular integrity critical to tissue regeneration. Antiviral assays demonstrated suppression of HSV-2 replication, particularly during early infection, which may help prevent infection-related delays in wound healing. Collectively, these findings suggest that C. nutans and schaftoside promote wound repair by attenuating inflammatory responses, supporting endothelial survival, and controlling viral reactivation. These multifunctional properties highlight their potential as natural therapeutic agents for enhancing wound-healing outcomes. Full article

Multiple lines of evidence suggest that endothelial dysfunction is a key player in the pathogenesis of COVID-19, with cytokine storm as one of the main primary causes. Among the mechanisms underlying endothelial damage, clinical findings identify alterations in arginine metabolism, as patients with severe COVID-19 exhibit lower levels of nitric oxide synthase (eNOS) and upregulated arginase. In this study, we investigated, in human endothelial cells (HUVECs), the effect of conditioned medium from macrophages activated with SARS-CoV-2 Spike protein (CM_S1) on arginine metabolism. The results indicate that CM_S1 causes a marked decrease in eNOS and an increase in arginase, along with a greater intracellular arginine content and the induction of the CAT2 transporter. These effects are ascribable to the inflammatory mediators released by macrophages in CM_S1, mainly TNFα and IL-1β. Since infliximab, an antibody targeting TNFα, and baricitinib, an inhibitor of the JAK/STAT pathway, correct the observed imbalance between eNOS and arginase, our findings suggest the potential efficacy of a combined therapy to counteract endothelial dysfunction in COVID-19. Full article

Lactic acid bacteria are components of the gastrointestinal tract microbiota in both humans and animals and are widely used as probiotics. Lactobacillus is the most closely related genus to probiotic activity. It is capable of releasing membrane microvesicles (MVs), whose primary functions include carrying and transmitting antigens to host tissues and modulating host defense responses. In the present study, MVs were isolated from Lactobacillus acidophilus resident in the ileum of free-living rats, and their immunostimulant effect was evaluated in two biological models. MVs were characterized using SDS-PAGE electrophoresis, electron microscopy, and nanoparticle tracking analysis. In the first model, the immunostimulatory effect of MVs was evaluated on ovine abomasal explants, which had been previously stimulated with MVs and then challenged with third-stage larvae of Haemonchus contortus. This resulted in a decrease in the percentage of larval association and favored the migration of inflammatory cells to the infection site. In the second model, the macrophage cell line RAW 264.7 was stimulated with MVs to evaluate the expression of transcripts encoding IL-1β and TNF-α. MVs isolated from L. acidophilus demonstrate immunostimulatory and probiotic effects in the two biological models assessed. This suggested that the MVs possess similar immunostimulatory effects as those reported for the parent bacteria. Full article

Triple-negative breast cancer (TNBC) and inflammatory breast cancer (IBC) are the most aggressive molecular subtypes of breast cancer. Poor clinical outcomes highlight the pressing need to discover novel targets for the effective treatment of these diseases. LMP7 (β5i/PSMB8), a proteolytic subunit of the immunoproteasome, is implicated in the pathogenesis of multiple myeloma, autoimmune and inflammatory diseases, and inflammation-related cancers. However, the role of LMP7 in TNBC and IBC remains poorly characterized. Here, we evaluated the function of LMP7 in TNBC and IBC using the selective LMP7 inhibitor M3258. In human TNBC patient samples, LMP7 expression correlated strongly with CD8⁺ T cell infiltration and activation markers. M3258 inhibited LMP7 activity, reduced viability, and induced apoptosis in TNBC/IBC cell lines in vitro. In a novel immunocompetent in vivo model of TNBC/IBC, M3258 reduced tumor growth and the tumor abundance of M2 macrophages. Additionally, M3258 activated tumor-infiltrating CD8⁺ T cells and suppressed the expression of specific inflammatory pathway gene signatures in immune cells. Co-culture with M2 macrophages enhanced the invasiveness of TNBC/IBC cells, which was effectively suppressed by M3258 treatment. Our results demonstrate for the first time that LMP7 shapes the pro-tumorigenic microenvironment of TNBC/IBC, in part by modulating the pathogenic role of M2 macrophages. These findings suggest that LMP7 may represent a novel target for therapeutic intervention in TNBC/IBC. Full article

Glucagon-like peptide-1 (GLP-1) is a hormone secreted from enteroendocrine cells that can promote weight loss and blood glucose improvement. We screened probiotic strains that effectively stimulate GLP-1 secretion from human enteroendocrine cells and then investigated the efficacy of this strain in a high-fat diet (HFD)-induced mouse model of obesity. Lactiplantibacillus plantarum GB104 greatly induced GLP-1 secretion by increasing expression of the proglucagon gene (GCG), but not the proprotein convertase subtilisin/kexin type 1 gene (PCSK1) in the human enteroendocrine cell line NCI-H716. In an HFD-induced mouse model of obesity, GB104 inhibited weight gain and improved blood glucose levels by increasing blood GLP-1 levels. It also tended to attenuate the HFD-induced changes in blood levels of other hormones and suppressed fat accumulation in the liver and adipose tissues. In white adipose tissue, GB104 suppressed inflammation by reducing pro-inflammatory M1 macrophages and increasing anti-inflammatory M2 macrophages and regulatory T cells. Probiotic strains that promote GLP-1 secretion, such as GB104, may serve as a promising candidate for dietary intervention against obesity and metabolic diseases. Full article

Traditionally, medicinal plants have served as the main resource for treating various human health conditions. Prionosciadium dissectum is a plant used in traditional medicine in the southern region of Jalisco, Mexico, to treat inflammatory respiratory problems. However, this species has not undergone pharmacological or biotechnological studies that validate these popular uses. The aim of this study was to induce calluses on P. dissectum leaves and then evaluate the antioxidant, anti-inflammatory, and antiproliferative activity of their extracts. The best callus induction was obtained using Murashige and Skoog (MS) culture medium with 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg/L kinetin (KIN). Extracts of hexane, dichloromethane, and methanol were obtained from the dry biomass, and the highest yield was obtained with methanol. The total phenolic content and antioxidant activity of the methanolic extracts were quantified. The methanolic extract showed 26.5 ± 0.4 mg equivalents of gallic acid/g extract, while, for antioxidant activity, it demonstrated IC₅₀ values of 49.4 ± 0.2 and 10.0 ± 0.0 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ((2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) (ABTS), respectively. Regarding anti-inflammatory potential, the extracts did not significantly affect cell viability in RAW 264.7 macrophages. In contrast, it was clear that all extracts significantly decreased nitric oxide (NO) production at concentrations of 5–40 µg/mL. Additionally, extracts evaluated in human cancer cell lines only had a significant inhibitory effect at 100 µg/mL after 48 h, mainly with dichloromethane extract. This first biotechnological study indicates that P. dissectum cell cultures may produce compounds that favor the biological activities evaluated; however, it is necessary to carry out more in-depth evaluations of its extracts. This study is the basis for future research to enable the sustainable use of this valuable resource. Full article

Tumor-associated macrophages (TAMs) play a pivotal role in cancer regulation by influencing tumor growth, metastasis, and the immune microenvironment. By providing low doses and ultra-low doses (ULD) of immune regulators to the organism, micro-immunotherapy (MI) medicines (MIM) could be seen as valuable adjuvant drugs in the context of a wide range of pathological conditions, including cancers. Thus, these MIM could target TAMs, affecting their phenotype and activities. In this study, the anti-tumor and the immune-stimulatory effects of four capsules out of the ten composing the Labo’life’s MIM 2LC1^® (2LC1-1, 2LC1-6, 2LC1-7, and 2LC1-8), as well as the specific nucleic acid (SNA^®) sequence SNA-MYC present at ULD in this medicine have been evaluated in vitro, in several cancer models, and in human monocyte-derived macrophages. Our results showed that the tested MI formulations increased the tumor cell death of spheroids from HCT-116 colon cancer cells, while reducing the spheroid volume. Moreover, the treatments impaired the clonogenic capabilities of two cancer cell lines from epithelial origin, the LNCaP prostate cancer and the MCF-7 breast cancer cells. Interestingly, ULD of the SNA-MYC shared similar anti-cancer capabilities in those models, and it led to a significant reduction in the expression of C-MYC when evaluated in a model of human M2 macrophages. In the same model, the MI formulations also increased the expression of CD86 and HLA-DR, two markers of M1 anti-tumor macrophages. In addition, the tested items modulated the secretion of a panel of chemokines related to macrophage activity and immune cell recruitment. Finally, our results showed that 2LC1-8 increased the phagocytosis capabilities of human monocyte-derived macrophages, thus possibly contributing to sustaining the immune functions of M1, which are crucial in the context of cancer. Even if more research is needed to uncover their exact mechanism of action, these results suggest that the tested capsules of 2LC1 as well as ULD of SNA-MYC display both anti-tumor and immune-enhancing effects. Full article

Tricyclic and tetracyclic lactone derivatives of thieno[2,3-b]pyrazine or thieno[2,3-b]quinoline, and 2H-pyrones were prepared using different methodologies. Pd/Cu-catalyzed Sonogashira coupling using Et₃N as a base, of methyl 7-bromothieno[2,3-b]pyrazine-6-carboxylate and (het)arylalkynes to yield the Sonogashira ester products, gave also the corresponding tricyclic lactones as minor products. However, the major products did not cyclize with TFA. Tricyclic lactones were then obtained by a tandem one-pot Sonogashira coupling and 6-endo-dig lactonization of 7-bromothieno[2,3-b]pyrazine-6-carboxylic acid with (het)arylalkynes, in good yields. Halogenated tricyclic lactones were synthesized by halocyclization using CuX and NXS. Tetracyclic lactones were synthesized through a Rh(III)-catalyzed formal [4+2] cycloaddition, between thieno[2,3-b]quinoline-2-carboxylic acid and internal alkynes, triggered by C-H activation, with the carboxylic group acting as a directing group. Using the SRB assay, the antitumor activity of both Sonogashira products and lactones was evaluated across five human cancer cell lines (CaCo-2, MCF-7, AGS, HeLa, NCI-H460). The best-performing compound was a Sonogashira product showing a GI₅₀ < 10 µM in all tumor cell lines and low toxicity in PLP2 cells. Additionally, antiparasitic testing against Trypanosoma brucei and Leishmania infantum revealed some compounds with IC₅₀ < 11 µM, though some level of cytotoxicity was observed in THP-1—derived macrophages. Full article

Mitochondrial-associated granulocyte macrophage colony-stimulating factor (Magmas) is a unique protein located in the inner membrane of mitochondria, with an active role in scavenging reactive oxygen species (ROS) in cellular systems. Ovarian cancer (OC), one of the deadliest gynaecological cancers, is characterised by genomic instability, affected by ROS production in the tumour microenvironment. This manuscript discusses the role of Magmas and efficacy of its novel small molecule inhibitor BT#9 in OC progression, metastasis, and chemoresistance. Magmas expression levels were significantly elevated in high-grade human OC compared to benign tumours by immunohistochemistry. The inhibition of Magmas by BT#9 enhanced ROS production and reduced mitochondrial membrane permeability, basal respiration, mitochondrial ATP production, and cellular functions, such as the proliferation and migration of OC cell lines in vitro. Oral administration of BT#9 in vivo significantly reduced tumour growth and spread and enhanced the survival of mice without having any effect on the peritoneal organs. These data suggest that Magmas is functionally important for OC growth and spread by affecting ROS levels and that the inhibition of Magmas activity by BT#9 may provide novel clinical benefits for patients with this malignancy. Full article

Zinc (Zn)- and copper (Cu)-containing welding fumes elevate inflammatory markers (CRP, TNF-α, IL-6, IL-8) in healthy individuals and welders. Zn- and Cu-containing nanoparticles are toxic to human macrophages. Therefore, ZnO exposure limits are under discussion. In this study, the effects of Zn/Cu-containing welding fume suspensions on A549 alveolar epithelial cells (exposure concentrations: 0.01/0.1/1/10/100 µg/mL) and THP-1 macrophages (additionally 0.001 µg/mL) were investigated over a period of 48 h. Effects on apoptosis, cytotoxicity, genotoxicity, superoxide dismutase (SOD) activity, and cytokine levels (IL-6, IL-8, MIP-1β/CCL4, TNF-α) were evaluated. Welding fume exposure increased SOD activity, and it increased Annexin-V binding and cytotoxicity effects starting at 10 µg/mL in A549 cells and particularly in THP-1 macrophages. A549 cells showed increased IL-6 at 10 and 100 µg/mL, and significant IL-8 release occurred at 10 µg/mL for A549 and 0.1 µg/mL for macrophages. Exposed macrophages released TNF-α at 1 µg/mL after 24 and 48 h and MIP-1β/CCL4 at 0.01 µg/mL after 6 h and at 0.001 µg/mL after 48 h. No genotoxic effects were detected. MIP-1β/CCL4 is a sensitive new biomarker for human macrophages exposed to Zn/Cu-containing welding fumes. The findings suggest that Zn/Cu particles affect lung cells already at doses below current occupational thresholds. Full article

Background: Besides conventional norms that recognize synovial fluid (SF) as a joint lubricant, nutritional channel, and a diagnostic tool in knee osteoarthritis (kOA), based on the authors previous studies, this study aims to define functional role of SF in kOA. Methods: U937, a monocytic, human myeloid cell line, was induced with progressive grades of kOA SF, and the induction response was assessed on various pro-inflammatory parameters. This ‘SF challenge test model’ was further extended to determine the impact of SF on U937 differentiation using macrophage-specific markers and associated transcription factor genes. Mitochondrial membrane potential changes in SF-treated cells were evaluated with fluorescent JC-1 probe. Results: a significant increase in nitric oxide, matrix metalloproteinase (MMP) 1, 13, and vascular endothelial growth factor (VEGF)-1 was noted in the induced cells. A marked increase was seen in CD68, CD86, and the transcription factors –activator protein (AP)-1, interferon regulatory factor (IRF)-1, and signal transducer and activator of transcription (STAT)-6 in the SF-treated cells indicating active monocytes to macrophage differentiation. Reduced mitochondrial membrane potential was reflected by a reduced red-to-green ratio in JC-1 staining. Conclusions: these results underline the active role of OA SF in stimulating and maintaining inflammation in joint cells, fostering monocyte differentiation into pro-inflammatory macrophages. The decline in the membrane potential suggestive of additional inflammatory pathway in OA via the release of pro-apoptotic factors and damaged associated molecular patterns (DAMPs) within the cells. Overall, biochemical modulation of SF warrants a potential approach to intervene inflammatory cascade in OA and mitigate its progression. Full article

Glatiramer acetate (GA) is the first-line therapy for relapsing-remitting multiple sclerosis (MS) and is increasingly demonstrating promising therapeutic benefits in a range of other conditions. Despite its extensive use, the precise pharmacological mechanism of GA remains unclear. In addition to T and B cells, dendritic cells (DCs) and monocytes play significant roles in the neuroinflammation associated with MS, positioning them as potential initial targets for GA. Here, we investigated GA’s influence on the differentiation of human monocytes from healthy donors into monocyte-derived dendritic cells (moDCs) and assessed their activation status. Our results indicate that GA treatment does not hinder the differentiation of monocytes into moDCs or macrophages. Notably, we observed a significant increase in the expression of molecules required for antigen recognition, presentation, and co-stimulation in GA-treated moDCs. Conversely, there was a significant downregulation of CD1a, which is crucial for activating auto-aggressive T cells that respond to the lipid components of myelin. Furthermore, GA treatment resulted in an increased expression of CD68 on both CD14⁺CD16⁺ and CD14⁺CD16⁻ monocyte subsets. These in vitro findings suggest that GA treatment does not impede the generation of moDCs under inflammatory conditions; however, it may modify their functional characteristics in potentially beneficial ways. This provides a basis for future clinical studies in MS patients to elucidate its precise mode of action. Full article

Background: Staphylococcus aureus is a highly lethal Gram-positive bacterium that is responsible for over one million deaths annually. As a member of the ESKAPE pathogens, its methicillin-resistant strains (MRSA) are prevalent worldwide and exhibit significant antimicrobial resistance (AMR). Bacterial efflux pumps play a pivotal role in the development of AMR by facilitating the expulsion of a range of antimicrobial agents. Methods: The S. aureus strain SA-1199B, which overexpresses NorA and carries a GrlA mutation, was utilized to comprehensively profile the mechanism of the compounds PQQ16P and PQK4F. To assess the toxicity and genotoxicity of these compounds, RAW macrophages, HEK 293T, and HepG2 cell lines were utilized. Female BALB/c mice were utilized to assess the in vivo synergism of EPIs with CPX, Results: NorA efflux pump inhibitors (EPIs), PQQ16P and PQK4F, enhanced the efficacy of the antibacterial ciprofloxacin (CPX) against resistant S. aureus strains. The mechanism of EPIs involved the inhibition of NorA efflux pump, without compromising bacterial membrane permeability, ATP levels, or mammalian calcium channels. Moreover, the EPIs significantly augmented the bactericidal and post-antibiotic effects of CPX, elevating its mutation prevention concentration without manifesting substantial toxicity to human cells. Furthermore, the EPIs reduced S. aureus invasiveness in macrophages, indicating a role for NorA in bacterial virulence. Notably, the in vivo synergism of these EPIs with CPX was observed in a mouse infection model. Conclusions: This study provides substantial evidence for the potential of employing EPIs in a combination with CPX to counteract AMR, both in vitro and in vivo. Full article