Search Results (1,331)

Background: Ulcerative colitis (UC), characterized by chronic intestinal inflammation, epithelial barrier dysfunction, and immune imbalance demands novel ameliorative strategies beyond conventional approaches. Methods: In this study, the probiotic properties of Lactobacillus paracasei L21 (L. paracasei L21) and its ability to ameliorate colitis were evaluated using an in vitro lipopolysaccharide (LPS)-induced intestinal crypt epithelial cell (IEC-6) model and an in vivo dextran sulfate sodium (DSS)-induced UC mouse model. Results: In vitro, L. paracasei L21 decreased levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-8) while increasing anti-inflammatory IL-10 levels (p < 0.05) in LPS-induced IEC-6 cells, significantly enhancing the expression of tight junction proteins (ZO-1, occludin, claudin-1), thereby restoring the intestinal barrier. In vivo, both viable L. paracasei L21 and its heat-inactivated postbiotic (H-L21) mitigated weight loss, colon shortening, and disease activity indices, concurrently reducing serum LPS and proinflammatory mediators. Interventions inhibited NF-κB signaling while activating HIF1α/AhR pathways, increasing IL-22 and mucin MUC2 to restore goblet cell populations. Gut microbiota analysis showed that both interventions increased the abundance of beneficial gut bacteria (Lactobacillus, Dubococcus, and Akkermansia) and improved faecal propanoic acid and butyric acid levels. H-L21 uniquely exerted an anti-inflammatory effect, marked by the regulation of Dubosiella, while L. paracasei L21 marked by the Akkermansia. Conclusions: These results highlight the potential of L. paracasei L21 as a candidate for the development of both probiotic and postbiotic formulations. It is expected to provide a theoretical basis for the management of UC and to drive the development of the next generation of UC therapies. Full article

Background: Acetaminophen (APAP) is a popular and safe pain reliever. Due to its widespread availability, it is commonly implicated in intentional or unintentional overdoses, which result in severe liver impairment. Pristimerin (Prist) is a natural triterpenoid that has potent antioxidant and anti-inflammatory properties. Our goal was to explore the protective effects of Prist against APAP-induced acute liver damage. Method: Mice were divided into six groups: control, Prist control, N-acetylcysteine (NAC) + APAP, APAP, and two Prist + APAP groups. Prist (0.4 and 0.8 mg/kg) was given for five days and APAP on day 5. Liver and blood samples were taken 24 h after APAP administration and submitted for different biochemical and molecular assessments. Results: Prist counteracted APAP-induced acute liver damage, as it decreased general liver dysfunction biomarkers, and attenuated APAP-induced histopathological lesions. Prist decreased oxidative stress and enforced hepatic antioxidants. Notably, Prist significantly reduced the genetic and protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-II), p-phosphatidylinositol-3-kinase (p-PI3K), p-protein kinase B (p-AKT), and the inflammatory cytokines: nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukins-(IL-6 and IL-1β) in hepatic tissues. Additionally, the m-RNA and protein levels of the apoptotic Bcl2-associated X protein (BAX) and caspase-3 were lowered and the anti-apoptotic B-cell leukemia/lymphoma 2 (BCL-2) was increased upon Prist administration. Conclusion: Prist ameliorated APAP-induced liver injury in mice via its potent anti-inflammatory/antioxidative and anti-apoptotic activities. These effects were mediated through modulation of NF-κB/iNOS/COX-II/cytokines, PI3K/AKT, and BAX/BCL-2/caspase-3 signaling pathways. Full article

Osteoclastogenesis—the activation and differentiation of osteoclasts—is one of the pivotal processes of bone remodeling and is regulated by RANKL/RANK signaling, the decoy function of osteoprotegerin (OPG), and a cascade of pro- and anti-inflammatory cytokines. The disruption of this balance leads to pathological bone loss in diseases such as osteoporosis and rheumatoid arthritis. FFAR4 (Free Fatty Acid Receptor 4), a G protein-coupled receptor for long-chain omega-3 fatty acids, has been confirmed as a key mediator of metabolic and anti-inflammatory effects. This review focuses on how FFAR4 acts as the selective receptor for the omega-3 fatty acid docosahexaenoic acid (DHA). It activates two divergent signaling pathways. The Gαq-dependent cascade facilitates intracellular calcium mobilization and ERK1/2 activation. Meanwhile, β-arrestin-2 recruitment inhibits NF-κB. These collective actions reshape the cytokine environment. In macrophages, DHA–FFAR4 signaling lowers the levels of TNF-α, interleukin-6 (IL-6), and IL-1β while increasing IL-10 secretion. Consequently, the activation of NFATc1 and NF-κB p65 is profoundly suppressed under TNF-α or RANKL stimulation. Additionally, DHA modulates the RANKL/OPG axis in osteoblastic cells by suppressing RANKL expression, thereby reducing osteoclast differentiation in an inflammatory mouse model. Full article

Background: Short-chain fatty acids (SCFAs), microbial metabolites also known as postbiotics, are essential for maintaining gut health. However, their antiproliferative effects on gastric cancer cells and potential interactions with conventional therapies remain underexplored. This study aimed to investigate the effects of three SCFA salts—magnesium acetate (A), sodium propionate (P), and sodium butyrate (B)—individually and in combination (APB), as well as in combination with dexamethasone (Dex), on AGS gastric adenocarcinoma cells. Methods: AGS cells were treated with PB, AP, AB, APB, Dex, and APB+Dex. Cell viability was assessed to determine antiproliferative effects, and the IC₅₀ of APB was calculated. Flow cytometry was used to evaluate apoptosis and necrosis. Reactive oxygen species (ROS) levels were measured to assess oxidative stress. Proteomic analysis via LC-MS was performed to identify differential protein expression and related pathways impacted by the treatments. Results: SCFA salts showed significant antiproliferative effects on AGS cells, with APB exhibiting a combined IC₅₀ of 568.33 μg/mL. The APB+Dex combination demonstrated strong synergy (combination index = 0.76) and significantly enhanced growth inhibition. Both APB and APB+Dex induced substantial apoptosis (p < 0.0001) with minimal necrosis. APB alone significantly increased ROS levels (p < 0.0001), while Dex moderated this effect in the combination group APB+Dex (p < 0.0001). Notably, the APB+Dex treatment synergistically targeted multiple tumour-promoting mechanisms, including the impairment of redox homeostasis through SLC7A11 suppression, and inhibition of the haemostasis, platelet activation network and NF-κB signalling pathway via downregulation of NFKB1 (−1.34), exemplified by increased expression of SERPINE1 (1.99) within the “Response to elevated platelet cytosolic Ca²⁺” pathway. Conclusions: These findings showed a multifaceted anticancer mechanism by APB+Dex that may collectively impair cell proliferation, survival signalling, immune modulation, and tumour microenvironment support in gastric cancer. Full article

Background: Cerebral aneurysm (CA) is a focal or diffuse pathological dilation of the cerebral arterial wall that arises due to various etiological factors. It represents a serious vascular condition, particularly affecting the elderly, and carries a high risk of rupture and neurological morbidity. Clonidine (CL), an α2-adrenergic receptor agonist, has been reported to suppress aneurysm progression; however, its underlying molecular mechanisms, especially in relation to cerebral endothelial dysfunction, remain unclear. This study aimed to investigate the potential of CL to mitigate CA development by modulating apoptosis, inflammation, and oxidative stress in an Angiotensin II (Ang II)-induced endothelial injury model. Methods: Human brain microvascular endothelial cells (HBMECs) were used to establish an in vitro model of endothelial dysfunction by treating cells with 1 µM Ang II for 48 h. CL was administered 2 h prior to Ang II exposure at concentrations of 0.1, 1, and 10 µM. Cell viability was assessed using the MTT assay. Oxidative stress markers, including reactive oxygen species (ROS) and Nitric Oxide (NO), were measured using 2′,7′–dichlorofluorescin diacetate (DCFDA). Gene expression levels of vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMP-2 and MMP-9), high mobility group box 1 (HMGB1), and nuclear factor kappa B (NF-κB) were quantified using RT-qPCR. Levels of proinflammatory cytokines; tumor necrosis factor-alpha (TNF-α), Interleukin-6 (IL-6), and interferon-gamma (IFN-γ); were measured using commercial ELISA kits. Results: Ang II significantly increased ROS production and reduced NO levels, accompanied by heightened proinflammatory cytokine release and endothelial dysfunction. MTT assay revealed a marked decrease in cell viability following Ang II treatment (34.18%), whereas CL preserved cell viability in a concentration-dependent manner: 44.24% at 0.1 µM, 66.56% at 1 µM, and 81.74% at 10 µM. CL treatment also significantly attenuated ROS generation and inflammatory cytokine levels (p < 0.05). Furthermore, the expression of VEGF, HMGB1, NF-κB, MMP-2, and MMP-9 was significantly downregulated in response to CL. Conclusions: CL exerts a protective effect on endothelial cells by reducing oxidative stress and suppressing proinflammatory signaling pathways in Ang II-induced injury. These results support the potential of CL to mitigate endothelial injury in vitro, though further in vivo studies are required to confirm its translational relevance. Full article

Chronic high-fat diet (HFD) feeding in male rats causes significant metabolic as well as inflammatory disturbances, including obesity, insulin resistance, dyslipidemia, liver and kidney dysfunction, oxidative stress, and hypothalamic dysregulation. This study assessed the therapeutic effects of chlorogenic acid (CGA), a natural polyphenol, administered at 10 mg and 100 mg/kg/day for the last 4 weeks of a 12-week HFD protocol. Both CGA doses reduced body weight gain, abdominal circumference, and visceral fat accumulation, with the higher dose showing greater efficacy. CGA improved metabolic parameters by lowering fasting glucose and insulin and enhancing lipid profiles. CGA suppressed orexigenic genes (Agrp, NPY) and upregulated anorexigenic genes (POMC, CARTPT), suggesting appetite regulation in the hypothalamus. In abdominal white adipose tissue (WAT), CGA boosted antioxidant defenses (SOD, CAT, GPx, HO-1), reduced lipid peroxidation (MDA), and suppressed pro-inflammatory cytokines including TNF-α, IFN-γ, and IL-1β, while increasing the anti-inflammatory cytokine IL-10. CGA modulated inflammatory signaling via upregulation of miR-146a and inhibition of IRAK1, TRAF6, and NF-κB. It also reduced apoptosis by downregulating p53, Bax, and Caspase-3, and restoring Bcl-2. These findings demonstrate that short-term CGA administration effectively reverses multiple HFD-induced impairments, highlighting its potential as an effective therapeutic for obesity-related metabolic disorders. Full article

Background/Objectives: Thiamethoxam (TMX) is one of the most extensively utilized insecticides of the neonicotinoid family; however, its application is associated with notable toxic effects on multiple organs of mammals. Our purpose was to explore the potential hepatoprotective effect of taurine (TAU) and/or gallic acid (GA) against TMX-induced liver damage, with an emphasis on their role in regulating SIRT-1/PGC-1α, NF-κB/iNOS, and p53/Bax/caspase-3 pathways. Methods: Rats were assigned to seven groups (n = 6) and gavaged daily for 28 days with saline (control group), TAU at 50 mg/kg, GA at 20 mg/kg, TMX at 78.15 mg/kg, TMX + TAU, TMX + GA, and TMX + TAU + GA. Results: The findings revealed that TAU and/or GA attenuated TMX-induced liver injury, as demonstrated by the restoration of hepatic performance hallmarks and histological structure. TAU and GA mitigated TMX-mediated oxidative stress and boosted the antioxidant defense mechanism by upregulating the transcription levels of SIRT-1, PGC-1α, Nrf2, and HO-1. Moreover, TAU and GA suppressed TMX-associated inflammatory response by increasing IL-10 concentration and lowering the levels of NF-κB, IL-1β, and iNOS; the mRNA levels of NLRP3; and TNF-α immunoexpression. Both compounds, individually or concurrently, exerted an anti-apoptotic effect in TMX-treated rats, evidenced by increased Bcl-2 expression and reduced p53 mRNA level, Bax expression, and caspase-3 concentration. Conclusions: TAU and/or GA may be regarded as promising remedies that can alleviate TMX-induced hepatotoxicity by activating SIRT-1/PGC-1α signaling and abolishing inflammation and apoptosis. Full article

There are currently no approved therapeutic treatments targeting metabolic dysfunction-associated steatotic liver disease (MASLD). Albumin, a liver-produced plasma protein with anti-inflammatory and antioxidant properties, is reduced in advanced liver disease. Considering the role of chronic obesity-induced inflammation in MASLD pathogenesis, we investigated whether albumin administration could prevent disease progression to metabolic dysfunction-associated steatohepatitis (MASH). MASLD was induced in mice using a high-fat and high-cholesterol (PC) treatment for 8 weeks, followed by treatment with bovine serum albumin (BSA; 0.8 mg/kg) every three days for another 8 weeks. This regimen prevented time-dependent weight gain, regardless of diet, with 57% and 27% reductions in mice fed a standard chow (Std Chow) or PC diet, respectively. Further, supplementation reduced nuclear factor kappa B (NF-κB) activation by 2.8-fold (p = 0.0328) in PC-fed mice, consistent with albumin’s known anti-inflammatory properties. Unexpectedly, albumin also reduced hepatic neutral lipid accumulation and circulating non-esterified fatty acids. While PC-fed mice did not exhibit full progression to MASH, albumin treatment significantly increased hepatic matrix metalloproteinase-2 expression, suggesting the inhibition of early fibrotic signalling. While further studies are needed to elucidate the underlying mechanisms, these findings offer new insight into the potential of albumin, either alone or in combination with other therapies, to reduce hepatic steatosis in MASLD. Full article

Tea is one of the most consumed beverages in the world, belonging to the category of compounds known as tannins and flavonoids. One of the polyphenols found in large amounts in green tea leaves (Camellia sinensis) is epigallocatechin-3-O-gallate (EGCG). Though EGCG has shown some pharmacological effects, to date, it has not been utilised as a therapeutic agent. This is attributed to the fact that EGCG lacks adequate stability, and it is known to degrade through epimerization or auto-oxidation processes, especially when it is exposed to light, temperature fluctuations, some pH values, or the presence of oxygen. Consuming green tea with EGCG can alleviate the effects of bone diseases, such as osteoporosis, and support faster bone regeneration in the case of fractures. Therefore, this review focuses on the current state of research, highlighting the effects of EGCG on bone biology, such as enhancing osteoblast differentiation, promoting bone mineralisation, improving bone microarchitecture, and inhibiting osteoclastogenesis through the modulation of the RANK/RANKL/OPG pathway. Additionally, EGCG exerts antioxidant, anti-inflammatory, and dose-dependent effects on bone cells. It also downregulates inflammatory markers (TNF-α, IL-1β, and COX-2) and reduces oxidative stress via the inhibition of reactive oxygen species generation and the activation of protective signalling pathways (e.g., MAPK and NF-κB). Studies in animal models confirm that EGCG supplementation leads to increased bone mass and strength. These findings collectively support the further exploration of EGCG as an adjunct in the treatment and prevention of metabolic bone diseases. The authors aim to present the relationship between EGCG and bone health, highlighting issues for future research and clinical applications. Full article

The developmental processes of microglia follow a general pattern, from immature amoeboid (activated) cells to fully ramified (inactivated) surveilling microglia. However, little is known about the mechanisms controlling the transition of microglia from an activated to an inactivated state during brain development. Due to the complexity of microenvironmentally dynamic changes during neuronal differentiation, interactions between developing nerve cells and microglia might be involved in this process. Extracellular vesicles (EVs) are cell-released particles that serve as mediators of cellular crosstalk and regulation. Using neural progenitor cells (NPCs) and a long-term neuron culture system, we found that EVs derived from NPCs or developing neurons possessed differential capacity on the induction of microglial activation. The exposure of microglia to NPC- or immature neuron (DIV7)-derived EVs resulted in the higher expression of protein and mRNA of multiple inflammatory cytokines (e.g., TNF-α, IL-1β, and IL-6), when compared with mature neuron-derived EVs. Exploration of the intracellular signaling pathways revealed that MAPK signaling, IκBα phosphorylation/degradation, and NF-κB p65 nuclear translocation were strongly induced in microglia treated with NPC- or immature neuron-derived EVs. Using a pharmacological approach, we further demonstrate that Toll-like receptor (TLR) 7-mediated activation of NF-κB and MAPK signaling cascades contribute to EV-elicited microglial activation. Additionally, the application of conditioned media derived from microglia treated with NPC- or immature neuron-derived EVs is found to promote the survival of late-developing dopaminergic neurons. Thus, our results highlight a novel mechanism used by NPCs and developing neurons to modulate the developmental phases and functions of microglia through EV secretion. Full article

In this study, we investigated the effects of dietary supplementation with thermally modified attapulgite on the daily weight gain, serum biochemical indices, and serum metabolites of Simmental fattening cattle. A total of 30 healthy Simmental fattening beef calves of similar age (8 to 9 months old) and body weight (370 ± 10 kg) were randomly divided into two groups, each containing 15 animals. A control group was fed the basal diet, and a treatment group was fed the same basal diet with the addition of 4 g/kg of thermally modified attapulgite. After 75 days of formal experiment, the calves in the two groups were weighed, and blood samples were collected by tail vein blood sampling for determinations of the serum biochemical indices and serum metabolites using liquid chromatography–mass spectrometry (LC-MS) analysis. The results indicated that the addition of thermally modified attapulgite to the diet had no significant effects on the daily weight gain of fattening beef cattle. After feeding with modified attapulgite, the glutathione peroxidase and superoxide dismutase activities in the serum of the experimental group were 55.02% (257.26 U·mL⁻¹ to 165.95 U·mL⁻¹, p < 0.05) and 13.11% (18.98 U·mL⁻¹ to 16.78 U·mL⁻¹, p < 0.05) higher than that in the control group. Compared with the control group, the tumor necrosis factor-alpha content was reduced by 14.50% (31.27 pg·mL⁻¹ to 36.57 pg·mL⁻¹, p < 0.01), and the concentration of interleukin-6 and lipopolysaccharide decreased by 17.00% (34.33 pg·mL⁻¹ to 41.36 pg·mL⁻¹, p < 0.001) and 23.05% (51.34 EU·L⁻¹ to 66.72 EU·L⁻¹, p < 0.001) in the serum of the experimental group. Contrastingly, the thermally modified attapulgite had no significant effects on the levels of serum total protein, albumin, or globulin in Simmental fattening cattle (p > 0.05). Furthermore, the results of serum metabolomic analyses revealed that there were a total of 98 differential metabolites, which were mainly enriched with respect to glycerophospholipid metabolism, Th1 and Th2 cell differentiation, autophagy-other, retrograde endogenous cannabinoid signaling, and the NF-κB signaling pathway. Overall, thermally modified attapulgite was found to effectively increase the activity of antioxidant enzymes, reduce serum inflammatory mediators, may suppress oxidative damage, enhance immunity, and have a positive influence on the health of Simmental fattening beef calves. Full article

Naturally occurring prostaglandin E₂ (PGE₂) influences cytokine production regulation in bovine neutrophils exposed to Staphylococcus aureus Rosenbach. Here, we employed bovine neutrophils as the primary experimental system, and administered specific inhibitors targeting various receptors, which were subsequently exposed to S. aureus. Cytokine expression levels in dairy cow neutrophils induced by S. aureus via the endogenous PGE₂-EP2/4 receptor pathway were investigated, and its effects on P38, extracellular signal-regulated kinase (ERK), P65 activation, and phagocytic function in Staphylococcus aureus Rosenbach-induced dairy cow neutrophils, were examined. Blocking cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) enzymes substantially decreased PGE₂ production and release in S. aureus-exposed bovine neutrophils. Cytokine output showed significant reduction compared to that in SA113-infected controls. Phosphorylation of P38, ERK, and P65 signaling molecules was depressed in the infected group. Pharmacological interference with EP2/EP4 receptors similarly diminished cytokine secretion and phosphorylation patterns of P38, ERK, and P65, with preserved cellular phagocytic function. During S. aureus infection of bovine neutrophils, COX-2 and mPGES-1 participated in controlling PGE₂ biosynthesis, and internally produced PGE₂ molecules triggered NF-κB and MAPK inflammatory pathways via EP2/EP4 receptor activation, later adjusting the equilibrium between cytokine types that promote or suppress inflammation. This signaling mechanism coordinated inflammatory phases through receptor-mediated processes. Full article

Background: Previous studies have shown Radix Hedysari (RH)’s gastroprotective potential, but its active components and mechanisms remain uncharacterized. This study aimed to identify RH’s bioactive fractions, elucidate protection mechanisms, establish flavonoid dose-effect relationships, and determine the pharmacodynamic basis. Methods: Chemical profiling quantified eight flavonoids via HPLC. Network pharmacology screened targets/pathways using TCMSP, GeneCards databases. In vivo validation employed cisplatin–induced injury models in Wistar rats (n = 10/group). Assessments included: behavioral monitoring; organ indices; ELISA (MTL, VIP, IFN–γ, IgG, IL–6, TNF–α etc.); H&E; and Western blot:(SCF, c–Kit, p65). Dose–effect correlations were analyzed by PLS–DA. Results: Content determination indicated that Calycosin–7–glucoside and Ononin were notably enriched on both the n–BuOH part and the EtOAc part. Network pharmacology identified 5 core flavonoids and 8 targets enriched in IL–17/TNF signaling pathways. n–BuOH treatment minimized weight loss vs. MCG, increased spleen/thymus indices. n–BuOH and HPS normalized gastrointestinal, immune, inflammatory biomarkers (p < 0.01 vs. MCG). Histopathology confirmed superior mucosal protection in n–BuOH group vs. MCG. Western blot revealed n–BuOH significantly downregulated SCF, c–kit, and p65 expressions in both gastric and intestinal tissues (p < 0.001 vs. MCG). PLS–DA demonstrated Calycosin–7–glucoside had the strongest dose–effect correlation (VIP > 1) with protective outcomes. Conclusions: The n–BuOH fraction of RH is the primary bioactive component against chemotherapy–induced gastrointestinal injury, with Calycosin–7–glucoside as its key effector. Protection is mediated through SCF/c–Kit/NF–κB pathway inhibition, demonstrating significant dose–dependent efficacy. These findings support RH’s potential as a complementary therapy during chemotherapy. Full article

There is a present need to develop alternative biotherapeutic drugs to mitigate the exacerbated inflammatory immune responses characteristic of sepsis. The potent endotoxin lipopolysaccharide (LPS), a major component of Gram-negative bacterial outer membrane, activates the immune system via Toll-like receptor 4 (TLR4), triggering macrophages and a persistent cascade of inflammatory mediators. Our previous studies have demonstrated that Fh15, a recombinant member of the Fasciola hepatica fatty acid binding protein family, can significantly increase the survival rate by suppressing many inflammatory mediators induced by LPS in a septic shock mouse model. Although Fh15 has been proposed as a TLR4 antagonist, the specific mechanisms underlying its immunomodulatory effect remained unclear. In the present study, we employed a quantitative proteomics approach using tandem mass tag (TMT) followed by LC-MS/MS analysis to identify and quantify differentially expressed proteins that participate in signaling pathways downstream TLR4 of macrophages, which can be dysregulated by Fh15. Data are available via ProteomeXchange with identifier PXD065520. Based on significant fold change (FC) cut-off of 1.5 and p-value ≤ 0.05 criteria, we focused our attention to 114 proteins that were upregulated by LPS and downregulated by Fh15. From these proteins, TNFα, IL-1α, Lck, NOS2, SOD2 and CD36 were selected for validation by Western blot on murine bone marrow-derived macrophages due to their relevant roles in the NF-κB, iNOS, oxidative stress, and phagosome signaling pathways, which are closely associated with sepsis pathogenesis. These results suggest that Fh15 exerts a broad spectrum of action by simultaneously targeting multiple downstream pathways activated by TLR4, thereby modulating various aspects of the inflammatory responses during sepsis. Full article

Background: Natural products are key sources of anti-inflammatory agents, yet the potential of fish visceral extracts remains largely unexplored. This study evaluated the anti-inflammatory activity of a spleen extract from rainbow trout (Oncorhynchus mykiss). Methods: A crude spleen extract and its four solvent fractions were tested in LPS-stimulated RAW264.7 macrophages. Nitric oxide production and expression of iNOS, COX-2, and cytokines were assessed by qRT-PCR and Western blotting. The most active fraction, OSB (n-butanol layer), was further analyzed for its effects on NF-κB signaling, macrophage polarization, and ROS generation. Results: The crude spleen extract significantly reduced NO production and downregulated iNOS and COX-2 expression at both the transcriptional and translational levels. Among the four fractions, the OSB fraction exhibited the most potent and consistent anti-inflammatory effects. OSB markedly suppressed LPS-induced expression of iNOS, COX-2, and pro-inflammatory cytokines, while enhancing anti-inflammatory cytokines. Mechanistic analyses demonstrated that OSB inhibited NF-κB activation by preventing the nuclear translocation of the p65 subunit. Additionally, OSB attenuated LPS-induced ROS production and reduced the expression of M1 macrophage markers, indicating inhibition of M1 polarization. Conclusions: The OSB fraction from rainbow trout spleen exhibits potent anti-inflammatory activity by modulating the NF-κB pathway and suppressing M1 macrophage polarization, suggesting its potential as a natural therapeutic agent. Full article