Search Results (193)

Global plastic production and inadequate waste management have led to widespread environmental contamination with microplastics (MPs), now detected in food, water, and air. Their small size, diverse polymer composition, and capacity to carry chemical additives and co-pollutants facilitate intestinal uptake and raise concerns about their potential impact on gut microbiota. This review synthesizes current evidence on how MPs influence gut microbial composition and function, gut barrier integrity, and associated inflammatory and metabolic pathways. We conducted a narrative review of in vivo animal studies, in vitro simulated gut systems, and human observational studies that assessed MP exposure, gut microbiota profiles, and downstream toxicological outcomes. MPs originate from primary and secondary sources and can act as vectors for metals and organic pollutants. Following ingestion, they may cross the intestinal barrier via endocytic and persorption routes, acquire a protein corona, and be recognized by immune cells, activating TLR/NF-κB, and MAPK pathways alongside oxidative stress. In these models, MP exposure induces dysbiosis, characterized by loss of beneficial SCFA-producing bacteria (e.g., Bifidobacterium, Lactobacillus, Bacteroides) and expansion of pathobionts (e.g., Escherichia/Shigella, Staphylococcus, Enterobacteriaceae), accompanied by altered bile acid metabolism. These microbiota and metabolic alterations are linked to increased gut permeability, intestinal inflammation, metabolic dysfunction, and, in some studies, reproductive and neurobehavioral effects. Current evidence supports MPs as emerging modulators of gut microbial and intestinal homeostasis. However, heterogeneity across experimental models, reliance on high exposure doses, and lack of standardized MP characterization limit robust risk assessment. These limitations underscore the need for harmonized methodologies, longitudinal large-scale human studies, and the development of targeted mitigation strategies. Full article

Mammary gland inflammation, clinically expressed as mastitis in dairy ruminants and lactating women, arises from a self-amplifying loop of pathogen sensing, oxidative stress and innate immune activation, and remains a leading driver of antibiotic use, milk-quality loss and morbidity. Mounting pressure to reduce antimicrobial dependence has refocused attention on flavonoids—structurally diverse plant polyphenols with multi-target bioactivity, derived mainly from in vitro and rodent mastitis models. This review integrates contemporary evidence on the six principal flavonoid subclasses within a unifying molecular framework. Across subclasses, flavonoids converge on shared targets: the TLR4–MyD88–NF-κB axis, MAPK cascades, the Keap1–Nrf2–ARE antioxidant pathway, the NLRP3 inflammasome and tight-junction proteins of the blood–milk barrier. Less canonical mechanisms—m⁶A epitranscriptomic regulation, ferroptosis suppression, AhR signalling, anti-virulence binding to bacterial enzymes such as IGPD, and gut-microbiota-driven remodelling of the gut–mammary axis—expand the pharmacological landscape. We additionally appraise the subclasses comparatively, identifying flavanones and the flavone baicalin as carrying the strongest translational evidence, and examine the conflicting findings, model limitations, and delivery, residue and regulatory barriers that currently separate mechanistic promise from on-farm application. We outline structure–activity considerations and translational priorities, and position flavonoids as mechanism-rich, antibiotic-sparing candidates for the prevention and adjunctive management of mammary gland inflammation in dairy ruminants. Full article

Dry eye disease (DED) is a multifactorial ocular surface disorder characterized by inflammation, oxidative stress, tear film instability, and secretory dysfunction. This study investigated the protective effects of Lute-gen^®, a lutein and zeaxanthin-based formulation, in both in vitro and in vivo DED models. Human corneal epithelial (HCE-T) cells were stimulated with TNF-α, while dry eye was induced in female Sprague–Dawley rats using subcutaneous scopolamine (SCP) administration. In HCE-T cells, Lute-gen^® showed no cytotoxicity, restored cell viability, reduced intracellular ROS, and was associated with increased expression of antioxidant-related markers (Nrf2, HO-1, SOD, CAT, and GPx), reduced expression of inflammatory mediators (TLR4/MyD88/NF-κB/NLRP3), and increased expression of AQP3 and AQP5. In SCP-induced rats, Lute-gen^® significantly improved tear secretion and reduced corneal fluorescein staining. Histopathological analyses revealed restoration of conjunctival goblet cells, mucin staining, corneal epithelial integrity, acinar area and cell density, and lacrimal gland architecture, with reduced inflammatory infiltration. Immunofluorescence further demonstrated reduced TLR4 and MMP9 immunoreactivity and decreased CD68⁺ inflammatory cell infiltration. Molecular analyses showed reduced expression of inflammatory cytokines and NF-κB/MAPK/MMP signaling-related inflammatory mediators, together with restoration of AQP1, AQP3, and AQP5 expression in corneal tissues. Collectively, these findings suggest that Lute-gen^® treatment was associated with improvements in dry eye-related pathological changes, including restoration of antioxidant-related markers, attenuation of inflammatory responses, restoration of aquaporin expression, and preservation of ocular surface and lacrimal gland integrity. These preclinical findings support further mechanistic investigations and the future clinical evaluation of Lute-gen^® as a potential nutritional intervention for dry eye disease. Full article

Research has shown a sex-specific immune response, with males having a worse prognosis in acute inflammatory diseases. While these disparities were initially attributed to sex hormones, increasing evidence points to a predominant role for X-linked genetic factors. Toll-like receptors and several components of their signaling pathway are encoded on the X chromosome and may contribute to these differences. We investigated whether increase in circulating oestradiol influences TLR-dependent immune response. Sixteen women undergoing controlled ovarian hyperstimulation for in vitro fertilisation were studied. Whole blood collected before treatment, during stimulation and at ovulation triggering was stimulated with ligands targeting TLR2/6, TLR1/2, TLR4 and TLR7/8. TLR2, TLR4 and CD99 expression, intracellular phosphorylated NF-κB p65, ERK1/2 and p38 MAPK, and cytokine production were assessed. Oestradiol levels increased markedly during treatment (48.1 to 1819.5 pg/mL; p < 0.001). Despite this rise, no or minimal impact on TLR2/4 and CD99 expression, intracellular signalling or cytokine release was detected. Only IL-6 and IL-10 in response to TLR2/6 stimulation increased significantly, with IL-6 positively associated with oestradiol variation. These findings indicate that oestradiol exerts a limited influence on TLR-dependent immune responses, supporting our view that sex-based immune differences are driven primarily by genetic rather than hormonal factors. Full article

Metabolic dysfunction-associated steatohepatitis (MASH; formerly non-alcoholic steatohepatitis, NASH) is characterized by oxidative stress, inflammatory activation, hepatocellular injury, and progressive liver dysfunction. However, the global transcriptomic landscape underlying stress-induced hepatic injury remains incompletely understood. In this study, we employed a methionine–choline-deficient (MCD) diet-induced murine model to characterize the phenotypic and transcriptomic alterations associated with liver injury. Male C57BL/6J mice were fed either a control or MCD diet, and hepatotoxicity was assessed by survival analysis, body and liver weight measurements, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, histopathological examination, RNA sequencing, quantitative real-time PCR (qRT-PCR), and tumor necrosis factor-alpha (TNF-α) enzyme-linked immunosorbent assay (ELISA). MCD feeding markedly reduced survival and body weight while inducing hepatomegaly and significant elevations in serum ALT and AST, indicating severe hepatocellular injury. Histopathological analysis demonstrated hepatic steatosis, hepatocellular ballooning, and lobular inflammation without histological evidence of fibrosis. Transcriptomic profiling revealed extensive gene expression remodeling, characterized by activation of inflammatory pathways, enrichment of MAPK-related signaling, dysregulation of lipid metabolism, suppression of antioxidant defense systems, impairment of cytochrome P450-mediated detoxification, and upregulation of apoptosis-associated genes. qRT-PCR further validated the differential expression of representative genes involved in inflammatory signaling (Tlr4, Nfkb1, Nlrp3, and Casp1), MAPK signaling (Fos), xenobiotic metabolism (Cyp4f18), lipid metabolism (Apoa4 and Lpl), extracellular matrix remodeling (Mmp12), and oxidative stress responses (Sod1 and Gstp1). In addition, elevated serum TNF-α levels provided protein-level evidence supporting activation of the TLR4/NF-κB/TNF-α/NLRP3 inflammatory axis. Although fibrosis-associated transcriptional responses were detected, the absence of histological fibrosis suggests transcriptional priming of fibrogenic pathways rather than established fibrogenesis. Collectively, these findings provide a transcriptomic framework linking oxidative stress, impaired detoxification, inflammatory activation, and stress-responsive signaling to MCD-induced hepatic injury. The MCD model provides a valuable experimental platform for characterizing hepatic stress-response transcriptomes and for generating hypotheses that can subsequently be evaluated in environmentally relevant toxicological models. Nevertheless, caution should be exercised when extrapolating these findings to obesity-associated human MASLD, as the MCD model lacks key metabolic features of the human disease, including obesity and insulin resistance. Therefore, the present findings should be interpreted primarily as transcriptomic signatures of stress-induced hepatic injury rather than as a direct representation of the pathophysiological processes underlying human obesity-associated MASLD. Full article

Epilepsy is a chronic neurological disorder prevalent worldwide, characterized by recurrent episodes of epileptic seizures. The primary current treatment approach is pharmacological, aimed at reducing the intensity and frequency of seizures, though it does not provide a cure. Neuroinflammation plays a central role in epilepsy by activating glial cells and stimulating the release of inflammatory mediators, further disrupting the balance between excitation and inhibition, thereby promoting the onset and recurrence of seizures. Furthermore, persistent inflammatory processes induce synaptic remodeling and the formation of dysfunctional neural circuits, establishing a pathological cycle in which inflammation and epileptic activity feed into each other. In this regard, natural products represent an important avenue for the discovery of new treatments. Thus, this review aimed to relate the role of the main inflammatory targets (Inflammasome/NLRP3, NF-κB, MAPK, mTOR, COX-2/PGE2, and TLR4/HMGB1) to epilepsy and to investigate in the literature natural products acting through these pathways in the treatment of epileptic seizures. Consequently, inflammatory pathways have emerged as critical targets in epilepsy, highlighting the importance of strategies capable of modulating neuroinflammatory processes. In this context, natural products stand out as promising therapeutic alternatives, given their multitarget mechanisms of action, potential to attenuate neuroinflammation and neuronal hyperexcitability. Full article

Toll-like receptors (TLRs) are essential components of the innate immune system that enable host cells to sense microbial and endogenous danger signals and to initiate inflammatory and antimicrobial responses. Activation of TLRs triggers complex intracellular signaling networks that culminate in the induction of pro-inflammatory cytokines, type I interferons, and co-stimulatory molecules. In addition to the well-characterized nuclear factor κB (NF-κB) and interferon regulatory factor (IRF) pathways, mitogen-activated protein kinases (MAPKs) play a critical modulatory role in TLR signaling. MAPK/ERK kinase (MEK) inhibitors were originally developed for the treatment of cancer and are widely used in clinical oncology. Accumulating evidence indicates that pharmacological inhibition of MEK/extracellular signal regulated kinase (ERK) signaling profoundly affects immune cell function and TLR-driven responses. Depending on timing, dose, and disease context, MEK inhibition can attenuate excessive inflammation but may also interfere with protective host defense mechanisms. This duality highlights the context-dependent role of MEK/ERK signaling in infection and inflammation. In this review, I summarize current knowledge on the integration of MEK/ERK signaling into TLR-mediated innate immune responses and discuss the immunological consequences of MEK inhibition in infectious and inflammatory settings. By synthesizing mechanistic and translational studies, I aim to provide a framework for understanding MEK inhibitors as immune modulators rather than as broadly acting anti-inflammatory agents. Full article

Associated with high morbidity and mortality, cisplatin-induced acute kidney injury (AKI) is a common clinical complication characterized by oxidative stress, inflammation, and mitochondria-associated signaling. Although multiple signaling pathways have been implicated in AKI progression, effective interventions targeting these complex mechanisms are still lacking. As a medicinal fungus with antioxidant and anti-inflammatory properties, Schizophyllum commune (SC) has shown potential biological activities; however, its renoprotective effects in cisplatin-induced AKI remain unclear. Therefore, this study aimed to investigate SC’s protective effects and underlying mechanisms in a cisplatin-induced AKI mouse model. SC treatment improved renal function and attenuated histopathological damage. It reduced oxidative stress and inflammatory responses, as evidenced by the modulation of malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO), and pro-inflammatory cytokines. Mechanistically, SC regulated multiple signaling pathways, including mitogen-activated protein kinase (MAPK), toll-like receptor 4/nuclear factor kappa B (TLR4/ NF-κB), PI3K/AKT, nuclear factor erythroid 2–related factor 2/heme oxygenase-1 (Nrf2/HO-1), and the calcium/calmodulin-dependent protein kinase kinase–AMP-activated protein kinase–sirtuin 1 (CaMKK–AMPK–Sirt1) axis. In addition, SC modulated apoptosis, autophagy, and PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy, suggesting improved mitochondrial homeostasis. These findings indicate that SC exerts renoprotective effects and may contribute to cisplatin-induced nephrotoxicity mitigation strategies. Full article

Natural homopolysaccharides (HoPSs), composed of a single monosaccharide type, are increasingly recognized as bioactive macronutrients with broad relevance to nutrition and health. This review summarizes the extraction, structural characterization, and structure-immunomodulatory activity relationships of HoPSs. Drawing on a comprehensive synthesis of existing studies, we integrate current knowledge into a unified hierarchical framework of HoPS structure–function relationships. This framework organizes the literature into three hierarchical levels, including primary structural recognition, mid-level regulatory mechanisms, and functional refinement, while integrating key determinants such as molecular weight, glycosidic linkages, chain conformation, branching, and chemical modifications. By bridging structural glycomics and nutritional immunology, this framework synthesizes current evidence and provides a structured reference for future investigations. HoPSs exert well-established anti-infection and anti-inflammatory effects, alongside important nutritional and metabolic benefits. These outcomes are supported by evidence from cellular receptor signaling (e.g., TLRs, Dectin-1; NF-κB, MAPK pathways), gut microbiota remodeling, and metabolite network interactions. Finally, we discuss current research gaps, particularly in fine structural analysis and multidimensional mechanistic studies, and propose future directions based on precise structural elucidation, multidimensional structure–activity relationship modeling, and interdisciplinary integration. This review aims to bridge structural glycomics with human nutritional immunology, providing a theoretical basis for the structural optimization, immune activity enhancement, and functional food development of natural HoPSs to promote their industrial application in medicine, nutrition, and health. Full article

Pyrrolizidine alkaloids (PAs), a category of naturally occurring secondary metabolites, are commonly found in various botanical sources. Accumulating evidence indicates that PAs and their biologically active metabolites can interact with cellular components and trigger a variety of toxic effects in animals and humans. Notably, PAs exhibit significant hepatotoxic potential via nutritional supplements, environmental dissemination, food chain contamination, and broader ecological pollution. In this review, we summarize PA-induced hepatotoxicity in humans and animals and the underlying molecular mechanisms. It involves oxidative stress, mitochondrial dysfunction, apoptosis, ER stress, inflammation, autophagy, and ferroptosis. Several key signaling pathways, such as nuclear factor-erythroid 2 related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), protein kinase RNA-like endoplasmic reticulum kinase (PERK), toll like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), transforming growth factor beta (TGF-β), p53, farnesoid X receptor (FXR), and pregnane X receptor (PXR), are also implicated. Furthermore, this review discusses diagnostic approaches, metabolic activation pathways, and detoxification strategies targeting PA-induced liver injury. Collectively, this review provides a comprehensive understanding of the molecular basis of PA hepatotoxicity and underscores the urgent need for improved risk assessment, early diagnosis, and effective detoxification interventions to mitigate PA-related liver diseases in humans and animals. Full article

Post-infectious bronchiolitis obliterans (PIBO) is a severe chronic airway disease in children following lower respiratory tract infections. Human adenovirus (HAdV) and Mycoplasma pneumoniae (MP) are the major associated pathogens, with geographic variations in their relative importance. This review analytically compares the mechanistic divergence and convergence between HAdV and MP. Both pathogens converge on MyD88/NF-κB/MAPK signaling and neutrophil-driven inflammation, but diverge in initial host engagement (CAR/integrins vs. TLR2/6 and CARDS toxin) and inflammasome activation (TLR9-related vs. NLRP3-related). This review aims to propose an integrative model linking acute immune activation to fibrotic bronchiolar narrowing and to evaluate the risk factors for PIBO. Genetic susceptibility and epigenetic regulation help explain population differences in PIBO risk and geographic distribution. Despite progress, significant knowledge gaps remain, including the lack of single-cell resolution studies, the absence of co-infection animal models, and uncertainty regarding the long-term efficacy of targeted immunomodulatory therapies. Addressing these gaps is essential for improving early diagnosis and clinical outcomes. Full article

This study investigated the gastroprotective effects of Salvia plebeia extract (SPE) against acute gastric mucosal injury induced by 150 mM HCl/60% ethanol in rats and explored its antioxidant and anti-inflammatory mechanisms. SPE exhibited strong in vitro antioxidant activity, with DPPH and ABTS radical scavenging rates of 86.2 ± 2.4% and 89.1 ± 1.9%, respectively, along with a high total polyphenol content (96.4 ± 3.1 mg gallic acid equivalents/g extract). In lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, SPE attenuated LPS-induced inflammatory signaling, as evidenced by reduced TLR4 and JNK expression and restoration of IκBα levels. In vivo, oral administration of SPE (100 or 300 mg/kg) 1 h prior to HCl/ethanol challenge significantly reduced gastric lesion area and improved histopathological damage compared with the HCl/ethanol-treated control group. SPE also increased gastric pH, reduced gastric juice volume, decreased serum levels of TNF-α and IL-6, and downregulated gastric mucosal mRNA expression of Nos2 and Ptgs2. Immunohistochemical analysis further showed that SPE attenuated NF-κB p65 immunoreactivity in gastric tissues. Collectively, these findings suggest that SPE exerts gastroprotective effects through antioxidant activity and suppression of inflammatory responses associated with the MAPK/NF-κB pathway in acute HCl/ethanol-induced gastric injury. Full article

Preterm labor is a major cause of neonatal morbidity and mortality and is frequently driven by infection-associated inflammation that promotes premature uterine activation. In this study, we investigated the effects of adipose stem cell-derived extracellular vesicles (ASC-EVs) on macrophage-mediated inflammatory signaling in uterine smooth muscle cells (HUtSMCs). An in vitro model was established by treating HUtSMCs with conditioned media derived from LPS-stimulated RAW264.7 macrophages. Activation of signaling pathways was assessed by Western blotting and immunofluorescence, and functional responses were evaluated using calcium flux and collagen gel contraction assays. Conditioned media from LPS-stimulated macrophages induced robust activation of MAPK (ERK1/2 and JNK) and NF-κB signaling, accompanied by IκB degradation and nuclear translocation of phosphorylated p65, whereas ASC-EVs pretreatment significantly attenuated these responses and reduced the expression of pro-inflammatory cytokines, including IL-6, IL-8, and MCP-1. Furthermore, macrophage-conditioned media enhanced intracellular calcium flux and contractile activity in HUtSMCs, both of which were suppressed by ASC-EVs. Inhibition of TLR4 signaling in macrophages reduced the inflammatory potency of conditioned media, indicating a key upstream role of macrophage TLR4 activation. Collectively, these findings demonstrate that ASC-EVs suppress macrophage-mediated inflammatory activation and downstream contractile responses, suggesting their potential as a cell-free therapeutic strategy for preventing inflammation-associated preterm labor. Full article

Background: Human diseases remain a major global health challenge, requiring effective therapeutic strategies. Traditional Chinese medicine (TCM) has been widely used in clinical settings. Many natural compounds, such as flavonoids from TCM, exhibit diverse pharmacological activities. Alpinetin and pinocembrin are structurally related flavonoids. Alpinetin is derived from Zingiberaceae plants, and pinocembrin is extracted from wild marjoram (origanum vulgare) or other natural sources. They possess a wide range of pharmacological activities or biological effects, including anti-inflammatory, anti-tumor, liver and kidney protection, cardiovascular protection, and antibacterial activities. Methods: The present comparative review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, using four major databases (PubMed, EMBASE, Web of Science, and Cochrane Library), as well as CNKI without language restrictions. Results: Pharmacokinetic studies reveal distinct absorption, metabolism, and excretion profiles. Alpinetin and pinocembrin undergo glucuronidation and interact with cytochrome P450 enzymes and transporters. However, alpinetin has demonstrated approximately 1.5-fold higher plasma exposure and slower clearance compared to pinocembrin. Mechanistically, alpinetin exerted therapeutic effects through modulation of the NF-κB/MAPK, PI3K/Akt, and PPAR-γ signaling pathways, resulting in a 2- to 3-fold reduction in pro-inflammatory cytokines. In contrast, pinocembrin exerted protective activity through the inhibition of HMGB1/TLR4 signaling, regulation of endoplasmic reticulum stress, and activation of Nrf2/HO-1, leading to a 1.8-fold increase in antioxidant enzyme activity. The minimum inhibitory concentrations were reduced by 2- to 4-fold against Gram-positive bacteria compared to alpinetin. Conclusions: These findings highlight the pharmacological potential of alpinetin and pinocembrin as promising candidates for the development of novel anti-tumor, anti-inflammatory, liver and kidney protection, cardiovascular protection, and antibacterial agents. However, research on the pharmacological actions of alpinetin and pinocembrin is still in the preclinical stage. Further research is required to validate their efficacy in clinical settings, especially for translation to clinical studies. This is critical to translating these natural flavonoids into effective therapeutic agents while addressing the regulatory challenges and pathways associated with botanical drugs in human diseases. Full article

The modulation of the tumour microenvironment represents a pivotal step in tumorigenesis and metastasis and results from direct and paracrine cellular interactions. The innate immune Toll-like receptor 4 (TLR4) controls immune and inflammatory signalling in the tumour microenvironment. A growing body of evidence shows that TLR4 activation in cancer, immune and stromal cells upregulate gelatinase expression and activity, linking innate immune responses to extracellular matrix (ECM) remodelling. Gelatinases, or matrix metalloproteinases (MMP2) and (MMP9) play a pivotal role in tumour matrix degradation, thereby facilitating invasion, angiogenesis and metastasis. Interestingly, although TLR4 signalling in cancer cells and tumour-associated macrophages leads to different activation outputs, they can both induce gelatinases through NF-κB, MAPK, and Akt pathways. Evidence from clinical tumour tissues, co-culture models, in vivo and in vitro studies supports the crucial interplay between TLR4 signalling and gelatinases production in tumour growth and metastasis. An in-depth understanding of this crosstalk may reveal new therapeutic opportunities in targeted strategies. Full article