Search Results (3,675)

Amiodarone (AMD) is an effective antiarrhythmic drug whose long-term use is limited by multi-organ toxicities linked to oxidative stress. This review synthesizes current evidence on how AMD induces reactive oxygen species (ROS) generation in vitro and in vivo, and the mechanistic pathways involved. AMD promotes ROS production through both direct and indirect mechanisms. Directly, AMD accumulates in mitochondria and impairs the electron transport chain, leading to electron leakage and superoxide formation. It also undergoes redox cycling, forming radical intermediates that trigger lipid peroxidation and deplete cellular antioxidants. AMD and its metabolites inhibit antioxidant enzymes (SOD, CAT, GPx) expression and/or activities and reduce glutathione level, compounding oxidative injury. Indirectly, AMD activates signaling pathways that exacerbate ROS generation. This compound can induce pro-inflammatory mediators such as TNF-α and modulate nuclear receptors such as AhR, PXR, CAR, and PPARs, altering the expression of metabolic enzymes and endogenous antioxidants. These processes are time- and dose-dependent: short exposures at low concentrations may transiently scavenge radicals, whereas chronic or higher-dose exposures consistently lead to net ROS accumulation. The oxidative effects of AMD vary by tissue and experimental models. In chronic models, organs such as the lung and liver show pronounced ROS-mediated injury, whereas acute or cell-based systems typically exhibit subtler changes. AMD-induced toxicity arises from multifactorial oxidative stress involving mitochondrial dysfunction, increased radical formation, depletion of antioxidant defenses, and activation of pro-oxidant signaling pathways. Recognizing these pathways suggests that antioxidant and mitochondria-targeted co-therapies could ameliorate the side effects of AMD. Full article

One of the major social issues worldwide is tobacco dependency and cigarette smoking (CS) abuse. Given the significant impact of cigarette smoking on human health and diseases, extensive tobacco use and cigarette smoking abuse are certainly a form of drug addiction and should be considered a serious threat to human health. Notably, healthcare spending attributable to cigarette smoking is very high. In this regard, a significant number of biomolecules of natural origin have been described as capable of mitigating the adverse effects of cigarette smoking. In this review, (a) we discuss the impact that the habit of smoking tobacco has on human health and (b) we describe products of natural origin capable of mitigating the effects of cigarette smoke. The conclusion of this review article is that the available information strongly indicates a possible use of the anti-inflammatory aged garlic extract (AGE) and its bioactive components for mitigating the detrimental effects of cigarette smoke on human tissues. The key reasons for proposing this application are that AGE and its key components S-allyl-cysteine and S1-propenyl-cysteine are potent anti-inflammatory agents, bind to Toll-like Receptor-4, inhibit Nuclear Factor-κB, inhibit the expression of pro-inflammatory genes, revert apoptosis induced by cigarette smoke in several cellular model systems and are strong inhibitors of Reactive Oxygen Species (ROS) formation. Full article

Excessive stress disrupts cardiac homeostasis via complex and multifactorial mechanisms, resulting in cardiac dysfunction, cardiovascular disease, or even sudden cardiac death, yet the underlying molecular mechanisms remain poorly understood. Accordingly, we aimed to elucidate how stress induces calcium dysregulation and contributes to cardiac dysfunction and injury through the nuclear receptor subfamily 3 group c member 1 (NR3C1)/Glomulin (GLMN)/FK506-binding protein 12.6 (FKBP12.6) signaling pathway. Using mouse models of acute and chronic restraint stress, we observed that stress-exposed mice exhibited reduced left ventricular ejection fraction, ventricular wall thickening, elevated serum and myocardial cTnI levels, along with pathological features of myocardial ischemia and hypoxia, through morphological, functional, and hormonal assessments. Using transmission electron microscopy and Western blotting, we found that stress disrupted mitochondrial quality control in cardiomyocytes, evidenced by progressive mitochondrial swelling, cristae rupture, decreased expression of fusion proteins (MFN1/OPA1) and biogenesis regulator PGC-1α, along with aberrant accumulation of fission protein (FIS1) and autophagy marker LC3. At the cellular level, ChIP-qPCR and siRNA knockdown confirmed that stress activates the glucocorticoid receptor NR3C1 to repress its downstream target GLMN, thereby preventing FKBP12.6 ubiquitination and degradation, resulting in calcium leakage and overload, which ultimately impairs mitochondrial quality control and damages cardiomyocytes. In conclusion, our findings reveal that stress induces myocardial damage through NR3C1/GLMN-mediated FKBP12.6 ubiquitination, disrupting calcium homeostasis and mitochondrial quality control, and lay a theoretical foundation for dissecting the intricate molecular network of stress-induced cardiomyopathy. Full article

Drought stress poses a significant threat to tree growth, making the development of drought-resistant species essential for ecological restoration. WRKY transcription factors are critical regulators of plant drought responses; however, the role of WRKY22 in the woody species Populus ussuriensis K. remains unclear. In this study, the PuWRKY22 gene was cloned from P. ussuriensis via homologous cloning and was found to be highly expressed in leaves and responsive to abscisic acid (ABA) signaling. Subcellular localization confirmed that PuWRKY22 is a nuclear protein. Using fluorescein enzyme complementation assays, PuWRKY22 was shown to bind specifically to W-box cis-elements, indicating its function as a transcriptional regulator. Under ABA and osmotic (sorbitol) stress, the seed germination rate, root growth, and biomass of tobacco and Populus davidiana × Populus bolleana strains overexpressing PuWRKY22 were significantly increased. Additionally, these overexpressed strains exhibited a reduction in reactive oxygen species (ROS) accumulation and a decrease in membrane lipid peroxidation. Transcriptomic analyses revealed that PuWRKY22 activates expression of the ABA receptor gene Ptr.PYL4 (Potri.006G104100.v4.1), which regulates stomatal closure to minimize water loss. Consistent with this, stomatal observations and photosynthetic measurements demonstrated that PuWRKY22 enhances drought tolerance by protecting photosystem II and preserving chlorophyll content. Collectively, this study elucidates the molecular mechanism by which PuWRKY22 enhances drought resistance in woody plants through ABA signaling, providing a foundation for breeding drought-tolerant forest species. Full article

Gallium-68 is a widely used positron-emitting radionuclide in nuclear medicine, traditionally obtained from ⁶⁸Ge/⁶⁸Ga generators. However, increasing clinical demand has driven interest in alternative production methods, such as medical cyclotrons equipped with solid targets. This study evaluates the functional equivalence of gallium-68 chloride obtained from cyclotron solid target and formulated to be equivalent to the eluate from a germanium-gallium generator, aiming to determine whether this production method can serve as a reliable alternative for PET radiopharmaceutical applications. Preparations of [⁶⁸Ga]Ga-PSMA-11 and [⁶⁸Ga]Ga-DOTATOC, labeled with cyclotron-derived gallium-68 chloride, were subjected to quality control analysis using radio thin layer chromatography and radio high performance liquid chromatography. Subsequently, biodistribution studies were performed in mouse oncological models of expression of PSMA antigen and SSTR receptor to compare uptake of preparations produced with generator and cyclotron-derived isotopes. All tested formulations met the required radiochemical purity specifications. Moreover, tumor accumulation of the radiolabeled compounds was comparable regardless of the isotope source. The results support the conclusion that gallium-68 produced via cyclotron is functionally equivalent to that obtained from a generator, demonstrating its potential for interchangeable use in clinical and research radiopharmaceutical applications. Full article

Chronic, low-grade inflammation is a key contributor to the development of numerous non-communicable diseases (NCDs), including cardiovascular, metabolic, and neurodegenerative disorders. Conventional anti-inflammatory drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids, often present safety concerns with prolonged use, highlighting the need for safer, multi-targeted therapeutic options. Iridoids, a class of monoterpenoid compounds abundant in several medicinal plants, have emerged as promising bioactive agents with diverse pharmacological properties. They exert anti-inflammatory and metabolic regulatory effects by modulating key signaling pathways, including nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducer and activator of transcription (JAK/STAT), adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor (PPAR) pathways. This review provides a comprehensive summary of the major iridoid metabolites derived from ten Bulgarian medicinal plant species, along with mechanistic insights from in vitro and in vivo studies. Documented biological activities include anti-inflammatory, antioxidant, immunomodulatory, antifibrotic, organoprotective, antibacterial, antiviral, analgesic, and metabolic effects. By exploring their phytochemical profiles and pharmacodynamics, we underscore the therapeutic potential of iridoid-rich Bulgarian flora in managing inflammation-related and metabolic diseases. These findings support the relevance of iridoids as complementary or alternative agents to conventional therapies and highlight the need for further translational and clinical research. Full article

In recent years, the bidirectional regulatory mechanism of the bone-brain axis has become a hotspot for interdisciplinary research. In this paper, we systematically review the anatomical and functional links between bone and the central nervous system, focusing on the regulation of brain function by bone-derived signals and their clinical translational potential. At the anatomical level, the blood–brain barrier permeability mechanism and the unique structure of the periventricular organs establish the anatomical basis for bone-brain information transmission. Innovative discoveries indicate that the bone cell network (bone marrow mesenchymal stem cells, osteoblasts, osteoclasts, and bone marrow monocytes) directly regulates neuroplasticity and the inflammatory microenvironment through the secretion of factors such as osteocalcin, lipid transporter protein 2, nuclear factor κB receptor-activating factor ligand, and fibroblast growth factor 23, as well as exosome-mediated remote signaling. Clinical studies have revealed a bidirectional vicious cycle between osteoporosis and Alzheimer’s disease: reduced bone density exacerbates Alzheimer’s disease pathology through pathways such as PDGF-BB, while AD-related neurodegeneration further accelerates bone loss. The breakthrough lies in the discovery that anti-osteoporotic drugs, such as bisphosphonates, improve cognitive function. In contrast, neuroactive drugs modulate bone metabolism, providing new strategies for the treatment of comorbid conditions. Additionally, whole-body vibration therapy shows potential for non-pharmacological interventions by modulating bone-brain interactions through the mechano-osteoclast signaling axis. In the future, it will be essential to integrate multiple groups of biomarkers to develop early diagnostic tools that promote precise prevention and treatment of bone-brain comorbidities. This article provides a new perspective on the mechanisms and therapeutic strategies of neuroskeletal comorbidities. Full article

This study investigated whether the Endocrine Disruptome and VirtualToxLab in silico platforms are suitable for predicting the endocrine disrupting effects of per- and polyfluoroalkyl substances (PFASs)—in particular, for interactions with oestrogen receptors (ERs) and androgen receptor (AR). Compounds included in the U.S. Environmental Protection Agency’s PFAS working list were analysed with both models, and the results were compared with the available in vitro data regarding their modulation of nuclear receptors. Based on the identified prediction parameters, such as sensitivity, specificity, accuracy, and Mathews’ correlation coefficient, VirtualToxLab was found to be a reliable model for predicting the reactivity of PFASs with AR, while a positive consensus approach of both platforms provided reliable predictions of the PFAS reactivity with ERα and ERβ. This study provides the evidence that Endocrine Disruptome and VirtualToxLab can be used as a tier 1 screening tool for assessment of the endocrine disrupting effect of PFASs. Furthermore, it demonstrates that the likelihood of endocrine disrupting properties increases with the lipophilicity of PFASs and identifies the understudied PFHpS, PFNS, PFDS, 9-Cl, NMeFOSAA, NEtFOSAA, 4:2 FTS, 6:2 FTS, 8:2 FTS, 6:2 monoPAP, 8:2 monoPAP, and 5:3 acid as potential ligands of AR and/or ERs. Full article

The Wntβ-catenin signaling pathway is a key regulator of gastrointestinal (GI) tumorigenesis, modulating cellular processes such as proliferation, differentiation, and epithelial-to-mesenchymal transition (EMT). In this review, we evaluate the expression and mutation profiles of core Wntpathway components in the most common GI malignancies. Our findings outline notable alterations in ligands, receptors, co-receptors, and intracellular effectors across different GI cancers. In gastric cancer tissue, elevated levels of Wnt proteins, FZD7 receptor, and LRP5/6, along with β-catenin accumulation and reduced APC expression, are associated with poor prognosis. In colorectal cancer samples, common APC mutations and Wnt ligand overexpression contribute to β-catenin nuclear localization and EMT. Esophageal cancer specimens exhibit co-overexpression of Wnt2 and Wnt5A, as well as receptors such as FZD2 and FZD6, which are linked to worse prognosis and reduced survival. Liver cancer tissue commonly harbors CTNNB1 mutations, which encode β-catenin and are associated with poor differentiation. In pancreatic cancer samples, overexpression of Wnt ligands, FZD receptors, and β-catenin is associated with the presence of distant metastasis and poor clinical outcomes. In conclusion, this pathway represents a promising avenue for identifying novel diagnostic, prognostic, and therapeutic biomarkers in GI cancers, warranting further clinical investigation. Full article

Orphan nuclear receptor 4A1 (NR4A1) is a member of the NR4A subfamily that was initially discovered as an intermediate early gene expressed in response to stressors, including inflammatory agents. This review addresses the hypothesis that NR4A1 is a key nutrient sensor that contributes to the anti-aging and health-protective effects of receptor ligands, dietary phenolics, and other diet-derived compounds. There is evidence in animal models including humans that NR4A1 serves as an important gene that decreases the rate of aging and its associated diseases. For example, in humans and mice, NR4A1 expression decreases with age and loss of NR4A1 enhances disease susceptibility, and survival curves show that NR4A1-deficient mice live 4 months less than wild-type animals. An extensive comparison of inflammatory diseases, immune dysfunction, and fibrosis in multiple tissues shows that in NR4A1^−/− mice and rats these diseases and injuries are enhanced compared to wild-type NR4A1^−/− animals. There is evidence showing that structurally diverse NR4A1 ligands reverse the induced adverse effects in NR4A1 wild-type mice. This raises an important question regarding the mechanisms of NR4A1-dependent inhibition of the aging process and the potential for this receptor as a nutrient sensor. It has been well established that polyphenolics, including flavonoids, resveratrol, and other compounds in the diet, are health-protective and decrease the aging process. Recent studies show that resveratrol and flavonoids such as quercetin and kaempferol bind NR4A1 and exhibit protective NR4A1-dependent inhibition of endometriosis and cancer. These limited studies support a role for NR4A1 as a potential dietary sensor of nutrients that are known to be health-protective and a potential nutrient target for improving health. Full article

Background: The therapeutic response in Graves’ Disease (GD) remains largely unpredictable. Patients often experience persistent symptoms that are poorly correlated with thyroid hormone levels, an undefined treatment duration, and the need for long-term or definitive therapies. Based on the nuclear antagonistic properties of L-carnitine (LCT) on thyroid hormone action and the immunomodulatory role of selenium (Se), we aimed to assess the impact of adding a combined LCT and Se supplement to standard methimazole (MMI) therapy on the biochemical profile and quality of life (QoL) of patients with overt GD. Methods: This multicenter prospective randomized trial enrolled 60 consecutive patients with newly diagnosed overt GD. Participants were randomized to receive either standard treatment with MMI alone (Control Group) or MMI plus the combined LCT/Se supplement (Intervention Group). TSH, fT3, fT4, and TSH–receptor antibodies (TRAb) levels were evaluated every two months for up to 24 months or until spontaneous remission or definitive therapy. At each visit, patients completed a symptom questionnaire addressing the frequency of typical thyrotoxic symptoms. Results: No significant differences were observed between groups in the trend or time-to-normalization of TSH, fT3, and fT4 levels. However, the Intervention Group reached TRAb negativity significantly earlier (HR = 2.35 (1.14–4.81), p = 0.016), with a synergistic interaction with MMI therapy. MMI requirements were consistently lower in the Intervention Group, both in average dosage (p = 0.013) and cumulative dose (p = 0.020). The rate of spontaneous remission was significantly higher (OR = 11.22 (3.35–46.11), p < 0.001). Overall symptom burden did not differ significantly between groups; however, the supplement exerted an independent effect in reducing the severity of tremor, irritability, mood lability, heat intolerance, and exertional dyspnea. Conclusions: Our findings suggest the clinical benefits of adding combined LCT and Se supplementation to MMI in the treatment of overt GD, including shorter disease duration, lower cumulative MMI exposure and earlier TRAb normality, that could positively influence TRAb-related prognostic outcomes. Full article

The renin–angiotensin–aldosterone system (RAAS) plays a pivotal role in regulating cardiovascular function, fluid balance, and blood pressure. Recent research has revealed the RAAS’s influence extends beyond cardiovascular physiology, encompassing key roles in inflammation, fibrosis, immune regulation, cancer progression, and organ-specific disease mechanisms. This review provides a comprehensive overview of classical and alternative RAAS pathways, focusing on the dual roles of angiotensin II (Ang II) and angiotensin-(1–7) (Ang 1–7), mediated through AT1R, AT2R, MasR, and MrgD receptors. We discuss molecular signaling cascades, including mitochondrial, nuclear, and caveolae-mediated mechanisms, and explore the impact of RAAS modulation on hepatic fibrosis, vascular remodeling, and autoimmune inflammation. Genetic models and emerging pharmacologic strategies illustrate tissue-specific RAAS actions, emphasizing the therapeutic potential of enhancing the ACE2/Ang 1–7/Mas axis while inhibiting the deleterious ACE/Ang II/AT1R signaling. Furthermore, we highlight implications for veterinary medicine, particularly in canine chronic inflammatory enteropathies, where RAAS dysfunction may contribute to treatment resistance. Understanding RAAS complexity and inter-receptor crosstalk is essential for developing new therapeutic strategies targeting cardiovascular, hepatic, and inflammatory diseases in both human and veterinary contexts. Full article

The pregnane X receptor (PXR), a ligand-activated nuclear receptor, plays a central role in regulating the metabolism of both endogenous substances and xenobiotics. In recent years, increasing evidence has highlighted its involvement in chronic diseases, particularly metabolic disorders and cancer. PXR modulates drug-metabolizing enzymes, transporters, inflammatory factors, lipid metabolism, and immune-related pathways, contributing to the maintenance of hepatic–intestinal barrier homeostasis, energy metabolism, and inflammatory responses. Specifically, in type 2 diabetes mellitus (T2DM), PXR influences disease progression by regulating glucose metabolism and insulin sensitivity. In obesity, it affects adipogenesis and inflammatory processes. In atherosclerosis (AS), PXR exerts protective effects through cholesterol metabolism and anti-inflammatory actions. In metabolic dysfunction-associated steatotic liver disease (MASLD), it is closely associated with lipid synthesis, oxidative stress, and gut microbiota balance. Moreover, PXR plays dual roles in various cancers, including hepatocellular carcinoma, colorectal cancer, and breast cancer. Currently, PXR-targeted strategies, such as small molecule agonists and antagonists, represent promising therapeutic avenues for treating metabolic diseases and cancer. This review comprehensively summarizes the structural features, signaling pathways, and gene regulatory functions of PXR, as well as its role in metabolic diseases and cancer, providing insights into its therapeutic potential and future drug development challenges. Full article

Paraoxonase 1 (PON1) is an antioxidant enzyme that plays physio-pathological roles. Prior in silico analysis revealed the presence of response elements of the nuclear receptor superfamily in the PON1 promoter, comparable to glucocorticoid receptors (GR), the vitamin D receptor (VDR), and the pregnenolone X receptor (PXR). The aim of this study was to evaluate the effects of 1α,25-dihydroxyvitamin D₃, a ligand specific to VDR, on the expression and activity of PON1 in hepatocarcinoma cells (HepG2 cells). PON1 activities (arylesterase/AREase and lactonase/LACase) were determined by spectrophotometry. Quantitative real-time PCR was used to evaluate the effect of VDR and PXR on the mRNA levels of PON1 and CYP3A4 genes. Molecular models and dynamics simulations were built using specialized software. Treatments with 1α,25-dyhydroxyvitamin D₃ (calcitriol), its active hormonal form, resulted in an induction of PON1 mRNA and AREase activity compared to control cultures. These results suggest that calcitriol plays a role in the regulation of PON1 transcription and provide evidence that this hormone increases PON1 levels in HepG2 cells. In addition, the molecular modeling suggests that calcitriol enhances PON1 activity and this increase could be caused by direct interaction on the PON1 protein. This study shows the effects of calcitriol on PON1 expression, proposing a new molecular mechanism for the transcriptional regulation of PON1 through a process linked to VDR activation and direct interaction of calcitriol on the PON1 protein. Full article

Atherosclerosis is a multifactorial, chronic inflammatory disorder characterized by the progressive accumulation of plaque within the arterial wall. Recent research has highlighted the pivotal role of bioactive peptides in modulating vascular homeostasis and inflammation. Among these, salusin-α and salusin-β have emerged as critical regulators of atherogenesis. These peptides are generated via differential proteolytic processing of preprosalusin: an amino acid precursor encoded by the torsin family 2 member A gene. Despite their common origin, salusin-α and salusin-β exhibit divergent biological activities. Salusin-β promotes vascular inflammation by enhancing oxidative stress, activating the nuclear factor kappa B signaling pathway, and upregulating proinflammatory cytokines as well as adhesion molecules, and it also facilitates foam cell formation by increasing the expression of acyl-CoA/cholesterol acyltransferase 1 and scavenger receptors, thereby contributing to plaque progression. In contrast, salusin-α appears to exert protective, anti-inflammatory, and anti-atherogenic effects by increasing the expression of the interleukin-1 receptor antagonist and inhibiting key proinflammatory mediators. Additionally, these peptides modulate the proliferation of vascular smooth muscle cells and fibroblasts, with salusin-β promoting cellular proliferation and fibrosis via calcium and 3′,5′-cyclic adenosine monophosphate-mediated pathways, while the role of salusin-α in these processes is less well defined. Altered plasma levels of salusins have been correlated with the presence and severity of atherosclerotic lesions, suggesting their potential as diagnostic biomarkers and therapeutic targets. This review provides a comprehensive overview of biosynthesis, tissue distribution, and dual roles of salusins in vascular inflammation and remodeling, emphasizing their significance in the pathogenesis and early detection of atherosclerotic cardiovascular disease. Full article