iNOS-mediated nitric oxide production and its regulation

Thermally optimized subcritical water hydrolysis for green extraction of bioactive compounds from sea cucumber Stichopus japonicus

This study investigated the bioactive compounds in Stichopus japonicus extracts obtained using subcritical water hydrolysis (SWH) at nine temperatures (115 °C-235 °C at 15 °C intervals). Increasing temperature enhanced the extraction efficiency and decreased the average molecular weight, extracts had abundant amino acids and phenolic compounds. Maximum protein (832.66 ± 15.00 mg BSA/g) and polysachchrides (32.02 ± 0.88 mg glucose/g) contents were achieved at 175 °C, while the highest phenolic content (23.93 ± 0.16 mg GAE/g) and antioxidant activity were observed at 220 °C. The highest α-amylase (18.62 % ± 1.17 %) and α-glucosidase (24.31 % ± 1.43 %) activities were observed at 115 °C. However, there was no significant trend between temperature and anti-inflammatory or anticholesterol activities. GC-MS analysis confirmed the presence of bioactive compounds with antioxidant, anti-inflammatory, antidiabetic, and anticholesterol potential. In conclusion, our results indicate that SWH is a sustainable approach for extracting bioactive compounds from S. japonicus, with promising applications in functional foods and therapeutics.

6'-O-caffeoylarbutin attenuates D-galactose-induced brain and liver damage in aging mice via regulating SIRT1/NF-κB pathway

BACKGROUND

Aging-related liver and brain damage caused by oxidative stress and inflammation significantly impacts health and quality of life. Natural bioactive compounds, such as 6'-O-caffeoylarbutin (CA), which is primarily distributed in Vaccinium species, have been studied for their antioxidant and anti-inflammatory properties. This study aims to investigate the protective effect on liver and brain damage induced by D-galactose (D-gal) in mice and to explore its potential molecular mechanisms.

PURPOSE

This study aims to investigate the protective effects of CA on D-galactose (D-gal)-induced liver and brain damage in mice and to explore its potential molecular mechanisms.

METHODS

CA was prepared from Vaccinium dunalianum and identified using UHPLC-ESI-HR-MS/MS. Molecular docking and network pharmacology analysis were performed to predict the binding of CA with SIRT1 and NF-κB1 targets. In vivo, a D-gal-induced aging mouse model was established to evaluate the biochemical, oxidative stress, and inflammatory parameters. The effects of CA on oxidative stress and inflammation were examined through enzymatic activity assays, cytokine level measurements, and histopathological analysis. Western blotting was used to validate the involvement of the SIRT1/NF-κB pathway.

RESULTS

CA treatment significantly alleviated liver and brain damage in D-gal-induced mice by decreasing AChE, AST, and ALT activities, improving organ indices, and reducing histopathological alterations. CA enhanced antioxidant defense by increasing SOD, CAT, and T-AOC activities, elevating GSH levels, and decreasing MDA content. Furthermore, CA suppressed the inflammatory response by downregulating IL-6 and TNF-α levels. Mechanistically, CA inhibited NF-κB p65 phosphorylation and suppressed iNOS and COX-2 expression, likely via activation of the SIRT1 protein.

CONCLUSION

This study demonstrates that CA protects against D-gal-induced oxidative stress and inflammation in liver and brain tissues via the SIRT1/NF-κB pathway, supporting its potential as a bioactive compound for preventing aging-related liver and brain damage.

Defence Warriors: Exploring the crosstalk between polyamines and oxidative stress during microbial pathogenesis

Microbial infections have been a widely studied area of disease research since historical times, yet they are a cause of severe illness and deaths worldwide. Furthermore, infections by pathogens are not just restricted to humans; instead, a diverse range of hosts, including plants, livestock, marine organisms and fish, cause significant economic losses and pose threats to humans through their transmission in the food chain. It is now believed that both the pathogen and the host contribute to the outcomes of a disease pathology. Researchers have unravelled numerous aspects of host-pathogen interactions, offering valuable insights into the physiological, cellular and molecular processes and factors that contribute to the development of infectious diseases. Polyamines are key factors regulating cellular processes and human ageing and health. However, they are often overlooked in the context of host-pathogen interactions despite playing a dynamic role as a defence molecule from the perspective of the host as well as the pathogen. They form a complex network interacting with several molecules within the cell, with reactive oxygen species being a key component. This review presents a thorough overview of the current knowledge of polyamines and their intricate interactions with reactive oxygen species in the infection of multiple pathogens in diverse hosts. Interestingly, the review covers the interplay of the commensals and pathogen infection involving polyamines and reactive oxygen species, highlighting an unexplored area within this field. From a future perspective, the dynamic interplay of polyamines and oxidative stress in microbial pathogenesis is a fascinating area that widens the scope of developing therapeutic strategies to combat deadly infections.

Inducible Nitric Oxide Synthase (iNOS): More Than an Inducible Enzyme? Rethinking the Classification of NOS Isoforms

Nitric oxide (NO) is a critical signaling molecule synthesized from L-arginine by nitric oxide synthase (NOS). The three NOS isoforms-neuronal NOS (nNOS; NOS1), inducible NOS (iNOS; NOS2), and endothelial NOS (eNOS; NOS3)-have traditionally been classified as either constitutive (nNOS and eNOS) or inducible (iNOS). However, this binary classification oversimplifies their functions, particularly by neglecting the physiological roles of iNOS and misrepresenting its involvement in pathological processes. Increasing evidence demonstrates that all three isoforms can exhibit both constitutive and inducible expression. Notably, iNOS is constitutively expressed at low levels in several tissues, including blood, heart, bone marrow, lung, brain, spinal cord, retina, colonic mucosa, liver, ileum, skeletal muscle, epidermis, adipose tissue, endometrium, ovary, and kidney under normal physiological conditions, a form we refer to as constitutive iNOS (ciNOS). This basal expression contributes to essential functions such as heart rate regulation, respiratory exchange, and microbiome balance in the gut. Moreover, in certain pathological contexts, iNOS may exert protective rather than harmful effects, challenging the prevailing view that it is solely a pro-inflammatory mediator. Current drug development strategies targeting NOS are largely based on the outdated dichotomy of constitutive "physiologic" versus inducible "pathologic" isoforms, focusing primarily on iNOS inhibition. The failure of iNOS inhibitors in most clinical trials highlights the limitations of this approach. To address these gaps, we propose a revised nomenclature that incorporates both gene expression mode (constitutive vs. inducible) and discovery order, offering a more nuanced framework for understanding NOS isoforms in both health and disease.

Evaluation of tetrahydropyridazine-based peripherally restricted dual inhibitors of CB1R and inducible nitric oxide synthase (iNOS) for treating metabolic syndrome disorders

BACKGROUND AND PURPOSE

The endocannabinoid system is a key regulator of metabolism, sparking interest in cannabinoid type 1 receptor (CB1R) antagonists as potential treatments for obesity and related conditions collectively called metabolic syndrome disorders. However, the neuropsychiatric liabilities associated with centrally acting CB1R antagonists led researchers to focus on developing peripherally restricted compounds that do not cross the blood-brain barrier (BBB). This study aimed to synthesize and evaluate novel CB1R antagonists based on tetrahydropyridazine core incorporating physicochemical design principles that would allow for negligible BBB penetration. The efficacy of the compounds was assessed in rodent models of diet induced obesity and diabetes.

EXPERIMENTAL APPROACH

In this study, we employed a rational-design approach along with structure-based modeling to develop small-molecule CB1R antagonists that are peripherally acting. Pharmacological profiles of two racemic compounds PB19A and PB95 were evaluated in cannabinoid receptor binding studies, and functional [35S]-GTPγS assays. Further chiral separation of enantiomers allowed for the evaluation of respective eutomers in in vitro ADME studies along with in vivo pharmacokinetic and tissue distribution studies in mice. The results showed that the compounds are orally bioavailable and had negligible brain penetrance. The design features also incorporated putative amidine moieties which inhibit the pro-inflammatory enzyme; inducible nitric oxide synthase (iNOS). Both biochemical and in vitro cell-based assays showed the CB1R antagonists having iNOS inhibitor properties. In vivo CB1R functional antagonism was assessed by upper gastrointestinal motility assay. The efficacy of our CB1R antagonists was compared with brain penetrant ibipinabant in a diet-induced obesity mouse model, assessing effects on lipid metabolism biomarkers, food intake, body weight reduction, glucose tolerance and insulin resistance.

KEY RESULTS

Novel compounds PB19AE2 and PB95E2 were designed and evaluated as peripherally restricted CB1R antagonists. In high fat diet fed mice, these compounds improved metabolic parameters, modestly reduced food intake, and ameliorated hepatic lipid metabolism markers.

CONCLUSION AND IMPLICATIONS

Overall, PB19AE2 and PB95E2 are orally bioavailable, peripherally acting CB1 antagonists and their preliminary evaluation show promising potential in utilizing the pyridazine-based compounds for generating potent leads for treating obesity- associated disorders.

Design, synthesis and biological evaluation of diarylmethyl amine derivatives with anti-ulcerative colitis activity via inhibiting inflammation and oxidative stress

Two series of diarylmethylamine derivatives were synthesized by 1,6-addition reaction between para-quinone methides and 1-methylpiperazine or 2-oxazolidinone, and their structures were identified by 1H NMR,13C NMR and HRMS. In the lipopolysaccharide-induced inflammatory Raw264.7 cells model, 3-CF3 modified active derivative 1l was screened out by inhibiting the excessive production of NO (IC50 = 5.82 μM), and can inhibit the excessive production of ROS. Western blot analyses indicated that 1l can also inhibit the excessive production of pro-inflammatory cytokines (IL-6 and TNF-α) and the nuclear transfer of NF-κB in inflammatory cells. In the dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice model, 1l can effectively inhibit the colonic shortening and suppress inflammatory symptoms of the colonic tissue (HE). Western blot analyses and biochemical indicators demonstrated that 1l can protect the colon of UC mice by regulating the inflammation-related TLR4/NF-κB signaling pathway and the oxidative stress-related Nrf2/HO-1 signaling pathway. Besides, the safety evaluation results of the UC mouse model (serum biochemical indicators, pathological tissue analysis and organ indexes) and the oral acute toxicity test revealed that 1l had certain safety in mice and can resist other tissues damage caused by DSS. In summary, 1l is an effective anti-inflammatory agent that can be developed as a potential drug for treating UC.

An Oxazole Alkaloid, Terpenoids, and Cyclodipeptides With Cytotoxic and Nitric Oxide Inhibitory Effects From a Mangrove-Derived Fungus Trichoderma sp. GXT-22.1

Chemical investigation of the mangrove-derived fungus Trichoderma sp. GXT-22.1 led to the isolation and identification of 10 secondary metabolites, including one new compound, 5'-(4-methoxyphenyl)-1',3'-oxazole (1), one new natural compound, (E)-6,10-dimethyl-5-undecene-2,9,10-triol (2), along with eight known compounds, tricholumin A (3), harzianol J (4), cyclonerodiol (5), 10,11-dihydro-11-hydroxycyclonerodiol (6), cyclonerodiol B (7), epicyclonerodiol oxide (8), cyclo(Val-Pro) (9), and cyclo-(4-hydroxyprolinyl-leucine) (10). The structural feature of oxazole in 1 was unusually found among the fungal metabolites. Compounds 1 and 4 exhibited weak cytotoxicity toward HepG2 and MCF-7 human carcinoma cell lines at the concentration of 100 µM, with induction of 41.5 ± 3.0% and 39.3 ± 2.3% cell death, respectively. Compounds 1-5, 8, and 10 showed their inhibitory effect against nitric oxide (NO) overproduction in lipopolysaccharide-stimulated RAW264.7 cells, with half inhibition concentration values ranging from 37.5 ± 2.6 to 86.5 ± 5.1 µM. Molecular docking simulation suggested that 1 inhibits NO overproduction via modulating the action of the inducible NO synthase protein.

Two new sesquiterpene glycosides from the stems of Dendrobium henanense and their anti-inflammatory activity

Two new sesquiterpene glycosides, 8α,12,15β-trihydroxycopacamphan-15-O-β-D-glucopyranoside (1) and dendrobiumane C-11-O-β-D-glucopyranoside (2), along with three known terpenoids (3-5) were isolated from the aerial stems of Dendrobium henanense. Their structures were elucidated based on NMR-spectroscopic and HR-MS analyses. All compounds could reduce the levels of NO, TNF-α and IL-1β in LPS-induced RAW264.7 cells with IC50 values ranging from 10.37 to 34.55 µΜ.

Acute COVID-19 and LongCOVID syndrome - molecular implications for therapeutic strategies - review

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been recognized not only for its acute effects but also for its ability to cause LongCOVID Syndrome (LCS), a condition characterized by persistent symptoms affecting multiple organ systems. This review examines the molecular and immunological mechanisms underlying LCS, with a particular focus on autophagy inhibition, chronic inflammation, oxidative, nitrosative and calcium stress, viral persistence and autoimmunology. Potential pathophysiological mechanisms involved in LCS include (1) autoimmune activation, (2) latent viral persistence, where SARS-CoV-2 continues to influence host metabolism, (3) reactivation of latent pathogens such as Epstein-Barr virus (EBV) or cytomegalovirus (CMV), exacerbating immune and metabolic dysregulation, and (4) possible persistent metabolic and inflammatory dysregulation, where the body fails to restore post-infection homeostasis. The manipulation of cellular pathways by SARS-CoV-2 proteins is a critical aspect of the virus' ability to evade immune clearance and establish long-term dysfunction. Viral proteins such as NSP13, ORF3a and ORF8 have been shown to disrupt autophagy, thereby impairing viral clearance and promoting immune evasion. In addition, mitochondrial dysfunction, dysregulated calcium signaling, oxidative stress, chronic HIF-1α activation and Nrf2 inhibition create a self-sustaining inflammatory feedback loop that contributes to tissue damage and persistent symptoms. Therefore understanding the molecular basis of LCS is critical for the development of effective therapeutic strategies. Targeting autophagy and Nrf2 activation, glycolysis inhibition, and restoration calcium homeostasis may provide novel strategies to mitigate the long-term consequences of SARS-CoV-2 infection. Future research should focus on personalized therapeutic interventions based on the dominant molecular perturbations in individual patients.

The prophylactic anti-aging effect of aspirin (acetylsalicylic acid) on oxidative stress-induced damage in the buccal mucosa of D-galactose-induced aged rats

Most living organisms experience time-dependent functional deterioration as they age. To combat aging, aspirin was proposed as an already well-studied drug. However, its antiaging effect is neither well studied nor understood. So, this study intended to assess the proposed antiaging effect of aspirin. Three groups of seven adult male albino rats were established. The control group received saline, the aging model group got a daily single D-galactose subcutaneous injection (300 mg/kg), and the aspirin group consisted of D-galactose-induced aged rats that received a daily aspirin oral dose (60 mg/kg). Drugs were given for 8 weeks. Then, malondialdehyde (MDA) blood level was evaluated, and rats were euthanized. Buccal mucosa samples were obtained for inducible nitric oxide synthase (iNOS) gene expression, histopathological, ultrastructural, and comet analyses. MDA blood level, iNOS gene expression and DNA damage examined by comet assay displayed a significant reduction in the aspirin group when compared to the aging model group. Histopathological and ultrastructural results showed that aspirin ameliorated most of the degenerative signs caused by D-galactose. Thus, it was deduced that aspirin had promising results as an antiaging pharmaceutical agent. However, more studies are needed regarding its translation to human trials.

Understanding chronic inflammation: couplings between cytokines, ROS, NO, Cai 2+, HIF-1α, Nrf2 and autophagy

Chronic inflammation is an important component of many diseases, including autoimmune diseases, intracellular infections, dysbiosis and degenerative diseases. An important element of this state is the mainly positive feedback between inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO), increased intracellular calcium, hypoxia-inducible factor 1-alpha (HIF-1α) stabilisation and mitochondrial oxidative stress, which, under normal conditions, enhance the response against pathogens. Autophagy and the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant response are mainly negatively coupled with the above-mentioned elements to maintain the defence response at a level appropriate to the severity of the infection. The current review is the first attempt to build a multidimensional model of cellular self-regulation of chronic inflammation. It describes the feedbacks involved in the inflammatory response and explains the possible pathways by which inflammation becomes chronic. The multiplicity of positive feedbacks suggests that symptomatic treatment of chronic inflammation should focus on inhibiting multiple positive feedbacks to effectively suppress all dysregulated elements including inflammation, oxidative stress, calcium stress, mito-stress and other metabolic disturbances.

Molecular insights into anti-inflammatory activities of selected Indian herbs

Inflammation is a universal response of mammalian tissue to harm, comprising reactions to injuries, pathogens, and foreign particles. Chronic inflammation, often present in allergies and autoimmune disorders, poses significant risks, potentially leading to conditions such as rheumatoid arthritis, Alzheimer's disease, asthma, and inflammatory bowel disease. It can also be a common precursor to cancer. However, Contemporary therapies like NSAIDs and corticosteroids often provide incomplete relief from chronic inflammation and carry significant side effects, underscoring the need for exploring traditional and plant-based medicines for new, effective treatments. As such, there is a growing demand for natural bioactive substances for health maintenance and disease risk reduction. Traditional and plant-based medicines, long-used in managing inflammation and other disorders, hold promise for the discovery of bioactive lead compounds and subsequent drug development for treating inflammatory disorders. This review encompasses an extensive study of the anti-inflammatory potential of selected traditional Indian herbal medicines and the associated pharmacological mechanisms of action. The inflammatory process often entails the activation of transcription factors, induction of various signaling cascades, gene expression, activation of inflammatory enzymes, and release of pro-inflammatory cytokines in inflammatory or immune cells. Detailed exploration of active components in traditional herbal medicines such as the Neem (Azadirachta indica), Salai guggul (Boswellia serrata), Green tea (Camellia sinensis), Saffron (Crocus sativus), Turmeric (Curcuma longa), Mangosteen (Garcinia mangostana), Indian mulberry (Morinda citrifolia), Black cumin (Nigella sativa), Ashwagandha (Withania somnifera), and Ginger (Zingiber officinale) reveals their potential anti-inflammatory properties. The in-depth study of these plants provides insight into their potential applications in managing inflammatory disorders. Further research and development are necessary to substantiate these findings and translate them into clinically effective therapeutics.

Shared early molecular mechanisms revealed in P301S and 5xFAD Alzheimer's disease mouse models

Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by early molecular events that influence disease progression. Still, the molecular mechanisms caused by different mutations of AD are not understood. We have performed a multidisciplinary study to investigate and compare the early stages of the pathology in two transgenic AD mouse models: P301S and 5xFAD. Using SNOTRAP-based mass spectrometry, we assessed changes in S-nitrosylation, a nitric oxide-mediated post-translational modification, of proteins in both models during their juvenile age. The increased levels of 3-nitrotyrosine confirmed nitrosative stress in the mutant mice. Systems biology analysis revealed shared processes between the models, particularly in the γ-aminobutyric acid (GABA)ergic and glutamatergic neurotransmission processes. In the P301S model, we identified 273 S-nitrosylated (SNOed) proteins in the cortex, with 244 proteins uniquely SNOed in the diseased mice. In the 5xFAD model, 309 SNOed proteins were identified. We have found altered proteins expression of different glutamate/GABA-related markers in the cortex and hippocampus of both AD mouse models. Additionally, the phosphorylation levels of the mTOR signaling components revealed hyperactivation of this pathway in P301S mice. Conversely, 5xFAD mice showed no significant changes in mTOR signaling except for elevated phosphorylation of the ribosomal protein S6 in the cortex. Our findings revealed key molecular mechanisms in the two AD mouse models during their early stages. These mechanisms could serve as potential biomarkers and therapeutic targets for early-stage AD.

Exploring the separation, characterization and antioxidant activity of proteins and peptides from selected seagrasses in Palk Bay region of Tamil Nadu in India

In this study, five seagrass species Halodule uninervis, Thalassia hemprichii, Enhalus acoroides, Cymodocea serrulata, and Syringodium isoetifolium collected from the Mandapam coastal region of Rameswaram (Palk Bay region), Tamil Nadu, India, were selected to identify the antioxidant-rich proteins/peptides. The primary objective was to identify the proteins/peptides present in these seagrass filtrates extracted by using four different pH-based buffer extracts and to assess their antioxidant activity. Among the various buffer extracts, 0.1 M Citrate buffer (pH 5.5) exhibited the highest proteins/peptides recovery in all species. Of these, S. isoetifolium showed the highest recovery percentage (20.18 %) in the 10 kDa filtrate. Notably, the 3 kDa filtrate of S. isoetifolium demonstrated the highest antioxidant activity (83 %). The peptides sequences in all five seagrass samples were identified by MALDI - TOF MS analysis, Furthermore, in silico protein-peptide docking studies were conducted to assess the interaction of the identified peptides with key antioxidant-related targets, including superoxide dismutase, xanthine oxidase, inducible nitric oxide synthase, keap 1 protein, and myeloperoxidase. With all these targets, the peptide derived from S. isoetifolium exhibited better binding affinity. This study emphasized that the potential peptides identified from seagrass are the natural antioxidant sources that can be used to treat disorders linked to oxidative stress.

Vagus nerve stimulation: A targeted approach for reducing tissue-specific ischemic reperfusion injury

Vagus Nerve Stimulation (VNS), a neuromodulation technique of applying controlled electrical impulses to the vagus nerve, has now emerged as a potential therapeutic approach for ischemia-reperfusion insults. It provides a pivotal link in improving functional outcomes for the central nervous system and multiple target organs affected by ischemia-reperfusion injury (I/RI). Reduced blood flow during ischemia and subsequent resumption of blood supply during reperfusion to the tissue compromises cellular health because of the combination of mitochondrial dysfunction, oxidative stress, cytokine release, inflammation, apoptosis, intracellular calcium overload, and endoplasmic reticulum stress, which ultimately leads to cell death and irreversible tissue damage. Furthermore, inflammation and apoptosis also play critical roles in the acute progression of ischemic injury pathology. Emerging evidence indicates that VNS in I/RI may act in an anti-inflammatory capacity, reducing oxidative stress and apoptosis, while also improving endothelial and mitochondrial function leading to reduced infarct sizes and cytoprotection in skeletal muscle, gastrointestinal tract, liver, kidney, lung, heart, and brain tissue. In this review, we attempt to shed light on the mechanistic links between tissue-specific damage following I/RI and the therapeutic approach of VNS in attenuating damage, considering both direct and remote I/RI scenarios. Thus, we want to advance the understanding of VNS that could further warrant its clinical implementation, especially as a treatment for I/RI.

Antioxidant and Anti-Inflammatory Activities of Cutlassfish Head Peptone in RAW 264.7 Macrophages

The rapid growth of the fisheries industry has resulted in numerous by-products, usually called waste, causing environmental and economic challenges. Recent advances in valorization techniques have highlighted the potential of these by-products as sources of bioactive compounds. This study aimed to investigate the antioxidant and anti-inflammatory activities of cutlassfish (Trichiurus lepturus) head peptone (CP) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. CP exhibited significant antioxidant activity, reducing ABTS and DPPH radical scavenging activity by up to 79.66% and 64.69%, respectively, with a maximum ferric-reducing antioxidant power (FRAP) value of 224.54 μM. CP enhanced macrophage proliferation (33.3%) and significantly mitigated LPS-induced oxidative and inflammatory responses, reducing nitric oxide (NO) production (60%) and reactive oxygen species levels (49.14%). CP suppressed the expression of inflammatory mediators, including inducible nitric oxide synthase (iNOS) and cyclooxygen-ase-2, and selectively inhibited the pro-inflammatory cytokines interleukin (IL)-1β and IL-6. Western blot analysis revealed that CP inhibited the phosphorylation of mitogen-activated protein kinases, including ERK, JNK, and p38, highlighting its role in modulating upstream inflammatory signaling pathways. CP exhibited significant antioxidant effects, particularly in scavenging ABTS and DPPH radicals, as well as reducing oxidative stress markers and inflammatory responses in LPS-stimulated macrophages. These findings suggest its potential not only as a therapeutic agent for conditions related to chronic inflammation, such as cardiovascular diseases and arthritis, but also as a functional ingredient in foods and nutraceuticals aimed at alleviating inflammation-related disorders.

Xanthine Derivative KMUP-3 Alleviates Periodontal Bone Resorption by Inhibiting Osteoclastogenesis and Macrophage Pyroptosis

AIM

This study investigated the function effects of KMUP-3, a self-developed synthetic xanthine-based derivative, in suppressing Porphyromonas gingivalis (Pg-LPS)-aggravated osteoclastogenesis and pyroptosis as a potential treatment for periodontitis.

METHODS

In vitro, the effects of Pg-LPS and KMUP-3 on osteoclast formation and macrophage pyroptosis were investigated using the receptor activator of nuclear factor-κB ligand (RANKL)-primed RAW264.7 macrophages. In vivo, the therapeutic effects of KMUP-3 were evaluated in a model of experimental periodontitis induced by gingival ligature placement.

RESULTS

We reveal that KMUP-3 suppressed osteoclastogenesis, inducible nitric oxide synthase activation, and reduced nitric oxide production enhanced by Pg-LPS in RANKL-primed RAW264.7 cells while also decreasing TLR4/NF-κB p65 pathway activation and decreased pro-inflammatory cytokine production; moreover, Pg-LPS promoted NLRP3 activation and exacerbated pyroptosis induction effects that were abolished by KMUP-3. Finally, KMUP-3 ameliorated alveolar bone loss and IL-1β levels in the gingival crevicular fluid in the rat ligature periodontitis model.

CONCLUSIONS

Our study demonstrated that KMUP-3 attenuates Pg-LPS-enhanced osteoclastogenesis and macrophage pyroptosis. Notably, KMUP-3 alleviates alveolar bone loss in experimental periodontitis rats and thus suggests its certain role in safeguarding against periodontal bone resorption.

Phytochemistry and Anti-Inflammatory and Antioxidant Activities of Cinnamomum osmophloeum and Its Bioactive Constituents: A Review

Cinnamomum osmophloeum, commonly known as indigenous cinnamon, is a tree species native to Taiwan's hardwood forests. It has been extensively investigated for its chemical composition and bioactivities. Several reports have shown that C. osmophloeum leaves are rich in aromatic oils, which are grouped into various chemotypes based on their major constituents. Components of the volatile oils included phenylpropanoids, monoterpenoids, sesquiterpenoids, phenols, coumarins, and other miscellaneous compounds. In addition, other secondary metabolites previously identified in this species included flavonol glycosides, phenolic acids, lignans, proanthocyanidins, and cyclopropanoids. C. osmophloeum is widely recognized for its medicinal and industrial applications, particularly its essential oils. In general, essential oils exhibit remarkable anti-inflammatory and antioxidant actions, enabling them to modulate key inflammatory mediators and neutralize free radicals. This review explored the phytochemical composition of the essential oils and extracts from C. osmophloeum as well as therapeutic potential of this species, focusing on the action mechanisms and clinical potential. We hope that this review will contribute to a better understanding of the biological effects of this plant and its potential applications in the management of conditions associated with inflammation and oxidative stress.

Echinococcus granulosus' laminated layer immunomodulates nitric oxide, cytokines, and MMPs in PBMC from rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that affects the joints. Treatments are symptomatic and can induce side effects in some patients. In this sense and based on previous studies, our aim was to investigate the ex vivo immunoregulatory effect of the laminated layer (LL) during rheumatoid arthritis. LL is the outside layer of parasitic cyst of the helminth Echinococcus granulosus.Our main objective was to study the effect of LL on nitric oxide (NO) and cytokines production, matrix metalloproteinases (MMPs) activities, inducible NO synthase (iNOS) and nuclear factor κappa B (NF-κB) expression. In this context, cultures of peripheral blood mononuclear cells (PBMC) from Algerian RA patients in active (ARA) and inactive (IRA) stage of the disease were stimulated with LL extract (50, 100, 150μg/mL). However, PBMC from ARA patients were stimulated with methotrexate (MTX; 0.5μg/mL) and biological disease modifying anti-rheumatic drugs (bDMARDs): anti-TNFα (10μg/mL), anti-IL6 (10μg/mL), anti-CD20 (10μg/mL), alone or combined with LL (50μg/mL).Our results showed that LL reduced NO, TNF-α, and IL-17A production, MMP9/2 activities, and iNOS/NF-κB expression in PBMC from ARA patients. Concomitantly, LL increases IL-10 and TGF-β1 production in the same cultures. Interestingly, the decrease in NO production induced by bDMARDs was greater in association with LL.Collectively, our findings indicate a strong immunoregulatory effect of LL on NO, MMPs, and cytokines. LL probably acts through the NF-κB pathway. The development of biodrugs derived from LL of E. granulosus could be a potential candidate to modulate inflammation during RA.

The Immune-Enhancing Effects of a Lactobacillus paracasei L-30 Extract Through the NF-κB and MAPK Pathways in RAW264.7

Immune enhancement is an important factor that not only helps prevent infections but also affects overall health. This study aims to evaluate the immunostimulatory effects of a novel Lactobacillus strain, Lactobacillus paracasei L-30, and to elucidate its underlying mechanisms. The extract obtained from Lactobacillus paracasei L-30 significantly increased phagocytosis and the production of NO and ROS in RAW264.7 macrophages. The protein and mRNA expression levels of COX-2 and iNOS which are immune regulators were upregulated by the L-30 extract. The levels of cytokines and chemokines, such as G-CSF, IL-6, MIP-1α, MIP-1γ, RANTES, sTNF RI, and sTNF RII, were increased by the treatment with the L-30 extract. In addition, the L-30 extract degraded IκB-α and induced the phosphorylation of NF-κB. Furthermore, the MAPK signaling pathways ERK, JNK, and p38 were activated by the L-30 extract. The production of iNOS, COX-2, and NO was inhibited by MAPK pathway inhibitors. Therefore, our data suggest that the Lactobacillus paracasei L-30 extract has the potential to be developed as a healthy functional food that can enhance immune responses by activating macrophages.

A Pair of Epimers of Lignan Alleviate Neuroinflammatory Effects by Modulating iNOS/COX-2 and MAPK/NF-κB Signaling Pathways

Neuroinflammation is a causative factor in neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis. Previous studies have shown that Artemisia mongolica has anti-inflammatory properties. Aschantin (AM3) has been shown to have anti-inflammatory effects. However, the mechanism of AM3 and its epimer epi-aschantin (AM2) remains controversial. Therefore, the present study explored the mechanism of neuroinflammation by AM2 and AM3 and attempted to reveal the relationship between the structure of AM2 and AM3 and anti-neuroinflammatory activity. We isolated for the first time 12 lignans from A. mongolica that inhibited NO content at 10 μM in LPS-stimulated BV2 cells. Among them, epi-aschantin (AM2) and Aschantin (AM3) showed significant inhibition in NO screening. With further studies, we found that both AM2 and AM3 effectively inhibited the overproduction of NO, PGE2, IL-6, TNF-α and MCP-1, as well as the overexpression of COX-2 and iNOS. Mechanistic studies have shown AM2 and AM3 significantly inhibited the phosphorylation of ERK, JNK and P-38 in the MAPK signaling pathway and p-IκBα,p-p65 and blocked p65 entry into the nucleus. The results suggested that the pair of epimers (AM2 and AM3) can be used as potential therapeutic agents in the treatment of various brain disorders and that structural differences do not differ in anti-neuroinflammatory effects.

Karnozin EXTRA® causes changes in mitochondrial bioenergetics response in MCF-7 and MRC-5 cell lines

Numerous studies reported about potential effects of L-carnosine in regulation of tumor growth and metabolism. We evaluated the effects of different concentrations of L-carnosine from Karnozin EXTRA® supplement on mitochondrial respiratory chain complexes of human embryo lung fibroblasts (MRC-5) and human breast cancer cells (MCF-7), with different energy pathways. Also, we analyzed the proliferation index and expression of various markers of oxidative stress. Treatment with Karnozin EXTRA® (concentration of L-carnosine were 2, 5 and 10 mM) for 24 hours gradually decreased the number of cells and changed their morphological features. In both cell lines, a dose-dependent reduction of cell viability was recorded compared to the control group. Also, experimental groups showed a concentration-dependent decrease in fluorescence intensity of SOD2 expressions in MCF-7, while in MRC-5 we noticed higher fluorescence intensity in Carnosine 2 mM group. Treated cells, in both cell lines, showed different intensity of iNOS cytoplasmic immunopositivity in a concentration-dependent manner. In all experimental groups, we noticed an increased expression of marker of oxidative stress-cytochrome P450 2E1 (CYP2E1). The effects of Karnozin EXTRA® capsule on mitochondrial respiration, assessed with the Clark-type electrode, were manifested as a reduction of: basal cell respiration, maximum capacity of electron transport chain and mitochondrial ATP-linked respiration. Also, significant decrease in the activity of complex I (NADH-ubiquinone oxidoreductase), complex II (succinate dehydrogenase) and complex IV (cytochrome c oxidase) was observed in both cell lines. Bearing in mind that Karnozin EXTRA® is a potential regulator of energy metabolism of MCF-7 and MRC-5, these results provide a good basis for further preclinical and clinical research.

Evidence That Long-Term Treatment Prevents Tissue Oxidative Damage in Patients With Inherited Disorders of the Propionate Pathway

Propionic and methylmalonic acidemias (PAcidemia and MMAcidemia, respectively) are genetic disorders clinically characterized by metabolic decompensation associated with life-threatening encephalopathic episodes in the neonatal period. Adequate and rapid therapeutic management is essential for patients' survival and prognosis. In this study, a restricted protein diet associated with L-carnitine (LC) supplementation was shown to decrease mortality and morbidity in patients affected by these disorders probably by decreasing the accumulation of the major metabolites and therefore their toxicity. Since oxidative stress was proposed as a contributing mechanism of tissue damage in PAcidemia and MMAcidemia and LC has potent antioxidant properties, our objective in this work was to investigate the effects of a long-term therapy consisting of reduced protein intake associated with LC supplementation on oxidative damage markers in patients affected by these diseases. We measured urinary isoprostanes, di-tyrosine, and oxidized guanine species, which reflect oxidative damage to lipids, proteins, and DNA/RNA, respectively, as well as the concentrations of NO products (nitrate plus nitrite) in patients untreated or submitted to short-term or a long-term treatment. Results revealed significant increases of isoprostanes, di-tyrosine, and oxidized guanine species, as well as a moderate nonsignificant increase of NO levels in the untreated patients, relatively to controls. Furthermore, these altered markers were attenuated after short-term treatment and normalized after prolonged treatment. In conclusion, data from this work show for the first time that long-standing treatment of patients with disorders of the propionate pathway can protect against oxidative damage. However, it remains to be elucidated whether oxidative stress identified in this study directly correlates with the clinical conditions of the affected patients.

Self-assembled eumelanin nanoparticles enhance IFN-I activation and cilia-driven intercellular communication to defend against Tulane virus, a human norovirus surrogate

Norovirus (NoV) infection is a leading cause of gastroenteritis and poses global health threats, with increasing incidence reported in immunocompromised individuals, which is further exacerbated by the globalization of the food industry. Eumelanin has demonstrated its potential in antiviral treatments, but its role in preventing viral infections remains underexplored. Therefore, in this study, we investigated the antiviral properties and potential mechanisms of self-assembled eumelanin nanoparticles (EmNPs) against Tulane virus (TuV), a surrogate with a similar infection mechanism to NoVs. EmNPs exhibited low cytotoxicity and strong antiviral activity in pre-incubated cells. Additionally, EmNPs stimulated the growth and endocytosis of cilia on the cell surface, exposing internal long-nanoparticle chains to interact with the cell membrane while promoting cilia growth and enhancing intercellular connections in cells. EmNPs were then transported to lysosomes via vesicles, leading to a perinuclear lysosome clustering. EmNPs activated several key intracellular signaling pathways, including Toll-like receptor (TLR) and C-type lectin receptor (CLR) pathways, along with activating NF-κB, Rap1, TNF, and Hippo pathways. This regulatory action initiated innate cellular immunity, significantly enhancing the production of type I interferons (IFN-α/β) and promoting the localization of lysosomes to the perinuclear region. Therefore, this study illustrated that EmNPs effectively stimulated immune responses, improved intercellular communication, and facilitated transport mechanisms, thereby bolstering resistance to subsequent viral infections. These findings position EmNPs as promising candidates for the prevention of norovirus infections.

Unleashing the role of potential adjuvants in leishmaniasis

Leishmaniasis is amongst one of the most neglected tropical disease, caused by an intracellular protozoan of genus Leishmania. Currently, the most promising strategy to combat leishmaniasis, relies on chemotherapy but the toxicity and increasing resistance of the standard drugs, presses the demand for new alternatives. Immunization is arguably the best strategy for cure because an individual once infected becomes immune to the disease. Yet, there is no efficient vaccine capable of providing enduring immunity against the parasite. Achieving the goal of developing highly efficacious and durable vaccine is limited due to lack of an appropriate adjuvant. Adjuvants are recognized as 'immune potentiators' which redirect or amplify the immune response. A number of adjuvants like alum, MPL-A, CpG ODN, GLA-SE, imiquimod, saponins etc. have been used in combination with various classes of Leishmania antigens. However, only few have reached clinical trials. Thus, the choice of an adjuvant is critically dependent on many factors such as the route of administration, the nature of antigen, formulation, the type of required immune response, their mode of action and the immunization schedule. This review provides an updated status on the types of adjuvants used in leishmaniasis so far and their mechanism of action if known.

Fucoidan alleviated colitis aggravated by fiber deficiency through protecting the gut barrier, suppressing the MAPK/NF-κB pathway, and modulating gut microbiota and metabolites

Insufficient dietary fiber intake has become a global public health issue, affecting the development and management of various diseases, including intestinal diseases and obesity. This study showed that dietary fiber deficiency enhanced the susceptibility of mice to colitis, which could be attributed to the disruption of the gut barrier integrity, activation of the NF-κB pathway, and oxidative stress. Undaria pinnatifida fucoidan (UPF) alleviated colitis symptoms in mice that fed with a fiber deficient diet (FD), characterized by increased weight gain and reduced disease activity index, liver and spleen indexes, and histological score. The protective effect of UPF against FD-exacerbated colitis can be attributed to the alleviation of oxidative stress, the preservation of the gut barrier integrity, and inhibition of the MAPK/NF-κB pathway. UPF ameliorated the gut microbiota composition, leading to increased microbiota richness, as well as increased levels of Muribaculaceae, Lactobacillaceae, and Bifidobacterium and reduced levels of Proteobacteria, Bacteroidetes, and Bacteroides. Metabolomics analysis revealed that UPF improved the profile of microbiota metabolites, with increased levels of carnitine and taurine and decreased levels of tyrosine and deoxycholic acid. This study suggests that UPF has the potential to be developed as a novel prebiotic agent to enhance human health.

The Anti-Inflammatory Activities of Benzylideneacetophenone Derivatives in LPS Stimulated BV2 Microglia Cells and Mice

A previously reported study highlighted the neuroprotective potential of the novel benzylideneacetophenone derivative, JC3, in mice. In pursuit of compounds with even more robust neuroprotective and anti-inflammatory properties compared to JC3, we synthesized substituted 1,3-diphenyl-2-propen-1-ones based on chalcones. Molecular modeling studies aimed at discerning the chemical structural features conducive to heightened biological activity revealed that JCII-8,10,11 exhibited the widest HOMOLUMO gap within this category, indicating facile electron and radical transfer between HOMO and LUMO in model assessments. From the pool of synthesized compounds, JCII-8,10,11 were selected for the present investigation. The biological assays involving JCII-8,10,11 demonstrated their concentration-dependent suppression of iNOS and COX-2 protein levels, alongside various cytokine mRNA expressions in LPS-induced murine microglial BV2 cells. Furthermore, western blot analyses were conducted to investigate the MAPK pathways and NF-κB/p65 nuclear translocation. These evaluations conclusively confirmed the inflammatory inhibition effects in both in vitro and in vivo inflammation models. These findings establish JCII-8,10,11 as potent anti-inflammatory agents, hindering inflammatory mediators and impeding NF-κB/p65 nuclear translocation via JNK and ERK MAPK phosphorylation in BV2 cells. The study positions them as potential therapeutics for inflammation-related conditions. Additionally, JCII-11 exhibited greater activity compared to other tested JCII compounds.

The Genus Paeonia: A Review of the Targeted Signaling Pathways and Underlying Mechanisms of Pharmacological and Clinical Properties

INTRODUCTION

The Paeoniaceae family contains only the Paeonia genus and is considered a major group of flowering plants. Several traditional and pharmacological applications of Paeoniaceae herbs have been described. This paper aimes to determine the pharmacological activities of the most prevalent herbs from the genus Paeonia by focusing on their underlying mechanism of action and signaling pathways, providing insight for further in-depth research on the medicinal resources of Paeonia.

METHODS

The "Paeoniaceae" keyword was searched from 1st January 1995 to 15th May 2024 through the PubMed and Scopus databases. Only papers related to pharmacology, pharmaceutics, and toxicology were extracted. The possible pharmacological activity of the Paeonia plants, including their underlying mechanisms of action and signaling pathways, was subsequently discussed.

RESULTS

Following our venture, only 15 Paeonia herbs were adequately evaluated for their pharmacological applications. Paeonia lactiflora Pall., Paeonia suffruticosa Andrews, and Paeonia emodi Royle are among the most prevalent Paeonia plants that have attracted increased attention in modern pharmacological studies. Paeonia herbs possess various pharmacological applications, such as antiinflammatory, anti-allergic, anticancer, antimicrobial, cardiovascular protective, cosmetic and skincare, radical scavenging, hepatoprotective and anti-ulcerative, anti-diabetic, musculoskeletal, and neuroprotective effects, and can be used as alternative therapies under critical medical conditions.

CONCLUSION

Among the applications of Paeonia herbs, anti-inflammatory and antioxidant activities are critical, as most other pharmacological effects are attributed to them. In other words, nuclear factor (NF)-κB and nuclear factor erythroid 2-related factor 2 (Nrf2) can be considered the most important signaling pathways involved in the pharmacological activity of Paeonia herbs.

Exposure to Subclinical Doses of Fumonisins, Deoxynivalenol, and Zearalenone Affects Immune Response, Amino Acid Digestibility, and Intestinal Morphology in Broiler Chickens

Fusarium mycotoxins often co-occur in broiler feed, and their presence negatively impacts health even at subclinical concentrations, so there is a need to identify the concentrations of these toxins that do not adversely affect chickens health and performance. The study was conducted to evaluate the least toxic effects of combined mycotoxins fumonisins (FUM), deoxynivalenol (DON), and zearalenone (ZEA) on the production performance, immune response, intestinal morphology, and nutrient digestibility of broiler chickens. A total of 960 one-day-old broilers were distributed into eight dietary treatments: T1 (Control); T2: 33.0 FUM + 3.0 DON + 0.8 ZEA; T3: 14.0 FUM + 3.5 DON + 0.7 ZEA; T4: 26.0 FUM + 1.0 DON + 0.2 ZEA; T5: 7.7 FUM + 0.4 DON + 0.1 ZEA; T6: 3.6 FUM + 2.5 DON + 0.9 ZEA; T7: 0.8 FUM + 1.0 DON + 0.3 ZEA; T8: 1.0 FUM + 0.5 DON + 0.1 ZEA, all in mg/kg diet. The results showed that exposure to higher mycotoxin concentrations, T2 and T3, had significantly reduced body weight gain (BWG) by 17% on d35 (p < 0.05). The T2, T3, and T4 groups had a significant decrease in villi length in the jejunum and ileum (p < 0.05) and disruption of tight junction proteins, occludin, and claudin-4 (p < 0.05). Higher mycotoxin groups T2 to T6 had a reduction in the digestibility of amino acids methionine (p < 0.05), aspartate (p < 0.05), and serine (p < 0.05); a reduction in CD4+, CD8+ T-cell populations (p < 0.05) and an increase in T regulatory cell percentages in the spleen (p < 0.05); a decrease in splenic macrophage nitric oxide production and total IgA production (p < 0.05); and upregulated cytochrome P450-1A1 and 1A4 gene expression (p < 0.05). Birds fed the lower mycotoxin concentration groups, T7 and T8, did not have a significant effect on performance, intestinal health, and immune responses, suggesting that these concentrations pose the least negative effects in broiler chickens. These findings are essential for developing acceptable thresholds for combined mycotoxin exposure and efficient feed management strategies to improve broiler performance.

Assessment of the effect of sodium tetraborate on oxidative stress, inflammation, and apoptosis in lead-induced nephrotoxicity

Exposure to Pb, a toxic heavy metal, is a risk factor for renal damage. Borax, an essential trace element in cellular metabolism, is a naturally occurring compound found in many foods. This study investigated the effects of sodium tetraborate (ST), a source of borax, on renal oxidative stress and inflammation in rats exposed to Pb. Wistar Albino rats (n = 24) were divided into four groups: Control (0.5 mL, i.p. isotonic), Pb (50 mg/kg/day/i.p.), ST (4.0 mg/kg/day/oral), and Pb + ST groups. At the end of the five-day experimental period, kidney tissue samples were obtained and analyzed. Histopathologically, the Pb-induced damage observed in the Pb group improved in the Pb + ST group. Immunohistochemically, Pb administration increased the expression of inducible nitric oxide synthase, cyclooxygenase-2, and caspase-3. When evaluated biochemically, Pb application inhibited catalase and glutathione peroxidase (GSH-Px) enzyme activities and activated superoxide dismutase enzyme activity. An increase in malondialdehyde levels was considered an indicator of damage. ST application increases glutathione peroxidase enzyme activity and decreased malondialdehyde levels. These results indicate that ST might play a protective role against Pb-induced renal damage via the upregulation of renal tissue antioxidants and cyclooxygenase-2, inducible nitric oxide synthase, and caspase-3 immunoexpression.

Flavonol-Ruthenium Complexes as Antioxidant and Anticancer Agents

Flavonol-metal complexes can enhance the biological activity of flavonols. Inspired by the potential of ruthenium-based drugs in pharmaceutical applications, seven flavonol-Ru (II) complexes were synthesized to evaluate their biological activities. Among these compounds, compounds 8, 11, and 12 showed potent antioxidant activities. Compound 12 exhibited superior anti-inflammatory activity to natural quercetin, which served as a positive control. This study is the first to report the free radical scavenging abilities and antioxidant activity of flavonol-Ru (II) complexes. Furthermore, compound 12 demonstrated comparable efficacy to 5-FU against human non-small-cell lung cancer cells (A549). These results strongly support the potential of flavonol-Ru (II) agents.

Muramyl dipeptide potentiates Staphylococcus aureus lipoteichoic acid-induced nitric oxide production via TLR2/NOD2/PAFR signaling pathways

Lipoteichoic acid (LTA) and peptidoglycan (PGN) are considered as key virulence factors of Staphylococcus aureus, which is a representative sepsis-causing Gram-positive pathogen. However, cooperative effect of S. aureus LTA and PGN on nitric oxide (NO) production is still unclear despite the pivotal roles of NO in initiation and progression of sepsis. We here evaluated the cooperative effects of S. aureus LTA (SaLTA) and muramyl dipeptide (MDP), the minimal structure of PGN, on NO production in both a mouse macrophage-like cell line, RAW 264.7 and mouse bone marrow-derived macrophages (BMMs). Although MDP alone did not affect NO production, MDP potently enhanced SaLTA-induced NO production via the expression of inducible NO synthases. The enhanced NO production was ameliorated in BMMs from TLR2-, CD14-, MyD88-, and NOD2-deficient mice. Moreover, the augmented SaLTA-induced NO production by MDP was attenuated by inhibitors specific for PAFR and MAP kinases. Furthermore, MDP also potently increased SaLTA-induced activities of STAT1, NF-κB, and AP-1 transcription factors, and specific inhibitors for these transcription factors suppressed the elevated NO production. Collectively, these results demonstrated that MDP potentiates SaLTA-induced NO production via TLR2/NOD2/PAFR, MAP kinases signaling axis, resulting in the activation of NF-κB, AP-1 and STAT1 transcription factors.

Neudesin, a secretory protein, attenuates activation of lipopolysaccharide-stimulated macrophages by suppressing the Jak/Stat1/iNOS pathway

AIMS

Neudesin, a heme-binding protein previously identified for its neurotrophic activity, has been implicated in various physiological and pathological processes, including immune regulation. However, its role in inflammatory macrophages remains unclear. Herein, we investigated the function of neudesin in the regulation of inflammatory macrophages.

MAIN METHODS

In vitro experiments were performed in bone marrow-derived macrophages (BMDMs). In vivo experiments were conducted on neudesin knockout mice with a murine endotoxic shock model.

KEY FINDINGS

We observed that neudesin deficiency led to elevated expression of Nos2/iNOS and increased nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BMDMs. Further, we found that neudesin, via the ERK/MAPK signaling pathway, promotes the proteasome-mediated degradation of Stat1, resulting in suppression of NO production. Furthermore, neudesin-deficient mice exhibited higher mortality rates following LPS administration, accompanied by increased Nos2/iNOS expression and nitrated proteins in the heart, compared to that in wildtype mice. Treatment with an iNOS inhibitor drastically improved the survival rate of neudesin-deficient mice, highlighting the significance of neudesin-mediated iNOS signaling in modulating immune responses and preventing excessive inflammation.

SIGNIFICANCE

Our findings suggest that neudesin acts as an anti-inflammatory cytokine, suppressing NO production in inflammatory macrophages, underscoring its potential as a therapeutic target for immune-related disorders.

The protective effects of orexin B in neuropathic pain by suppressing inflammatory response

Chronic pain induced by pathological insults to the sensorimotor system is a typical form of neuropathic pain (NP), and the underlying mechanism is complex. Currently, there are no successful therapeutic interventions for NP. Orexin B is a neuropeptide with a wide range of biological functions. However, the pharmacological function of orexin B in chronic neuropathic pain has been less studied. Here, we aim to examine the neuroprotective effects of orexin B in chronic constriction injury (CCI)- induced NP. Firstly, we found that orexin type 2 receptor (OX2R) but not orexin type 1 receptor (OX1R) was reduced in the spinal cord (SC) of CCI-treated rats. Mechanical withdrawal threshold and thermal withdrawal latency assays display that administration of orexin B clearly ameliorated CCI-evoked neuropathic pain dose-dependently. Notably, orexin B treatment also effectively prevented microglia activation by reducing the levels of IBA1. Additionally, orexin B was also found to suppress the inflammatory response in the SC tissue by reducing the levels of IL-6, TNF-α, iNOS, and COX-2 as well as the production of NO and PGE2 in CCI-treated rats. Furthermore, orexin B administration attenuated oxidative stress (OS) by increasing the activity of SOD and the levels of GSH. Mechanically, orexin B prevented activation of JNK/NF-κB signaling in the SC of CCI-treated rats. Based on these findings, we conclude that orexin B might have a promising role in ameliorating CCI-evoked neuropathic pain through the inhibition of microglial activation and inflammatory response.

Riboflavin kinase binds and activates inducible nitric oxide synthase to reprogram macrophage polarization

Riboflavin kinase (RFK) is essential in riboflavin metabolism, converting riboflavin to flavin mononucleotide (FMN), which is further processed to flavin adenine dinucleotide (FAD). While RFK enhances macrophage phagocytosis of Listeria monocytogenes, its role in macrophage polarization is not well understood. Our study reveals that RFK deficiency impairs M(IFN-γ) and promotes M(IL-4) polarization, both in vitro and in vivo. Mechanistically, RFK interacts with inducible nitric oxide (NO) synthase (iNOS), which requires FMN and FAD as cofactors for activation, leading to increased NO production that alters energy metabolism by inhibiting the tricarboxylic acid cycle and mitochondrial electron transport chain. Exogenous FAD reverses the metabolic and polarization changes caused by RFK deficiency. Furthermore, bone marrow adoptive transfer from high-riboflavin-fed mice into wild-type tumor-bearing mice reprograms tumor-associated macrophage polarization and inhibits tumor growth. These results suggest that targeting RFK-iNOS or modulating riboflavin metabolism could be potential therapies for macrophage-related immune diseases.

Characterization and quantification of the phytochemical constituents and anti-inflammatory properties of Lindera aggregata

The dry roots of Lindera aggregata (Sims) Kosterm have a long-standing history in traditional Chinese medicine, renowned for their ability to regulate vital energy, relieve pain, warm the kidney, and dissipate cold. Recently, L. aggregata has been approved as a new food resource. To gain insights into the bioactive phytochemicals in L. aggregata, an ultrahigh-performance liquid chromatography coupled with high-resolution electrospray ionization quadrupole orbitrap spectrometry method was developed to investigate the chemical profiles of the ethanol extract of L. aggregata. This approach identified 80 compounds, predominantly alkaloids and sesquiterpenoids. Furthermore, 16 selected compounds were simultaneously quantified using the parallel reaction monitoring mode. The quantification method was validated and showed good linearity, sensitivity, and accuracy. The anti-inflammatory activities of the ethanol extract and selected compounds were assessed in vitro using lipopolysaccharide-stimulated RAW 264.7 macrophages. The results revealed that the ethanol extract of L. aggregata and norisoboldine, isolinderalactone, methyllinderone, and linderin B inhibited the production or expression of nitric oxide, inducible nitric oxide synthase (iNOS), tumor necrosis factor-α, and interleukin-6. Molecular docking of iNOS with isolinderalactone, methyllinderone, and linderin B showed that hydrogen bonds, π-π interactions, and hydrophobic interactions contributed to their iNOS inhibitory effects. The results offer insights that may be instrumental in enhancing the quality control for L. aggregata.

Probiotic Characteristics and the Anti-Inflammatory Effects of Lactiplantibacillus plantarum Z22 Isolated from Naturally Fermented Vegetables

Currently, there is increasing interest in the commercial utilization of probiotics isolated from traditional fermented food products. Therefore, this study aimed to investigate the probiotic potential of Lactiplantibacillus plantarum (L. plantarum) Z22 isolated from naturally fermented mustard. The results suggest that L. plantarum Z22 exhibits good adhesion ability, antibacterial activity, safety, and tolerance to acidic conditions and bile salts. We further determined the anti-inflammatory mechanism and properties of L. plantarum Z22 and found that L. plantarum Z22 could significantly reduce the secretion of pro-inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the expression of the pro-inflammatory mediator cyclooxygenase-2 (COX-2) protein in LPS-induced RAW 264.7 cells. In addition, L. plantarum Z22 also effectively inhibited the signaling pathways of nuclear factor κB (NF-κB) and mitogen-activated protein kinases (MAPKs). This effect can be attributed to a decrease in the levels of reactive oxygen species (ROS) and increased heme oxygenase-1 (HO-1) expression. Moreover, whole-genome sequencing revealed that L. plantarum Z22 contains gene-encoding proteins with anti-inflammatory functions, such as beta-glucosidase (BGL) and pyruvate kinase (PK), as well as antioxidant functions, including thioredoxin reductase (TrxR), tyrosine-protein phosphatase, and ATP-dependent intracellular proteases ClpP. In summary, these results indicated that L. plantarum Z22 can serve as a potential candidate probiotic for use in fermented foods such as yogurt (starter cultures), providing a promising strategy for the development of functional foods to prevent chronic diseases.

Dual Functionality of Papaya Leaf Extracts: Anti-Coronavirus Activity and Anti-Inflammation Mechanism

Papaya leaves have been used as food and traditional herbs for the treatment of cancer, diabetes, asthma, and virus infections, but the active principle has not been understood. We hypothesized that the anti-inflammatory activity could be the predominant underlying principle. To test this, we extracted papaya leaf juice with different organic solvents and found that the ethyl acetate (EA) fraction showed the most outstanding anti-inflammatory activity by suppressing the production of nitric oxide (NO, IC50 = 24.94 ± 2.4 μg/mL) and the expression of pro-inflammatory enzymes, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and cytokines including interleukins (IL-1β and IL-6), and a tumor necrosis factor (TNF-α) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Transcriptomic analysis and Western blot results revealed its anti-inflammatory mechanisms were through the MAPK signaling pathway by inhibiting the phosphorylation of ERK1/2, JNKs, and p38 and the prevention of the cell surface expression of TLR4. Furthermore, we discovered that the EA fraction could inhibit the replication of alpha-coronavirus (HCoV-229E) and beta-coronavirus (HCoV-OC43 and SARS-CoV-2) and might be able to prevent cytokine storms caused by the coronavirus infection. From HPLC-QTOF-MS data, we found that the predominant phytochemicals that existed in the EA fraction were quercetin and kaempferol glycosides and carpaine. Counter-intuitively, further fractionation resulted in a loss of activity, suggesting that the synergistic effect of different components in the EA fraction contribute to the overall potent activity. Taken together, our results provide preliminary evidence for papaya leaf as a potential anti-inflammatory and anti-coronavirus agent, warranting further study for its use for human health promotion.

Metabolic reprogramming of the inflammatory response in the nervous system: the crossover between inflammation and metabolism

Metabolism is a fundamental process by which biochemicals are broken down to produce energy (catabolism) or used to build macromolecules (anabolism). Metabolism has received renewed attention as a mechanism that generates molecules that modulate multiple cellular responses. This was first identified in cancer cells as the Warburg effect, but it is also present in immunocompetent cells. Studies have revealed a bidirectional influence of cellular metabolism and immune cell function, highlighting the significance of metabolic reprogramming in immune cell activation and effector functions. Metabolic processes such as glycolysis, oxidative phosphorylation, and fatty acid oxidation have been shown to undergo dynamic changes during immune cell response, facilitating the energetic and biosynthetic demands. This review aims to provide a better understanding of the metabolic reprogramming that occurs in different immune cells upon activation, with a special focus on central nervous system disorders. Understanding the metabolic changes of the immune response not only provides insights into the fundamental mechanisms that regulate immune cell function but also opens new approaches for therapeutic strategies aimed at manipulating the immune system.

The roles of G protein-coupled receptor kinase 2 in renal diseases

G protein-coupled receptor (GPCR) kinase 2 (GRK2) is an integrative node in many signalling network cascades. An emerging study indicates that GRK2 can interact with GPCRs and non-GPCR substrates in both kinase-dependent and -independent modes. Alterations in the functional levels of GRK2 have been found in a variety of renal diseases, such as hypertension-related kidney injury, sepsis-associated acute kidney injury (S-AKI), cardiorenal syndrome (CRS), acute kidney injury (AKI), age-related kidney injury or hyperglycemia-related kidney injury. Abnormal GRK2 expression contribute to the development of renal diseases, making them promising molecular targets for treating renal diseases. Blocking the prostaglandin E2 (PGE2)-EP1-Gaq-Ca2+ signal pathway in glomerular mesangial cells (GMCs) by internalizing prostaglandin E2 receptor 1 (EP1) with GRK2 may be a potential treatment for diabetic nephropathy (DN). In addition, GRK2 inhibition may have therapeutic effects in a variety of renal diseases, such as SLE-related kidney injury, DN, age-related kidney injury, hypertension-related kidney injury, and CRS. However, there is still a long way to go for the large-scale application of GRK2 inhibition in the field of renal diseases. In this review, we discuss recent updates in understanding the role of GRK2 in kidney dysfunction. Furthermore, we explore the potential of GRK2 as a possible therapeutic target for renal pathologies. We believe it will shed light on the future development of small-molecule inhibitors of GRK, as well as the clinical applications in renal diseases.

Carthamus tinctorius seeds-Taraxacum coreanum combination attenuates scopolamine-induced memory deficit through regulation of inflammatory response and cholinergic function

BACKGROUND/OBJECTIVES

There is growing interest in herbal medicines for managing age-related diseases, such as Alzheimer's and Parkinson's. Safflower seeds (Carthamus tinctorius L. seeds, CTS) and dandelions (Taraxacum coreanum, TC) are widely used to treat bone- or inflammation-related diseases in Oriental countries. This study investigated the protective effect of the CTS-TC combination on scopolamine (Sco)-induced memory deficits through inflammatory response and cholinergic function. Moreover, marker components such as serotonin, N-(p-coumaroyl) serotonin, N-feruloylserotonin, chlorogenic acid, and chicoric acid in the CTS-TC combination were analyzed for their potential benefits on memory function.

MATERIALS/METHODS

Water extracts of CTS, TC, and the CTS-TC combination at various ratios (4:1, 1:1, and 1:4) (100 mg/kg) were orally administered to mice for 14 days. Sco (1 mg/kg) was intraperitoneally injected into the mice before each behavioral test. T-maze and novel object recognition tests were conducted to monitor behavioral changes after the treatment. Western blotting was performed to detect protein expression. In addition, the presence of 5 biomarkers, serotonin, N-(p-coumaroyl) serotonin, N-feruloylserotonin, chlorogenic acid, and chicoric acid, was analyzed using high-performance liquid chromatography (HPLC).

RESULTS

Behavioral tests showed that the CTS-TC combination enhanced memory function in Sco-injected mice. Inflammation-related proteins (inducible nitric oxide synthase, cyclooxygenase-2, and glial fibrillary acidic protein) were downregulated after treatment with the CTS-TC combination. The acetylcholinesterase protein expression was also downregulated. HPLC analysis revealed that N-feruloylserotonin and chicoric acid were the predominant components, followed by N-(p-coumaroyl) serotonin, chlorogenic acid, and serotonin.

CONCLUSION

These findings suggest that the CTS-TC combination protects against Sco-induced memory deficits by inhibiting inflammatory responses and cholinergic dysfunction. N-feruloylserotonin and chicoric acid, along with N-(p-coumaroyl) serotonin, chlorogenic acid, and serotonin, might be biomarkers for the CTS-TC combination, and their effects on memory protection warrant further study.

NIR-triggered NO production combined with photodynamic therapy for tumor treatment

Photodynamic therapy (PDT), as one of the most promising cancer therapy methods, is still limited by several drawbacks, such as tissue hypoxia and shallow light penetration of blue-violet light (200-450 nm), and red light (750 nm) is more penetrating to tissues than blue-violet light, but still lower than near-red light (750-1350 nm). Therefore, we proposed a synergistic therapy system by combining the near-infrared light-triggered PDT with nitric oxide (NO)-based gas therapy to enhance the anti-tumor effects. Upconversion nanoparticles (UCNPs) were loaded with the photosensitizers of ZnPc and the NO donors of l-arginine (L-Arg) to obtain the nanocomposites of UCN@mSiO2@ZnPc@L-Arg. Under 980 nm laser irradiation, reactive oxygen species (ROS) could be produced for PDT and react with l-Arg to produce NO, which is previously reported to have a greater killing effect on tumor cells than ROS and also plays an important role in promoting PDT in our study. Both the in vitro and in vivo tests demonstrated that the combined therapy of PDT with NO therapy could enhance the tumor killing effect significantly compared with the unique application of PDT. The UCNPs-based nanocomposites are expected to be widely used in biomedicine for tumor inhibition.

Therapeutic Plasma Exchange to Reverse Plasma Failure in Multiple Organ Dysfunction Syndrome

Plasma plays a crucial role in maintaining health through regulating coagulation and inflammation. Both are essential to respond to homeostatic threats such as traumatic injury or microbial infection; however, left unchecked, they can themselves cause damage. A well-functioning plasma regulatory milieu controls the location, intensity, and duration of the response to injury or infection. In contrast, plasma failure can be conceptualized as a state in which these mechanisms are overwhelmed and unable to constrain coagulation and inflammation appropriately. This dysregulated state causes widespread tissue damage and multiple organ dysfunction syndrome. Unlike plasma derangements caused by individual factors, plasma failure is characterized by a heterogeneous set of plasma component deficiencies and excesses. Targeted therapies such as factor replacement or recombinant antibodies are thus inadequate to restore plasma function. Therapeutic plasma exchange offers the unique ability to remove harmful factors and replete exhausted components, thereby reestablishing appropriate regulation of coagulation and inflammation.

Alterations of urine microRNA-7977/G6PD level in patients with diabetic kidney disease and its association with dysfunction of albumin-induced autophagy in proximal epithelial tubular cells

Diabetic kidney disease (DKD) remains as one of the leading long-term complications of type 2 diabetic mellitus (T2DM). Studies have shown that decreased expression of glucose-6-phosphate dehydrogenase (G6PD) plays an important role in DKD. However, the upstream and downstream pathways of G6PD downregulation leading to DKD have not been elucidated. We conducted a series of studies including clinical study, animal studies, and in vitro studies to explore this. First, a total of 90 subjects were evaluated including 30 healthy subjects, 30 patients with T2DM, and 30 patients with DKD. The urinary G6PD activity and its association with the clinical markers were analyzed. Multivariate linear regression analysis was used to analyze the risk factors of urinary G6PD in these patients. Then, microRNAs that were differentially expressed in urine and could bind and degrade G6PD were screened and verified in patients with DKD. After that, high glucose (HG)-cultured human kidney cells (HK-2) and Zucker diabetic fatty (ZDF) rats were used to test the roles of miR-7977/G6PD/albumin-induced autophagy in DKD. Beclin and P62 were used as markers of kidney autophagy indicators. A dual-luciferase reporter assay system was used to test the binding of G6PD by mir-7977. The plasma and urinary G6PD activity were decreased significantly in patients with DKD, accompanied by increased urinary mir-7977 level. The fasting plasma glucose (FPG), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and urinary albumin excretion were independent predictors of urinary G6PD activity, according to multiple linear regression analysis. The increased expression of miR-7977 and decreased expression of G6PD were also found in the kidney of ZDF rats with early renal tubular damage. The correlation analysis showed that beclin protein expression levels were positively correlated with kidney G6PD activity, whereas P62 protein expression was negatively correlated with kidney G6PD activity in rats. In HK-2 cells cultured with normal situation, a low level of albumin could induce autophagy along with the stimulation of G6PD, although this was impaired under high glucose. Overexpression of G6PD reversed albumin-induced autophagy in HK-2 cells under high glucose. Further study revealed that G6PD was a downstream target of miR-7977. Inhibition of miR-7977 expression led to significantly increased expression of G6PD and reversed the effects of high glucose on albumin-induced autophagy. In conclusion, our study supports a new mechanism of G6PD downregulation in DKD. Therapeutic measures targeting the miR-7977/G6PD/autophagy signaling pathway may help in the prevention and treatment of DKD.NEW & NOTEWORTHY This study provides new evidence that reduced glucose-6-phosphate dehydrogenase (G6PD) may damage the endocytosis of renal tubular epithelial cells by reducing albumin-induced autophagy. More importantly, for the first time, our study has provided evidence from humans that the decrease in urinary G6PD activity is positively associated with renal injury, and abnormal glucose and lipid metabolism may be important reasons for reduced G6PD levels. Increased miR-7977 may at least in part explain the downregulation of G6PD.

Arterial stiffness in adults with Long COVID in sub-Saharan Africa

Severe acute coronavirus-2 (SARS-CoV-2) infection has been associated with endothelial damage, and impaired nitric oxide production, which results in arterial stiffness and increased risk of cardiovascular disease. Long COVID is a term used to describe the persistence or the development of new symptoms that can occur after an acute infection. Little is known about the association between arterial stiffness and Long COVID. An observational, cross-sectional study in which arterial stiffness was measured with pulse wave velocity (PWV) was carried out in 74 participants between 19 and 40 years old (53 with Long COVID, 21 age and gender-matched controls). Data was collected from participants between 1 and 9 months after acute COVID-19 infection using the Complior analyze unit protocol. The Long COVID group had higher carotid-radial-PWV (crPWV) than controls (10 m/s interquartile range [IQR] 8.5-11.2 m/s) versus 8.8 m/s (IQR 7.7-9.2 m/s) as was their carotid-radial-arterial stiffness index (crASI) (2.26 cm/ms (IQR 1.9-2.56 cm/ms) vs. 2.01 cm/ms (IQR 1.82-2.27 cm/ms); p < 0.05) in both. They also had more type-A waveforms, indicating increased arterial stiffening. Peripheral arterial stiffness was higher in adults with Long COVID than in controls who were never infected with SARS-CoV-2 as noted by the elevated levels of crPWV and crASI among adults with Long COVID.

The Interplay of HIV and Long COVID in Sub-Saharan Africa: Mechanisms of Endothelial Dysfunction

PURPOSE OF REVIEW

Long COVID affects approximately 5 million people in Africa. This disease is characterized by persistent symptoms or new onset of symptoms after an acute SARS-CoV-2 infection. Specifically, the most common symptoms include a range of cardiovascular problems such as chest pain, orthostatic intolerance, tachycardia, syncope, and uncontrolled hypertension. Importantly, these conditions appear to have endothelial dysfunction as the common denominator, which is often due to impaired nitric oxide (NO) mechanisms. This review discusses the role of mechanisms contributing to endothelial dysfunction in Long COVID, particularly in people living with HIV.

RECENT FINDINGS

Recent studies have reported that increased inflammation and oxidative stress, frequently observed in Long COVID, may contribute to NO dysfunction, ultimately leading to decreased vascular reactivity. These mechanisms have also been reported in people living with HIV. In regions like Africa, where HIV infection is still a major public health challenge with a prevalence of approximately 26 million people in 2022. Specifically, endothelial dysfunction has been reported as a major mechanism that appears to contribute to cardiovascular diseases and the intersection with Long COVID mechanisms is of particular concern. Further, it is well established that this population is more likely to develop Long COVID following infection with SARS-CoV-2. Therefore, concomitant infection with SARS-CoV-2 may lead to accelerated cardiovascular disease. We outline the details of the worsening health problems caused by Long COVID, which exacerbate pre-existing conditions such as endothelial dysfunction. The overlapping mechanisms of HIV and SARS-CoV-2, particularly the prolonged inflammatory response and chronic hypoxia, may increase susceptibility to Long COVID. Addressing these overlapping health issues is critical as it provides clinical entry points for interventions that could improve and enhance outcomes and quality of life for those affected by both HIV and Long COVID in the region.

The arginine and nitric oxide metabolic pathway regulate the gut colonization and expansion of Ruminococcous gnavus

Ruminococcus gnavus is a mucolytic commensal bacterium whose increased gut colonization has been associated with chronic inflammatory and metabolic diseases in humans. Whether R. gnavus metabolites can modulate host intestinal physiology remains largely understudied. We performed untargeted metabolomic and bulk RNA-seq analyses using R. gnavus monocolonization in germ-free mice. Based on transcriptome-metabolome correlations, we tested the impact of specific arginine metabolites on intestinal epithelial production of nitric oxide (NO) and examined the effect of NO on the growth of various strains of R. gnavus in vitro and in nitric oxide synthase 2 (Nos2)-deficient mice. R. gnavus produces specific arginine, tryptophan, and tyrosine metabolites, some of which are regulated by the environmental richness of sialic acid and mucin. R. gnavus colonization promotes expression of amino acid transporters and enzymes involved in metabolic flux of arginine and associated metabolites into NO. R. gnavus induced elevated levels of NOS2, while Nos2 ablation resulted in R. gnavus expansion in vivo. The growth of various R. gnavus strains can be inhibited by NO. Specific R. gnavus metabolites modulate intestinal epithelial cell NOS2 abundance and reduce epithelial barrier function at higher concentrations. Intestinal colonization and interaction with R. gnavus are partially regulated by an arginine-NO metabolic pathway, whereby a balanced control by the gut epithelium may restrain R. gnavus growth in healthy individuals. Disruption in this arginine metabolic regulation will contribute to the expansion and blooming of R. gnavus.

Donepezil protects against cyclophosphamide-induced premature ovarian failure in mice: A focus on proinflammatory cytokines and NLRP3/TLR-4/NF-κB interplay

BACKGROUND AND AIM

Cyclophosphamide (CP) chemotherapy is a significant iatrogenic component of premature ovarian failure (POF). The aim of this work was to evaluate the potential protective effects of donepezil, a centrally acting acetylcholinesterase (AChE) inhibitor, on CP-induced POF in mice.

METHODS

40 female Swiss albino mice were split into 5 equal groups: group 1 (control), group 2 (CP-POF); induced by intraperitoneal injection of CP on 8th day of the experiment, and group (3-5); mice received oral donepezil daily (1, 2, or 4 mg/kg, respectively) 8 days before CP injection. Mice were euthanized after 24 h of CP injection, and blood samples were collected to assay serum anti-Mullerian hormone (AMH) levels. Ovarian tissues were dissected, and the right ovary was processed for further assays of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interlukin-6 (IL-6), nucleotide-binding domain-like receptor family, the Pyrin domain-containing 3 (NLRP3) inflammasome, and Toll-like receptor 4 (TLR-4), while the left one was processed for histopathological and immunohistochemical examination of nuclear factor-Kappa beta (NF-κB) and caspase-3.

RESULTS

Donepezil, in a dose-dependent manner particularly (4 mg/kg), has an inhibitory action on NO (40 ± 2.85 vs. 28.20 ± 2.23, P < 0.001), proinflammatory cytokines (P < 0.001), the TLR-4/ NF-κB / NLRP3 inflammasome pathway (P < 0.001), and apoptosis (P < 0.001), with a significant elevation in the AMH levels (4.57 ± 1.08 vs. 8.57 ± 0.97, P < 0.001) versus CP-POF group.

CONCLUSION

Donepezil may be a potential protective agent against CP-induced POF in mice, but further research is needed to fully understand its therapeutic function experimentally and clinically.

Unveiling the significance of inducible nitric oxide synthase: Its impact on cancer progression and clinical implications

The intricate role of inducible nitric oxide synthase (iNOS) in cancer pathophysiology has garnered significant attention, highlighting the complex interplay between tumorigenesis, immune response, and cellular metabolism. As an enzyme responsible for producing nitric oxide (NO) in response to inflammatory stimuli. iNOS is implicated in various aspects of cancer development, including DNA damage, angiogenesis, and evasion of apoptosis. This review synthesizes the current findings from both preclinical and clinical studies on iNOS across different cancer types, reflecting the variability depending on cellular context and tumor microenvironment. We explore the molecular mechanisms by which iNOS modulates cancer cell growth, survival, and metastasis, emphasizing its impact on immune surveillance and response to treatment. Additionally, the potential of targeting iNOS as a therapeutic strategy in cancer treatment is examined. By integrating insights from recent advances, this review aims to elucidate the significant role of iNOS in cancer and pave the way for novel diagnostic and therapeutic approaches.