Nitric oxide in immunity and inflammation

An Exploration of the Effects of an Early Postpartum Intravenous Infusion with Carnosic Acid on Physiological Responses of Transition Dairy Cows

The objective of the present study was to evaluate the effects of an antioxidant and anti-inflammatory compound found in rosemary plants (Salvia rosmarinus) named carnosic acid during the transition period of dairy cows. From day 1 to 3 after calving, 16 multiparous Holstein cows received a daily intravenous infusion of either 500 mL of saline (NaCl 0.9%; Saline; n = 8) or carnosic acid at a rate of 0.3 mg/kg of BW supplied in 500 mL of saline (CA; n = 8). Blood samples were taken at –7, 2, 5, 7, 14, and 21 d relative to parturition, then analyzed for metabolites related to energy metabolism, muscle mass catabolism, liver function, inflammation, and oxidative stress. CA infusion tended to improve milk performance; however, DMI was unaffected by treatment. At 2 d relative to parturition, CA cows had lower blood concentrations of haptoglobin, paraoxonase, FRAP, and NO₂^– than saline cows. After treatment infusions, haptoglobin remained lower in CA cows than saline at 5 d relative to parturition. Our results demonstrate that carnosic acid promoted positive responses on inflammation and oxidative stress biomarkers and may promote beneficial effects on lactation performance in peripartal dairy cows.

Single-Walled Carbon Nanotube-Based Biosensors for Detection of Bronchial Inflammation

Inflammation is a protective mechanism against invading pathogens and tissue damage. However, the inflammatory process is implicated in a wide range of diseases affecting all organs and body systems. Nitric oxide — a multifunctional signaling molecule that plays a critical role in systemic blood pressure homeostasis, prevention of platelet aggregation, antimicrobial resistance, immunoregulation, tumor suppression and as a neurotransmitter — is used as a surrogate marker for inflammation. However, the most commonly used Griess assay is an indirect and expensive method for the determination of nitric oxide concentration. Hence, single-walled carbon nanotube-based biosensors have been explored as real-time, sensitive, selective and safe methods to determine nitric oxide released during the inflammatory process. In this review, we explore current developments in single-walled carbon nanotube-based biosensors for the detection of nitric oxide in exhaled breath as a direct and noninvasive test for detection of bronchial inflammation.

Serum nitric oxide levels are depleted in depressed patients treated with electroconvulsive therapy

BACKGROUND

Nitric oxide (NO) is an endogenous substance which has several endocrine functions and may act as neurotransmitter in the brain. High levels of NO may provoke nitrosative stress.

AIM

It was aimed to examine serum levels of NO in patients with depressive episodes who were treated with electroconvulsive therapy (ECT) in this study.

METHODS

The design was a case-control, follow-up study. Patients with depressive episodes (n = 23) and a healthy control group (n = 21) were enrolled. Three serum samples were obtained from the patient group (before ECT, after first and seventh sessions). NO, nitrite, and nitrate levels were examined.

STATISTICAL ANALYSIS

Differences between groups were examined with t-test or Mann-Whitney U-test. Longitudinal data were evaluated with Panel Regression Analysis and Kruskal-Wallis Test.

RESULTS

Serum levels of NO and nitrite decreased significantly after the seventh session of ECT administration compared to the baseline and first session. Nitrate levels did not differ between the assessments.

CONCLUSIONS

Reduction of the serum NO and nitrite levels might be a contributing factor for hypertension during the sessions. These findings are reflect the circulating NO levels. Further studies may dissect NO physiology in the brain in mental disorders and potential external effects.

Aqueous Extract from Leaves of Citrus unshiu Attenuates Lipopolysaccharide-Induced Inflammatory Responses in a Mouse Model of Systemic Inflammation

Inflammation is related to various life-threatening diseases including cancer, neurodegenerative diseases, and metabolic syndrome. Because macrophages are prominent inflammatory cells, regulation of macrophage activation is a key issue to control the onset of inflammation-associated diseases. In this study, we aimed to evaluate the potential anti-inflammatory activity of Citrus unshiu leaf extract (CLE) and to elucidate the mechanism underlying its anti-inflammatory effect. We found the inhibitory activity of CLE on the secretion of proinflammatory cytokines and a chemokine from mouse macrophage-like RAW 264.7 cells and mouse peritoneal macrophages. The inhibitory activity of CLE was attributed to downregulated JNK, p38 MAPK, and NF-κB signaling pathways, leading to suppressed gene expression of inflammation-associated proteins. Oral administration of CLE significantly decreased the serum level of proinflammatory cytokines IL-6 and TNFα and increased that of anti-inflammatory cytokine IL-10 in lipopolysaccharide-induced systemic inflammation mice. In addition, oral administration of CLE decreased secretion and gene expression of several proinflammatory proteins in the liver and spleen of the model mice. Overall results revealed that C. unshiu leaf is effective to attenuate inflammatory responses in vitro and in vivo.

Omega-3- and Resveratrol-Loaded Lipid Nanosystems for Potential Use as Topical Formulations in Autoimmune, Inflammatory, and Cancerous Skin Diseases

Resveratrol (RSV) and omega 3 (ω₃), because of their biological favorable properties, have become subjects of interest for researchers in dermocosmetic and pharmaceutical industries; however, these bioactives present technological limitations that hinder their effective delivery to the target skin layer. To overcome the stability and skin permeation limitations of free bioactives, this work proposes a combined strategy involving two different lipid nanosystems (liposomes and lipid nanoparticles) that include ω₃ in their lipid matrix. Additionaly, RSV is only encapsulated in liposomes that provid an adequate amphiphilic environment. Each formulation is thoroughly characterized regarding their physical–chemical properties. Subsequently, the therapeutic performance of the lipid nanosystems is evaluated based on their protective roles against lipid peroxidation, as well as inhibition of cicloxygenase (COX) and nitric oxid (NO) production in the RWA264.7 cell line. Finally, the lipid nanosystems are incorporated in hydrogel to allow their topical administration, then rheology, occlusion, and RSV release–diffusion assays are performed. Lipid nanoparticles provide occlusive effects at the skin surface. Liposomes provide sustained RSV release and their flexibility conferred by edge activator components enhances RSV diffusion, which is required to reach NO production cells and COX cell membrane enzymes. Overall, the inclusion of both lipid nanosystems in the same semisolid base constitutes a promising strategy for autoimmune, inflammatory, and cancerous skin diseases.

Deficiency of the novel high mobility group protein HMGXB4 protects against systemic inflammation-induced endotoxemia in mice

Sepsis is a major cause of mortality in intensive care units, which results from a severely dysregulated inflammatory response that ultimately leads to organ failure. While antibiotics can help in the early stages, effective strategies to curtail inflammation remain limited. The high mobility group (HMG) proteins are chromosomal proteins with important roles in regulating gene transcription. While HMGB1 has been shown to play a role in sepsis, the role of other family members including HMGXB4 remains unknown. We found that expression of HMGXB4 is strongly induced in response to lipopolysaccharide (LPS)-elicited inflammation in murine peritoneal macrophages. Genetic deletion of Hmgxb4 protected against LPS-induced lung injury and lethality and cecal ligation and puncture (CLP)-induced lethality in mice, and attenuated LPS-induced proinflammatory gene expression in cultured macrophages. By integrating genome-wide transcriptome profiling and a publicly available ChIP-seq dataset, we identified HMGXB4 as a transcriptional activator that regulates the expression of the proinflammatory gene, Nos2 (inducible nitric oxide synthase 2) by binding to its promoter region, leading to NOS2 induction and excessive NO production and tissue damage. Similar to Hmgxb4 ablation in mice, administration of a pharmacological inhibitor of NOS2 robustly decreased LPS-induced pulmonary vascular permeability and lethality in mice. Additionally, we identified the cell adhesion molecule, ICAM1, as a target of HMGXB4 in endothelial cells that facilitates inflammation by promoting monocyte attachment. In summary, our study reveals a critical role of HMGXB4 in exacerbating endotoxemia via transcriptional induction of Nos2 and Icam1 gene expression and thus targeting HMGXB4 may be an effective therapeutic strategy for the treatment of sepsis.

Comparative Inhibitory Efficacy on the iNOS/NO System of Curcuminand Tetrahydrocurcumin-Self-Microemulsifying Liquid Formulation in Chronic Gastric Ulcer Model

BACKGROUND

Curcumin was found to accelerate gastric ulcer healing by the main mechanism, i.e., the suppression of iNOS mediated inflammation. Although Tetrahydrocurcumin (THC) is claimed to be an active antioxidant element of curcumin, its antiulcer activity has not been systematically examined. The utility of Self-Microemulsifying Drug Delivery Systems (SMEDDSs) for curcumin and THC formulations in the liquid form was also found to increase the rate and extent of release of curcumin- and THC-SMEDDS. Nevertheless, the beneficial antiulcer effect of these nanoproducts has not yet been evaluated.

OBJECTIVE

This study aimed to evaluate and compare the antiulcer efficacy of curcumin- and THCSMEDDS through the inhibition of the iNOS/NO system in the rat model.

METHODS

Antiulcer efficacy was compared in terms of the ability to accelerate healing of gastric ulcer including the efficient inhibitory action on inflammatory NO production in activated macrophages and iNOS mRNA expression at the ulcerated area.

RESULTS

THC was found to have less ulcer healing capacity than curcumin with a lack of significant inhibitory effect on the iNOS/NO system. The SMEDDS used in the study significantly increased the inhibitory efficacy of THC on iNOS/NO production and iNOS mRNA expression compared to the inhibitory potency of curcumin. An oral administration of curcumin- or THC-SMEDDS once a day was appropriate for exerting a comparable curative efficacy to a twice-daily oral administration of curcumin or THC.

CONCLUSION

The SMEDDS used in the study was observed to enhance the inhibitory efficacy of the antiulcer drug on the iNOS/NO system, leading to a reduction of daily dosing and dosing frequency.

Sophoraflavanone M, a prenylated flavonoid from Sophora flavescens Ait., suppresses pro-inflammatory mediators through both NF-κB and JNK/AP-1 signaling pathways in LPS-primed macrophages

(2R)-3α,7,4'-trihydroxy-5-methoxy-8-(γ,γ-dimethylallyl)-flavanone is a prenylated flavonoid isolated from the anti-inflammatory herb Sophora flavescens Ait. We firstly named it sophoraflavanone M (SFM) in accordance with trivial names of related constitutes from this plant. Although various studies investigated the anti-inflammatory properties of prenylated flavonoids from Sophora flavescens Ait., that of SFM remains unclear and is yet to be determined. In the current study, we assessed the anti-inflammatory effects of SFM in LPS-induced in vivo and in vitro models. In the serum of endotoxemia mice, SFM significantly suppressed LPS-elevated inflammatory cytokines. Furthermore, at nontoxic concentrations, SFM reduced LPS-induced production of inflammatory mediators NO, IL-6, TNF-α, and MCP-1 in mouse primary peritoneal macrophages. Accordingly, in LPS-primed RAW264.7 cell line, it also inhibited these mediators' expression at both transcriptional and translational levels without cytotoxicity. Mechanistically, SFM is found to concurrently inhibit two important inflammatory signaling pathways, NF-κB and JNK/AP-1. SFM restrained phosphorylation and degradation of IκBα as well as the subsequent p65 translocation to dampen NF-κB activity. Meanwhile, it also suppressed JNK phosphorylation to inhibit the transcriptional activity of AP-1. These results provide material basis for traditional application of the anti-inflammatory herb Sophora flavescens Ait. and suggest SFM is a promising natural candidate for alleviating inflammatory conditions.

Measurement of Intracellular Nitric Oxide with a Quantitative Mass Spectrometry Probe Approach

Nitric oxide (NO) is a molecule of physiological importance, and the function of NO depends on its concentration in biological systems, particularly in cells. Concentration-based analysis of intracellular NO can provide insight into its precise role in health and disease. However, current methods for detecting intracellular NO are still inadequate for quantitative analysis. In this study, we report a quantitative mass spectrometry probe approach to measure NO levels in cells. The probe, Amlodipine (AML), comprises a Hantzsch ester group that reacts with NO to form a pyridine, Dehydro Amlodipine (DAM). Quantification of DAM by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) allows specific measurement of intracellular NO levels. Notably, the AML/NO reaction proceeds rapidly (within 1 s), which is favorable for NO detection considering its large diffusivity and short half-life. Meanwhile, studies under simulated physiological conditions revealed that the AML response to NO is proportional and selective. The presented UPLC-MS/MS method showed high sensitivity (LLOQ = 0.24 nM) and low matrix interference (less than 15%) in DAM quantification. Furthermore, the mass spectrometry probe approach was demonstrated by enabling the measurement of endogenous and exogenous NO in cells. Hence, the quantitative UPLC-MS/MS method developed using AML as a probe is expected to be a new method for intracellular NO analysis.

A new approach for activation of the kiwifruit cysteine protease for usage in in-vitro testing

Actinidin (Act d 1), a highly abundant cysteine protease from kiwifruit, is one of the major contributors to the development of kiwifruit allergy. Many studies have focused on the optimization of Act d 1 purification and its role in the development of food allergies. Testing on cell culture monolayers is a common step in the elucidation of food allergen sensitization. In the case of cysteine proteases, an additional activation step with L-cysteine is required before the testing. Hence, we aimed to evaluate whether L-cysteine already present in commonly used cell culture media would suffice for Act d 1 activation. Successfully activated Act d 1 (98.1% of proteolytic activity, as compared to L-cysteine activated Act d 1) was further tested in two commonly used 2D model systems (Caco-2 and HEK293 cells) to evaluate its role on the mRNA expression of cytokines involved in the innate immunity (IL-1β, IL-6, TNFα, TSLP). Furthermore, the contribution of Act d 1 in the promotion of inflammation through regulation of inducible nitric oxide synthase (iNOS) mRNA expression was also examined. These results demonstrate that activation of cysteine proteases can be achieved without previous enzyme incubation in L-cysteine -containing solution. Act d 1 incubated in cell culture medium was able to modulate gene expression of pro-inflammatory cytokines when tested on two model systems of the epithelial barrier.

New Multiscale Characterization Methodology for Effective Determination of Isolation-Structure-Function Relationship of Extracellular Vesicles

Extracellular vesicles (EVs) have been lauded as next-generation medicines, but very few EV-based therapeutics have progressed to clinical use. Limited clinical translation is largely due to technical barriers that hamper our ability to mass produce EVs, i.e., to isolate, purify, and characterize them effectively. Technical limitations in comprehensive characterization of EVs lead to unpredicted biological effects of EVs. Here, using a range of optical and non-optical techniques, we showed that the differences in molecular composition of EVs isolated using two isolation methods correlated with the differences in their biological function. Our results demonstrated that the isolation method determines the composition of isolated EVs at single and sub-population levels. Besides the composition, we measured for the first time the dry mass and predicted sedimentation of EVs. These parameters were likely to contribute to the biological and functional effects of EVs on single cell and cell cultures. We anticipate that our new multiscale characterization approach, which goes beyond traditional experimental methodology, will support fundamental understanding of EVs as well as elucidate the functional effects of EVs in in vitro and in vivo studies. Our findings and methodology will be pivotal for developing optimal isolation methods and establishing EVs as mainstream therapeutics and diagnostics. This innovative approach is applicable to a wide range of sectors including biopharma and biotechnology as well as to regulatory agencies.

Assessment of nitric oxide (NO) potential to mitigate COVID-19 severity

Novel coronavirus disease by SARS-CoV-2 virus (also known as COVID-19) has emerged as major health concern worldwide. While, there is no specific drugs for treating this infection till date, SARS-CoV-2 had spread to most countries around the globe. Nitric oxide (NO) gas serves as an important signaling molecule having vasodilatory effects as well as anti-microbial properties. Previous studies from the 2004 SARS-CoV infection demonstrated that NO may also help to reduce respiratory tract infection by inactivating viruses and inhibiting their replication cycle and is an effective supportive measure for treating infection in patients with pulmonary complications. NO gas inhalation is being suggested as potential therapy for managing severe acute respiratory distress syndrome in COVID-19 patients. In view of COVID-19 pandemic, several clinical trials are underway to examine the effects of NO inhalation on infected patients. Previously published reports on beneficial effects of endogenous NO and NO inhalation therapy were thoroughly searched to assess the potential of NO therapy for treating COVID-19 patients. Present report summarized the therapeutic importance of NO to reverse pulmonary hypertension, restore normal endothelial activity and produce anti-thrombotic effects. In addition to this, NO also reduces viral infection by inhibiting its replication and entry into the host cell. In absence of vaccine and effective treatment strategies, we suggest that NO inhalation therapy and NO releasing foods/compounds could be considered as an alternative measure to combat COVID-19 infection.

Antioxidant and Anti-Inflammatory Activities of Zingiber montanum Oil in HepG2 Cells and Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Improvement of antioxidant and anti-inflammatory functions is believed to be an effective strategy for protection against various diseases such as cancer, aging, and neurodegenerative disease. This study focused on investigating antioxidant and anti-inflammatory abilities of Zingiber montanum oil (ZMO) extracted by the supercritical CO₂ fluid system in HepG2 cells and lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Ten predominant constituents of ZMO were identified, in which triquinacene, 1,4-bis (methoxy), terpinen-4-ol, triquinacene, 1,4,7-tris (methoxy), α-terpinene, sabinene hydrate, and (E and Z)-1-(3,4-dimethoxyphenyl)butadiene account for 86.47%. ZMO exhibited anti-inflammatory capacity by inhibiting the formation of pro-inflammatory markers such as nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1 in LPS-treated macrophages. The LPS-induced stimulation of nuclear factor-kappa B, signal transducer and activator of transcription 3 (Stat3) and mitogen-activated protein kinase (MAPK) pathways as evident from increased phosphorylation of IKKα/β, IκBα, p65, Stat3, ERK, JNK, and p38 MAPK was also suppressed by ZMO pretreatment. Further, ZMO enhanced the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1), and concurrently, reduced intracellular reactive oxygen species accumulation in LPS-treated RAW 264.7 cells. In addition, ZMO treatment markedly upregulated the expression of Nrf2 as well as its target genes, HO-1 and NAD(P)H:quinone oxidoreductase 1 in HepG2 cells. These data propose that ZMO may be a potent candidate for prevention and/or treatment of inflammatory and oxidative conditions.

Effect of Reactive Oxygen Species on the Endoplasmic Reticulum and Mitochondria during Intracellular Pathogen Infection of Mammalian Cells

Oxidative stress, particularly reactive oxygen species (ROS), are important for innate immunity against pathogens. ROS directly attack pathogens, regulate and amplify immune signals, induce autophagy and activate inflammation. In addition, production of ROS by pathogens affects the endoplasmic reticulum (ER) and mitochondria, leading to cell death. However, it is unclear how ROS regulate host defense mechanisms. This review outlines the role of ROS during intracellular pathogen infection, mechanisms of ROS production and regulation of host defense mechanisms by ROS. Finally, the interaction between microbial pathogen-induced ROS and the ER and mitochondria is described.

Can Plant Lectins Help to Elucidate Insect Lectin-Mediated Immune Response?

Simple Summary

Lectins are proteins that can recognize and selectively bind specific sugar structures. These proteins are present in all kingdoms of life, including plants, animals, fungi and microorganisms and play a role in a broad range of processes. The interactions between lectins and their target carbohydrates play a primordial role in plant and animal immune systems. Despite being the largest and most diverse taxa on earth, the study of lectins and their functions in insects is lagging behind. To study the role of insect lectins in the immune response, plant lectins could provide an interesting tool. Plant lectins have been well characterized and many of them possess immunomodulatory properties in vertebrate cells. The increasing knowledge on the immunomodulatory effects of plant lectins could complement the missing knowledge on the endogenous insect lectins and contribute to understanding the processes and mechanisms by which lectins participate in insect immunity. This review summarizes existing studies of immune responses stimulated by endogenous or exogenous lectins.

Abstract

Lectins are carbohydrate-binding proteins that recognize and selectively bind to specific sugar structures. This group of proteins is widespread in plants, animals, and microorganisms, and exerts a broad range of functions. Many plant lectins were identified as exogenous stimuli of vertebrate immunity. Despite being the largest and most diverse taxon on earth, the study of lectins and their functions in insects is lagging behind. In insects, research on lectins and their biological importance has mainly focused on the C-type lectin (CTL) family, limiting our global understanding of the function of insect lectins and their role in insect immunity. In contrast, plant lectins have been well characterized and the immunomodulatory effects of several plant lectins have been documented extensively in vertebrates. This information could complement the missing knowledge on endogenous insect lectins and contribute to understanding of the processes and mechanisms by which lectins participate in insect immunity. This review summarizes existing studies of immune responses stimulated by endogenous or exogenous lectins. Understanding how lectins modulate insect immune responses can provide insight which, in turn, can help to elaborate novel ideas applicable for the protection of beneficial insects and the development of novel pest control strategies.

Hypoxia and Inflammation: Insights From High-Altitude Physiology

The key regulators of the transcriptional response to hypoxia and inflammation (hypoxia inducible factor, HIF, and nuclear factor-kappa B, NF-κB, respectively) are evolutionarily conserved and share significant crosstalk. Tissues often experience hypoxia and inflammation concurrently at the site of infection or injury due to fluid retention and immune cell recruitment that ultimately reduces the rate of oxygen delivery to tissues. Inflammation can induce activity of HIF-pathway genes, and hypoxia may modulate inflammatory signaling. While it is clear that these molecular pathways function in concert, the physiological consequences of hypoxia-induced inflammation and how hypoxia modulates inflammatory signaling and immune function are not well established. In this review, we summarize known mechanisms of HIF and NF-κB crosstalk and highlight the physiological consequences that can arise from maladaptive hypoxia-induced inflammation. Finally, we discuss what can be learned about adaptive regulation of inflammation under chronic hypoxia by examining adaptive and maladaptive inflammatory phenotypes observed in human populations at high altitude. We aim to provide insight into the time domains of hypoxia-induced inflammation and highlight the importance of hypoxia-induced inflammatory sensitization in immune function, pathologies, and environmental adaptation.

Neuroimmunomodulation by gut bacteria: Focus on inflammatory bowel diseases

Microbes colonize the gastrointestinal tract are considered as highest complex ecosystem because of having diverse bacterial species and 150 times more genes as compared to the human genome. Imbalance or dysbiosis in gut bacteria can cause dysregulation in gut homeostasis that subsequently activates the immune system, which leads to the development of inflammatory bowel disease (IBD). Neuromediators, including both neurotransmitters and neuropeptides, may contribute to the development of aberrant immune response. They are emerging as a regulator of inflammatory processes and play a key role in various autoimmune and inflammatory diseases. Neuromediators may influence immune cell’s function via the receptors present on these cells. The cytokines secreted by the immune cells, in turn, regulate the neuronal functions by binding with their receptors present on sensory neurons. This bidirectional communication of the enteric nervous system and the enteric immune system is involved in regulating the magnitude of inflammatory pathways. Alterations in gut bacteria influence the level of neuromediators in the colon, which may affect the gastrointestinal inflammation in a disease condition. Changed neuromediators concentration via dysbiosis in gut microbiota is one of the novel approaches to understand the pathogenesis of IBD. In this article, we reviewed the existing knowledge on the role of neuromediators governing the pathogenesis of IBD, focusing on the reciprocal relationship among the gut microbiota, neuromediators, and host immunity. Understanding the neuromediators and host-microbiota interactions would give a better insight in to the disease pathophysiology and help in developing the new therapeutic approaches for the disease.

Exposure to artificial light at night alters innate immune response in wild great tit nestlings

The large-scale impact of urbanization on wildlife is rather well documented; however, the mechanisms underlying the effects of urban environments on animal physiology and behaviour are still poorly understood. Here, we focused on one major urban pollutant - artificial light at night (ALAN) - and its effects on the capacity to mount an innate immune response in wild great tit (Parus major) nestlings. Exposure to ALAN alters circadian rhythms of physiological processes, by disrupting the nocturnal production of the hormone melatonin. Nestlings were exposed to a light source emitting 3 lx for seven consecutive nights. Subsequently, nestlings were immune challenged with a lipopolysaccharide injection, and we measured haptoglobin and nitric oxide levels pre- and post-injection. Both haptoglobin and nitric oxide are important markers for innate immune function. We found that ALAN exposure altered the innate immune response, with nestlings exposed to ALAN having lower haptoglobin and higher nitric oxide levels after the immune challenge compared with dark-night nestlings. Unexpectedly, nitric oxide levels were overall lower after the immune challenge than before. These effects were probably mediated by melatonin, as ALAN-treated birds had on average 49% lower melatonin levels than the dark-night birds. ALAN exposure did not have any clear effects on nestling growth. This study provides a potential physiological mechanism underlying the documented differences in immune function between urban and rural birds observed in other studies. Moreover, it gives evidence that ALAN exposure affects nestling physiology, potentially causing long-term effects on physiology and behaviour, which ultimately can affect their fitness.

STING regulates metabolic reprogramming in macrophages via HIF-1α during Brucella infection

Macrophages metabolic reprogramming in response to microbial insults is a major determinant of pathogen growth or containment. Here, we reveal a distinct mechanism by which stimulator of interferon genes (STING), a cytosolic sensor that regulates innate immune responses, contributes to an inflammatory M1-like macrophage profile upon Brucella abortus infection. This metabolic reprogramming is induced by STING-dependent stabilization of hypoxia-inducible factor-1 alpha (HIF-1α), a global regulator of cellular metabolism and innate immune cell functions. HIF-1α stabilization reduces oxidative phosphorylation and increases glycolysis during infection with B. abortus and, likewise, enhances nitric oxide production, inflammasome activation and IL-1β release in infected macrophages. Furthermore, the induction of this inflammatory profile participates in the control of bacterial replication since absence of HIF-1α renders mice more susceptible to B. abortus infection. Mechanistically, activation of STING by B. abortus infection drives the production of mitochondrial reactive oxygen species (mROS) that ultimately influences HIF-1α stabilization. Moreover, STING increases the intracellular succinate concentration in infected macrophages, and succinate pretreatment induces HIF-1α stabilization and IL-1β release independently of its cognate receptor GPR91. Collectively, these data demonstrate a pivotal mechanism in the immunometabolic regulation of macrophages during B. abortus infection that is orchestrated by STING via HIF-1α pathway and highlight the metabolic reprogramming of macrophages as a potential treatment strategy for bacterial infections.

The impact of host cell metabolism on pathogen growth or restriction represent an emerging field in immunology and shed light on the intricate network of signaling pathways during immune cells response. Here, we dissected a distinct mechanism by which STING regulates macrophage metabolic reprogramming eliciting an inflammatory profile during Brucella infection. Brucella abortus is an intracellular bacterium that causes brucellosis, an infectious disease that promotes abortion in domestic animals leading to severe economic losses and an inflammatory condition in humans. The metabolite reprogramming orchestrated by STING relies on HIF-1α stabilization through increased succinate and mROS levels. We demonstrated that HIF-1α stabilization enhances nitric oxide production, inflammasome activation and IL-1β release in infected macrophages, and this inflammatory profile participates in the control of bacterial replication. Thus, our findings bring new insights on this intricate circuit by which the host immune senses intracellular pathogens contributing to development of drugs and/or vaccines to control infectious diseases.

Comparative evaluation of the protective effects of oral administration of auraptene and umbelliprenin against CFA-induced chronic inflammation with polyarthritis in rats

This study aimed to evaluate the anti-inflammatory effect of Auraptene (AUR) and Umbelliprenin (UMB) in a rat model of rheumatoid arthritis (RA) induced by using complete Freund's adjuvant (CFA). Paw swelling of adjuvant arthritis rats measured at various times after CFA injection. Over 15 days of RA induction, mediator/cytokine-mediated processes involved in managing the regulation and resolving RA's inflammation were also quantified with ELISA. Histopathological changes were also assessed under a microscope 15 days after the CFA injection. AUR at all doses and UMB administration only at a 16 mM /kg administration dose significantly reduced CFA-induced paw edema level compared to the control group. UMB (64 and 32 mM) and AUR (64, 32, and 16 mM) could reduce the PGE2 (p < .0001-.01) and NO (p < .0001-.05) levels in the treatment groups compared to the negative control group. However, these compounds showed no significant effect on the TNF-α, IFN-γ, TGF-β, IL-4, and IL-10 levels than the control group (p > .05). Unlike indomethacin and prednisolone, treatment of rats with AUR (16, 32, and 64 mM/kg) and UMB (16 and 32 mM/kg) reduced the level of IL-2 (p < .0001). In all treatment groups, the serum level of IL-17 was significantly reduced compared to the CFA group (p < .001-0.05). We suggested AUR and UMB could diminish inflammation by reducing the serum level of IL-17 and could be considered a proper alternative in the treatment of IL-17 related inflammatory diseases such as rheumatoid arthritis. Given that AUR and UMB apply their anti-inflammatory effects by changing distinct cytokine release/inhibition patterns, their potential application in diverse inflammatory diseases seems different.

Macrophage activation in vitro by Parachartergus fraternus venom

Parachartergus fraternus wasp induces inflammation with a predominance of mononuclear cells, that can acquire macrophage functions at the sting site, amplifying the response. These cells can be activated by venomous animals and are involved in destruction of injurious agents and release of inflammatory mediators. The objective of this work was to evaluate the activity of P. fraternus venom (Pfv) on isolated murine macrophage function. The cells were obtained from peritoneal cavity of Swiss male mice and incubated with Pfv (2.5, 5 and 10 μg/mL). Cytotoxicity was determined using MTT assay. Adhesion and detachment were evaluated using violet crystal dye. Spreading was evaluated based on morphological parameters. Phagocytosis was performed with opsonized zymosan. Production of hydrogen peroxide (H₂O₂) and nitric oxide (NO) were quantified using the phenol red and Griess assays, respectively. Pfv at concentrations evaluated was not cytotoxic in MTT assay and did not cause macrophage detachment in cell culture plates. However, it increased adhesion of macrophage, spreading and phagocytosis of opsonized zymosan, as well as induced production of H₂O₂ and NO. Therefore, Pfv induces macrophage activation in vitro and the response of these cells can be correlated with the previously reported inflammatory process triggered by this wasp.

Carnosine Protects Macrophages against the Toxicity of Aβ1-42 Oligomers by Decreasing Oxidative Stress

Carnosine (β-alanyl-L-histidine) is a naturally occurring endogenous peptide widely distributed in excitable tissues such as the brain. This dipeptide has well-known antioxidant, anti-inflammatory, and anti-aggregation activities, and it may be useful for treatment of neurodegenerative disorders such as Alzheimer’s disease (AD). In this disease, peripheral infiltrating macrophages play a substantial role in the clearance of amyloid beta (Aβ) peptides from the brain. Correspondingly, in patients suffering from AD, defects in the capacity of peripheral macrophages to engulf Aβ have been reported. The effects of carnosine on macrophages and oxidative stress associated with AD are consequently of substantial interest for drug discovery in this field. In the present work, a model of stress induced by Aβ1-42 oligomers was investigated using a combination of methods including trypan blue exclusion, microchip electrophoresis with laser-induced fluorescence, flow cytometry, fluorescence microscopy, and high-throughput quantitative real-time PCR. These assays were used to assess the ability of carnosine to protect macrophage cells, modulate oxidative stress, and profile the expression of genes related to inflammation and pro- and antioxidant systems. We found that pre-treatment of RAW 264.7 macrophages with carnosine counteracted cell death and apoptosis induced by Aβ1-42 oligomers by decreasing oxidative stress as measured by levels of intracellular nitric oxide (NO)/reactive oxygen species (ROS) and production of peroxynitrite. This protective activity of carnosine was not mediated by modulation of the canonical inflammatory pathway but instead can be explained by the well-known antioxidant and free-radical scavenging activities of carnosine, enhanced macrophage phagocytic activity, and the rescue of fractalkine receptor CX3CR1. These new findings obtained with macrophages challenged with Aβ1-42 oligomers, along with the well-known multimodal mechanism of action of carnosine in vitro and in vivo, substantiate the therapeutic potential of this dipeptide in the context of AD pathology.

Study on hypoxia-inducible factor and its roles in immune system

The Hypoxia-Inducible Factor-1 (HIF-1) is a dimeric protein complex that plays a significant role in responding to low oxygen or hypoxia concentrations. Chronic inflammation is one of the immune system responses and can increase HIF expression in involved tissues through lowering the oxygen and hypoxia. The HIF factor has many critical roles in immunity, and thus, we reviewed the crucial roles of this factor in the immune system. The results showed various key roles on the immune system, including physical defenses, innate immune (neutrophils apoptosis, macrophages) and inflammatory responses (pyrexia and local heat, iron access, etc.), upregulation in response to microbial infections, cytokines expression (IL-1, IL-2, IL-6, IL-8, IL-12, IL-18, TNF, etc.), drug targeting, etc. The HIF roles in the acquired immune system include: enhance the adaptation of cells (dendritic cells) to new conditions and triggering the signal pathways. The findings of the present review demonstrated that the HIF has important roles in the immune system, including physical defense, innate immune as well as acquired immunity; therefore, it may be considered as a potent drug targeting several diseases such as cancers, infectious diseases, etc.

Antioxidant and C5a-blocking strategy for hepatic ischemia-reperfusion injury repair

BACKGROUND

Nonspecific liver uptake of nanomaterials after intravenous injection has hindered nanomedicine for clinical translation. However, nanomaterials' propensity for liver distribution might enable their use in hepatic ischemia-reperfusion injury (IRI) repair. During hepatic IRI, reactive oxygen species (ROS) are generated and the fifth component of complement (C5a) is activated. In addition, C5a is confirmed to exacerbate the vicious cycle of oxidative stress and inflammatory damage. For these reasons, we have investigated the development of nanomaterials with liver uptake to scavenge ROS and block C5a for hepatic IRI repair.

RESULTS

To achieve this goal, a traditional nanoantioxidant of nanoceria was surface conjugated with the anti-C5a aptamers (Ceria@Apt) to scavenge the ROS and reduce C5a-mediated inflammation. High uptake of Ceria@Apt in the liver was confirmed by preclinical positron emission tomography (PET) imaging. The clinical symptoms of hepatic IRI were effectively alleviated by Ceria@Apt with ROS scavenging and C5a blocking in mice model. The released pro-inflammatory cytokines were significantly reduced, and subsequent inflammatory reaction involved in the liver was inhibited.

CONCLUSIONS

The synthesized Ceria@Apt has great potential of medical application in hepatic IRI repair, which could also be applied for other ischemic-related diseases.

Implications of SARS-Cov-2 infection on eNOS and iNOS activity: Consequences for the respiratory and vascular systems

Symptoms of COVID-19 range from asymptomatic/mild symptoms to severe illness and death, consequence of an excessive inflammatory process triggered by SARS-CoV-2 infection. The diffuse inflammation leads to endothelium dysfunction in pulmonary blood vessels, uncoupling eNOS activity, lowering NO production, causing pulmonary physiological alterations and coagulopathy. On the other hand, iNOS activity is increased, which may be advantageous for host defense, once NO plays antiviral effects. However, overproduction of NO may be deleterious, generating a pro-inflammatory effect. In this review, we discussed the role of endogenous NO as a protective or deleterious agent of the respiratory and vascular systems, the most affected in COVID-19 patients, focusing on eNOS and iNOS roles. We also reviewed the currently available NO therapies and pointed out possible alternative treatments targeting NO metabolism, which could help mitigate health crises in the present and future CoV's spillovers.

Seco-type β-Apocarotenoid Generated by β-Carotene Oxidation Exerts Anti-inflammatory Effects against Activated Macrophages

β-Apocarotenoids are the cleavage products of β-carotene. They are found in plants, carotenoid-containing foods, and animal tissues. However, limited information is available regarding the health benefits of β-apocarotenoids. Here, we prepared seco-type β-apocarotenoids through the chemical oxidation of β-carotene and investigated their anti-inflammatory effects against activated macrophages. Oxidation of β-carotene with potassium permanganate produced seco-β-apo-8'-carotenal, in which one end-group formed an "open" β-ring and the other was cleaved at the C-7',8' position. In lipopolysaccharide-stimulated murine macrophage-like RAW264.7 cells, seco-β-apo-8'-carotenal inhibited the secretion and mRNA expression of inflammatory mediators such as nitric oxide, interleukin (IL)-6 and IL-1β, and monocyte chemoattractant protein-1. Furthermore, seco-β-apo-8'-carotenal suppressed phosphorylation of c-Jun N-terminal kinase and the inhibitor of nuclear factor (NF)-κB as well as the nuclear accumulation of NF-κB p65. Notably, since seco-β-apo-8'-carotenal exhibited remarkable anti-inflammatory activity compared with β-apo-8'-carotenal, its anti-inflammatory action could depend on the opened β-ring structure. These results suggest that seco-β-apo-8'-carotenal has high potential for the prevention of inflammation-related diseases.

Anti-Inflammatory Investigations of Extracts of Zanthoxylum rhetsa

Zanthoxylum rhetsa has been consumed in the diet in northern Thailand and also used as a medicament in ancient scripture for arthropathies. Thus, this study aimed to evaluate the activity of various extracts from differential parts of Z. rhetsa via inhibition of inflammatory mediators (NO, TNF-α, and PGE₂) in RAW264.7 macrophages. The chemical composition in active extracts was also analyzed by GC/MS. The parts of this plant studied were whole fruits (F), pericarp (P), and seed (O). The methods of extraction included maceration in hexane, 95% ethanol and 50% ethanol, boiling in water, and water distillation. The results demonstrated that the hexane and 95% ethanolic extract from pericarp (PH and P95) and seed essential oil (SO) were the most active extracts. PH and P95 gave the highest inhibition of NO production with IC₅₀ as 11.99 ± 1.66 μg/ml and 15.33 ± 1.05 μg/ml, respectively, and they also showed the highest anti-inflammatory effect on TNF-α with IC₅₀ as 36.08 ± 0.55 μg/ml and 34.90 ± 2.58 μg/ml, respectively. PH and P95 also showed the highest inhibitory effect on PGE₂ but less than SO with IC₅₀ as 13.72 ± 0.81 μg/ml, 12.26 ± 0.71 μg/ml, and 8.61 ± 2.23 μg/ml, respectively. 2,3-Pinanediol was the major anti-inflammatory compound analyzed in PH (11.28%) and P95 (19.82%) while terpinen-4-ol constituted a major anti-inflammatory compound in SO at 35.13%. These findings are the first supportive data for ethnomedical use for analgesic and anti-inflammatory activity in acute (SO) and chronic (PH and P95) inflammation.

Identification of Bioactive Natural Product from the Stems and Stem Barks of Cornus walteri: Benzyl Salicylate Shows Potential Anti-Inflammatory Activity in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Cornus walteri (Cornaceae), known as Walter's dogwood, has been used to treat dermatologic inflammation and diarrheal disease in traditional oriental medicine. As part of an ongoing research project to discover natural products with biological activities, the anti-inflammatory potential of compounds from C. walteri in lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 macrophages were explored. Phytochemical analysis of the methanol extract of the stem and stem bark of C. walteri led to the isolation of 15 chemical constituents. These compounds were evaluated for their inhibitory effects on the production of the proinflammatory mediator nitric oxide (NO) in LPS-stimulated macrophages, as measured by NO assays. The molecular mechanisms underlying the anti-inflammatory activity were investigated using western blotting. Our results demonstrated that among 15 chemical constituents, lupeol and benzyl salicylate inhibited NO production in LPS-activated RAW 264.7 macrophages. Benzyl salicylate was more efficient than NG-monomethyl-L-arginine mono-acetate salt (L-NMMA) in terms of its inhibitory effect. In addition, the mechanism of action of benzyl salicylate consisted of the inhibition of phosphorylation of IκB kinase alpha (IKKα), IκB kinase beta (IKKβ), inhibitor of kappa B alpha (IκBα), and nuclear factor kappa B (NF-κB) in LPS-stimulated macrophages. Furthermore, benzyl salicylate inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Taken together, these results suggest that benzyl salicylate present in the stem and stem bark of C. walteri has potential anti-inflammatory activity, supporting the potential application of this compound in the treatment of inflammatory diseases.

Protection against Doxorubicin-Induced Cardiotoxicity through Modulating iNOS/ARG 2 Balance by Electroacupuncture at PC6

Background

Doxorubicin (DOX) is a commonly used chemotherapeutic drug but is limited in clinical applications by its cardiotoxicity. Neiguan acupoint (PC6) is a well-recognized acupoint for the treatment of cardiothoracic disease. However, whether acupuncture at PC6 could be effective in preventing DOX-induced cardiotoxicity is still unknown.

Methods

A set of experiments were performed with myocardial cells, wild type, inducible nitric oxide synthase knockout (iNOS-/-), and myocardial-specific ablation arginase 2 (Myh6-ARG 2-/-) mice. We investigated the protective effect and the underlying mechanisms for electroacupuncture (EA) against DOX-induced cardiotoxicity by echocardiography, immunostaining, biochemical analysis, and molecular biotechnology in vivo and in vitro analysis.

Results

We found that DOX-mediated nitric oxide (NO) production was positively correlated with the iNOS level but has a negative correlation with the arginase 2 (ARG 2) level in both myocardial cells and tissues. Meanwhile, EA at PC6 alleviated cardiac dysfunction and cardiac hypertrophy in DOX-treated mice. EA at PC6 blocked the upregulation of NO production in accompanied with the downregulated iNOS and upregulated ARG 2 levels in myocardial tissue induced by DOX. Furthermore, knockout iNOS prevented cardiotoxicity and EA treatment did not cause the further improvement of cardiac function in iNOS-/- mice treated by DOX. In contrast, deficiency of myocardial ARG 2 aggravated DOX-induced cardiotoxicity and reduced EA protective effect.

Conclusion

These results suggest that EA treatment at PC6 can prevent DOX-induced cardiotoxicity through modulating NO production by modulating the iNOS/ARG 2 balance in myocardial cells.

Assessment of Anti-inflammatory Activity of 3-Acetylmyricadiol in LPS Stimulated Raw 264.7 Macrophages

BACKGROUND

Pentacyclic triterpenoids are a biologically active class of phytoconstituents with diverse pharmacological activity including anti-inflammatory action.

OBJECTIVE

In the current study, we isolated 3-Acetylmyricadiol, a pentacyclic triterpenoid, from the ethyl acetate bark-extract of Myrica esculenta and evaluated it for anti-inflammatory potential.

METHODS

The ethyl acetate bark-extract of the M. esculenta was subjected to column chromatography to isolate 3-Acetylmyricadiol. MTT assay was performed to check cell viability. The production of proinflammatory mediators like Nitric oxide, IL-6, TNF-α was observed after administration of 5, 10, 20 μM of 3-Acetylmyricadiol in LPS-activated Raw 246.7 macrophages by the reported methods.

RESULTS

MTT assay indicated more than 90% cell viability up to 20 μM of 3-Acetylmyricadiol. The administration of 3-Acetylmyricadiol inhibited the production of Nitric oxide, IL-6, TNF-α in a dose-dependent manner significantly in comparison to LPS treated cells. The maximum effect was observed at 20 μM of 3-Acetylmyricadiol which resulted in 52.37, 63.10, 55.37 % inhibition of Nitric oxide, IL-6, TNF-α respectively.

CONCLUSION

Our study demonstrated the anti-inflammatory action of 3-Acetylmyricadiol and can serve as a potential candidate in the development of the clinically efficient anti-inflammatory molecule.

Metabolic Profile Reveals the Immunosuppressive Mechanisms of Methionyl-Methionine in Lipopolysaccharide-Induced Inflammation in Bovine Mammary Epithelial Cell

Our previous transcriptomic study found that methionyl-methionine (Met-Met) exerts an anti-inflammatory effect in the bovine mammary epithelial cell (MAC-T) at a molecular level. However, evidence of whether the metabolic production of Met-Met confers protection was scarce. To investigate the inflammatory response and metabolite changes of Met-Met in lipopolysaccharide (LPS)-induced inflammation of MAC-T, mass spectrometry-based metabolomics and qPCR were conducted. The increased levels of IL-8, TNF-α, AP-1, and MCP-1 were reduced by pretreating with 2 mM Met-Met after LPS exposure. Metabolomics profiling analysis demonstrated that LPS induced significant alteration of metabolites, including decreased tryptophan, phenylalanine, and histidine levels and increased palmitic acid and stearic acid levels as well as purine metabolism disorder, whereas Met-Met reversed these changes significantly. Pathways analysis revealed that overlapping metabolites were mainly enriched in the cysteine and methionine metabolism, fatty acids biosynthesis, and purines degradation. Correlation networks showed that the metabolic profile was significantly altered under the conditions of inflammation and Met-Met treatment. Collectively, Met-Met might relieve MAC-T cell inflammation via hydrolysate methionine, which further changes the processes of amino acid, purine, and fatty acid metabolism.

Lutonarin from Barley Seedlings Inhibits the Lipopolysacchride-Stimulated Inflammatory Response of RAW 264.7 Macrophages by Suppressing Nuclear Factor-κB Signaling

Extracts from barley seedlings (BS) have known antioxidant and anti-inflammatory activities. The flavonoid lutonarin (LN) is a component of BS extract and has several known bioactivities. Here, we evaluated LN anti-inflammatory efficacy against lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Lutonarin was isolated from BS by methanol extraction and characterized by ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Lutonarin did not reduce the viability or enhance the apoptosis rate of RAW 264.7 macrophages at concentrations up to 150 µM. Concentrations within 20-60 µM dose-dependently suppressed the LPS-induced expression, phosphorylation, and nuclear translocation of the inflammatory transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Furthermore, LN suppressed the LPS-induced upregulation of proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α and of the inflammatory enzyme cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Lutonarin may be a safe and effective therapeutic agent for alleviation of pathological inflammation.

Nitric oxide modulation in neuroinflammation and the role of mesenchymal stem cells

Nitric oxide is a versatile mediator formed by enzymes called nitric oxide synthases. It has numerous homeostatic functions and important roles in inflammation. Within the inflamed brain, microglia and astrocytes produce large amounts of nitric oxide during inflammation. Excessive nitric oxide causes neuronal toxicity and death and mesenchymal stem cells can be used as an approach to limit the neuronal damage caused by neuroinflammation. Mesenchymal stem cell therapy ameliorates inflammation and neuronal damage in disease models of Alzheimer's disease, Parkinson's disease, and other neuroinflammatory disorders. Interestingly, we have reported that in vitro, mesenchymal stem cells themselves contribute to a rise in nitric oxide levels through microglial cues. This may be an undesirable effect and highlights a possible need to explore acellular approaches for mesenchymal stem cell therapy in the central nervous system.

Synthetic, Natural, and Semisynthetic Polymer Carriers for Controlled Nitric Oxide Release in Dermal Applications: A Review

Nitric oxide (NO•) is a free radical gas, produced in the human body to regulate physiological processes, such as inflammatory and immune responses. It is required for skin health; therefore, a lack of NO• is known to cause or worsen skin conditions related to three biomedical applications- infection treatment, injury healing, and blood circulation. Therefore, research on its topical release has been increasing for the last two decades. The storage and delivery of nitric oxide in physiological conditions to compensate for its deficiency is achieved through pharmacological compounds called NO-donors. These are further incorporated into scaffolds to enhance therapeutic treatment. A wide range of polymeric scaffolds has been developed and tested for this purpose. Hence, this review aims to give a detailed overview of the natural, synthetic, and semisynthetic polymeric matrices that have been evaluated for antimicrobial, wound healing, and circulatory dermal applications. These matrices have already set a solid foundation in nitric oxide release and their future perspective is headed toward an enhanced controlled release by novel functionalized semisynthetic polymer carriers and co-delivery synergetic platforms. Finally, further clinical tests on patients with the targeted condition will hopefully enable the eventual commercialization of these systems.

Lupeol-induced nitric oxide elicits apoptosis-like death within Escherichia coli in a DNA fragmentation-independent manner

Lupeol is known to be plentiful in fruits or plant barks and has an antimicrobial effect, however, its mode of action(s) has yet to be determined. To elucidate lupeol generates nitric oxide (NO), which is recognized for possessing an antimicrobial activity, intracellular NO was measured in Escherichia coli using DAF-FM. Using the properties of NO passing through plasma membrane easily, increased malondialdehyde levels have shown that lupeol causes lipid peroxidation, and the resulting membrane depolarization was confirmed by DiBAC4(3). These data indicated that lupeol-induced NO is related to the destruction of bacterial membrane. Further study was performed to examine whether NO, known as a cell proliferation inhibitor, affects bacterial cell division. As a result, DAPI staining verified that lupeol promotes cell division arrest, and followed by early apoptosis is observed in Annexin V/PI double staining. Even though these apoptotic hallmarks appeared, the endonuclease failed to perform properly with supporting data of decreased intracellular Mg2+ and Ca2+ levels without DNA fragmentation, which is confirmed using a TUNEL assay. These findings indicated that lupeol-induced NO occurs DNA fragmentation-independent bacterial apoptosis-like death (ALD). Additionally, lupeol triggers DNA filamentation and morphological changes in response to DNA repair system called SOS system. In accordance with the fact that ALD deems to SOS response, and that the RecA is considered as a caspase-like protein, increase in caspase-like protein activation occurred in E. coli wild-type, and no ΔRecA mutant. In conclusion, these results demonstrated that the antibacterial mode of action(s) of lupeol is an ALD while generating NO.

Anti-inflammatory effects of Fritillaria thunbergii Miquel extracts in LPS-stimulated murine macrophage RAW 264.7 cells

The aim of the present study was to demonstrate that Fritillaria thunbergii Miquel extract exerts anti-inflammatory and antioxidant effects on lipopolysaccharide-stimulated RAW 264.7 cells. To confirm the inhibitory effect of ethyl acetate fraction of FTM (EAFM) on inflammation, the expression of nitric oxide (NO) and inflammatory cytokines was assessed by performing ELISA. Expression of intracellular mRNA and protein was confirmed by reverse transcription PCR and western blotting. In addition, the anti-inflammatory and anti-oxidant mechanisms of NF-κB, MAPK and heme oxygenase-1 (HO-1) were also investigated. EAFM significantly inhibited the expression of inflammatory factors including NO, IL-6 and TNF-α at non-toxic concentrations. EAFM also inhibited the mRNA and protein expression of inducible nitric oxide synthase in a concentration-dependent manner, but did not alter the expression of cyclooxygenase-2. Pre-treatment with EAFM inhibited the nuclear translocation of NF-κB, and suppressed the phosphorylation of ERK and JNK. In addition, EAFM induced 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and an increase in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1. The results indicated that EAFM inhibited the expression of pro-inflammatory cytokines by inhibiting ERK/JNK phosphorylation and NF-κB translocation. EAFM also exerted antioxidant effects via Nrf2/HO-1 stimulation. Collectively, the results of the present study indicated that EAFM may be a valuable alternative for the treatment of a variety of inflammatory diseases.

S-deoxydihydroglyparvin from Glycosmis parva inhibits lipopolysaccharide induced murine macrophage activation through inactivating p38 mitogen activated protein kinase

Macrophages play major roles to produce several pro-inflammatory and inflammatory mediators in chronic inflammatory diseases. All current anti-inflammatory drugs target these mediators to alleviate inflammation. Searching for new anti-inflammatory agents is always needed due to problems from the clinical use of current anti-inflammatory drugs. We intended to evaluate the anti-inflammatory potential of three main compounds, arborinine, methylatalaphylline, and S-deoxydihydroglyparvin (DDGP), from Glycosmis parva leaves and branches on macrophage stimulated by lipopolysaccharide (LPS). Only DDGP demonstrated a potent inhibitor of LPS-activated macrophages. Results indicated that the mRNA level of inducible nitric oxide synthase (iNOS) was inhibited by the treatment in accompany with the decreased nitric oxide (IC50 at 3.47 ± 0.1 μM). DDGP was shown to suppress tumor necrosis factor-α, interleukin (IL)-1, and IL-6 at the mRNA expression and at the released protein levels. In addition, DDGP inhibited the several chemokines, monocyte chemoattractant protein-1 and macrophage inflammatory proteins-1α, and enzymes for prostaglandin (PG) synthesis. It also inhibited PGE2 production. On LPS signaling pathways, DDGP profoundly decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK) in the LPS-treated cells. It had little or no effect on the activation of JNK, ERK and nuclear factor kappa B. In conclusion, results suggested that DDGP from G. parva inhibited expression and production of inflammatory molecules in LPS-activated macrophages through suppressing p38 MAPK activation. DDGP should be a good candidate anti-inflammatory agent in the future.

Chemically-Induced Inflammation Changes the Number of Nitrergic Nervous Structures in the Muscular Layer of the Porcine Descending Colon

Simple Summary

The enteric nervous system (ENS) is the part of the nervous system that is located in the wall of the gastrointestinal tract and regulates the majority of the functions of the stomach and intestine. The ENS is characterized by a complex structure and a high degree of independence from the brain. It is known that the ENS changes under the impact of physiological and pathological stimuli. One of the active substances synthetized by enteric neurons is nitric oxide (NO), which is involved in the regulation of intestinal motility, blood flow, secretory activity, and immunological processes in the gastrointestinal tract. In the present study, the influence of chemically-induced inflammatory process on a number of nitrergic neuronal structures located in the muscular layer of the descending colon is investigated. An increase in the number of structures that nitric oxide takes part in is correlated with the inflammatory processes.

Abstract

The enteric nervous system (ENS) is the part of the nervous system that is located in the wall of the gastrointestinal tract and regulates the majority of the functions of the stomach and intestine. Enteric neurons may contain various active substances that act as neuromediators and/or neuromodulators. One of them is a gaseous substance, namely nitric oxide (NO). It is known that NO in the gastrointestinal (GI) tract may possess inhibitory functions; however, many of the aspects connected with the roles of this substance, especially during pathological states, remain not fully understood. An experiment is performed here with 15 pigs divided into 3 groups: C group (without any treatment), C1 group (“sham” operated), and C2 group, in which experimental inflammation was induced. The aim of this study is to investigate the influence of inflammation on nitrergic nervous structures in the muscular layer of the porcine descending colon using an immunofluorescence method. The obtained results show that inflammation causes an increase in the percentage of nitric oxide synthase (nNOS)-positive neurons in the myenteric plexus of the ENS, as well as the number of nitrergic nerve fibers in the muscular layer of the descending colon. The obtained results suggest that NO is involved in the pathological condition of the large bowel and probably takes part in neuroprotective and/or adaptive processes.

Inflammatory Response Mechanisms of the Dentine-Pulp Complex and the Periapical Tissues

The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.

Current Advances of Nitric Oxide in Cancer and Anticancer Therapeutics

Nitric oxide (NO) is a short-lived, ubiquitous signaling molecule that affects numerous critical functions in the body. There are markedly conflicting findings in the literature regarding the bimodal effects of NO in carcinogenesis and tumor progression, which has important consequences for treatment. Several preclinical and clinical studies have suggested that both pro- and antitumorigenic effects of NO depend on multiple aspects, including, but not limited to, tissue of generation, the level of production, the oxidative/reductive (redox) environment in which this radical is generated, the presence or absence of NO transduction elements, and the tumor microenvironment. Generally, there are four major categories of NO-based anticancer therapies: NO donors, phosphodiesterase inhibitors (PDE-i), soluble guanylyl cyclase (sGC) activators, and immunomodulators. Of these, NO donors are well studied, well characterized, and also the most promising. In this study, we review the current knowledge in this area, with an emphasis placed on the role of NO as an anticancer therapy and dysregulated molecular interactions during the evolution of cancer, highlighting the strategies that may aid in the targeting of cancer.

Tryptanthrin from microwave-assisted reduction of isatin using solid-state-supported sodium borohydride: DFT calculations, molecular docking and evaluation of its analgesic and anti-inflammatory activity

Tryptanthrin is a potent natural alkaloid with good in vitro pharmacological properties. Herein, we report the synthesis of the compound via a new method involving the reduction of isatin with solid-state-supported sodium borohydride under microwave irradiation. The title compound has been tested for its analgesic and anti-inflammatory activity. The results showed that tryptanthrin dose dependently inhibits oedema and pain formation in all the models used. The agent also exhibited significant higher effects in its anti-inflammatory and analgesic activities better than positive drugs (aspirin and indomethacin) being currently used in the treatment and in the management of acute and chronic forms of pain and inflammatory disorders. The inhibitory potential of the compound was investigated by molecular docking using the software AutoDock Vina. The docking results were used to better rationalize the action and prediction of the binding affinity of tryptanthrin. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (2df, 2pd) level of theory showed that compared to ascorbic acid, tryptanthrin shows higher antioxidant activity which may be improved upon by functionalizing the aromatic core to enhance its solubility in polar solvents. The calculated electronic and thermodynamic properties obtained for tryptanthrin compete well with the standard ascorbic acid.

Antileishmanial Chemotherapy through Clemastine Fumarate Mediated Inhibition of the Leishmania Inositol Phosphorylceramide Synthase

Current chemotherapeutics for leishmaniasis have multiple deficiencies, and there is a need for new safe, efficacious, and affordable medicines. This study describes a successful drug repurposing approach that identifies the over-the-counter antihistamine, clemastine fumarate, as a potential antileishmanial drug candidate. The screening for inhibitors of the sphingolipid synthase (inositol phosphorylceramide synthase, IPCS) afforded, following secondary screening against Leishmania major (Lmj) promastigotes, 16 active compounds. Further refinement through the dose response against LmjIPCS and intramacrophage L. major amastigotes identified clemastine fumarate with good activity and selectivity with respect to the host macrophage. On target engagement was supported by diminished sensitivity in a sphingolipid-deficient L. major mutant (ΔLmjLCB2) and altered phospholipid and sphingolipid profiles upon treatment with clemastine fumarate. The drug also induced an enhanced host cell response to infection indicative of polypharmacology. The activity was sustained across a panel of Old and New World Leishmania species, displaying an in vivo activity equivalent to the currently used drug, glucantime, in a mouse model of L. amazonensis infection. Overall, these data validate IPCS as an antileishmanial drug target and indicate that clemastine fumarate is a candidate for repurposing for the treatment of leishmaniasis.

Response of meat chickens to different sources of arginine in low-protein diets

Arginine activity in broiler diets can be supplied by L-arginine (Arg), guanidinoacetic acid (GAA) and L-citrulline (Cit), all of which are commercially available. This study was conducted to assess the effects of Arg source and level on broiler performance, nutrient digestibility and carcass parameters. Day-old Ross 308 cockerels (n = 768) were assigned to one of eight dietary treatments using a completely randomized design: normal protein (NP), low protein deficient in Arg (LP) and LP with two levels of either Arg (0.238% and 0.476%), GAA (0.309% and 0.618%) or Cit (0.238 and 0.476%). The LP was 5 percentage points lower in protein level than the NP. Wheat, sorghum, soya bean meal, canola meal, and meat and bone meal-based diets were fed over three feeding phases to 6 replicate floor pens with 16 birds each. Compared to NP, birds fed LP had reduced feed intake (FI, p < 0.001), reduced body weight gain (BWG, p < 0.001) and increased feed conversion ratio (FCR, p < 0.001) from day 0 to day 35. Additions of Arg or Cit to the LP at both levels resulted in increased BWG and reduced FCR (p < 0.05). Birds fed LP with GAA added had lower FCR (p < 0.05) but not higher BWG (p > 0.05) compared with the LP observed from day 0 to day 35. Supplementation of Arg, Cit and the low level of GAA to LP resulted in increased carcass yield, bone length, diameter and ash (p < 0.05) but did not increase ileal energy or nitrogen digestibility (p > 0.05). The findings indicate that Cit is an efficacious source of Arg activity in Arg-deficient diets.

Reference method for off-line analysis of nitrogen oxides in cell culture media by an ozone-based chemiluminescence detector

Nitric oxide (NO) and its by-products are important biological signals in human physiology and pathology particularly in the vascular and immune systems. Thus, in situ determination of the NO-related molecule (NO_x) levels using embedded sensors is of high importance particularly in the context of cellular biocompatibility testing. However, NO_x analytical reference method dedicated to the evaluation of biomaterial biocompatibility testing is lacking. Herein, we demonstrate a PAPA-NONOate-based reference method for the calibration of NO_x sensors. After, the validation of this reference method and its potentialities were demonstrated for the detection of the oxidative stress-related NO secretion of vascular endothelial cells in a 3D tissue issued from 3D printing. Such NO_x detection method can be an integral part of cell response to biomaterials. Graphical abstract.