Animal Models Of Inflammation Research Articles

Istradefylline, an adenosine A2a receptor antagonist, ameliorates neutrophilic airway inflammation and psoriasis in mice

AbstractObjectiveExtracellular adenosine is produced from secreted adenosine triphosphate by cluster of differentiation (CD)39 and CD73. Both are critical nucleotide metabolizing enzymes of the adenosine generating pathway and are secreted by neuronal or immune cells. Adenosine plays a role in energy processes, neurotransmission and endogenous regulation of inflammatory responses. Istradefylline is a selective adenosine A2a receptor antagonist used for the treatment of Parkinson's disease. We have reported that adenosine primes hypersecretion of interleukin (IL)‐17A through the adenosine A2a receptor. Istradefylline, as well as an inhibitor of CD39 (ARL67156) and an inhibitor of CD73 (AMP‐CP), suppressed IL‐17A production, and the administration of istradefylline to mice with experimental autoimmune encephalomyelitis led to the marked amelioration of the disease. These previous results suggest that adenosine is an endogenous modulator of neutrophilic inflammation. We investigated the effect of istradefylline, ARL67156 and AMP‐CP on other mouse models of neutrophilic inflammation.MethodsWe tested the effect of istradefylline, ARL67156 and AMP‐CP on ovalbumin‐induced neutrophilic airway inflammation or imiquimod‐induced psoriasis in mice. The two mice models received these drugs orally or percutaneously, respectively. The production of IL‐17A in the lung and ear thickness were used as an index of the effects.ResultsWe show that istradefylline, ARL67156 and AMP‐CP suppressed the ovalbumin‐induced IL‐17A production in the lung and imiquimod‐induced psoriasis.ConclusionThese results show that adenosine‐mediated IL‐17A production plays a role in neutrophilic inflammation models, and furthermore, istradefylline, ARL67156 and AMP‐CP are effective in animal models of neutrophilic inflammation. Some clinical relevancies in coronavirus disease 2019 are discussed.

Pharmacological evaluation of the gabapentin salicylaldehyde derivative, gabapentsal, against tonic and phasic pain models, inflammation, and pyrexia.

Gabapentinoids are effective drugs in most animal models of pain and inflammation with variable effects in humans. The current study evaluated the pharmacological activity of gabapentin (GBP) and its salicylaldehyde derivative (gabapentsal; [2-(1-(((2-hydroxybenzylidene) amino) methyl) cyclohexyl) acetic acid]; GPS) in well-established mouse models of nociceptive pain, inflammatory edema, and pyrexia at doses of 25-100 mg/kg. GPS allayed tonic visceral pain as reflected by acetic acid-induced nociception and it also diminished thermally induced nociception as a mimic of phasic thermal pain. Antagonism of GPS-induced antinociceptive activities by naloxone (NLX, 1.0 mg/kg, subcutaneously, s.c), beta-funaltrexamine (β-FNT, 5.0 mg/kg, s.c), naltrindole (NT, 1.0 mg/kg, s.c), and nor-binaltorphimine (NOR-BNI, 5.0 mg/kg, s.c), and pentylenetetrazole (PTZ-15 mg/kg, intraperitoneally, i.p) implicated an involvement of both opioidergic and GABAergic mechanisms. Tail immersion test was conducted in order to delineate the mechanistic insights of antinociceptive response. Inflammatory edema induced by carrageenan, histamine, or serotonin was also effectively reversed by GPS in a fashion analogous to aspirin (150 mg/kg, i.p), chlorpheniramine (1.0 mg/kg, i.p), and mianserin (1.0 mg/kg, i.p), respectively. Additionally, yeast-induced pyrexia was decreased by GPS in a comparable manner to acetaminophen (50 mg/kg, i.p). These observations suggest that GPS possesses ameliorative properties in tonic, phasic, and tail immersion tests of nociception via opioidergic and GABAergic mechanisms, curbs inflammatory edema, and is antipyretic in nature.

Extracellular vesicles of Echinococcus granulosus have therapeutic effects in allergic airway inflammation.

Previous studies have shown that Echinococcus granulosus cystic fluid can alleviate Th2 allergic airway inflammatory responses by increasing the number of CD4+ CD25+ Foxp3+ T (regulatory T; Treg) cells. Parasite-derived extracellular vesicles (EV) are known to not only promote parasite infection by communicating between parasites but also regulate the inflammatory response by acting as an immunomodulatory agent in the host. To evaluate the effect of EV extracted from the cystic fluid of E. granulosus on allergic airway inflammation, gene expression was investigated after administering EV to mouse lung epithelial cells (MLE-12) following 2h of pretreatment with Aspergillus proteins. An allergic airway inflammation animal model was used to investigate the regulation of the inflammatory response by EV and induced with ovalbumin. EV treatment significantly reduced airway resistance and the number of eosinophils and other immune cells in the bronchoalveolar lavage fluid and Th2- and Th17-related cytokine levels. EV pretreatment decreased the number of IL-4+ CD4+ T cells and increased the number of Treg cells in the lung-draining lymph nodes and spleen. Echinococcus granulosus cystic fluid derived EV ameliorated Th2 allergic airway inflammatory through Treg cells, similar to whole cystic fluid treatment. Thus, EV may be important immunomodulatory molecules in cystic fluid.

Models of Inflammation: Carrageenan- or Complete Freund's Adjuvant (CFA)-Induced Edema and Hypersensitivity in the Rat.

Animal models of inflammation are used to assess the production of inflammatory mediators at sites of inflammation, the processing of pain sensation at CNS sites, the anti-inflammatory properties of agents such as nonsteroidal anti-inflammatory drugs (NSAIDs), and the efficacy of putative analgesic compounds in reversing cutaneous hypersensitivity. Detailed in this article are methods to elicit and measure carrageenan- and complete Freund's adjuvant (CFA)-induced cutaneous inflammation. Due to possible differences between the dorsal root sensory system and the trigeminal sensory system, injections into either the footpad or vibrissal pad are described. In this manner, cutaneous inflammation can be assessed in tissue innervated by the lumbar dorsal root ganglion neurons (footpad) or by the trigeminal ganglion neurons (vibrissal pad). © 2021 Wiley Periodicals LLC.

Oral Carbon Monoxide Therapy in Murine Models of Sickle Cell Disease: Beneficial Effects on Vaso-Occlusion, Inflammation and Anemia

Carbon monoxide (CO) at low, non-toxic concentrations has recently emerged as a powerful biological response modifier that exerts anti-inflammatory protection in many animal models of tissue inflammation and injury including sickle cell disease (SCD). The protection observed was associated with modulation of the innate and adaptive immune response and restoration of tissue and organ function. CO may also have a role as an antipolymerization hemoglobin S agent. Inhaled CO gas has been used to generate the majority of preclinical and clinical data regarding CO. However, inhaled CO is challenging to precisely dose given the variability of patient ventilation. Furthermore inhaled CO has environmental safety concerns for patients, as it requires the presence of large amounts of compressed CO gas in cylinders. Oral administration of CO avoids many of the issues associated with gas administration and provides a platform for outpatient administration. An oral formulation that would deliver low, non-toxic concentrations of CO, might be a better alternative for treating SCD patients.To test the efficacy of oral administration of CO, a liquid CO formulation (HBI-002) was administered by gavage to NY1DD and Townes-SS transgenic mouse models of SCD. Blood CO-hemoglobin (COHb) levels peaked within 5 minutes of oral administration. Baseline COHb levels were 1.6% and 1.8% in vehicle-treated NY1DD and Townes-SS sickle mice, respectively, compared to 0.9% in untreated Townes AA control mice (p<.05). Five minutes after oral gavage with HBI-002 (10 ml/kg, ~0.2 ml/mouse), COHb levels peaked at 5.4% in NY1DD mice and 4.7% in Townes-SS mice (p<.05 compared to vehicle).Oral CO (10 ml/kg) administered once daily for 1, 3 or 5 days inhibited hypoxia-induced microvascular stasis in NY1DD SCD mice in a duration dependent manner. Stasis was 27% in vehicle-treated mice, 21% when oral CO was administered 1 hour before hypoxia and 16% when administered 24 hours before hypoxia. Stasis was 10% after 3 daily treatments, and 6% after 5 daily treatments (Figure). In Townes-SS mice, stasis was 33% in vehicle-treated mice and 10% after 5 daily CO treatments (p<.01, CO versus vehicle).The effects of oral CO on blood counts were examined in Townes-SS mice treated with oral CO (n=4) or vehicle (n=3) (10 ml/kg, once daily X 10 days). Hemoglobin levels rose from 5.3 g/dL in vehicle-treated mice to 6.3 g/dL in CO-treated mice (p<.05). Similarly, red blood cell counts rose from 2.36 X 106/µL in vehicle-treated mice to 2.89 X 106/µL in CO-treated mice (p<.05). In concordance with these findings, hematocrits rose from 26.3% in vehicle-treated mice to 30.0% in CO-treated mice (p<.05). The percent reticuloctyes was not significantly different: 48.4% in vehicle-treated mice and 45.0% in CO-treated mice. The percentage of stained F-cells was similar (16%) in both treatment groups. White blood cell counts decreased from 29.1 X 103/µL in vehicle-treated mice to 20.3 X 103/µL in CO-treated mice (p<.01). Hepatic expression of two key anti-inflammatory proteins, Nrf2 and heme oxygenase-1 (HO-1), was increased in CO-treated SS mice. In agreement with these findings, hepatic expression of two pro-inflammatory proteins, NF-κB phospho-p65 and VCAM-1, was decreased in CO-treated SS mice.These data suggest that once daily oral CO treatment, at COHb levels below known toxicity, may have therapeutic potential in SCD. Further research is needed to carefully elucidate the safety and benefits of this potential gasotransmitter therapy in SCD patients who have many pathophysiological complications of this devastating disease. [Display omitted] DisclosuresBelcher:Hillhurst Biopharmaceuticals, Inc.: Other: I have an SBIR grant from NHLBI with Hillhurst Biopharmaceuticals, Inc.. Gomperts:Hillhurst Biopharmaceuticals, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Levy:Hillhurst Biopharmaceuticals, Inc.: Consultancy, Other: Senior Medical Advisor. Otterbein:Hillhurst Biopharmaceuticals, Inc.: Consultancy, Other: Principal Scientific Advisor. Vercellotti:Hillhurst Biopharmaceuticals, Inc.: Other: I have an SBIR grant with Hillhurst Biopharmaceuticals, Inc.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles attenuate experimental autoimmune encephalomyelitis via regulating pro and anti-inflammatory cytokines

The therapeutic effects of mesenchymal stem cells-extracellular vesicles have been proved in many inflammatory animal models. In the current study, we aimed to investigate the effect of extracellular vesicles (EVs) derived from human umbilical cord-MSC (hUCSC-EV) on the clinical score and inflammatory/anti-inflammatory cytokines on the EAE mouse model. After induction of EAE in C57Bl/6 mice, they were treated intravenously with hUCSC-EV or vehicle. The clinical score and body weight of all mice was registered every day. On day 30, mice were sacrificed and splenocytes were isolated for cytokine assay by ELISA. Cytokine expression of pro-/anti-inflammatory cytokine by real-time PCR, leukocyte infiltration by hematoxylin and eosin (H&E) staining, and the percent of glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) positive cells by immunohistochemistry were assessed in the spinal cord. Our results showed that hUCSC-EV-treated mice have lower maximum mean clinical score (MMCS), pro-inflammatory cytokines, and inflammatory score in comparison to the control mice. We also showed that hUCSC-EV administration significantly improved body weight and increased the anti-inflammatory cytokines and the frequency of Treg cells in the spleen. There was no significant difference in the percent of GFAP and MBP positive cells in the spinal cord of experimental groups. Finally, we suggest that intravenous administration of hUCSC-EV alleviate induce-EAE by reducing the pro-inflammatory cytokines, such as IL-17a, TNF-α, and IFN-γ, and increasing the anti-inflammatory cytokines, IL-4 and IL-10, and also decrease the leukocyte infiltration in a model of MS. It seems that EVs from hUC-MSCs have the same therapeutic effects similar to EVs from other sources of MSCs, such as adipose or bone marrow MSCs.

Anti-inflammatory Effects of Ojeok-san in LPS-induced Inflammatory Rat Model

Objectives The aim of this study is to investigate the anti-inflammatory effects of Ojeok-san and compare the therapeutic effects according to its formation. Methods We evaluated the anti-inflammatory effects of Ojeok-san using lipopolysaccharide (LPS) induced inflammatory animal model. Male SD rats were administered intra-orally with two different formulation types of Ojeok-san according to prescribed dosage. One hour later, to induce inflammatory responses, subsequent intra-peritoneal injection of LPS was conducted. After 5 hours later, serum TNF-α, IL-1β, IL-6 and PGE2 levels were measured by ELISA to assess the alteration of pro-inflammatory markers. Results In our experiment, regardless of its formation, administration of Ojeok-san decreased TNF-α, IL-1β, IL-6 and PGE2 level in serum. Furthermore, LPS-induced toxicity of liver and kidney was not detected by Ojeok-san administration. Conclusions The anti-inflammatory effect of Ojeok-san was shown in LPS-induced inflammatory model by decreasing pro-inflammatory markers, and there would be no significant difference in therapeutic effect between two formulation types of Ojeok-san. Keywords: Ojeok-san, lipopolysaccharide(LPS)-induced model, anti-inflammatory effect, pro-inflammatory markers

PA-Int5: An isatin-thiosemicarbazone derivative that exhibits anti-nociceptive and anti-inflammatory effects in Swiss mice.

Pain and inflammation are symptoms of various diseases, and they can be modulated by different pathways, thus highlighting the importance of investigating the therapeutic effects of novel compounds. Previous studies have shown that isatin-thiosemicarbazone exhibits antitumor, antifungal antibacterial and other biological properties. Based on the wide range of biological effects of these compounds, the aim of the present study was to investigate the central nervous system (CNS) performance, and the anti-nociceptive and anti-inflammatory activity of (Z)-2-(5-nitro-2-oxoindolin-3-ilidene)-N-hydroazinecarbothioamide (PA-Int5) in treated mice. Three doses of PA-Int5 were tested orally (1.0, 2.5 and 5.0 mg/kg) in the nociceptive and inflammatory animal models. Additionally, the potential sedative effects of PA-Int5 (5 mg/kg, oral gavage) were investigated using an open field and rotarod tests, to exclude any possible unspecific effects of the nociceptive assays. Anti-nociceptive activity was assessed using the acetic acid-induced abdominal contortion and formalin tests, whereas anti-inflammatory activity was assessed using a carrageenan-induced paw edema and zymosan-induced air-pouch models. PA-Int5 (5 mg/kg) induced anti-nociceptive activity in the abdominal contortion model. In the formalin test, PA-Int5 (at 2.5 and 5 mg/kg) reduced nociception in the second phase. At the higher dose tested, PA-Int5 did not affect spontaneous locomotion or motor coordination. The data revealed that at all doses tested, the compound significantly reduced paw edema following carrageenan administration. In the zymosan-induced air-pouch model, PA-Int5 potently inhibited leukocyte migration and protein levels at the site of inflammation. When combined, the results revealed, for the first time, that PA-Int5 exhibited anti-nociceptive and anti-inflammatory activities, and highlights its potential, as well that of other derivatives, as novel candidates for pain relief.

Magnolol attenuates inflammatory pain by inhibiting sodium currents in mouse dorsal root ganglion neurons.

Voltage-gated sodium channels are currently recognized as one of the targets of analgesics. Magnolol (Mag), an active component isolated from Magnolia officinalis, has been reported to exhibit analgesic effects. The objective of this study was to investigate whether the analgesic effect of Mag was associated with blocking Na+ channels. Inflammatory pain was induced by the injection of carrageenan into the hind paw of mice. Mag was administered orally. Mechanical hyperanalgesia was evaluated by using von Frey filaments. Na+ currents and neuronal excitability in acutely isolated mouse dorsal root ganglion (DRG) neurons were recorded with the whole-cell patch clamp technique. Results showed that Mag (10~40mg/kg) dose-dependently inhibited the paw edema and reduced mechanical pain in the inflammatory animal model. Injection of carrageenan significantly increased the amplitudes of TTX-sensitive and TTX-resistant Na+ currents. Compared with the carrageenan group, Mag inhibited the upregulation of two types of Na+ currents induced by carrageenan in a dose-dependent manner. Mag 40mg/kg shifted the inactivation curves of two types of Na+ currents to hyperpolarization and returned to normal animal level without changing their activation curves. Mag 40mg/kg significantly reduced the percentage of cells firing multiple spikes and inhibited the neuronal hyperexcitability induced by carrageenan. Our data suggest that the analgesic effect of Mag may be associated with a decreased neuronal excitability by blocking Na+ current.

High-fat diet promotes hypothalamic inflammation in animal models: a systematic review.

Hypothalamic inflammation and dysfunction may be induced by high-fat diets. However, the mechanisms involved in this process have not been fully elucidated. To evidence, in animal models, of how a high-fat diet influence the mechanisms involved in hypothalamic inflammation. Scopus, PubMed/Medline, Web of Science, Science Direct, and Embase databases were searched. The exclusion criteria were human studies, studies with medicinal products or other substances not related to food, paper reviews, studies that used a surgical intervention or an intervention with food to reverse hypothalamic inflammation, and studies with genetically modified animals. The identified studies were evaluated according to the following inclusion criteria: animal studies, studies in which a control group was included in the experimental design, and studies in which markers of inflammation in the hypothalamus were evaluated. A total of 322 studies were found, of which 9 met the inclusion criteria for a systematic review, conducted in accordance with the PRISMA guidelines, and were included in this review. The exposure of rodents to high-fat diets promoted an increase in levels of several pro-inflammatory cytokines and other proteins involved in the inflammatory process in the hypothalamus. This process was associated with increased glial cell activity.

Inhibition of hyaluronan secretion by novel coumarin compounds and chitin synthesis inhibitors.

Elevated plasma levels of hyaluronic acid (HA) is a disease marker in liver pathology and other inflammatory disorders. Inhibition of HA synthesis with coumarin 4-methylumbelliferone (4MU) has a beneficial effect in animal models of fibrosis, inflammation, cancer and metabolic syndrome. 4MU is an active compound of approved choleretic drug hymecromone with low bioavailability and a broad spectrum of action. New, more specific and efficient inhibitors of hyaluronan synthases (HAS) are required. We have tested several newly synthesized coumarin compounds and commercial chitin synthesis inhibitors to inhibit HA production in cell culture assay. Coumarin derivative compound VII (10′-methyl-6′-phenyl-3′H-spiro[piperidine-4,2′-pyrano[3,2-g]chromene]-4′,8′-dione) demonstrated inhibition of HA secretion by NIH3T3 cells with the half-maximal inhibitory concentration (IC50) = 1.69 ± 0.75 μΜ superior to 4MU (IC50 = 8.68 ± 1.6 μΜ). Inhibitors of chitin synthesis, etoxazole, buprofezin, triflumuron, reduced HA deposition with IC50 of 4.21 ± 3.82 μΜ, 1.24 ± 0.87 μΜ and 1.48 ± 1.44 μΜ, respectively. Etoxazole reduced HA production and prevented collagen fibre formation in the CCl4 liver fibrosis model in mice similar to 4MU. Bioinformatics analysis revealed homology between chitin synthases and HAS enzymes, particularly in the pore-forming domain, containing the proposed site for etoxazole binding.

The effective interplay of (non-) selective NSAIDs with neostigmine in animal models of analgesia and inflammation

BackgroundSurgical procedures cause perioperative immunosuppression and neuroendocrine stress, exerted by activation of the autonomic nervous system and the hypothalamic-pituitary-adrenal axis. The acetylcholinesterase inhibitor (ACHEI); neostigmine, is known clinically for its analgesic effect in the perioperative phases proving high efficacy; besides possessing anti-inflammatory properties controlling immune cells and cytokine level. Hence, this study evaluated and compared the analgesic and anti-inflammatory activities of the combination of selective Cox-2 inhibitor; celecoxib, with neostigmine versus a combination of the non-selective Cox inhibitor; diclofenac, with neostigmine; in different experimental models of analgesia and inflammation in rats.MethodsAnalgesic activity of neostigmine with/without diclofenac or celecoxib was assessed in female Sprague-Dawely rats using the tail clip model and acetic acid induced writhing. Serum level of β-endorphin was assessed after the tail clip test. The anti-inflammatory activity was evaluated using acute and sub-chronic formalin induced paw edema. At the end of the sub-chronic formalin test, blood samples were collected for analysis of anti-inflammatory, liver and kidney function markers. Livers, kidneys and hind paws were also examined histopathologically.ResultsAddition of neostigmine to selective or non-selective NSAIDs (celecoxib or diclofenac) causes an increased level of analgesia of NSAIDs with rapid onset of action and short duration, while causing potentiation of the anti-inflammatory effect of neostigmine as seen in the tail clip, writhing, formalin test, Cox-1 and Cox-2 activities, serum β-endorphin, TNF-α, NF-кB and HS-CRP. All combinations of this study disturb some kidney and liver functions, however with normal histopathological appearances, while hind paws reveal improved inflammatory infiltration in all treated groups.ConclusionsSelective and non-selective NSAIDs examined in this study could be good adjunct options to general anesthetic agents and neostigmine in perioperative stages, an outcome that needs further clinical investigations.

The Effects of Cannabinoids on Pro- and Anti-Inflammatory Cytokines: A Systematic Review of In Vivo Studies.

Introduction: Some cannabinoids have been identified as anti-inflammatory agents; however, their potential therapeutic or prophylactic applications remain controversial. The aim of this systematic review was to provide a timely and comprehensive insight into cannabinoid-mediated pro- and anti-inflammatory cytokine responses in preclinical in vivo studies. Methods and Materials: A systematic search was conducted using PubMed, Web of Science, EMBASE, and Scopus. Eligible studies where cannabinoids had been evaluated for their effect on inflammation in animal models were included in the analysis. Data were extracted from 26 of 4247 eligible full text articles, and risk of bias was assessed using the SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) tool. Studies examined cannabidiol (CBD; n=20); cannabigerol (CBG; n=1); delta 9-tetrahydrocannabinol (THC; n=2); THC and CBD separately (n=1); and THC and CBD in combination (n=2). Results: Tumor necrosis factor alpha, interleukin (IL)-1β, IL-6, and interferon gamma were the most commonly studied pro-inflammatory cytokines and their levels were consistently reduced after treatment with CBD, CBG, or CBD+THC, but not with THC alone. The association between cannabinoid-induced anti-inflammatory response and disease severity was examined. In 22 studies where CBD, CBG, or CBD in combination with THC were administered, a reduction in the levels of at least one inflammatory cytokine was observed, and in 24 studies, some improvements in disease or disability were apparent. THC alone did not reduce pro-inflammatory cytokine levels (n=3), but resulted in improvements in neuropathic pain in one study. Conclusions: This review shows that CBD, CBG, and CBD+THC combination exert a predominantly anti-inflammatory effect in vivo, whereas THC alone does not reduce pro-inflammatory or increase anti-inflammatory cytokines. It is anticipated that this information could be used to inform human clinical trials of cannabinoids, focusing on CBD and CBG to reduce inflammation across a range of pathophysiological processes.

Antibacterial Mechanisms and Efficacy of Sarecycline in Animal Models of Infection and Inflammation.

Prolonged broad-spectrum antibiotic use is more likely to induce bacterial resistance and dysbiosis of skin and gut microflora. First and second-generation tetracycline-class antibiotics have similar broad-spectrum antibacterial activity. Targeted tetracycline-class antibiotics are needed to limit antimicrobial resistance and improve patient outcomes. Sarecycline is a narrow-spectrum, third-generation tetracycline-class antibiotic Food and Drug Administration (FDA)-approved for treating moderate-to-severe acne. In vitro studies demonstrated activity against clinically relevant Gram-positive bacteria but reduced activity against Gram-negative bacteria. Recent studies have provided insight into how the structure of sarecycline, with a unique C7 moiety, interacts with bacterial ribosomes to block translation and prevent antibiotic resistance. Sarecycline reduces Staphylococcus aureus DNA and protein synthesis with limited effects on RNA, lipid, and bacterial wall synthesis. In agreement with in vitro data, sarecycline demonstrated narrower-spectrum in vivo activity in murine models of infection, exhibiting activity against S. aureus, but reduced efficacy against Escherichia coli compared to doxycycline and minocycline. In a murine neutropenic thigh wound infection model, sarecycline was as effective as doxycycline against S. aureus. The anti-inflammatory activity of sarecycline was comparable to doxycycline and minocycline in a rat paw edema model. Here, we review the antibacterial mechanisms of sarecycline and report results of in vivo studies of infection and inflammation.

2D vanadium carbide MXenzyme to alleviate ROS-mediated inflammatory and neurodegenerative diseases

Reactive oxygen species (ROS) are generated and consumed in living organism for normal metabolism. Paradoxically, the overproduction and/or mismanagement of ROS have been involved in pathogenesis and progression of various human diseases. Here, we reported a two-dimensional (2D) vanadium carbide (V2C) MXene nanoenzyme (MXenzyme) that can mimic up to six naturally-occurring enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPx), thiol peroxidase (TPx) and haloperoxidase (HPO). Based on these enzyme-mimicking properties, the constructed 2D V2C MXenzyme not only possesses high biocompatibility but also exhibits robust in vitro cytoprotection against oxidative stress. Importantly, 2D V2C MXenzyme rebuilds the redox homeostasis without perturbing the endogenous antioxidant status and relieves ROS-induced damage with benign in vivo therapeutic effects, as demonstrated in both inflammation and neurodegeneration animal models. These findings open an avenue to enable the use of MXenzyme as a remedial nanoplatform to treat ROS-mediated inflammatory and neurodegenerative diseases.

Acquired platelet GPVI receptor dysfunction in critically ill patients with sepsis

Glycoprotein VI (GPVI), the platelet immunoreceptor tyrosine activating motif (ITAM) receptor for collagen, plays a striking role on vascular integrity in animal models of inflammation and sepsis. Understanding ITAM-receptor signaling defects in humans suffering from sepsis may improve our understanding of the pathophysiology, especially during disease onset. In a pilot study, platelets from 15 patients with sepsis were assessed consecutively at day of admission, day 5 to 7, and the day of intensive care unit (ICU) discharge and subjected to comprehensive analyses by flow cytometry, aggregometry, and immunoblotting. Platelet function was markedly reduced in all patients. The defect was most prominent after GPVI stimulation with collagen-related peptide. In 14 of 15 patients, GPVI dysfunction was already present at time of ICU admission, considerably before the critical drop in platelet counts. Sepsis platelets failed to transduce the GPVI-mediated signal to trigger tyrosine phosphorylation of Syk kinase or LAT. GPVI deficiency was partially inducible in platelets of healthy donors through coincubation in whole blood, but not in plasma from patients with sepsis. Platelet aggregation upon GPVI stimulation increased only in those patients whose condition ameliorated. As blunted GPVI signaling occurred early at sepsis onset, this defect could be exploited as an indicator for early sepsis diagnosis, which needs to be confirmed in prospective studies.

Curcumin alleviates LPS-induced retinal inflammation by inhibiting PI3k/Akt signaling pathway

AIM: To investigate whether the curcumin reduce retinal inflammation in animal model and human retinal pigment epithelium (ARPE)-19 cells. METHODS: In vivo, male C57/B6 mice received intraperitoneal injections of curcumin for 3d before intraperitoneal injection of lipopolysaccharide (LPS; 10 mg/kg) to induce retinal inflammation. 24h after LPS application, the mRNA levels of pro-inflammatory cytokines were detected by real-time polymerase chain reaction (RT-PCR). Concanavalin A lectin perfusion-labeling technique evaluated leukocyte adhesion to the retinal vasculature. The protein concentration in the anterior chamber was measured with a protein quantification kit. In vitro, ARPE-19 cells were cultured. The optimum concentration of curcumin was detected by cell counting kit-8 (CCK-8) assay. Before stimulated with 5 μg/mL LPS, ARPE-19 cells were incubated with or without curcumin for 1h. Pro-inflammatory cytokines were measured by RT-PCR and ELISA. PI3K/Akt expression was analyzed by Western blotting. RESULTS: Curcumin pre-treatment led to significant inhibition of EIU-associated leukocyte adhesion to retinal blood vessels and anterior-chamber protein leakage. The mRNA expression level of inflammatory cytokines was also significantly reduced with application of curcumin in vivo, such as IL-1β, IL-6 and TNF-α. Meanwhile, Curcumin significantly attenuated the expression of IL-6, IL-8 and MCP-1 at both mRNA and protein levels in ARPE-19 cells. Curcumin suppressed PI3K/Akt phosphorylation as well as NF-κB activation in LPS-activated ARPE-19 cells. CONCLUSION: Curcumin plays a preventive effect on LPS-induced retinal inflammation. The beneficial effect appears associated with inhibiting of the PI3k/Akt signaling pathway.

Anti-Inflammatory Effect of Phytoncide in an Animal Model of Gastrointestinal Inflammation.

Background: Phytoncide is known to have antimicrobial and anti-inflammatory properties. Purpose: This study was carried out to confirm the anti-inflammatory activity of two types of phytoncide extracts from pinecone waste. Methods: We made two types of animal models to evaluate the efficacy, an indomethacin-induced gastroenteritis rat model and a dextran sulfate sodium-induced colitis mouse model. Result: In the gastroenteritis experiment, the expression of induced-nitric oxide synthase (iNOS), a marker for inflammation, decreased in the phytoncide-supplemented groups, and gastric ulcer development was significantly inhibited (p < 0.05). In the colitis experiment, the shortening of the colon length and the iNOS expression were significantly suppressed in the phytoncide-supplemented group (p < 0.05). Conclusions: Through this study, we confirmed that phytoncide can directly inhibit inflammation in digestive organs. Although further research is needed, we conclude that phytoncide has potential anti-inflammatory properties in the digestive tract and can be developed as a functional agent.

Simple heteroaryl modifications in the 4,5-diarylisoxazol-3-carboxylic acid scaffold favorably modulates the activity as dual mPGES-1/5-LO inhibitors with in vivo efficacy

Microsomal prostaglandin E2 synthase-1 (mPGES-1), 5-lipoxygenase (5-LO) and 5- lipoxygenase-activating protein (FLAP) are key for biosynthesis of proinflammatory lipid mediators and pharmacologically relevant drug targets. In the present study, we made an attempt to explore the role of small heteroaromatic fragments on the 4,5-diarylisoxazol-3-carboxylic acid scaffold, which are selected to interact with focused regions in the active sites of mPGES-1, 5-LO and FLAP. We report that the simple structural variations on the benzyloxyaryl side-arm of the scaffold significantly influence the selectivity against mPGES-1, 5-LO and FLAP, enabling to produce multi-target inhibitors of these protein targets, exemplified by compound 18 (IC50 mPGES-1 = 0.16 µM; IC50 5-LO = 0.39 µM) with in vivo efficacy in animal model of inflammation. The computationally modeled binding structures of these new inhibitors for three targets provide clues for rational design of modified structures as multi-target inhibitors. In conclusion, the simple synthetic procedure, and the possibility of enhancing the potency of this class of inhibitors through structural modifications pave the way for further development of new multi-target inhibitors against mPGES-1, 5-LO and FLAP, with potential application as anti-inflammatory agents.

Burn Ointment Promotes Cutaneous Wound Healing by Modulating the PI3K/AKT/mTOR Signaling Pathway.

Burn ointment (BO) is a clinically useful medicine for the treatment of burns and scalds. However, there is no enough scientific evidence to report the effect of BO on wound healing and its analgesic and anti-inflammatory efficacy. The aim of this work was to evaluate the anti-inflammatory and analgesic efficacy of BO and to reveal the potential wound healing properties and related mechanisms of BO. In this work, the content of active ingredients of BO was determined by high-performance liquid chromatography (HPLC). Two animal models of inflammation were used to study its anti-inflammatory activity, and a hot plate method was used to evaluate its analgesic effect. In addition, mouse incision and rat burn models were used to investigate the effect of BO on the anti-inflammatory and wound healing mechanisms. The results showed that BO was safe for topical application, and BO could significantly inhibit auricular swelling in mice and paw swelling in rats and significantly prolong the latency period of paw licking in the hot plate experiment in mice. It can also accelerate wound healing and repair scars by promoting the formation of new epithelial tissues in rat burn models. In addition, BO significantly downregulated the serum level of TNF-α and significantly increased the serum levels of VEGF and TGF-β1. Also, BO promoted the expression of collagen I and increased the ratio in p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR pathways. Our results demonstrate the safety and efficacy of BO and suggest that activation of the PI3K/AKT/mTOR signaling pathway may play an important role in the promotion of wound healing by BO.