Zymosan-induced Inflammation Research Articles

The Involvement of Glutamate-mGluR5 Signaling in the Development of Vulvar Hypersensitivity.

Provoked vulvodynia (PV) is the leading cause of vulvar pain and dyspareunia. The etiology of PV is multifactorial and remains poorly understood. PV is associated with a history of repeated vulvar inflammation and is often accompanied by sensory neuromodulation as a result of activation of the metabotropic glutamate receptor 5 (mGluR5) in the sensory nerve terminals. Therefore, this study aims to examine the role of glutamate-mGluR5 signaling during the initial inflammatory phase in chronic vulvar pain development in an animal model of PV.Thermal and mechanical vulvar sensitivity was assessed for three weeks following zymosan vulvar challenges. Anxiety-like behavior and locomotor activity were assessed at the end of the experiment. To investigate the role of glutamate mGluR5, the MTEP (mGluR5 antagonist) was injected into the vulva during vulvar inflammation. On the other hand, glutamate or CHPG (mGluR5 agonist) were injected in order to examine the effects of mGluR5 activation. RT-PCR was performed to assess changes in the transcription of genes related to neuroinflammation, neuromodulation, and neuroplasticity in the spinal cord (L6-S3). Zymosan-induced inflammation resulted in a significant thermal and mechanical vulvar hypersensitivity that persisted for over a month after the zymosan injection. However, local treatment with MTEP enhanced the vulvar mechanical and thermal hypersensitivity. On the other hand, activation of the mGluR5 via injection of glutamate or CHPG into the vulva leads to long-lasting vulvar mechanical and thermal hypersensitivity. The activation of the glutamate pathway was found to be accompanied by an increase in the transcription level of genes related to neuroinflammation and neuroplasticity in the sacral spine region. The present findings indicate that vulvar hypersensitivity is mediated by mGluR5 activation during inflammation. Hence, modulation of the mGluR5 pathway during the critical period of inflammation contributes to preventing chronic vulvar pain development. Conversely, activation of the mGluR5 pathway leads to long-lasting mechanical and thermal hypersensitivity.

Anti-arthritic potential and antioxidant properties of infusion, fractions and flavonoid glycosides from Dipteryx alata (baru) leaves

Ethnopharmacological relevanceDipteryx alata Vogel., popularly known as “baru", is a native species of Brazilian cerrado used by “Ribeirinhos” in the North Araguaia microregion. In the traditional medicine, maceration of barks or leaves infusion are used to treat back and muscle pain, osteoporosis and rheumatism. However, few studies have demonstrated the pharmacological effects of this species. Aim of the studyThe goal of this study was to perform phytochemicals studies of lyophilized infusion of D. alata leaves (LI-DA), as well as obtaining ethyl acetate fraction (EAF-DA) and hydromethanolic fraction (HMF-DA), and isolated flavonoids. The antioxidant of LI-DA, EAF-DA and HMF-DA, anti-inflammatory effects of LI-DA and quercetin-3-O-β-glucoside-7-O-α-rhamnoside (DA-1) and quercetin-7-O-α-rhamnoside (DA-2) were performed while in silico tests were used for absorption, distribution, metabolism, excretion and toxicity predictions of DA-1 and DA-2. Materials and methodsLI-DA, EAF-DA and HMF-DA were evaluated in antioxidant assays (2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid – ABTS; 2,2-diphenyl-1-picrylhydrazyl – DPPH; hydrogen peroxide - H2O2; reducing power and oxidation of β-carotene). The DA-1 and DA-2 were isolated from EAF-DA using chromatographic methods and characterized by Nuclear Magnetic Resonance (NMR) spectrometer. The Programs ProTox 3.0 and ADMETlab 2.0 were used for the prediction studies of DA-1 and DA-2. Mice received a single dose of LI-DA (3, 30, and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) and were subjected to inflammation induced by Complete Freund's Adjuvant (CFA) and in the zymosan-induced articular inflammation model. ResultsDA-1 and DA-2 have been identified for the first time in the leaves of D. alata. LI-DA, EAF-DA and HMF-DA demonstrated a high level of antioxidant activity as measured by ABTS (IC50 ≤ 5.62 μg/mL) and DPPH (IC50 ≤ 11.45 μg/mL). Oral administration of LI-DA (3, 30 and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) showed significantly reduced edema, cold and mechanical allodynia in the CFA-induced inflammation model (24 h). LI-DA (3, 30, and 100 mg/kg) and DA-1 (3 mg/kg) reduced leukocytes migration into the joint cavity, mechanical allodynia, edema and NO production in mice (24 h) in the zymosan-induced articular inflammation model. Additionally, DA-2 (3 mg/kg) reduced leukocyte migration and LI-DA (30 mg/kg) reduced protein exudation (24 h) in zymosan model. DA-1 and DA-2 showed good oral bioavailability and low toxicity predicted by the ProTox model. ConclusionThis is the first chemical and biological study performed of D. alata infusion and two quercetin glycoside derivatives. The results indicated promising potential for the treatment of inflammation, pain, and rheumatism, supporting the traditional use of the infusion obtained from the leaves of D. alata.

Analgesic and Anti-Arthritic Potential of Methanolic Extract and Palmatine Obtained from Annona squamosa Leaves

Background/Objectives: Annona squamosa is used in folk medicine to treat pain and arthritis. Palmatine is an alkaloid isolated from several plants, including A. squamosa leaves. The aim of the present study was to investigate the analgesic, anti-arthritic, and anti-inflammatory potential of the methanolic extract of A. squamosa (EMAS) and palmatine. Methods: The chemical profile of EMAS was evaluated by ultra high-performance liquid chromatography with electrospray ionization coupled to mass spectrometry (UHPLC-ESI/MS). EMAS and palmatine were evaluated in carrageenan-induced pleurisy, zymosan-induced joint inflammation, formalin-induced nociception, and tumor necrosis factor (TNF)-induced mechanical hyperalgesia in experimental models in mice. A cytotoxicity test of EMAS and palmatine was performed using a methylthiazolidiphenyl-tetrazolium (MTT) bromide assay. Results: The analysis of the chemical profile of the extract showed the presence of palmatine, liriodenine, and anonaine. Oral administration of EMAS and palmatine significantly reduced leukocyte migration and oxide nitric production in the carrageenan-induced pleurisy model. EMAS and palmatine reduced mechanical hyperalgesia, leukocyte migration, and edema formation in the joint inflammation induced by zymosan. In the formalin test, palmatine was effective against the second-phase nociceptive response, mechanical hyperalgesia, and cold allodynia. In addition, palmatine reduced mechanical hyperalgesia induced by TNF. EMAS and palmatine did not demonstrate cytotoxicity. Conclusions: The present study showed that A. squamosa and palmatine are analgesic and anti-inflammatory agents, and that the anti-hyperalgesic properties of palmatine may involve the TNF pathway. Palmatine may be one of the compounds responsible for the anti-hyperalgesic and/or anti-arthritic properties of this medicinal plant.

Low-dose pro-resolving mediators temporally reset the resolution response to microbial inflammation

BackgroundSpecialized pro-resolving mediators (SPMs) promote resolution of inflammation, clear infections and stimulate tissue regeneration. These include resolvins, protectins, and maresins. During self-resolving acute inflammation, SPMs are produced and have key functions activating endogenous resolution response for returning to homeostasis. Herein, we addressed whether infections initiated with ongoing inflammation alter resolution programs, and if low-dose repetitive SPM regimen re-programs the resolution response.MethodsInflammation was initiated with zymosan (1 mg/mouse) followed by E. coli (105 CFU/mouse) infections carried out in murine peritonitis, and exudates collected at 4-72 h. Leukocytes were enumerated using light microscopy, percentages of PMN, monocytes and macrophages were determined using flow cytometry, and resolution indices calculated. Lipid mediators and SPM profiles were established using mass spectrometry-based metabololipidomics. Repetitive dosing with a SPM panel consisting of RvD1, RvD2, RvD5, MaR1 and RvE2 (0.1 ng/mouse each, i.p.) was given to mice, followed by zymosan challenge. Leukocyte composition, resolution indices and RNA-sequencing were carried out for the repetitive SPM treatments.ResultsE. coli infections initiated acute inflammation-resolution programs with temporal SPM production in the infectious exudates. Zymosan-induced inflammation prior to E. coli peritonitis shifted exudate resolution indices and delayed E. coli clearance. Lipid mediator metabololipidomics demonstrated that E. coli infection with ongoing zymosan-induced inflammation shifted the time course of exudate SPMs, activating a SPM cluster that included RvD1, RvD5 and MaR1 during the initiation phase of infectious inflammation (0-4 h); RvD5 and MaR1 were present also in the resolution phase (24-48 h). To emulate daily SPM regimens used in humans, a repetitive subthreshold dosing of the SPM panel RvD1, RvD2, RvD5, MaR1 and RvE2 each at 0.1 ng per mouse was administered. This low-dose SPM regimen accelerated exudate PMN clearance following zymosan-induced inflammation, and shortened the resolution interval by > 70%. These low-dose SPMs regulated genes and pathways related to immune response, chemokine clearance and tissue repair, as demonstrated by using RNA-sequencing.ConclusionsInfections encountered during ongoing inflammation in mice reset the resolution mechanisms of inflammation via SPM clusters. Low-dose SPMs activate innate immune responses and pathways towards the resolution response that can be reprogrammed.

A miR-383-5p Signaling Hub Coordinates the Axon Regeneration Response to Inflammation.

Neuroinflammation can positively influence axon regeneration following injury in the central nervous system. Inflammation promotes the release of neurotrophic molecules and stimulates intrinsic proregenerative molecular machinery in neurons, but the detailed mechanisms driving this effect are not fully understood. We evaluated how microRNAs are regulated in retinal neurons in response to intraocular inflammation to identify their potential role in axon regeneration. We found that miR-383-5p is downregulated in retinal ganglion cells in response to zymosan-induced intraocular inflammation. MiR-383-5p downregulation in neurons is sufficient to promote axon growth in vitro, and the intravitreal injection of a miR-383-5p inhibitor into the eye promotes axon regeneration following optic nerve crush. MiR-383-5p directly targets ciliary neurotrophic factor (CNTF) receptor components, and miR-383-5p inhibition sensitizes adult retinal neurons to the outgrowth-promoting effects of CNTF. Interestingly, we also demonstrate that CNTF treatment is sufficient to reduce miR-383-5p levels in neurons, constituting a positive-feedback module, whereby initial CNTF treatment reduces miR-383-5p levels, which then disinhibits CNTF receptor components to sensitize neurons to the ligand. Additionally, miR-383-5p inhibition derepresses the mitochondrial antioxidant protein peroxiredoxin-3 (PRDX3) which was required for the proregenerative effects associated with miR-383-5p loss-of-function in vitro. We have thus identified a positive-feedback mechanism that facilitates neuronal CNTF sensitivity in neurons and a new molecular signaling module that promotes inflammation-induced axon regeneration.

EGR2 is an epigenomic regulator of phagocytosis and antifungal immunity in alveolar macrophages.

Alveolar macrophages (AMs) act as gatekeepers of the lung's immune responses, serving essential roles in recognizing and eliminating pathogens. The transcription factor (TF) early growth response 2 (EGR2) has been recently described as required for mature AMs in mice; however, its mechanisms of action have not been explored. Here, we identified EGR2 as an epigenomic regulator and likely direct proximal transcriptional activator in AMs using epigenomic approaches (RNA sequencing, ATAC sequencing, and CUT&RUN). The predicted direct proximal targets of EGR2 included a subset of AM identity genes and ones related to pathogen recognition, phagosome maturation, and adhesion, such as Clec7a, Atp6v0d2, Itgb2, Rhoc, and Tmsb10. We provided evidence that EGR2 deficiency led to impaired zymosan internalization and reduced the capacity to respond to Aspergillus fumigatus. Mechanistically, the lack of EGR2 altered the transcriptional response, secreted cytokines (i.e., CXCL11), and inflammation-resolving lipid mediators (i.e., RvE1) of AMs during in vivo zymosan-induced inflammation, which manifested in impaired resolution. Our findings demonstrated that EGR2 is a key proximal transcriptional activator and epigenomic bookmark in AMs responsible for select, distinct components of cell identity and a protective transcriptional and epigenomic program against fungi.

A new acyl derivative of sulfadimethoxine inhibits phagocyte oxidative burst and ameliorates inflammation in a mice model of zymosan-induced generalised inflammation.

Chronic inflammation and oxidative stress play a pivotal role in the pathophysiology of most challenging illnesses, including cancer, Alzheimer's, cardiovascular and autoimmune diseases. The present study aimed to investigate the anti-inflammatory potential of a new sulfadimethoxine derivative N-(4-(N-(2,6-dimethoxypyrimidin-4-yl) sulfamoyl) phenyl) dodecanamide (MHH-II-32). The compound was characterised by applying 1H-, 13C-NMR, EI-MS and HRFAB-MS spectroscopic techniques. The compound inhibited zymosan-induced oxidative bursts from whole blood phagocytes and isolated polymorphonuclear cells with an IC50 value of (2.5 ± 0.4 and 3.4 ± 0.3µg/mL), respectively. Furthermore, the inhibition of nitric oxide with an IC50 (3.6 ± 2.2µg/mL) from lipopolysaccharide-induced J774.2 macrophages indicates its in vitro anti-inflammatory efficacy. The compound did not show toxicity towards normal fibroblast cells. The observational findings, gross anatomical analysis of visceral organs and serological tests revealed the non-toxicity of the compound at the highest tested intraperitoneal (IP) dose of 100mg/kg in acute toxicological studies in Balb/c mice. The compound treatment (100mg/kg) (SC) significantly (P < 0.001) downregulated the mRNA expression of inflammatory markers TNF-α, IL-1β, IL-2, IL-13, and NF-κB, which were elevated in zymosan-induced generalised inflammation (IP) in Balb/c mice while upregulated the expression of anti-inflammatory cytokine IL-10, which was reduced in zymosan-treated mice. No suppressive effect was observed at the dose of 25mg/kg. Ibuprofen was taken as a standard drug. The results revealed that the new acyl derivative of sulfadimethoxine has an immunomodulatory effect against generalised inflammatory response with non-toxicity both in vitro and in vivo, and has therapeutic potential for various chronic inflammatory illnesses.

Modulating Effects of the Hydroethanolic Leaf Extract of Persicaria lanigera R. Br. Soják (Polygonaceae) against Acute Inflammation.

Plant species have been used traditionally to treat numerous inflammatory disorders because of their known medicinal properties. This study aimed to assess the anti-inflammatory effect of aqueous ethanolic leaf extract of Persicaria lanigera using acute inflammatory models. The safety profile of the Persicaria lanigera extract was assessed using an acute toxicity model. The anti-inflammatory effect of the Persicaria lanigera leaf extract (100-600 mg·kg-1, p.o.) was studied in carrageenan-induced paw oedema, zymosan-induced knee joint arthritis, and histamine-induced paw oedema in Sprague-Dawley rats (n = 5). It was observed that the Persicaria lanigera leaf extract administered prophylactically significantly inhibited paw oedema from 99.01 ± 12.59 to 59.10 ± 4.94%, 56.08 ± 3.65%, and 48.62 ± 3.27% at 100 mg·kg-1, 300 mg·kg-1, and 600 mg·kg-1, while the standard drug, aspirin, showed 41.84 ± 9.25% in carrageenan-induced paw oedema, respectively. Furthermore, the extract decreased knee joint inflammation significantly from 62.43 ± 5.73% to 32.07 ± 2.98% and 24.33 ± 8.58% at 300 mg·kg-1 and 600 mg·kg-1 in zymosan-induced knee joint inflammation, respectively. In the histamine-induced paw oedema model, the extract significantly inhibited oedema to 61.53 ± 9.17%, 54.21 ± 9.38%, and 54.22 ± 9.37% at the same doses. Aqueous ethanolic leaf extract of Persicaria lanigera is safe and attenuates inflammation in acute inflammation models.

Analgesic and Anti-Inflammatory Properties of Ethanolic Extract of Piper vicosanum Leaves.

Nonclinical trials are important to validate the efficacy and safety of medicinal plants. Scientific toxicological studies with Piper vicosanum Yuncker have showed its safety; however, no studies have indicated the analgesic or antiarthritic potential of the ethanolic extract of P. vicosanum leaves (EEPV). The objective of the present work was to evaluate the antiarthritic and antinociceptive effects of EEPV in experimental mouse models. The oral administration of EEPV (100, 300, and 700 mg/kg) and dexamethasone (1 mg/kg) were performed in carrageenan-induced pleurisy, in formalin and acetic-acid-induced nociception, and in zymosan-induced articular inflammation models in Swiss mice. The EEPV (300 mg/kg) was tested in zymosan-articular inflammation, the complete Freund's adjuvant (CFA) inflammatory model, and in in situ intravitreal microscopy analysis of rolling and adhesion events of leukocytes in the mesenteric microcirculation in mice. EEPV significantly inhibited: (i) nociceptive response at phase 1 and 2, and also in the cold response in the formalin model; (ii) abdominal contortion induced by acetic acid; (iii) mechanical hyperalgesia after 4 and 6 h, knee edema after 6 h, and leukocyte migration in articular inflammation induced by zymosan. All doses of EEPV reduced the leukocyte migration to the inflamed pleural cavity and knee edema 4 h after the zymosan knee injection. The treatment with the EEPV significantly inhibited the CFA-induced edema, mechanical and cold hyperalgesia, and NAG and MPO. The EEPV also significantly inhibited carrageenan-induced leukocyte rolling and adhesion. The present study revealed, for the first time, the antiarthritic and antinociceptive effects of the EEPV.

Potential anti-arthritic and analgesic properties of essential oil and viridiflorol obtained from Allophylus edulis leaves in mice

Ethnopharmacological relevanceViridiflorol was identified and isolated from the essential oil of Allophylus edulis leaves (EOAE). A. edulis was used as "tereré", which is a drink made by the infusion of herbs in cold water, to treat pain (toothache and headache). All anti-nociceptive (analgesic) and anti-arthritic properties of EOAE and viridiflorol have not been completely scientifically clarified. Aim of the studyThe aim of the present study was to investigate the analgesic (anti-hyperalgesic and anti-nociceptive) and anti-arthritic properties of EOAE and viridiflorol using in vivo models. Materials and methodsThe oral administration (p.o.) of EOAE (30, 100 and 300 mg/kg), viridiflorol (30, 100 and 200 mg/kg), morphine (1 mg/kg, subcutaneous route (s.c.)) and the intraplantar (local) administration (i.pl.) of viridiflorol (100 μg/paw) were tested using formalin model in Swiss mice. EOAE (100 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), and dexamethasone (1 mg/kg, s.c.) were tested by zymosan-articular inflammation and in open-field models. Viridiflorol (0.3, 20 and 200 μg/paw) was also tested in carrageenan model, and viridiflorol (200 μg/paw) was also tested in tumor necrosis factor-α (TNF-α), and dopamine (DOPA) models. ResultsThe oral administration of EOAE (100 and 300 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), morphine (1 mg/kg, s.c.) (MOR) and local administration of viridiflorol (100 μg/paw) significantly inhibited edema and nociception in formalin model. Oral treatments with EOAE and viridiflorol (200 mg/kg) did not cause motor impairment in the open field test since they did not reduce locomotor activity. EOAE, viridiflorol and dexamethasone significantly reduced mechanical hyperalgesia, edema, total leukocytes, polymorphonuclear cells, nitric oxide and protein exudation in the zymosan-induced articular inflammation model. The local administration of viridiflorol (200 μg/paw, i.pl.) significantly inhibited mechanical hyperalgesia and edema induced by carrageenan, TNF-α and DOPA. ConclusionsThis study confirms the potential anti-arthritic, anti-nocicepttive and anti-hyperalgesic properties of EOAE and viridiflorol. These properties could explain, at least in part, the folk use of A. edulis against including pain (toothache and headache). Viridiflorol could be partially responsible for the EOAE anti-hyperalgesic, anti-nociceptive and anti-arthritic properties and its mechanism of action could involve the inhibition of TNF-α and DOPA pathways.

Mesothelium-Derived Factors Shape GATA6-Positive Large Cavity Macrophages.

The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln-/- and Muc16-/- mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell-produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.

Anti-PCSK9 monoclonal antibody attenuates high-fat diet and zymosan-induced vascular inflammation in C57BL/6 mice by modulating TLR2/NF-ƙB signaling pathway.

Objective(s):Excess intake of a high-fatty diet (HFD) together with zymosan administration mediates vasculitis response which leads to impaired serum lipid levels and causes arterial stiffness. In the development of new cholesterol-lowering medications, PCSK9 inhibitor (proprotein convertase subtilisin/kexin type 9) is an emerging therapeutic. The goal of the present study was to see whether anti-PCSK9 mAb1 might prevent vasculitis in C57BL/6 mice by blocking TLR2/NF-B activation in HFD and Zymosan-induced vasculitis. Materials and Methods:Protein-protein molecular docking was performed to validate the binding affinity of anti-PCSK9 mAb1 against TLR2. Under the experimental study, mice were randomly allocated to the following groups: Group I: standard mice diet (30 days) + Zymosan vehicle (sterile PBS solution of 5mg/ml on 8th day); Group II: HFD (30 days) + Zymosan ( single IP dose 80 mg/kg on day 8th); Group III: HFD+Zymosan + anti-PCSK9 mAb1 (6 mg/kg, s.c. on 10th and 20th days); Group IV: HFD+Zymosan+anti-PCSK9 mAb1 (10 mg/kg, s.c. on 10th and 20th days).Results:In comparison with the low dose of anti-PCSK9 mAb1 (6 mg/kg), the high dose of anti-PCSK9 mAb1 (10 mg/kg) together with HFD and Zymosan inhibited vasculitis more effectively by decreasing aortic TLR2 and NF-B levels, reducing serum TNF- and IL-6, and up-regulating liver LDLR levels, which down-regulated serum LDL-C and improved serum lipids levels. Histopathological studies showed that anti-PCSK9 mAb1 treatment reduced plaque accumulation in the aorta of mice.Conclusion:These findings indicate that anti-PCSK9 mAb1 has therapeutic potential in reducing HFD and Zymosan-induced vascular inflammation.

Novel Small Molecule Inhibitors Targeting the IL-6/STAT3 Pathway or IL-1β.

Development of small molecules that inhibit inflammatory cytokines is a desirable strategy for the treatment of inflammatory diseases such as rheumatoid arthritis (RA). Following up a previous study, we synthesized 10 novel compounds with a 2,5-diaminobenzoxazole moiety and evaluated their biological activities. Among them, compound 3e showed potent inhibitory activity on Interleukin 6 (IL-6)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling inhibition (71.5%), and 3a showed excellent inhibitory activity on Interleukin 1 (IL-1β) (92.1%). To test in vivo anti-inflammatory activity, compounds 3a and 3e were administered by intraperitoneal (IP) injection after subcutaneous (SC) injection of zymosan A into the right footpad of mice. Inflammation on the footpad was reduced after administration of compounds 3a and 3e. Especially, compound 3a showed a significant ameliorative effect on zymosan-induced inflammation. From the in vivo and in vitro test results, we confirmed that our synthesized compounds are effective on the RA animal model through inhibition of the IL-6/STAT3 signaling pathway. Since drugs developed with small molecule inhibitors have several advantages over biological drugs, further study on these compounds is needed for the development of potent SMI drugs on RA.

Amiodarone Provides Long-Lasting Local Anesthesia and Analgesia in Open-State Mouse Nociceptors.

Local anesthetics with long-lasting effects and selectivity for nociceptors have been sought over the past decades. In this study, we investigated whether amiodarone, a multiple channel blocker, provides long-lasting local anesthesia and whether adding a TRPV1 channel activator selectively prolongs sensory anesthetic effects without prolonging motor blockade. Additionally, we examined whether amiodarone provides long-lasting analgesic effects against inflammatory pain without TRPV1 channel activator co-administration. In the sciatic nerve block model, 32 adult C57BL/6J mice received either bupivacaine, amiodarone with or without capsaicin (a TRPV1 agonist), or vehicle via peri-sciatic nerve injection. Sensory and motor blockade were assessed either by pinprick and toe spread tests, respectively. In another set of 16 mice, inflammatory pain was induced in the hind paw by zymosan injection, followed by administration of either amiodarone or vehicle. Mechanical and thermal sensitivity and paw thickness were assessed using the von Frey and Hargreaves tests, respectively. The possible cardiovascular and neurological side effects of local amiodarone injection were assessed in another set of 12 mice. In the sciatic nerve block model, amiodarone produced robust anesthesia, and the co-administration of TRPV1 agonist capsaicin prolonged the duration of sensory blockade, but not that of motor blockade [complete sensory block duration: 195.0 ± 9.8 min vs. 28.8 ± 1.3 min, F (2, 21) = 317.6, p < 0.01, complete motor block duration: 27.5 ± 1.6 min vs. 21.3 ± 2.3 min, F (2, 22) = 11.1, p = 0.0695]. In the zymosan-induced inflammatory pain model, low-dose amiodarone was effective in reversing the mechanical and thermal hypersensitivity not requiring capsaicin co-administration [50% withdrawal threshold at 8 h (g): 0.85 ± 0.09 vs. 0.25 ± 0.08, p < 0.01, withdrawal latency at 4 h (s) 8.5 ± 0.5 vs. 5.7 ± 1.4, p < 0.05]. Low-dose amiodarone did not affect zymosan-induced paw inflammation. Local amiodarone did not cause cardiovascular or central nervous system side effects. Amiodarone may have the potential to be a long-acting and nociceptor-selective local anesthetic and analgesic method acting over open-state large-pore channels.

Evaluation of calcium-sensitive adenylyl cyclase AC1 and AC8 mRNA expression in the anterior cingulate cortex of mice with spared nerve injury neuropathy

The anterior cingulate cortex (ACC) is a critical region of the brain for the emotional and affective components of pain in rodents and humans. Hyperactivity in this region has been observed in neuropathic pain states in both patients and animal models and ablation of this region from cingulotomy, or inhibition with genetics or pharmacology can diminish pain and anxiety. Two adenylyl cyclases (AC), AC1 and AC8 play an important role in regulating nociception and anxiety-like behaviors through an action in the ACC, as genetic and pharmacological targeting of these enzymes reduces mechanical hypersensitivity and anxiety-like behavior, respectively. However, the distribution of these ACs in the ACC has not been studied in the context of neuropathic pain. To address this gap in knowledge, we conducted RNAscope in situ hybridization to assess AC1 and AC8 mRNA distribution in mice with spared nerve injury (SNI). Given the key role of AC1 in nociception in neuropathic, inflammatory and visceral pain animal models, we hypothesized that AC1 would be upregulated in the ACC of mice following nerve injury. This hypothesis was also founded on data showing increased AC1 expression in the ACC of mice with zymosan-induced visceral inflammation. We found that AC1 and AC8 are widely expressed in many regions of the mouse brain including the hippocampus, ACC, medial prefrontal cortex and midbrain regions, but AC1 is more highly expressed. Contrary to our hypothesis, SNI causes an increase in AC8 mRNA expression in NMDAR-2B (Nr2b) positive neurons in the contralateral ACC but does not affect AC1 mRNA expression. Our findings show that changes in Adcy1 mRNA expression in the ACC are insufficient to explain the important role of this AC in mechanical hypersensitivity in mice following nerve injury and suggest a potential unappreciated role of AC8 in regulation of ACC synaptic changes after nerve injury.

A Model in Female Rats With Phenotypic Features Similar to Interstitial Cystitis/Bladder Pain Syndrome.

This report describes methodological and exploratory investigations of the zymosan-induced neonatal bladder inflammation (NBI) model of interstitial cystitis/bladder pain syndrome (IC/BPS) in female rats. These results validate and extend the currently employed model by evaluating critical timepoints for obtaining treatment effects and identified that a second insult as an adult including repeat intravesical zymosan, intravesical lipopolysaccharide, acute footshock stress, neuropathic nociception (facial) or somatic inflammation (hindpaw) all resulted in magnified visceromotor responses to urinary bladder distension (UBD) in rats which had experienced NBI when compared with their controls. NBI also resulted in increased tone and reactivity of pelvic floor musculature to UBD, as well as increased responsiveness to intravesical potassium chloride solutions, abnormal anxiety measures (elevated plus maze) and an increased number of submucosal petechial hemorrhages following 30 min of hydrodistension of the bladder. These phenotypic findings have correlates to the clinical features of IC/BPS in humans and so support use of this model system to examine mechanisms of and treatments for IC/BPS.

5-Dodecanolide, a Compound Isolated from Pig Lard, Presents Powerful Anti-Inflammatory Properties.

Background: Pork lard (PL) is traditionally used as an anti-inflammatory agent. We propose to demonstrate the anti-inflammatory properties of PL, and elucidate which compounds could be responsible for the anti-inflammatory effects. Methods: The anti-inflammatory effects of PL were tested in a rat model of zymosan-induced hind paw inflammation. Further, the hydroalcoholic extract from PL was obtained, the composition analyzed, and the anti-inflammatory activity of the extracts and isolated components assayed using immune cells stimulated with lipopolysaccharide (LPS). Results: Applying the ointment on the inflamed rat feet reduced the foot diameter, foot weight, and activities of antioxidant enzymes and inflammatory markers of circulating neutrophils. The main components of the hydroalcoholic extract were 5-dodecanolide, oleamide, hexadecanoic acid, 9-octadecenoic acid, hexadecanamide, and resolvin D1. Conclusions: PL reduces the immune response in an animal model stimulated with zymosan. Hydroalcoholic PL extract and its components (5-Dodecanolide, Oleamide, and Resolvin D1) exerted an anti-inflammatory effect on LPS-stimulated neutrophils and peripheral mononuclear cells reducing the capability to produce TNFα, as well as the activities of antioxidant and pro-inflammatory enzymes. These effects are attributable to 5-dodecanolide, although the effects of this compound alone do not reach the magnitude of the anti-inflammatory effects observed by the complete hydroalcoholic extract.

Thrombin-Derived C-Terminal Peptide Reduces Candida-Induced Inflammation and Infection In Vitro and In Vivo.

ABSTRACTInfections due to the opportunistic fungus Candida have been on the rise in the last decades, especially in immunocompromised individuals and hospital settings. Unfortunately, the treatments available today are limited. Thrombin-derived C-terminal peptide (TCP-25) is an antimicrobial peptide (AMP) with antibacterial and immunomodulatory effects. In this work, we, for the first time, demonstrate the ability of TCP-25 ability to counteract Candida in vitro and in vivo. Using a combination of viable count assay (VCA), radial diffusion assay (RDA), and fluorescence and transmission electron microscopy analyses, TCP-25 was found to exert a direct fungicidal activity. An inhibitory activity of TCP-25 on NF-κB activation induced by both zymosan alone and heat-killed C. albicans was demonstrated in vitro using THP-1 cells, and in vivo using NF-κB reporter mice. Moreover, the immunomodulatory property of TCP-25 was further substantiated in vitro by analyzing cytokine responses in human blood stimulated with zymosan, and in vivo employing a zymosan-induced peritonitis model in C57BL/6 mice. The therapeutic potential of TCP-25 was demonstrated in mice infected with luminescent C. albicans. Finally, the binding between TCP-25 and zymosan was investigated using circular dichroism spectroscopy and intrinsic fluorescence analysis. Taken together, our results show that TCP-25 has a dual function by inhibiting Candida as well as the associated zymosan-induced inflammation. The latter function is accompanied by a change in secondary structure upon binding to zymosan. TCP-25, therefore, shows promise as a novel drug candidate against Candida infections.

Characteristics of the mechanisms of anti-inflammatory action of cryopreserved placenta extract and diclofenac sodium by their threaded administration

Introduction. Inflammation is a complex multicomponent adaptive pathological process based on three enzymatic pathways of arachidonic acid metabolism: cyclooxygenase, lipoxygenase and epoxygenase. Nonsteroidal anti-inflammatory drugs are the most numerous and most widely used group of drugs used in the pharmacocorrection of inflammatory processes of various etiologies.&#x0D; Purpose of the study. The aim is to characterize the effect of cryopreserved placenta extract on the anti-inflammatory activity of diclofenac sodium with their threaded administration in a model of zymosan-induced inflammation.&#x0D; Materials and methods. In vivo experimental studies were performed on 28 nonlinear laboratory male rats weighing 200–220 g. Acute exudative inflammation was reproduced by subplantar administration of rat limb 0,1 ml of 2,0% zymosan suspension. The anti-exudative effect was assessed by the magnitude of limb edema, which was assessed using an aqueous plethysmometer.&#x0D; Results and discussion. The study showed that subplantar administration of 2,0% suspension of zymosan led to a statistically significant (p &lt; 0,05) increase in the volume of the damaged limb after 30 minutes. by 28,1 ± 5,4% relative to baseline and was 2,01 ± 0,06 ml. The most pronounced and almost comparable anti-inflammatory activity was observed against the background of the use of cryopreserved placenta extract and the combined use of diclofenac sodium and cryopreserved placenta extract. Thus, for 60 min the antiinflammatory activity was (p &lt; 0,05) 46,5% and 53,2%, respectively.&#x0D; Conclusions. It is established that one of the leading mechanisms of anti-inflammatory activity of cryopreserved placenta extract is the inhibition of the lipoxygenase pathway of arachidonic acid metabolism. This was indicated by statistically significant (p &lt; 0,05) suppression of zymosaninduced inflammation in rats by 78,8% and 74,8% by 120 and 180 min, respectively.

Dexmedetomidine promotes inflammation resolving through TGF-β1 secreted by F4/80+Ly6G+ macrophage

Dexmedetomidine (DEX) is a highly selective α2-adrenoceptor agonist, which can regulate inflammatory responses. However, whether DEX interferes with the inflammation resolving remains unclear. Here, we reported the effects of DEX on zymosan-induced generalized inflammation in mice during resolution. Mice were administered intraperitoneally with DEX after the initiation of sepsis. The resolution interval (Ri), a vital resolution indice, decreased from twelve hours to eight hours after the administration of DEX. The induction of peritoneal pro-inflammatory interleukin [IL] - 1β and tumour necrosis factor-α (TNF-α) appeared to be inhibited. Of interest, the anti-inflammatory transforming growth factor-β1 (TGF-β1) but not IL-10 levels were up-regulated at twenty-four hours in the DEX group along with 1.0 mg/mice zymosan A (ZyA) treatment. The expression levels of multiple genes related to protective immune processes and clearance functions were detected and revealed the same trends. DEX markedly increased the F4/80+Ly6G+ macrophage population. Additionally, the adequate apoptotic neutrophil clearance from injury after DEX installation could be reverse by opsonization or co-instillation of TGF-β1 neutralizing antibody in vivo, promoting the inflammation-resolution programs. In conclusion, DEX post-treatment, via the increase of F4/80+Ly6G+ macrophages, provokes further secretion of TGF-β1, leading to the attenuated cytokine storm and accelerated inflammation resolving.