Associations of neutral pH, low-GDP peritoneal dialysis solutions with patient survival, transfer to haemodialysis and peritonitis.

BACKGROUND: Peritoneal dialysis (PD) solutions containing low levels of glucose degradation products (GDPs) are associated with attenuation of peritoneal membrane injury and vascular complications. However, clinical benefits associated with neutral-pH, low-GDP (N-pH/L-GDP) solutions remain unclear. METHODS: Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the associations between N-pH/L-GDP solutions and all-cause mortality, cause-specific mortality, transfer to haemodialysis (HD) for ≥30 days and PD peritonitis in adult incident PD patients in Australia and New Zealand between 1 January 2005 and 31 December 2020 using adjusted Cox regression analyses. RESULTS: Of 12 814 incident PD patients, 2282 (18%) were on N-pH/L-GDP solutions. The proportion of patients on N-pH/L-GDP solutions each year increased from 11% in 2005 to 33% in 2017. During the study period, 5330 (42%) patients died, 4977 (39%) experienced transfer to HD and 5502 (43%) experienced PD peritonitis. Compared with the use of conventional solutions only, the use of any form of N-pH/L-GDP solution was associated with reduced risks of all-cause mortality {adjusted hazard ratio [aHR] 0.67 [95% confidence interval (CI) 0.61-0.74]}, cardiovascular mortality [aHR 0.65 (95% CI 0.56-0.77)], infection-related mortality [aHR 0.62 (95% CI 0.47-0.83)] and transfer to HD [aHR 0.79 (95% CI 0.72-0.86)] but an increased risk of PD peritonitis [aHR 1.16 (95% CI 1.07-1.26)]. CONCLUSIONS: Patients who received N-pH/L-GDP solutions had decreased risks of all-cause and cause-specific mortality despite an increased risk of PD peritonitis. Studies assessing the causal relationships are warranted to determine the clinical benefits of N-pH/L-GDP solutions.

Vancomycin flushing reaction after intraperitoneal vancomycin: A case report.

Vancomycin has been reported to cause vancomycin flushing reaction (VFR), a hypersensitivity reaction that mostly occurs after intravenous administration. The incidence of VFR in a patient receiving intraperitoneal vancomycin is rare. We report a case of a female peritoneal dialysis (PD) patient with a PD-related peritonitis who developed VFR after intraperitoneal administration of 2000 mg vancomycin. Seventy-five minutes after instillation, she developed flushing, a pruritic erythema on the upper body and swelling of the lips. Blood results revealed a vancomycin plasma concentration of 54.8 mg/L and a normal tryptase level. During a relapse of her PD-related peritonitis, vancomycin was successfully reintroduced in a 50% reduced dose. No symptoms of VFR developed, and the corresponding vancomycin plasma concentration was 33.6 mg/L. Intraperitoneal treatment was continued with 500 mg vancomycin every 2-3 days with frequently measured, adequate trough levels ranging from 15-22 mg/L. This case illustrates the risk factors for the development of VFR after intraperitoneal administration of vancomycin, namely a high and concentrated loading dose together with a low body weight, a fast peritoneal transport state and peritonitis. Reintroduction of vancomycin after occurrence of VFR is safe, but a lower loading dose or a slower instillation rate is recommended.

The antioxidant, anti-inflammatory and analgesic activity effect of ethyl acetate extract from the flowers of Syringa pubescens Turcz.

ETHNOPHARMACOLOGICAL RELEVANCE: Syringa Pubescens Turcz. (SP), a member of the Oleaceae family, is a species of plant known as Syringa. Flowers, as the medicinal part, are commonly used in the treatment of hepatitis and tonsillitis. AIM OF THE STUDY: The research was the first to assess the antioxidant and anti-inflammatory potential of different parts of SP flowers (SPF) in vitro. The most promising fraction was ethyl acetate fraction of SP flower (SPFEA). The antioxidant, anti-inflammatory and analgesic activities of SPFEA were further studied, and the chemical components were identified. METHODS: HPLC was used to identify the major components in various fraction of SPF. DPPH and ABTS + radical scavenging assays as well as FRAP test and ß-carotene bleaching test were employed to assess the antioxidant potential of SPF fraction in vitro. The inhibitory effect on NO production in LPS-treated RAW264.7 cells and heat-induced protein denaturation test were used to evaluate the anti-inflammatory potential of SPF fraction. Further analysis of the biological activity of SPFEA was performed. Acute toxicity test was conducted to assess the toxicity of SPFEA. The anti-inflammatory effect was assessed by utilizing xylene induced ear edema model, carrageenan-induced foot edema model and peritonitis model in vivo. The analgesic effect of SPFEA was evaluated using hot plate test, tail immersion test, formaldehyde test as well as acetic acid-induced abdominal writhing pain experiment in vivo. In carrageenan induced foot edema model, ELISA kits were employed to measure levels of inflammation factors (NO, TNF-α, IL-6, COX-2, IL-1ß) in foot tissue as well as MDA, CAT, SOD, GSH-PX levels in liver tissue. RESULTS: HPLC results showed that there were significant differences in bioactive substances among different fractions of SPF, and SPFEA was rich in bioacitve components. Compared with other fractions of SPF, SPFEA exhibited better antioxidant and anti-inflammatory abilities. The 3000 mg/kg SPFEA group in mice had no obvious side effects. The xylene-induced ear edema model, carrageenan-induced foot edema and peritonitis models demonstrated that the SPFEA had significant anti-inflammatory effect. Moreover, inflammation factors including NO, TNF-α, IL-6, COX-2, IL-1ß were significantly reduced in SPFEA groups in foot tissue induced by carrageenan. Additionally, SPFEA effectively decreased liver tissue oxidative stress levels (MDA, SOD, GSH-PX and CAT). The bioactivities of SPFEA demonstrated a clear dose-dependent relationship. The results of the hot plate test, tail immersion test, formaldehyde test and acetic acid-induced abdominal writhing pain experiments indicated the SPFEA possessed an excellent analgesic effect, and this effect was in dose-dependent manner. CONCLUSION: The study provides a scientific foundation for understanding the pharmacological action of SPFEA. It has been indicated that SPFEA has excellent antioxidant, analgesic and anti-inflammatory effects.

Semaphorin 7A is protective during inflammatory peritonitis through integrin receptor signaling.

Introduction: The study explores the role of endothelial Semaphorin 7A (SEMA7A) in inflammatory processes. SEMA7A is known for enhancing inflammation during tissue hypoxia and exhibiting anti-inflammatory properties in the intestinal system during colitis. This research extends the understanding of SEMA7A's function by examining its role in inflammatory peritonitis and intestinal inflammation. Methods: The research involved inducing peritonitis in SEMA7A knockout (SEMA7A-/-) and wild-type (WT) animals through Zymosan A (ZyA) injection. The inflammatory response was assessed by measuring cell count and cytokine release. In parallel, the study investigated the expression of SEMA7A in intestinal epithelial cells under inflammatory stimuli and its impact on interleukin 10 (IL-10) production using an in vitro co-culture model of monocytes and epithelial cells. Additionally, the distribution of SEMA7A target receptors, particularly ITGAV/ITGB1 (CD51/CD29), was analyzed in WT animals. Results: The results revealed that SEMA7A-/- animals exhibited increased inflammatory peritonitis compared to the WT animals. Inflammatory conditions in intestinal epithelial cells led to the induction of SEMA7A. The co-culture experiments demonstrated that SEMA7A induced IL-10 production, which depended on integrin receptors and was independent of PLXNC1 expression. Furthermore, ITGAV/ITGB1 emerged as the predominant SEMA7A receptor in the intestinal area of WT animals. Discussion: These findings underscore the multifaceted role of SEMA7A in inflammatory processes. The differential responses in peritonitis and intestinal inflammation suggest that SEMA7A's function is significantly influenced by the expression and distribution of its target receptors within different organ systems. The study highlights the complex and context-dependent nature of SEMA7A in mediating inflammatory responses.

Anti-Inflammatory Activity of Fucan from Spatoglossum schröederi in a Murine Model of Generalized Inflammation Induced by Zymosan.

Fucans from marine algae have been the object of many studies that demonstrated a broad spectrum of biological activities, including anti-inflammatory effects. The aim of this study was to verify the protective effects of a fucan extracted from the brown algae Spatoglossum schröederi in animals submitted to a generalized inflammation model induced by zymosan (ZIGI). BALB/c mice were first submitted to zymosan-induced peritonitis to evaluate the treatment dose capable of inhibiting the induced cellular migration in a simple model of inflammation. Mice were treated by the intravenous route with three doses (20, 10, and 5 mg/kg) of our fucan and, 1 h later, were inoculated with an intraperitoneal dose of zymosan (40 mg/kg). Peritoneal exudate was collected 24 h later for the evaluation of leukocyte migration. Doses of the fucan of Spatoglossum schröederi at 20 and 10 mg/kg reduced peritoneal cellular migration and were selected to perform ZIGI experiments. In the ZIGI model, treatment was administered 1 h before and 6 h after the zymosan inoculation (500 mg/kg). Treatments and challenges were administered via intravenous and intraperitoneal routes, respectively. Systemic toxicity was assessed 6 h after inoculation, based on three clinical signs (bristly hair, prostration, and diarrhea). The peritoneal exudate was collected to assess cellular migration and IL-6 levels, while blood samples were collected to determine IL-6, ALT, and AST levels. Liver tissue was collected for histopathological analysis. In another experimental series, weight loss was evaluated for 15 days after zymosan inoculation and fucan treatment. The fucan treatment did not present any effect on ZIGI systemic toxicity; however, a fucan dose of 20 mg/kg was capable of reducing the weight loss in treated mice. The treatment with both doses also reduced the cellular migration and reduced IL-6 levels in peritoneal exudate and serum in doses of 20 and 10 mg/kg, respectively. They also presented a protective effect in the liver, with a reduction in hepatic transaminase levels in both doses of treatment and attenuated histological damage in the liver at a dose of 10 mg/kg. Fucan from S. schröederi presented a promising pharmacological activity upon the murine model of ZIGI, with potential anti-inflammatory and hepatic protective effects, and should be the target of profound and elucidative studies.

Discovery of a selective NLRP3-targeting compound with therapeutic activity in MSU-induced peritonitis and DSS-induced acute intestinal inflammation.

The aberrant activation of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is known to contribute to the pathogenesis of various human inflammation-related diseases. However, to date, no small-molecule NLRP3 inhibitor has been used in clinical settings. In this study, we have identified SB-222200 as a novel direct NLRP3 inhibitor through the use of drug affinity responsive target stability assay, cellular thermal shift assay, and surface plasmon resonance analysis. SB-222200 effectively inhibits the activation of the NLRP3 inflammasome in macrophages, while having no impact on the activation of NLRC4 or AIM2 inflammasome. Furthermore, SB-222200 directly binds to the NLRP3 protein, inhibiting NLRP3 inflammasome assembly by blocking the NEK7 - NLRP3 interaction and NLRP3 oligomerization. Importantly, treatment with SB-222200 demonstrates alleviation of NLRP3-dependent inflammatory diseases in mouse models, such as monosodium urate crystal-induced peritonitis and dextran sulfate sodium-induced acute intestinal inflammation. Therefore, SB-222200 holds promise as a lead compound for the development of NLRP3 inhibitors to combat NLRP3-driven disease and serves as a versatile tool for pharmacologically investigating NLRP3 biology.

Exosomal PPARγ derived from macrophages suppresses LPS-induced peritonitis by negative regulation of CD14/TLR4 axis.

BACKGROUND: Intercellular communication between macrophages and peritoneal mesothelial cells (PMCs) has been suggested as a key factor regulating peritonitis development. Here, we explored whether PPARγ (peroxisome proliferator-activated receptor gamma) can be packaged into macrophage exosomes to mediate intercellular communication and regulate peritonitis. METHODS: Macrophage exosomes were isolated by ultracentrifugation and identified by nanoparticle tracking analysis and transmission electron microscopy. Proteomic analysis of macrophage-derived exosomes was performed using mass spectrometry. Co-culture models of supernatants or exosomes with PMCs, as well as a mouse peritonitis model induced by lipopolysaccharide (LPS), were employed. RESULTS:  In this study, using stable Raw264.7 cells overexpressing GFP-FLAG-PPARγ (OE-PPARγ), we found that PPARγ inhibited LPS-induced inflammatory responses in Raw264.7 cells and that PPARγ was incorporated into macrophage exosomes during this process. Overexpression of PPARγ mainly regulated the secretion of differentially expressed exosomal proteins involved in the biological processes of protein transport, lipid metabolic process, cell cycle, apoptotic process, DNA damage stimulus, as well as the KEGG pathway of salmonella infection. Using co-culture models and mouse peritonitis model, we showed that exosomes from Raw264.7 cells overexpressing PPARγ inhibited LPS-induced inflammation in co-cultured human PMCs and in mice through downregulating CD14 and TLR4, two key regulators of the salmonella infection pathway. Pretreatment of the PPARγ inhibitor GW9662 abolished the anti-inflammatory effect of exosomes from Raw264.7 OE-PPARγ cells on human PMCs. CONCLUSIONS: These results suggested that overexpression of PPARγ largely altered the proteomic profile of macrophage exosomes and that exosomal PPARγ from macrophages acted as a regulator of intercellular communication to suppress LPS-induced inflammatory responses in vitro and in vivo via negatively regulating the CD14/TLR4 axis.

Uncovering the anti-inflammatory mechanisms of phenolic-enriched maple syrup extract in lipopolysaccharide-induced peritonitis in mice: insights from data-independent acquisition proteomics analysis.

Our group has previously reported on the phytochemical composition and biological activities of a phenolic-enriched maple syrup extract (MSX), which showed promising anti-inflammatory effects in several disease models including diabetes and Alzheimer's disease. However, the efficacious doses of MSX and its molecular targets involved in the anti-inflammatory effects are not fully elucidated. Herein, the efficacy of MSX in a peritonitis mouse model was evaluated in a dose-finding study and the underlying mechanisms were explored using data-independent acquisition (DIA) proteomics assay. MSX (at 15, 30 and 60 mg kg-1) alleviated lipopolysaccharide-induced peritonitis by reducing the levels of pro-inflammatory cytokines including interleukin-1 beta (IL-1ß), IL-6, and tumor necrosis factor alpha (TNF-α) in the serum and major organs of the mice. Furthermore, DIA proteomics analyses identified a panel of proteins that were significantly altered (both up- and down-regulated) in the peritonitis group, which were counteracted by the MSX treatments. MSX treatment also modulated several inflammatory upstream regulators including interferon gamma and TNF. Ingenuity pathway analysis suggested that MSX may modulate several signaling pathways in the processes of initiation of cytokine storm, activation of liver regeneration, and suppression of hepatocyte apoptosis. Together, these proteomic and in vivo findings indicate that MSX could regulate inflammation signaling pathways and modulate inflammatory markers and proteins, providing critical insight to its therapeutic potential.

Extraction, Structural Characterization, and In Vivo Anti-Inflammatory Effect of Alginate from Cystoseira crinita (Desf.) Borry Harvested in the Bulgarian Black Sea.

The aim of this study was to identify the chemical composition and sequential structure of alginate isolated from C. crinita harvested in the Bulgarian Black Sea, as well as its effects in histamine-induced paw inflammation in rats. The serum levels of TNF-α, IL-1ß, IL-6, and IL-10 in rats with systemic inflammation, and the levels of TNF-α in a model of acute peritonitis in rats were also investigated. The structural characterization of the polysaccharide was obtained by FTIR, SEC-MALS, and 1H NMR. The extracted alginate had an M/G ratio of 1.018, a molecular weight of 7.31 × 104 g/mol, and a polydispersity index of 1.38. C. crinita alginate in doses of 25 and 100 mg/kg showed well-defined anti-inflammatory activity in the model of paw edema. A significant decrease in serum levels of IL-1ß was observed only in animals treated with C. crinita alginate in a dose of 25 mg/kg bw. The concentrations of TNF-α and IL-6 in serum were significantly reduced in rats treated with both doses of the polysaccharide, but no statistical significance was observed in the levels of the anti-inflammatory cytokine IL-10. A single dose of alginate did not significantly alter the levels of the pro-inflammatory cytokine TNF-α in the peritoneal fluid of rats with a model of peritonitis.

Chondroitin Sulfate from Oreochromis niloticus Waste Reduces Leukocyte Influx in an Acute Peritonitis Model.

Oreochromis niloticus (tilapia) is one of the most cultivated fish species worldwide. Tilapia farming generates organic waste from fish removal processes in nurseries. Visceral waste can damage natural ecosystems. Therefore, the use of this material as a source of biomolecules helps reduce environmental impacts and improve pharmacological studies. Tilapia viscera were subjected to proteolysis and complexation with an ion-exchange resin. The obtained glycosaminoglycans were purified using ion exchange chromatography (DEAE-Sephacel). The electrophoretic profile and analysis of 1H/13C nuclear magnetic resonance (NMR) spectra allowed for the characterization of the compound as chondroitin sulfate and its sulfation position. This chondroitin was named CST. We tested the ability of CST to reduce leukocyte influx in acute peritonitis models induced by sodium thioglycolate and found a significant reduction in leukocyte migration to the peritoneal cavity, similar to the polymorphonuclear population of the three tested doses of CST. This study shows, for the first time, the potential of CST obtained from O. niloticus waste as an anti-inflammatory drug, thereby contributing to the expansion of the study of molecules with pharmacological functions.

Novel Aspects of the Immune Response Involved in the Peritoneal Damage in Chronic Kidney Disease Patients under Dialysis.

Chronic kidney disease (CKD) incidence is growing worldwide, with a significant percentage of CKD patients reaching end-stage renal disease (ESRD) and requiring kidney replacement therapies (KRT). Peritoneal dialysis (PD) is a convenient KRT presenting benefices as home therapy. In PD patients, the peritoneum is chronically exposed to PD fluids containing supraphysiologic concentrations of glucose or other osmotic agents, leading to the activation of cellular and molecular processes of damage, including inflammation and fibrosis. Importantly, peritonitis episodes enhance peritoneum inflammation status and accelerate peritoneal injury. Here, we review the role of immune cells in the damage of the peritoneal membrane (PM) by repeated exposure to PD fluids during KRT as well as by bacterial or viral infections. We also discuss the anti-inflammatory properties of current clinical treatments of CKD patients in KRT and their potential effect on preserving PM integrity. Finally, given the current importance of coronavirus disease 2019 (COVID-19) disease, we also analyze here the implications of this disease in CKD and KRT.

The aqueous extracts of Ageratum conyzoides inhibit inflammation by suppressing NLRP3 inflammasome activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Ageratum conyzoides L. (Asteraceae), a well-known and widely distributed traditional tropical medicinal herb, has been used to treat diverse diseases. Our preliminary research has shown that aqueous extracts of A. conyzoides leaf (EAC) have anti-inflammatory activity. However, the detailed underlying anti-inflammatory mechanism of EAC is still unclear. AIM OF THE STUDY: To determine the anti-inflammatory mechanism of action of EAC. MATERIALS AND METHODS: The major constituents of EAC were identified by ultra-performance liquid chromatography (UPLC) combined with quadrupole-time-of-flight mass/mass spectrometry (UPLC-Q-TOF-MS/MS). LPS and ATP were used to activate the NLRP3 inflammasome in two types of macrophages (RAW 264.7 and THP-1 cells). The cytotoxicity of EAC was measured by the CCK8 assay. The levels of inflammatory cytokines and NLRP3 inflammasome-related proteins were detected by ELISA and western blotting (WB), respectively. The oligomerization of NLRP3 and ASC and the resulting inflammasome complex formation were observed by immunofluorescence. The intracellular reactive oxygen species (ROS) level was measured by flow cytometry. Finally, an MSU-induced peritonitis model was established to evaluate the anti-inflammatory effects of EAC in vivo. RESULTS: Twenty constituents were identified in the EAC. Kaempferol 3,7-diglucoside, 1,3,5-tricaffeoylquinic acid, and kaempferol 3,7,4'-triglucoside were found to be the most potent ingredients. EAC significantly reduced the levels of IL-1ß, IL-18, TNF-α, and caspase-1 in the two types of activated macrophages, implying that EAC can inhibit the activation of the NLRP3 inflammasome. A mechanistic study revealed that EAC inhibited NLRP3 inflammasome activation by blocking NF-κB signalling pathway activation and scavenging the level of intracellular ROS to prevent NLRP3 inflammasome assembly in macrophages. Furthermore, EAC attenuated the in vivo expression of inflammatory cytokines by suppressing NLRP3 inflammasome activation in a peritonitis mouse model. CONCLUSION: Our results demonstrated that EAC inhibited inflammation by suppressing NLRP3 inflammasome activation, highlighting that this traditional herbal medicine might be used to treat NLRP3 inflammasome-driven inflammatory diseases.

Zymosan-Induced Murine Peritonitis Is Associated with an Increased Sphingolipid Synthesis without Changing the Long to Very Long Chain Ceramide Ratio.

Sphingolipids are key molecules in inflammation and defense against pathogens. Their role in dectin-1/TLR2-mediated responses is, however, poorly understood. This study investigated the sphingolipidome in the peritoneal fluid, peritoneal cells, plasma, and spleens of mice after intraperitoneal injection of 0.1 mg zymosan/mouse or PBS as a control. Samples were collected at 2, 4, 8, and 16 h post-injection, using a total of 36 mice. Flow cytometry analysis of peritoneal cells and measurement of IL-6, IL-1ß, and TNF-α levels in the peritoneal lavages confirmed zymosan-induced peritonitis. The concentrations of sphingoid bases, dihydroceramides, ceramides, dihydrosphingomyelins, sphingomyelins, monohexosylceramides, and lactosylceramides were increased after zymosan administration, and the effects varied with the time and the matrix measured. The greatest changes occurred in peritoneal cells, followed by peritoneal fluid, at 8 h and 4 h post-injection, respectively. Analysis of the sphingolipidome suggests that zymosan increased the de novo synthesis of sphingolipids without change in the C14-C18:C20-C26 ceramide ratio. At 16 h post-injection, glycosylceramides remained higher in treated than in control mice. A minor effect of zymosan was observed in plasma, whereas sphinganine, dihydrosphingomyelins, and monohexosylceramides were significantly increased in the spleen 16 h post-injection. The consequences of the observed changes in the sphingolipidome remain to be established.

Efficacy and safety of corticosteroids in cardiac arrest: a systematic review, meta-analysis and trial sequential analysis of randomized control trials.

BACKGROUND: Post-cardiac arrest, outcomes for most patients are poor, regardless of setting. Many patients who do achieve spontaneous return of circulation require vasopressor therapy to maintain organ perfusion. There is some evidence to support the use of corticosteroids in cardiac arrest. RESEARCH QUESTION: Assess the efficacy and safety of corticosteroids in patients following in- and out-of-hospital cardiac arrest. STUDY DESIGN AND METHODS: We searched databases CINAHL, EMBASE, LILACS, MEDLINE, Web of Science, CENTRAL, ClinicalTrails.gov, and ICTRP. We included randomized controlled trials (RCTs) that examined the efficacy and safety of corticosteroids, as compared to placebo or usual care in patients post-cardiac arrest. We pooled estimates of effect size using random effects meta-analysis and report relative risk (RR) with 95% confidence intervals (CIs). We assessed risk of bias (ROB) for the included trials using the modified Cochrane ROB tool and rated the certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation methodology. RESULTS: We included 8 RCTs (n = 2213 patients). Corticosteroids administered post-cardiac arrest had an uncertain effect on mortality measured at the longest point of follow-up (RR 0.96, 95% CI 0.90-1.02, very low certainty, required information size not met using trial sequential analysis). Corticosteroids probably increase return of spontaneous circulation (ROSC) (RR 1.32, 95% CI 1.18-1.47, moderate certainty) and may increase the likelihood of survival with good functional outcome (RR 1.49, 95% CI 0.87-2.54, low certainty). Corticosteroids may decrease the risk of ventilator associated pneumonia (RR 0.76, 95% CI 0.46-1.09, low certainty), may increase renal failure (RR 1.29, 95% CI 0.84-1.99, low certainty), and have an uncertain effect on bleeding (RR 2.04, 95% CI 0.53-7.84, very low certainty) and peritonitis (RR 10.54, 95% CI 2.99-37.19, very low certainty). CONCLUSIONS: In patients during or after cardiac arrest, corticosteroids have an uncertain effect on mortality but probably increase ROSC and may increase the likelihood of survival with good functional outcome at hospital discharge. Corticosteroids may decrease ventilator associated pneumonia, may increase renal failure, and have an uncertain effect on bleeding and peritonitis. However, the pooled evidence examining these outcomes was sparse and imprecision contributed to low or very low certainty of evidence.

The lysosomal Ragulator complex activates NLRP3 inflammasome in vivo via HDAC6.

The cellular activation of the NLRP3 inflammasome is spatiotemporally orchestrated by various organelles, but whether lysosomes contribute to this process remains unclear. Here, we show the vital role of the lysosomal membrane-tethered Ragulator complex in NLRP3 inflammasome activation. Deficiency of Lamtor1, an essential component of the Ragulator complex, abrogated NLRP3 inflammasome activation in murine macrophages and human monocytic cells. Myeloid-specific Lamtor1-deficient mice showed marked attenuation of NLRP3-associated inflammatory disease severity, including LPS-induced sepsis, alum-induced peritonitis, and monosodium urate (MSU)-induced arthritis. Mechanistically, Lamtor1 interacted with both NLRP3 and histone deacetylase 6 (HDAC6). HDAC6 enhances the interaction between Lamtor1 and NLRP3, resulting in NLRP3 inflammasome activation. DL-all-rac-α-tocopherol, a synthetic form of vitamin E, inhibited the Lamtor1-HDAC6 interaction, resulting in diminished NLRP3 inflammasome activation. Further, DL-all-rac-α-tocopherol alleviated acute gouty arthritis and MSU-induced peritonitis. These results provide novel insights into the role of lysosomes in the activation of NLRP3 inflammasomes by the Ragulator complex.

Anti-inflammatory and antinociceptive effects of a pectinolide-enriched fraction from Mesosphaerum pectinatum (L.) Kuntze.

ETHNOPHARMACOLOGICAL RELEVANCE: Mesosphaerum pectinatum (L.) Kuntze (Lamiaceae), also known as sambacaitá, is a medicinal plant widely used in northeastern Brazil for the treatment of inflammatory and painful conditions, bacterial infections and cancer. Hence, the medicinal use of this species is quite meaningful to the search for bioactive compounds. AIM OF THE STUDY: To evaluate the antinociceptive and anti-inflammatory activities of the pectinolide-enriched fraction of Mesosphaerum pectinatum (PEF) in animal models. MATERIALS AND METHODS: The PEF was analyzed with HPLC-DAD and 1H and 13C NMR. After the analysis, compounds of the pectinolide class were detected as major constituents in this fraction. The PEF (50, 100 and 200 mg/kg, p.o.) and the reference drugs - morphine (3.0 mg/kg, p.o.) and dexamethasone (2.0 mg/kg, p.o.) - were evaluated using models for nociception (hot plate, formalin-induced licking response) or inflammation (carrageenan-induced peritonitis and ear edema model). RESULTS: The PEF significantly decreased the licking time of the animals treated when compared to the control group (second phase). In the carrageenan-induced peritonitis model, PEF (100 and 200 mg/kg) significantly decreased total and differential leukocyte counts. The PEF (0.3, 1.0 and 3.0 mg/ear) significantly reduced mice ear edema at the same extent and like the results obtained with the standard drug (dexamethasone). The MPO activity was reduced in mice ear at doses of 1 and 3 mg/ear. Antinociceptive effect on the hot plate test was not observed, demonstrating that there is no analgesic activity. CONCLUSION: Our results suggest that the pectinolide-enriched fraction exhibits anti-inflammatory effects and that it is involved with inhibiting the release of the inflammatory mediators.

Analgesic and anti-inflammatory potential of ethanolic extract from Serjania erecta leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: The infusion of Serjania erecta Radlk (Sapindaceae) (popular name "cipó-cinco-folhas") leaves is used in popular medicine to treat back pain. The anti-inflammatory, anti-hyperalgesic and anti-nociceptive properties of the ethanolic extract from S. erecta leaves (EESE) has not been yet completely clarified. AIM OF THE STUDY: The present study investigated the anti-hyperalgesic, anti-nociceptive and anti-inflammatory properties of EESE in experimental models in mice. MATERIAL AND METHODS: EESE was fractionated by chromatographic techniques and the compound was identified by nuclear magnetic resonance (NMR), infrared (IR) spectrum, ultraviolet (UV) methods. Mice received a single dose of EESE by oral route (30, 100, and 300 mg/kg, p.o.) and were submitted to nociception induced by formalin, pleurisy induced by carrageenan and peritonitis induced by zymosan models. Mice also received EESE (30 and 100 mg/kg, p.o.) for 22 days in Complete Freund Adjuvant (CFA) model and another group received EESE for 7 days (30 and 100 mg/kg, p.o.) in pleurisy induced by Bacillus Calmette-Guerin (BCG). The cytotoxicity (MTT), phagocytic and chemotactic inhibitory activities of EESE were performed in in vitro assays. RESULTS: The fractionation of EESE led to the identification of kaempferol-3-O-α-L-rhamnopyranoside. The oral administration of all doses of EESE decreased the nociceptive response induced by formalin. EESE significantly inhibited leukocyte migration in carrageenan-induced pleurisy and zymosan peritonitis models. The daily administration of EESE during for 7 days inhibited the leukocyte migration and the mycobacteria growth of pleural material obtained from animals which received BCG. EESE significantly reduced edema, cold allodynia and mechanical hyperalgesia responses induced by CFA. EESE did not induce cytotoxicity, and also decreased the leukocyte phagocytic activity, as well as, neutrophil chemotaxis. CONCLUSIONS: EESE showed analgesic and anti-inflammatory properties in acute and persistent experimental models in mice. EESE also reduced in vitro leukocyte chemotaxis and phagocytic activity without inducing cytotoxicity. The continuous oral treatment with EESE was effective against hyperalgesia and inflammation and these results could explain the popular use of S. erecta as an analgesic natural agent.

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates caspase-1-dependent processing of inflammatory cytokines such as IL-1ß, an essential endothelial activator, and contributes to the pathology of inflammatory diseases. To evaluate the role of NLRP3 in neutrophils in endothelial activation, which is still elusive, we used the thioglycollate-induced peritonitis model characterized by an early neutrophil influx, on Nlrp3-/- and Nlrp3+/+ mice. Nlrp3-/- mice recruited fewer neutrophils than Nlrp3+/+ into the peritoneum and showed lower IL-1ß in peritoneal lavage fluid. The higher production of IL-1ß in Nlrp3+/+ was neutrophil-dependent as neutrophil depletion prevented the IL-1ß production. The Nlrp3+/+ neutrophils collected from the peritoneal fluid formed significantly more filaments (specks) than Nlrp3-/- neutrophils of ASC (apoptosis-associated speck-like protein containing a caspase activating and recruitment domain), a readout for inflammasome activation. Intravital microscopy revealed that leukocytes rolled significantly slower in Nlrp3+/+ venules than in Nlrp3-/-. Nlrp3-/- endothelial cells isolated from mesenteric vessels demonstrated a lower percentage of P-selectin-positive cells with lower intensity of surface P-selectin expression than the Nlrp3+/+ endothelial cells evaluated by flow cytometry. We conclude that neutrophils orchestrate acute thioglycollate-induced peritonitis by producing IL-1ß in an NLRP3-dependent manner. This increases endothelial P-selectin expression and leukocyte transmigration.

Structural Characterization and In Vivo Anti-Inflammatory Activity of Fucoidan from Cystoseira crinita (Desf.) Borry.

The aim of this study was to evaluate the effects of fucoidan isolated from C. crinita on histamine-induced paw inflammation in rats, and on the serum levels of TNF-α, IL-1ß, IL-6, and IL-10 in rats during systemic inflammation response. The levels of TNF-α in a model of acute peritonitis in rats were also investigated. The isolated crude fucoidan was identified as a sulfated xylogalactofucan with high, medium, and low molecular weight fractions and a content of fucose of 39.74%, xylose of 20.75%, and galactose of 15.51%. Fucoidan from C. crinita showed better anti-inflammatory effects in the rat paw edema model, and this effect was present during all stages of the experiment. When compared to controls, a commercial fucoidan from F. vesiculosus, the results also displayed anti-inflammatory activity on the 60th, 90th, and 120th minute of the experiment. A significant decrease in serum levels of IL-1ß in rats treated with both doses of C. crinita fucoidan was observed in comparison to controls, whereas TNF-α concentrations were reduced only in the group treated with fucoidan from C. crinita at the dose of 25 mg/kg bw. In the model of carrageenan-induced peritonitis, we observed a tendency of decrease in the levels of the pro-inflammatory cytokine TNF-α in peritoneal fluid after a single dose of C. crinita fucoidan, but this did not reach the statistical significance margin. Single doses of C. crinita fucoidan did not alter serum levels of the anti-inflammatory cytokine IL-10 in animals with lipopolysaccharide-induced systemic inflammation.