Anti-inflammatory and anti-necrotic effects of lectins from Canavalia ensiformis and Canavalia brasiliensis in experimental acute pancreatitis.

Lectins isolated from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) are promising molecules to prevent cell death. Acute pancreatitis, characterized by acinar cell necrosis and inflammation, presents significant morbidity and mortality. This study has investigated the effects of ConA and ConBr in experimental acute pancreatitis and pancreatic acinar cell death induced by bile acid. Pancreatitis was induced by retrograde pancreatic ductal injection of 3% sodium taurocholate (Na-TC) in male Swiss mice. ConA or ConBr (0.1, 1 or 10 mg/kg) were intravenously applied to mice 1 h and 12 h after induction. After 24 h, the severity of pancreatitis was evaluated by serum amylase and lipase, histopathological changes and myeloperoxidase assay. Pancreatic acinar cells were incubated with ConA (200 µg/ml) or ConBr (200 µg/ml) and taurolithocholic acid 3-sulfate (TLCS; 500 µM). Necrosis and changes in mitochondrial membrane potential (ΔÑ°m) were detected by fluorescence confocal microscopy. Treatment (post-insult) with ConA and ConBr decreased pancreatic damage caused by retrograde injection of Na-TC in mice, reducing pancreatic neutrophil infiltration, edema and necrosis. In addition, ConA and ConBr decreased pancreatic acinar cell necrosis and depolarization of ΔÑ°m caused by TLCS. The inhibition of necrosis was prevented by the lectin domain blockade. In conclusion, ConA and ConBr markedly inhibited in vitro and in vivo damage, effects partly dependent on the interaction with mannose residues on acinar cells. These data support the potential application of these proteins for treatment of acute pancreatitis.

Euterpe oleracea Mart. (Açaí) attenuates experimental colitis in rats: involvement of TLR4/COX-2/NF-ĸB.

Euterpe oleracea Mart., commonly known as açaí, has been demonstrated to exhibit significantly antioxidant and inflammatory activities in experimental models. These effects of the hydroalcoholic extract from the açaí seed (ASE) were investigated in TNBS-induced (2,4,6-trinitrobenzenesulfonic acid) acute colitis model in rats. Wistar rats (180-220 g) were orally pretreated with saline (0.3 mL), ASE (10, 30 and 100 mg/kg) and dexamethasone (control group, 1 mg/kg) once daily for 3 days starting before TNBS instillation. On day 3 after TNBS, the animals were euthanized, the portion of distal colon was collected and washed with 0.9% saline for macroscopy and histological evaluation, glutathione (GSH) and malonyldialdehyde (MDA) levels, myeloperoxidase (MPO) and catalase (CAT) activity, nitrate and nitrite (NO3/NO2) concentration, pro-inflammatory cytokines levels and intestinal barrier integrity. We also evaluated Toll-like Receptor 4/cyclooxygenase-2/nuclear factor kappa B expression as a possible mechanism related to the ASE effects. Treatment with ASE 100 mg/kg decreased significantly macroscopic and microscopic damage induced by TNBS. In addition, MPO activity, TNF-α (tumor necrosis factor-alpha) and IL-1ß (interleukin 1) levels were reduced in rats with colitis. ASE 100 mg/kg restored GSH and MDA levels, CAT activity, NO3/NO2 concentration and improved the intestinal barrier integrity in the TNBS group. ASE 100 mg/kg significantly reduced TNBS-induced expression of the TLR4, COX-2 and NF-κB p65. ASE 100 mg/kg improved macroscopy and histological parameters, inflammation, intestinal barrier integrity and nitric and oxidative stress through the TLR-4/COX-2/NF-κB pathway.

The galactose-binding lectin isolated from Bauhinia bauhinioides Mart seeds inhibits neutrophil rolling and adhesion via primary cytokines.

In this study, the amino acid sequence and anti-inflammatory effect of Bauhinia bauhinioides (BBL) lectin were evaluated. Tandem mass spectrometry revealed that BBL possesses 86 amino acid residues. BBL (1 mg/kg) intravenously injected in rats 30 min prior to inflammatory stimuli inhibited the cellular edema induced by carrageenan in only the second phase (21% - 3 h, 19% - 4 h) and did not alter the osmotic edema induced by dextran. BBL also inhibited carrageenan peritoneal neutrophil migration (51%), leukocyte rolling (58%) and adhesion (68%) and the neutrophil migration induced by TNF-α (64%). These effects were reversed by the association of BBL with galactose, demonstrating that the carbohydrate-binding domain is essential for lectin activity. In addition, BBL reduced myeloperoxidase activity (84%) and TNF-α (68%) and IL1-ß (47%) levels. In conclusion, the present investigation demonstrated that BBL contains highly homologous isolectins, resulting in a total of 86 amino acid residues, and exhibits anti-inflammatory activity by inhibiting neutrophil migration by reducing TNF-α and IL1-ß levels via the lectin domain.

Exploring the clinical relevance of "Angico Gum": an effective biopolymer for topical protection of oesophageal mucosa in gastroesophageal reflux disease patients.

OBJECTIVES: Angico gum (AG) (Anadenanthera colubrina var. Cebil [Griseb.] Altschul) is utilized by some Brazilian communities to alleviate symptoms from gastroesophageal reflux disease. Here, we aimed to investigate the "in vitro" topical protective capacity of AG on human esophageal mucosa. METHODS: Biopsies of the distal esophageal mucosa were collected from 35 patients with heartburn (24 non-erosive and 11 with erosive oesophagitis (EE)) and mounted in Üssing chambers. AG was applied topically, followed by exposure with acid solution (pH 2.0 or pH 1.0), where transepithelial electrical resistance (TER) and The transepithelial permeability for fluorescein was assessed. The incubation of the AG labeled with FITC in the esophageal mucosa was localized by fluorescence microscopy. KEY FINDINGS: Pretreatment with AG prevented the drop in TER induced by acid solution, as well as significantly decreases the fluorescein permeability in non-erosive patients. The protective effect of AG was sustained for up to 120 min both in biopsies of non-erosive and erosive esophagitis. Confocal microscope images showed mucosal luminal adherence of FITC-labeled AG. CONCLUSION: AG had a prolonged topical protective effect against acid solution in mucosal biopsies of patients with non-erosive and erosive esophagitis.

A polyphenol-rich açaí seed extract protects against 5-fluorouracil-induced intestinal mucositis in mice through the TLR-4/MyD88/PI3K/mTOR/NF-κBp65 signaling pathway.

Açaí seed extract (ASE) is obtained from Euterpe oleracea Mart. (açaí) plant (Amazon region) has high nutritional and functional value. ASE is rich in polyphenolic compounds, mainly proanthocyanidins. Proanthocyanidins can modulate the immune system and oxidative stress by inhibiting the toll-like receptor-4 (TLR-4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. A great deal of evidence suggests that inflammatory cytokines and oxidative stress contribute to the pathogenesis of intestinal mucositis, and these events can lead to intestinal dysmotility. We hypothesized that ASE acts as an anti-inflammatory and antioxidant compound in intestinal mucositis induced by 5-fluorouracil (5-FU) through modulation of the TLR-4/MyD88/phosphatidylinositol-3-kinase α/mechanistic target of rapamycin/NF-κBp65 pathway. The animals were divided into linear 5-FU (450 mg/kg) and 5-FU + ASE (10, 30, and 100 mg/kg) groups. The weight loss of the animals was evaluated daily. Samples from duodenum, jejunum, and ileum were obtained for histopathological, biochemical, and functional analyses. ASE reduced weight loss, inflammatory parameters (interleukin-1ß; tumor necrosis factor-α; myeloperoxidase activity) and the gene expression of mediators involved in the TLR-2/MyD88/NF-κB pathway. ASE prevented histopathological changes with beneficial effects on gastrointestinal transit delay, gastric emptying, and intestinal absorption/permeability. In conclusion, ASE protects the integrity of the intestinal epithelial barrier by inhibiting the TLR/MyD88/PI3K/mechanistic target of rapamycin/NF-κBp65 pathway.

Phosphatidylinositol 3-kinase gamma participates in nimesulide-induced hepatic damage.

OBJECTIVE: To evaluate the participation of the phosphatidylinositol 3-kinase pathway in the liver damage caused by nimesulide. METHODS: Liver damage been induced by nimesulide. Mice were treated with either 2% dimethyl sulfoxide or AS605240, a phosphatidylinositol 3-kinase gamma pathway antagonist. Blood samples were collected for function assays of liver. The liver was removed for analysis of liver weight/animal weight ratio, histopathological parameters, oxidative and nitrous stress, cytokine levels, and the immunostaining for cyclooxygenase 2 and nuclear factor kappa B. KEY FINDINGS: Liver injured by nimesulide and treated with phosphatidylinositol 3-kinase gamma inhibitor significantly reversed (P < 0.05) the damage; it decreased the liver weight/animal weight ratio, histopathological scores, and neutrophil infiltration, consequently reducing oxidative stress. In addition, we show that phosphatidylinositol 3-kinase gamma is associated with hepatic damage induced by nimesulide, because it altered liver function and increased the protein immunostaining of cyclooxygenase 2 and nuclear factor kappa B in the liver tissue of nimesulide-treated animals. CONCLUSIONS: The findings from the present study allows us to infer that nimesulide causes liver damage through the phosphatidylinositol 3-kinase gamma pathway.

McN-A-343, a muscarinic agonist, reduces inflammation and oxidative stress in an experimental model of ulcerative colitis.

AIM: The aim of the present study was to investigate the anti-inflammatory response mediated of the M1 muscarinic acetylcholine receptor (mAChR) during experimental colitis. MATERIAL AND METHODS: After the induction of 6% acetic acid colitis, mice were treated with McN-A-343 0.5, 1.0, and 1.5 mg/kg or dexamethasone (DEXA, 2.0 mg/kg) or pirenzepine (PIR, 10 mg/kg; M1 mAChR antagonist). Colonic inflammation was assessed by macroscopic and microscopic lesion scores, colonic wet weight, myeloperoxidase (MPO) activity, interleukin-1 beta (IL1-ß) levels and tumor necrosis factor alpha (TNF-α), glutathione (GSH), malondialdehyde (MDA) and nitrate and nitrite (NO3/NO2), mRNA expression of IKKα, nuclear factor kappa beta (NF-kB) and cyclooxygenase-2 (COX-2), as well protein expression of NF-kB and COX-2. RESULTS: Treatment with McN-A-343 at a concentration of 1.5 mg/kg showed a significant reduction in intestinal damage as well as a decrease in wet weight, MPO activity, pro-inflammatory cytokine concentration, markers of oxidative stress and expression of inflammatory mediators. The action of the M1 agonist by the administration of pirenzepine, which promoted the blocking of the mAChR M1-mediated anti-inflammatory response, has also been proven. CONCLUSION: The results suggest that peripheral colonic M1 mAChR is involved in reversing the pro-inflammatory effect of experimentally induced colitis, which may represent a promising therapeutic alternative for patients with ulcerative colitis.

Gabapentin attenuates intestinal inflammation: Role of PPAR-gamma receptor.

Gabapentin is an anticonvulsant drug that is also used for post-herpetic neuralgia and neuropathic pain. Recently, gabapentin showed anti-inflammatory effect. Nuclear factor kappa B (NFκB) is a regulator of the inflammatory process, and Peroxisome Proliferator-activated Receptor gamma (PPAR-gamma) is an important receptor involved in NFκB regulation. The aim of the present work was to study the potential role of PPAR-gamma receptor in gabapentin-mediated anti-inflammatory effects in a colitis experimental model. We induced colitis in rats using trinitrobenzenosulfonic acid and treated them with gabapentin and bisphenol A dicyldidyl ether (PPAR-gamma inhibitor). Macroscopic lesion scores, wet weight, histopathological analysis, mast cell count, myeloperoxidase, malondialdehyde acid, glutathione, nitrate/nitrite, and interleukin levels in the intestinal mucosa were determined. In addition, western blots were performed to determine the expression of Cyclooxygenase-2 (COX-2) and NFκB; Nitric Oxide Inducible Synthase (iNOS) and Interleukin 1 beta (IL-1ß) levels were also determined. Gabapentin was able to decrease all inflammatory parameters macroscopic and microscopic in addition to reducing markers of oxidative stress and cytokines such as IL-1ß and Tumor Necrosis Factor alpha (TNF-α) as well as enzymes inducible nitric oxide synthase and cyclooxygenase 2 and inflammatory genic regulator (NFκB). These effect attributed to gabapentin was observed to be lost in the presence of the specific inhibitor of PPAR-gamma. Gabapentin inhibits bowel inflammation by regulating mast cell signaling. Furthermore, it activates the PPAR-gamma receptor, which in turn inhibits the activation of NFκB, and consequently results in reduced activation of inflammatory genes involved in inflammatory bowel diseases.

Polysaccharides derived from Morinda citrifolia Linn reduce inflammatory markers during experimental colitis.

ETHNOPHARMACOLOGICAL RELEVANCE: There are many reports of pharmacological activities of extracts and fractions of different vegetable-derived products in the scientific literature and in folk medicine. Ethnopharmacological use of these products by various communities continues to be extensively explored, and they account for more than half of all medications used worldwide. Polysaccharides (PLS) extracted from plants such as Morinda Citrifolia Linn present therapeutic potential in treatment of inflammatory bowel diseases (IBD) such as ulcerative colitis (UC). AIM OF THE STUDY: To evaluate the anti-inflammatory action of Noni-PLS against the intestinal damage in UC induced by acetic acid in mice. MATERIALS AND METHODS: In acetic acid-induced colitis, the mice were treated intraperitoneally (ip) with Noni-PLS (0.1, 0.3, and 3.0 mg/kg) or subcutaneously (sc) with dexamethasone (2.0 mg/kg) 30 min before euthanasia to determine the best dose of Noni-PLS with an anti-inflammatory effect in the course of UC. The colonic tissue samples were collected for macroscopic, wet weight, microscopic and biochemical (myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), nitrate/nitrite (NO3/NO2), cytokines, cyclooxygenase (COX-2) and inducible nitric oxide (iNOS)) analyses. RESULTS: Treatment with Noni-PLS reduced the intestinal damage induced by acetic acid as it reduced macroscopic and microscopic scores and the wet weight of the colon. In addition, MPO activity and levels of GSH, MDA, NO3/NO2, pro-inflammatory cytokines, and COX-2 expression reduced. CONCLUSIONS: This study suggests that Noni-PLS exhibits anti-inflammatory action against intestinal damage by reducing inflammatory cell infiltration, oxidative stress, pro-inflammatory action of cytokines, COX-2 and iNOS expression in the inflamed colon. Noni-PLS shows therapeutic potential against inflammatory disorders like UC.

Gastroprotective effects of N-acylarylhydrazone derivatives on ethanol-induced gastric lesions in mice are dependent on the NO/cGMP/KATP pathway.

The gastroprotective effects of N-acylarylhydrazone derivatives on ethanol-induced gastric lesions in mice were investigated with respect to the NO/cGMP/KATP pathway. To investigate our hypothesis, the mice were intraperitoneally pretreated with glibenclamide, L-NAME, or ODQ 30 min before treatment with DMSO, LASSBio-294 (1, 2, and 4 mg/kg, p.o.), LASSBio-897 (0.5, 1, and 2 mg/kg, p.o.), or omeprazole. After 1 h, the mice received absolute ethanol (4 ml/kg) by gavage to induce gastric mucosal lesions, and the microscopic and macroscopic parameters were evaluated. GSH (non-protein sulfhydryl groups) and MDA (malondialdehyde) concentrations, hemoglobin levels, nitric oxide production, myeloperoxidase (MPO) activity, and TNF-α and IL-1ß levels were also analyzed in the stomach after absolute ethanol administration. Pretreatment with LASSBio-294 or LASSBio-897 significantly reduced the microscopic and macroscopic lesion area. The compounds restored the GSH, MDA, and hemoglobin levels and reduced MPO activity. Moreover, the compounds significantly reduced nitrate and nitrite concentrations in the stomach samples after ethanol administration. Molecular docking studies revealed that LASSBio-294 and LASSBio-897 interact with active sites of the eNOS (endothelial nitric oxide synthase) enzymes through hydrogen bonds. LASSBio-294 and LASSBio-897 also reduced TNF-α and IL-1ß levels. It was observed that a NO synthase inhibitor, an ATP-sensitive potassium channel blocker, and a guanylate cyclase inhibitor significantly reversed the gastroprotective effects of these compounds. Thus, the gastroprotective effect of LASSBio-294 and LASSBio-897 against gastric lesions is mediated through the NO/cGMP cascade, followed by blocking of the KATP channels.

Galactomannan from the seeds of Caesalpinia pulcherrima prevents indomethacin-induced gastrointestinal damage via neutrophil migration.

Galactomannans are neutral polysaccharides isolated from the endosperm of some Leguminosae seeds. They consist of a (1 → 4) linked ß-mannopyranosyl backbone partially substituted at O-6 with α-d-galactopyranosyl side groups. C. pulcherrima have anti-inflammatory and muco-adhesive proprieties. Acute gastritis is an inflammatory disease triggered by use of non-steroidal anti-inflammatory drugs. We investigated the gastroprotective effect of galactomannan obtained from the seeds of Caesalpinia pulcherrima L. (GM-CP) in acute gastritis model induced by indomethacin. Gastritis was induced with indomethacin (30 mg/kg, P.·O.) in female Swiss mice. Animal groups (n = 7) were pretreated with saline-dissolved GM-CP (3 mg/kg, 10 mg/kg, 30 mg/kg, P.O.) or vehicle 1 h before gastritis induction. Mice were euthanized seven hours after the induction. The stomach and blood samples were collected for analysis. At 10 mg/kg, GP-CP reduced the extension of macroscopic lesion and the loss of superficial cells by alleviating inflammatory symptoms (neutrophil infiltration, migration and adhesion of mesenteric leukocytes, production of TNF-α and thiobarbituric acid reactive species (TBARS) and helping to maintain mucin labeling of the tissue. Thus, the findings of the study suggest that GM-CP exhibits gastroprotective effects.

A lectin fraction from green seaweed Caulerpa cupressoides inhibits inflammatory nociception in the temporomandibular joint of rats dependent from peripheral mechanisms.

Temporomandibular disorders are the second most common cause of orofacial pain mediated by inflammatory compounds, which in many cases leads to chronic orofacial pain. This study assessed the antinociceptive and anti-inflammatory effects of a lectin from the green seaweed Caulerpa cupressoides (CcL) on hypernociception inflammatory in TMJ of rats and investigated the involvement of different mechanisms. Rats received i.v. CcL 30 min prior to injection of flogistic agentes or 0.9% saline into the left TMJ. Pretreatment with CcL (0. 1; 1 or 10 mg/kg) promoted a reduction (p < 0.05) of inflammatory hypernociception induced by 1.5% Formalin along with inhibition of inflammatory plasma extravasation, cytokines levels, ciclooxigenase-2, and intercellular adhesion molecule (ICAM-1). CcL was able to inhibit the nociceptive response induced by 1.5% Capsaicin, suggesting that CcL has an antinociceptive effect, acting directly on the primary nociceptive neurons. CcL also inhibited the nociceptive response induced by Carrageenan (100 µg/TMJ) or Serotonin (5-HT) (225 µg/TMJ). In conclusion, the results demonstrate that administration of CcL has a potential antinociceptive and anti-inflammatory effect, with a mechanism that is partially dependent on TNF-α, IL-1ß, COX-2 and ICAM-1 inhibition and independently from the cannabinoide and opioid system and NO/cGMP/PKG/K+ATP channel pathway.

Protective effects of fucoidan, a P- and L-selectin inhibitor, in murine acute pancreatitis.

OBJECTIVE: The objective of this study was to investigate the potential protective effects of fucoidan, an L- and P-selectin modulator, in 2 murine models of acute pancreatitis. METHODS: Acute pancreatitis was induced in mice either by the retrograde infusion of taurolithocholic acid sulfate into the pancreatic duct or by intraperitoneal injections of cerulein (50 µg/kg per hour). The experimental groups received fucoidan (25 mg/kg, intravenously) before pancreatitis induction, whereas control groups received only saline. After 24 hours, serum amylase, lipase, interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α), and nitrite were measured. In addition, myeloperoxidase (MPO) activity (lung and pancreas) and histological assessment (pancreas) were determined. RESULTS: Serum amylase, lipase, nitrite, TNF-α, and IL-1ß, and pancreatic and lung MPO were increased in both taurolithocholic acid sulfate and cerulein acute pancreatitis compared with the respective control groups. Fucoidan significantly decreased the augmented levels of amylase, lipase, pancreatic and lung MPO, TNF-α, IL-1ß, and nitrite in both models. Pancreas histological changes observed in both acute pancreatitis models were significantly attenuated by fucoidan. CONCLUSIONS: Fucoidan reduced the severity of acute pancreatitis in mice by decreasing neutrophil infiltration and systemic inflammation, suggesting that modulation of selectins may constitute a promising therapeutic approach.

Anti-inflammatory effect of a sulphated polysaccharide fraction extracted from the red algae Hypnea musciformis via the suppression of neutrophil migration by the nitric oxide signalling pathway.

OBJECTIVES: The aim of this study was to evaluate the anti-inflammatory effect of a sulphated polysaccharide fraction (PLS) extracted from the alga Hypnea musciformis and investigate the possible involvement of the nitric oxide (NO) pathway in this effect. METHODS: The anti-inflammatory activity of PLS was evaluated using inflammatory agents (carrageenan and dextran) to induce paw oedema and peritonitis in Swiss mice. Samples of paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity, NO3 /NO2 levels, and interleukin-1ß (IL-1ß) level. The involvement of NO in the modulation of neutrophil migration in carrageenan-induced paw oedema or peritonitis was also investigated. KEY FINDINGS: Compared with vehicle-treated mice, mice pretreated with PLS (10 mg/kg) inhibited carrageenan-induced and dextran-induced oedema; it also inhibited total and differential peritoneal leucocyte counts in a model of peritonitis. These PLS effects were reversed by l-arginine treatment and recovered with the administration of a NO synthase blocker (aminoguanidine). Furthermore, PLS reduced the MPO activity, decreased IL-1ß levels, and increased NO3 /NO2 levels in the peritoneal cavity. CONCLUSIONS: PLS reduced the inflammatory response by modulating neutrophil migration, which appeared to be dependent on the NO pathway.