Pepsin Inhibitors Prevent Inflammation and Loss of Laryngeal Barrier Function in Mice with Gastroesophageal Reflux.

OBJECTIVE: This study aimed to evaluate the role of pepsin inhibitors in the inflammatory response and their effects on laryngeal mucosal integrity during gastroesophageal reflux (GERD) under in vivo conditions. METHODS: A surgical model of GERD was used, in which mice were treated with pepstatin (0.3 mg/kg) or darunavir (8.6 mg/kg) for 3 days. On the third day after the experimental protocol, the laryngeal samples were collected to assess the severity of inflammation (wet weight and myeloperoxidase activity) and mucosal integrity (transepithelial electrical resistance and paracellular epithelial permeability to fluorescein). RESULTS: The surgical GERD model was reproduced. It showed features of inflammation and loss of barrier function in the laryngeal mucosa. Pepstatin and darunavir administration suppressed laryngeal inflammation and preserved laryngeal mucosal integrity. CONCLUSION: Pepsin inhibition by the administration of pepstatin and darunavir improved inflammation and protected the laryngeal mucosa in a mouse experimental model of GERD. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Anti-diarrheal therapeutic potential of diminazene aceturate stimulation of the ACE II/Ang-(1-7)/Mas receptor axis in mice: A trial study.

The angiotensin (Ang) II converting enzyme (ACE II) pathway has recently been shown to be associated with several beneficial effects on the body, especially on the cardiac system and gastrointestinal tract. ACE II is responsible for converting Ang II into the active peptide Ang-(1-7), which in turn binds to a metabotropic receptor, the Mas receptor (MasR). Recent studies have demonstrated that Diminazene Aceturate (DIZE), a trypanosomicide used in animals, activates the ACE II pathway. In this study, we aimed to evaluate the antidiarrheal effects promoted by the administration of DIZE to activate the ACE II/Ang-(1-7)/MasR axis in induced diarrhea mice models. The results show that activation of the ACE II pathway exerts antidiarrheal effects that reduce total diarrheal stools and enteropooling. In addition, it increases Na+/K+-ATPase activity and reduces gastrointestinal transit and thus inhibits contractions of intestinal smooth muscle; decreases transepithelial electrical resistance, epithelial permeability, PGE2-induced diarrhea, and proinflammatory cytokines; and increases anti-inflammatory cytokines. Enzyme-linked immunosorbent assay (ELISA) demonstrated that DIZE, when activating the ACE II/Ang-(1-7)/MasR axis, can still interact with GM1 receptors, which reduces cholera toxin-induced diarrhea. Therefore, activation of the ACE II/Ang-(1-7)/MasR axis can be an important pharmacological target for the treatment of diarrheal diseases.

Protective effect against gastric mucosa injury of a sulfated agaran from Acanthophora spicifera.

In this study, a polysaccharide from marine alga Acanthophora spicifera (PAs) was isolated and structurally characterized. Its protective potential against chemically-induced gastric mucosa injury was evaluated. The gel permeation chromatography experiments and spectroscopy spectrum showed that PAs is a sulfated polysaccharide with a high molecular mass (6.98 × 105g/mol) and degree of sulfation of 1.23, exhibiting structural characteristic typical of an agar-type polysaccharide. Experimental results demonstrated that PAs reduced the hemorrhagic gastric injury, in a dose-dependent manner. Additionally, PAs reduced the intense gastric oxidative stress, measured by glutathione (GSH) and malondialdehyde (MDA) levels. PAs also prevented the reduction of mucus levels adhered to the gastric mucosa, promoted by the aggressive effect of ethanol. In summary, the sulfated polysaccharide from A. spicifera protected the gastric mucosa through the prevention of lipid peroxidation and enhanced the defense mechanisms of the gastric mucosa, suggesting as a promising functional food as gastroprotective agent.

Neuropathy and primary headaches affect different subgroups of inflammatory bowel disease patients.

BACKGROUND: Peripheral neuropathies (PN) and primary headaches (PH) are common comorbidities in inflammatory bowel disease (IBD) patients. We aimed to evaluate whether PN and PH affect the same subgroups of IBD patients. METHODS: Since 2004, we established a cohort study to evaluate neurological diseases in IBD patients. Over 2 years, all consecutive (N = 155) IBD patients (either Crohn's disease (CD) or ulcerative colitis (UC) were evaluated for the presence of PN and PH. PH were also evaluated in dyspeptic patients (N = 84) and IBD relatives (controls, N = 101). After neurological evaluation, symptomatic patients underwent skin wrinkling test to evaluate small fiber function and/or electromyography. RESULTS: Headaches and migraine were more prevalent in IBD than control patients: 52.3 and 34.2% vs. 40.6 and 20.8% (P < 0.05). Migraine was 2.6 times more common in CD patients than controls (CI = 1.34-5.129) and 8.6 times (13.3 times in the CD group) more common in men with IBD (P < 0.05). Headache and migraine were also more common in dyspeptic patients (P < 0.05). Chi-square, univariate, and multivariate regression analysis did not disclose any association between PN, headache, or PH (P > 0.05). Multivariate regression analysis disclosed that headaches were more prevalent in women, co-existing psychiatric disease, IBD, CD, and UC. After age, gender distribution, and prevalence of hypertension and psychiatric diseases were matched among the groups, there were still differences in the prevalence of headaches and migraine among IBD, CD, and UC versus control patients. CONCLUSION: In summary, PH and PN are common in IBD and do not affect the same subgroups of patients.

Chemical structure, anti-inflammatory and antinociceptive activities of a sulfated polysaccharide from Gracilaria intermedia algae.

The present work aimed at carrying out the isolation and biochemical characterization of a sulfated polysaccharide fraction (PLS) from the marine algae Gracilaria intermedia and investigating its anti-inflammatory and antinociceptive potential. PLS was obtained through enzymatic digestion with papain and analyzed by means of gel permeation chromatography and Nuclear Magnetic Resonance to 1H and 13C. In order to evaluate the potential of anti-inflammatory action of PLS, we performed paw edema induced by carrageenan, dextran, compound 48/80, histamine and serotonin. In addition, we also measured the concentration of myeloperoxidase, cytokines, the count of inflammatory cells and performed tests of the nociception. The PLS isolated was of high purity and free of contaminants such as proteins, and had molecular weight of 410 kDa. The same macromolecule was able to decrease the paw edema induced by all inflammatory agents (P < 0.05), myeloperoxidase (MPO) activity, neutrophil migration and IL-1ß levels. It also decreased acetic acid-induced writhing (P < 0.05) and formalin-induced paw licking time (P < 0.05), but no in hot plate test. In summary, the PLS decreased the inflammatory response by reducing neutrophil migration and modulating IL-1ß production and antinociceptive effects by a peripheral mechanism dependent on the down-modulation of the inflammatory mediators.

Laryngeal Mucosa Alterations in Mice Model of Gastroesophageal Reflux: Effects of Topical Protection.

OBJECTIVES/HYPOTHESIS: The objectives of this study were to evaluate laryngeal inflammation and mucosal integrity in a murine model of reflux disease and to assess the protective effects of topical agents including alginate, hyaluronic acid, and cashew gum. STUDY DESIGN: Animal study. METHODS: A surgical murine model of reflux disease was evaluated at 3 or 7 days postsurgery, and laryngeal samples were collected to measure inflammation (wet weight and myeloperoxidase [MPO]) and mucosal integrity (transepithelial resistance [TER] and mucosal permeability to fluorescein). Additional groups of animals were administered one of several topical agents (alginate, hyaluronic acid, or cashew gum) daily, and laryngeal inflammation and mucosal integrity were evaluated at 3 days postsurgery. RESULTS: At 3 days, and not 7 days postsurgery, we observed increased laryngeal wet weight and MPO, decreased laryngeal TER, and increased laryngeal mucosa permeability. Alginate partially decreased laryngeal inflammation (wet weight and not MPO) and dramatically improved laryngeal mucosal integrity. Conversely, hyaluronic acid eliminated the inflammation; however, it had no effect on laryngeal mucosal integrity impairment. Cashew gum eliminated laryngeal inflammation as well as the impairment in laryngeal mucosal integrity. CONCLUSIONS: This study shows that a surgical model of reflux disease induced laryngeal inflammation and impairment in laryngeal barrier function. These observed alterations were partially attenuated by alginate and hyaluronic acid and completely reversed by cashew gum. LEVEL OF EVIDENCE: NA Laryngoscope, 2020.

Biopolymer Extracted from Anadenanthera colubrina (Red Angico Gum) Exerts Therapeutic Potential in Mice: Antidiarrheal Activity and Safety Assessment.

Anadenanthera colubrina var. cebil (Griseb.) Altschul (Fabaceae family), commonly known as the red angico tree, is a medicinal plant found throughout Brazil's semi-arid area. In this study, a chemical analysis was performed to investigate the antidiarrheal activity and safety profile of red angico gum (RAG), a biopolymer extracted from the trunk exudate of A. colubrina. Upon FT-IR spectroscopy, RAG showed bands in the regions of 1608 cm-1, 1368 cm-1, and 1029 cm-1, which relate to the vibration of O-H water molecules, deformation vibration of C-O bands, and vibration of the polysaccharide C-O band, respectively, all of which are relevant to glycosidic bonds. The peak molar mass of RAG was 1.89 × 105 g/mol, with the zeta potential indicating electronegativity. RAG demonstrated high yield and solubility with a low degree of impurity. Pre-treatment with RAG reduced the total diarrheal stool and enteropooling. RAG also enhanced Na+/K+-ATPase activity and reduced gastrointestinal transit, and thereby inhibited intestinal smooth muscle contractions. Enzyme-Linked Immunosorbent Assay (ELISA) demonstrated that RAG can interact with GM1 receptors and can also reduce E. coli-induced diarrhea in vivo. Moreover, RAG did not induce any signs of toxicity in mice. These results suggest that RAG is a possible candidate for the treatment of diarrheal diseases.

Modulation of 5-fluorouracil activation of toll-like/MyD88/NF-κB/MAPK pathway by Saccharomyces boulardii CNCM I-745 probiotic.

BACKGROUND AND AIM: Chemotherapy drugs that act via Toll-like receptors (TLRs) can exacerbate mucosal injury through the production of cytokines. Intestinal mucositis can activate TLR2 and TLR4, resulting in the activation of NF-κB. Intestinal mucositis characterized by intense inflammation is the main side effect associated with 5-fluorouracil (5-FU) treatment. Saccharomyces boulardii CNCM I-745 (S.b) is a probiotic yeast used in the treatment of gastrointestinal disorders. The main objective of the study was to evaluate the effect of S.b treatment on the Toll-like/MyD88/NF-κB/MAPK pathway activated during intestinal mucositis and in Caco-2 cells treated with 5-FU. METHODS: The mice were divided into three groups: saline (control), saline + 5-FU, and 5-FU + S.b (1.6 × 1010 colony forming units/kg). After 3 days of S.b administration by gavage, the mice were euthanized and the jejunum and ileum were removed. In vitro, Caco2 cells were treated with 5-FU (1 mM) alone or in the presence of lipopolysaccharide (1 ng/ml). When indicated, cells were exposed to S.b. The jejunum/ileum samples and Caco2 cells were examined for the expression or concentration of the inflammatory components. RESULTS: Treatment with S.b modulated the expressions of TLR2, TLR4, MyD88, NF-κB, ERK1/2, phospho-p38, phospho-JNK, TNF-α, IL-1ß, and CXCL-1 in the jejunum/ileum and Caco2 cells following treatment with 5-FU. CONCLUSION: Toll-like/MyD88/NF-κB/MAPK pathway are activated during intestinal mucositis and their modulation by S.b suggests a novel and valuable therapeutic strategy for intestinal inflammation.

Cashew gum, a biopolymer, topically protects oesophageal mucosa in non erosive reflux disease: A promising translational study.

This study aimed to investigate a standardized biopolymer, cashew gum (CG), in human oesophageal mucosa and mice with experimentally-induced non-erosive reflux disease (NERD). Human oesophageal biopsies from NERD patients were collected to evaluate the mucosal protection of CG through transepithelial electrical resistance (TER), mucosal permeability, and mucoadhesiveness tests. A surgical model of NERD in mice was induced, and barrier functions followed by suggestive oesophageal inflammatory hallmarks were evaluated. Pre-coating of CG was effective in human oesophageal mucosa by attenuating drop of TER and mucosal permeability. Labelled-CG adheres to human oesophageal mucosa for up to 1 h. In animal studies, CG improved parameters of barrier function (TER and mucosal permeability) in distal oesophagus mucosa. CG also promoted sequential support by reducing inflammatory hallmarks of oesophageal damage. CG confers topical oesophageal mucosal protection due to its mucoadhesiveness and anti-inflammatory profile. Long-duration mucoprotective products can be further explored as first-line/adjuvant NERD therapy.

Efficacy of a phenol derivative, isopropyl vanillate, as an anti-inflammatory agent: A new small molecule inhibitor of COX and neutrophil migration.

Inflammation is the response of the body to noxious stimuli such as infections, trauma, or injury. Experimental studies have shown that vanillic acid has anti-inflammatory effects. The objective of this study was to investigate the anti-inflammatory and antipyretic properties of the derivative of vanillic acid, isopropyl vanillate (ISP-VT), in mice. The results of this study indicated that ISP-VT reduced paw edema induced by carrageenan, dextran sulfate (DEX), compound 48/80, serotonin, bradykinin (BK), histamine (HIST), and prostaglandin E2 (PGE2). Furthermore, ISP-VT reduced recruitment of leukocytes and neutrophils and reduced its adhesion and rolling, and decreased myeloperoxidase enzyme activity (MPO), cytokine levels (tumor necrosis factor-α and interleukin-6), and vascular permeability. ISP-VT also significantly reduced the expression of cyclooxygenase-2 (COX-2) in subplantar tissue of mice. ISP-VT inhibited COX-2 selectively compared to the standard drug. Our results showed that although ISP-VT binds to COX-1, it is less toxic than indomethacin, as evidenced by MPO analysis of gastric tissue. Treatment with the ISP-VT significantly reduced rectal temperature in yeast-induced hyperthermia in mice. Our results showed that the main mechanism ISP-VT-induced anti-inflammatory activity is by inhibition of COX-2. In conclusion, our results indicate that ISP-VT has potential as an anti-inflammatory and antipyretic therapeutic compound.

Lactobacillus reuteri DSM 17938 Protects against Gastric Damage Induced by Ethanol Administration in Mice: Role of TRPV1/Substance P Axis.

This study aimed to evaluate the effect of Lactobacillus reuteri DSM 17938 (DSM) on ethanol-induced gastric injury, and if its possible mechanism of action is related to inhibiting the transient receptor potential vanilloid type 1 (TRPV1). We evaluated the effect of supplementing 108 CFU•g body wt-1•day-1 of DSM on ethanol-induced gastric injury. DSM significantly reduced the ulcer area (1.940 ± 1.121 mm²) with 3 days of pretreatment. The effects of DSM supplementation were reversed by Resiniferatoxin (RTX), TRPV1 agonist (3 nmol/kg p.o.). Substance P (SP) (1 µmol/L per 20 g) plus 50% ethanol resulted in hemorrhagic lesions, and DSM supplementation did not reverse the lesion area induced by administering SP. TRPV1 staining intensity was lower, SP, malondialdehyde (MDA) and nitrite levels were reduced, and restored normal levels of antioxidant parameters (glutathione and superoxide dismutase) in the gastric mucosa in mice treated with DSM. In conclusion, DSM exhibited gastroprotective activity through decreased expression of TRPV1 receptor and decreasing SP levels, with a consequent reduction of oxidative stress.

AMPK activation promotes gastroprotection through mutual interaction with the gaseous mediators H2S, NO, and CO.

Activation of 5' adenosine monophosphate-activated protein kinase (AMPK) stimulates production of the gaseous mediators nitric oxide (NO) and carbon monoxide (CO), which are involved in mucosal defense and gastroprotection. As AMPK itself has gastroprotective effects against several gastric ulcer etiologies, in the present study, we aimed to elucidate whether AMPK may also prevent ethanol-induced injury and play a key role in the associated gastroprotection mediated by hydrogen sulfide (H2S), NO, and CO. Mice were pretreated with AICAR (20 mg/kg, an AMPK activator) alone or with 50% ethanol. Other groups were pretreated with respective gaseous mediator inhibitors PAG, l-NAME, or ZnPP IX 30 min prior to AICAR, or with gaseous mediator donors NaHS, Lawesson's reagent and l-cysteine (H2S), SNP, l-Arginine (NO), Hemin, or CORM-2 (CO) 30 min prior to ethanol with or without compound C (10 mg/kg, a non-selective AMPK inhibitor). H2S, nitrate/nitrite (NO3-/NO2-), bilirubin levels, GSH and MDA concentration were evaluated in the gastric mucosa. The gastric mucosa was also collected for histopathological analysis and AMPK expression assessment by immunohistochemistry. Pretreatment with AICAR attenuated the ethanol-induced injury and increased H2S and bilirubin levels but not NO3-/NO2- levels in the gastric mucosa. In addition, inhibition of H2S, NO, or CO synthesis exacerbated the ethanol-induced gastric damage and inhibited the gastroprotection by AICAR. Pretreatment with compound C reversed the gastroprotective effect of NaHS, Lawesson's reagent, l-cysteine, SNP, l-Arginine, CORM-2, or Hemin. Compound C also reversed the effect of NaHS on H2S production, SNP on NO3-/NO2- levels, and Hemin on bilirubin levels. Immunohistochemistry revealed that AMPK is present at basal levels mainly in the gastric mucosa cells, and was increased by pretreatment with NaHS, SNP, and CORM-2. In conclusion, our findings indicate that AMPK activation exerts gastroprotection against ethanol-induced gastric damage and mutually interacts with H2S, NO, or CO to facilitate this process.

H2S is a key antisecretory molecule against cholera toxin-induced diarrhoea in mice: Evidence for non-involvement of the AC/cAMP/PKA pathway and AMPK.

Hydrogen sulphide (H2S) is a gasotransmitter that participates in various physiological and pathophysiological processes within the gastrointestinal tract. We studied the effects and possible mechanism of action of H2S in secretory diarrhoea caused by cholera toxin (CT). The possible mechanisms of action of H2S were investigated using an intestinal fluid secretion model in isolated intestinal loops on anaesthetized mice treated with CT. NaHS and Lawesson's reagent and l-cysteine showed antisecretory activity through reduction of intestinal fluid secretion and loss of Cl- induced by CT. Pretreatment with an inhibitor of cystathionine-γ-lyase (CSE), dl-propargylglycine (PAG), reversed the effect of l-cysteine and caused severe intestinal secretion. Co-treatment with PAG and a submaximal dose of CT increased intestinal fluid secretion, thus supporting the role of H2S in the pathophysiology of cholera. CT increased the expression of CSE and the production of H2S. Pretreatment with PAG did not reverse the effect of SQ 22536 (an AC inhibitor), bupivacaine (inhibitor of cAMP production), KT-5720 (a PKA inhibitor), and AICAR (an AMPK activator). The treatment with Forskolin does not reverse the effects of the H2S donors. Co-treatment with either NaHS or Lawesson's reagent and dorsomorphin (an AMPK inhibitor) did not reverse the effect of the H2S donors. H2S has antisecretory activity and is an essential molecule for protection against the intestinal secretion induced by CT. Thus, H2S donor drugs are promising candidates for cholera therapy. However, more studies are needed to elucidate the possible mechanism of action.

Topical protection of mice laryngeal mucosa using the natural product cashew gum.

OBJECTIVES/HYPOTHESIS: Evaluate the effect of in vitro exposure of mice laryngeal mucosa to solutions that simulated human gastric juice and to assess the topical protective effect of cashew gum on mice laryngeal mucosal integrity in vitro. STUDY DESIGN: Animal study. METHODS: Murine (Swiss) laryngeal samples were mounted in Ussing chambers. The luminal side of biopsies was exposed to solutions of different acidity with or without pepsin and/or taurodeoxycholic acid (TDC). Transepithelial electrical resistance (TER) was continuously recorded. The topical protective effect of cashew gum solution was evaluated by precoating the biopsies before the exposure with a solution at pH 5 containing 5 mM TDC. Changes in TER and mucosal permeability to fluorescein were measured. RESULTS: Exposure of laryngeal mucosa to acidic solutions containing pepsin and TDC provoked a pH-dependent drop in TER with the maximal effect at pH 1, but still present at pH 5 (weakly acidic). The exposure of the laryngeal mucosa to a solution of pH 5 with TDC, but not with pepsin, produced a dose-dependent decrease in TER. Precoating the mucosa with cashew gum prevented the reduction of TER and increased transepithelial permeability by exposure to a solution at pH5 containing TDC. CONCLUSIONS: Weakly acidic solutions containing bile acids can produce impairment of laryngeal epithelial barrier, which may be protected by topical treatment with cashew gum. LEVEL OF EVIDENCE: NA. Laryngoscope, 128:1157-1162, 2018.

A novel murine model of esophageal nonerosive reflux disease: from inflammation to impairment in mucosal integrity.

Nonerosive reflux disease (NERD) is a highly prevalent phenotype of the gastroesophageal reflux disease. In this study, we developed a novel murine model of NERD in mice with microscopic inflammation and impairment in the epithelial esophageal barrier. Female Swiss mice were subjected to the following surgical procedure: the transitional region between the forestomach and the glandular portion of the stomach was ligated, and a nontoxic ring was placed around the duodenum near the pylorus. The control group underwent sham surgery. The animals were euthanized at 1, 3, 7, and 14 days after surgery. Survival and body weight were monitored daily. Esophageal wet weight, macroscopic lesion, histopathological alterations, myeloperoxidase (MPO) activity, cytokine levels, transepithelial electrical resistance (TEER), and mucosal permeability were evaluated. The survival rate was 78% at 14 days, with mild loss in body weight. Surgery did not induce erosive esophagitis but instead induced microscopic inflammation and increased esophageal wet weight, IL-6, keratinocyte-derived cytokine (KC) levels, and MPO activity with maximal peak between 3 and 7 days and resolution at 14 days postsurgery. Epithelial esophageal barrier was evaluated in operated mice at 7 and 14 days postsurgery; a decrease in TEER and increase in the esophageal epithelial permeability were observed compared with the sham-operated group. In addition, the inhibition of acid secretion with omeprazole significantly prevented the esophageal inflammation and impairment of barrier function at 7 days postsurgery. Thus we established a novel experimental model of NERD in mice, which can contribute to understanding the pathophysiological events associated with NERD.NEW & NOTEWORTHY In this study, we standardized an experimental model of nonerosive reflux disease (NERD) in mice. This model involves an acute inflammatory response followed by impaired esophageal mucosal integrity, even in the absence of inflammation. Thus this model can serve for evaluation of pathophysiological aspects of NERD and open new perspectives for therapeutic strategies for patients with this disorder.

Epiisopiloturine hydrochloride, an imidazole alkaloid isolated from Pilocarpus microphyllus leaves, protects against naproxen-induced gastrointestinal damage in rats.

OBJECTIVE: This study aimed to investigate the protective effect of epiisopiloturine hydrochloride (EPI), an imidazole alkaloid, on NAP-induced gastrointestinal damage in rats. METHODS: Initially, rats were pretreated with 0.5% carboxymethylcellulose (vehicle) or EPI (3, 10 and 30mg/kg, p.o. or i.p., groups 3-5, respectively) twice daily, for 2days. After 1h, NAP (80mg/kg, p.o.) was given. The control group received only vehicle (group 1) or vehicle+naproxen (group 2). Rats were euthanized on 2nd day, 4h after NAP treatment. Stomachs lesions were measured. Samples were collected for histological evaluation and glutathione (GSH), malonyldialdehyde (MDA), myeloperoxidase (MPO), and cytokines levels. Moreover, gastric mucosal blood flow (GMBF) was evaluated. RESULTS: EPI pretreatment prevented NAP-induced macro and microscopic gastric damage with a maximal effect at 10mg/kg. Histological analysis revealed that EPI decreased scores of damage caused by NAP. EPI reduced MPO (3.4±0.3U/mg of gastric tissue) and inhibited changes in MDA (70.4±8.3mg/g of gastric tissue) and GSH (246.2±26.4mg/g of gastric tissue). NAP increased TNF-α levels, and this effect was reduced by EPI pretreatment. Furthermore, EPI increased GMBF by 15% compared with the control group. CONCLUSION: Our data show that EPI protects against NAP-induced gastric and intestinal damage by reducing pro-inflammatory cytokines, reducing oxidative stress, and increasing GMBF.

Biochemical Profile, Biological Activities, and Toxic Effects of Proteins in the Rhinella schneideri Parotoid Gland Secretion.

Parotoid glands of amphibians are known for the production of several biologically active compounds having pharmacological and toxic effects in mammals. In the present work, a protein fraction obtained from Rhinella schneideri parotoid gland (RsPP) was characterized to study its biological and toxic effects. Rhinella schneideri parotoid secretion is composed of up to 30% (w/w) of soluble proteins. Tandem mass spectrometric analysis of the RsPP identified 104 proteins, including actin, beta-actin, ribosomal proteins, catalase, galectin, and uncharacterized proteins; however, no peptidases were found, and this result was reinforced by the absence of proteolytic activity. In addition, RsPP did not exhibit pro-coagulant or antibacterial effects. However, pretreatment of mice with different doses of RsPP intraperitoneally inhibited carrageenan-induced paw edema and increased tissue myeloperoxidase activity. RsPP also reduced interleukin 1ß levels in the peritoneal cavities and cell migration in the peritoneal cavities of an animal model of carrageenan-induced peritonitis. Subchronic treatment of animals with RsPP for 7 consecutive days did not alter the serum biochemical, renal, or liver parameters. However, a significant reduction in blood leukocyte count was observed. Our results showed that R. schneideri parotoid secretion contains proteins with anti-inflammatory and slight toxic effects.

Irinotecan- and 5-fluorouracil-induced intestinal mucositis: insights into pathogenesis and therapeutic perspectives.

PURPOSE: Intestinal mucositis and diarrhea are common manifestations of anticancer regimens that include irinotecan, 5-fluorouracil (5-FU), and other cytotoxic drugs. These side effects negatively impact therapeutic outcomes and delay subsequent cycles of chemotherapy, resulting in dose reductions and treatment discontinuation. Here, we aimed to review the experimental evidence regarding possible new targets for the management of irinotecan- and 5-FU-related intestinal mucositis. METHODS: A literature search was performed using the PubMed and MEDLINE databases. No publication time limit was set for article inclusion. RESULTS: Here, we found that clinical management of intestinal mucositis and diarrhea is somewhat ineffective at reducing symptoms, possibly due to a lack of specific targets for modulation. We observed that IL-1ß contributes to the apoptosis of enterocytes in mucositis induced by 5-FU. However, 5-FU-related mucositis is far less thoroughly investigated with regard to specific molecular targets when compared to irinotecan-related disease. Several studies have proposed that a correlation exists between the intestinal microbiota, the enterohepatic recirculation of active metabolites of irinotecan, and the establishment of mucositis. However, as reviewed here, this association seems to be controversial. In addition, the pathogenesis of irinotecan-induced mucositis appears to be orchestrated by interleukin-1/Toll-like receptor family members, leading to epithelial cell apoptosis. CONCLUSIONS: IL-1ß, IL-18, and IL-33 and the receptors IL-1R, IL-18R, ST2, and TLR-2 are potential therapeutic targets that can be modulated to minimize anticancer agent-associated toxicity, optimize cancer treatment dosing, and improve clinical outcomes. In this context, the pathogenesis of mucositis caused by other anticancer agents should be further investigated.

Sulfated polysaccharide fraction from marine algae Solieria filiformis: Structural characterization, gastroprotective and antioxidant effects.

A sulfated polysaccharide (SFP) fraction from the marine alga Solieria filiformis was extracted and submitted to microanalysis, molar mass estimation and spectroscopic analysis. We evaluated its gastroprotective potential in vivo in an ethanol-induced gastric damage model and its in vitro antioxidant properties (DPPH, chelating ferrous ability and total antioxidant capacity). Its chemical composition revealed to be essentially an iota-carrageenan with a molar mass of 210.9kDa and high degree of substitution for sulfate groups (1.08). In vivo, SFP significantly (P<0.05) reduced, in a dose dependent manner, the ethanol-induced gastric damage. SFP prevents glutathione consume and increase of malondialdehyde and hemoglobin levels. SFP presented an IC50 of 1.77mg/mL in scavenging DPPH. The chelating ferrous ability was 38.98%, and the total antioxidant capacity was 2.01mg/mL. Thus, SFP prevents the development of ethanol-induced gastric damage by reducing oxidative stress in vivo and possesses relevant antioxidant activity in vitro.