It has been reported that piplartine and piperine, alkaloid/amide compounds from Piper species, show antitumor activities. In the present paper, the effects of the combination of 5-fluorouracil (5-FU) with piplartine or piperine was determined using in vitro and in vivo experimental models. Hematological and biochemical analyses, as well as histopathological and morphological analyses of the tumor and the organs, including liver, spleen and kidney, were performed in order to evaluate the toxicological aspects associated with different treatments. The incubation of tumor cell lines with 5-FU in the presence of piplartine or piperine produced an increase in growth inhibition, as observed by lower IC50 values for 5-FU. These effects were also observed in vivo, where the combination with piplartine but not piperine with 5-FU led to a higher tumor growth inhibition. The results indicated that either piplartine- or 5-FU-treated animals showed a low inhibition rate when they were used individually at low doses of 28.67% and 47.71%, respectively, but when they were combined at the same dose, the inhibition rate increased significantly to 68.04%. The histopathological analysis showed that the livers and the kidneys of treated animals were only slightly and reversibly affected. Neither the enzymatic activity of transaminases nor the urea levels were significantly modified when compared with the control group. Hematological analysis showed leukopenia after 5-FU treatment, which was reversed by the combined use of piplartine and piperine. These findings indicate that piplartine may enhance the therapeutic effectiveness of chemotherapeutic drugs, and moreover, this combination could improve immunocompetence hampered by 5-FU.

In recent years, much attention has been focused on polysaccharides isolated from natural sources. The aim of this study was to investigate the in vitro and in vivo antitumor properties of a sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf-PLS). Hematological, biochemical and histopathological analyses were performed in order to evaluate the toxicological aspects related to Cf-PLS treatment. Its effects on the immunological system were also investigated. The Cf-PLS did not show any significant in vitro cytotoxicity at the experimental exposure levels that were used, but showed in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.62 and 48.16% at the doses of 10 and 25 mg kg(-1), respectively. In addition, Cf-PLS was also able to increase the response elicited by 5-fluorouracil (5-FU) from 48.66 to 68.32%. The histopathological analysis of liver and kidney showed that both organs were moderately affected by Cf-PLS-treatment. Neither enzymatic activity of alanine aminotransferase nor urea or creatinine levels were significantly altered. In hematological analysis, leucopeny was observed after 5-FU treatment, but this effect was prevented when the treatment was associated with the Cf-PLS. It was also demonstrated that Cf-PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and increasing the production of OVA-specific antibodies. It also induced a discreet hyperplasia of lymphoid folicules of the white pulp in the spleen of treated mice. In conclusion, Cf-PLS has some interesting anticancer activity that could be associated with its immunostimulating properties.

Sulfated-polysaccharides are complex macromolecular constituents of the extracellular matrix of marine algae that play an important role in mechanical, osmotic and ionic regulation.1) In Biomedicine the anticoagulant and antithrombotic properties have been most widely exploited and, at least for galactans, appear to be dependent on the sulfatation content and/or position of the sulfate groups.2) A natural sulfated polymer of L-fucose (fucoidan) showed a dose-dependent inhibition of leukocyte migration in the in vivo peritonitis model, 3) and sulfated fucans isolated from brown algae showed potent in vitro and in vivo inhibition of the human complement system. 4,5) It was demonstrated that a sulfatedpolysaccharide fraction extracted from the brown algae Porphyra haitanesis presents an in vivo antioxidant property, causing an increase in the spleen and thymus size, suggestive of an immunostimulant action. 6) Additionally, sulfated galactans of the red marine algae Bryothamnion seaforthii presented antinociceptive activity in mice 7) and of the red micro algae Pophyridium sp. anti-inflammatory action inhibiting eritema formation after topical use in humans.8) However, studies of sulfated galactans role in models of inflammation in vivo are rare in the literature. Here we isolated and investigated the effects of a sulfated galactan from the red marine algae Champia feldmannii, widely encountered along the South East and North East Brazilian sea coast, in experimental models of acute inflammation, coagulation and nociception. MATERIALS AND METHODS AnimalsMale Wistar rats (150-250 g) and Swiss mice (25-35 g) were maintained with a controlled 12/12 h light/dark cycle, at a temperature of 25°C with free access to food and water. The experimental protocols used in this study were approved by the Institutional Animal Care and Use Committee of the State University of Ceará (UECE), Fortaleza-CE, Brazil, in accordance with international guidelines (NIH publication No. 85-23, revised 1985).Algae Champia feldmannii belongs to the order Rhodymeniales, family Lomentariaceae and was collected in the Pacheco beach of Caucaia, Ceará, Brazil. Algae were classified by Wladimir R. L. Farias, Department of Fishery Engeneering of Federal University of Ceará-Brazil.Erythrocytes Human erythrocytes were obtained from healthy donors at the Hematology Center of the Federal University of Ceará-Brazil.Drugs and Reagents Dextran sulphate, L-carrageenan, Evans blue, zymosan, morphine, cethylpiridinium chloride, sodium acetate, calcium chloride, ketamine, sulphuric acid, papain, 1-9-di-metylene blue (DMB), ethylenodiaminotetracetic acid (EDTA), indomethacin, dexamethasone, pentoxifylline, L-N-nitro-arginine methyl ester (L-NAME), meclyzine and formamide, N-acetyl-N,N,N-trimethylammonium bromide, 1,3-diaminopropane, toluidine blue, agarose gel (Sigma Chemical Co., St. Louis, MO, U.S.A. or SigmaAldrich Chemie, Steinheim, Germany); absolute ethanol, sodium chloride, sodium dodecyl sulfate (SDS) and 2-mer- 907, 60.455-970, Fortaleza-Ceará-Brasil. R...

In this study, we have addressed the role of H2S in modulating neutrophil migration in either innate (LPS-challenged naive mice) or adaptive (methylated BSA (mBSA)-challenged immunized mice) immune responses. Treatment of mice with H2S synthesis inhibitors, dl-propargylglycine (PAG) or β-cyanoalanine, reduced neutrophil migration induced by LPS or methylated BSA (mBSA) into the peritoneal cavity and by mBSA into the femur/tibial joint of immunized mice. This effect was associated with decreased leukocyte rolling, adhesion, and P-selectin and ICAM-1 expression on endothelium. Predictably, treatment of animals with the H2S donors, NaHS or Lawesson’s reagent, enhanced these parameters. Moreover, the NaHS enhancement of neutrophil migration was not observed in ICAM-1-deficient mice. Neither PAG nor NaHS treatment changed LPS-induced CD18 expression on neutrophils, nor did the LPS- and mBSA-induced release of neutrophil chemoattractant mediators TNF-α, keratinocyte-derived chemokine, and LTB4. Furthermore, in vitro MIP-2-induced neutrophil chemotaxis was inhibited by PAG and enhanced by NaHS treatments. Accordingly, MIP-2-induced CXCR2 internalization was enhanced by PAG and inhibited by NaHS treatments. Moreover, NaHS prevented MIP-2-induced CXCR2 desensitization. The PAG and NaHS effects correlated, respectively, with the enhancement and inhibition of MIP-2-induced G protein-coupled receptor kinase 2 expression. The effects of NaHS on neutrophil migration both in vivo and in vitro, together with CXCR2 internalization and G protein-coupled receptor kinase 2 expression were prevented by the ATP-sensitive potassium (KATP+) channel blocker, glybenclamide. Conversely, diazoxide, a KATP+ channel opener, increased neutrophil migration in vivo. Together, our data suggest that during the inflammatory response, H2S augments neutrophil adhesion and locomotion, by a mechanism dependent on KATP+ channels.

Latex from Calotropis procera is widely used in folk medicine as a rich source of biologically active compounds capable of promoting diverse benefits such as control of dermal fungal infections, antimicrobial activities and pain relief among other useful properties. The aim of this work was to characterize the anti-inflammatory effect of a non-dialysable protein fraction recovered from the rubber-free latex using three different experimental models when administrated intravenously. In vivo neutrophil migration induced by carrageenin (500 microg) was severely inhibited by doses of latex proteins reaching maximum inhibition (80%) at 100 mg/kg. Paw edema exacerbated by the effect of carrageenin was almost completely suppressed after 4 hours and was controlled within the first hour following latex protein administration. However, the same latex fraction was completely unable to control the paw edema invoked with dextran stimulation (400 microg), suggesting that the inhibitory effect of the latex is likely to be cell-mediated. Iphosphamide-induced vesical edema in mice was also largely prevented by the latex protein fraction. These results indicate that an effect similar to that of mesna, the classical drug used for this purpose, is operative. Our findings suggest that the sample tested seems to act over a wide spectrum as a novel anti-inflammatory agent. The results also suggest that the active molecules are of a proteinaceous nature despite the presence of numerous secondary metabolites naturally occurring in the C. procera latex.

The natural physiological ligands for selectins are oligosaccharides found in glycoprotein or glycolipid molecules in cell membranes. In order to study the role of sugar residues in the in vivo lectin anti-inflammatory effect, we tested three leguminous lectins with different carbohydrate binding affinities in the peritonitis and paw oedema models induced by carrageenin in rats. L. sericeus lectin was more anti-inflammatory than D. virgata lectin, the effects being reversed by their specific binding sugars (N-acetylglucosamine and alpha-methylmannoside, respectively). However, V. macrocarpa, a galactose-specific lectin, was not anti-inflammatory. The proposed anti-inflammatory activity of lectins could be due to a blockage of neutrophil-selectin carbohydrate ligands. Thus, according to the present data, we suggest an important role for N-acetylglucosamine residue as the major ligand for selectins on rat neutrophil membranes.

No abstract

Many authors have already emphasized that phytochemicals from spices have biological applications. Piperlonguminine is a known alkaloid amide from peppers, including Piper divaricatum. The aim of this study was to investigate the in vitro and in vivo antitumor effects of piperlonguminine in experimental models. In order to evaluate the toxicological aspects related to piperlonguminine treatment, hematological, biochemical, histopathological and morphological analyses of treated animals were performed. Piperlonguminine did not show any significant in vitro cytotoxic effect at experimental exposure levels, but showed an in vivo antitumor effect. After 7 days of treatment, the inhibition rates were 38.71% and 40.68% at doses of 25 mg kg(-1) and 50 mg kg(-1), respectively. The histopathological analysis suggests that the liver and kidney were only weakly affected by piperlonguminine treatment. Neither the enzymatic activity of transaminases (AST and ALT) nor the urea levels were significantly altered. In the hematological analysis, all parameters analysed remained constant after piperlonguminine treatment. In conclusion, these data reinforce the anticancer potential of spice components.