Proinflammatory activity of an alginate isolated from Sargassum vulgare.

Alginates are unbranched polymers of polysaccharide presented as the structural components of marine brown algae. The proinflammatory activity of SVHV, an alginate isolated from Sargassum vulgare, was investigated using models of paw edema, mast cells degranulation and neutrophil migration in vivo. SVHV induced a dose dependent paw edema, with a peak at 2 h, associated with an increased myeloperoxidase activity and production of TNF-α and IL-1ß. Pharmacological modulators, remarkably dexamethasone and indomethacin, inhibited the edema. SVHV (1.0 mg) also led to a significant induction of neutrophil migration in the peritoneal cavity of rats. This neutrophil migration was significantly reduced by peritoneal resident macrophages depletion, but was not affected by the depletion of mast cells. Our data suggest that SVHV has proinflammatory activity dependent of the activation of resident cells, being the macrophages the main cells involved.

Polysaccharide isolated from Passiflora edulis: Characterization and antitumor properties.

A hot water-extracted polysaccharide fraction (PFCM) of Passiflora edulis was characterized by microanalysis, infrared spectroscopy, NMR and high performance size-exclusion chromatography. The major component in PFCM is (1→4) linked galacturonic acid (esterified and unesterified). Neutral sugars such as arabinose, glucose, rhamnose, mannose, and fucose were also present. Traces of xylose and ribose were detected. The PFCM sample had a similar molar mass to that of pectin extracted from P. edulis under acidic conditions. Sarcoma 180 tumors treated with PFCM showed a growth inhibition ratio ranging from 40.59% to 48.73% depending on the dosage and type of PFCM administration (oral or intraperitoneal). Toxicological analysis shows that PFCM increases the cell types involved in primary defense mechanisms and no significant changes in the biochemical parameters and organs (e.g., kidney and liver) were observed. However, the use of PFCM treatment increased the spleen weight when compared with the use of 5-fluorouracil.

Antitumor properties of a sulfated polysaccharide from the red seaweed Champia feldmannii (Diaz-Pifferer).

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.