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-1β. 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.