Studies on the anti-allergic activity of Mikania glomerata.

A fraction (MG1) obtained from the ethanolic extract of Mikania glomerata Sprengel (Compositae), popularly known as 'guaco' and used as 'an' anti-allergic and anti-inflammatory agent, was evaluated for these properties on ovalbumin-induced allergic pleurisy and in models of local inflammation induced by biogenic amines, carrageenan and PAF. Plasma exudation as well as neutrophil and eosinophil infiltration evoked by the intrapleural injection of the antigen were significantly reduced by the fraction. Likewise, PAF-induced pleural neutrophil migration was inhibited by the treatment with MG1. On the other hand, pre-treatment of the animals with MG1 failed to modify the pleurisy induced by histamine, serotonin or carrageenan. These results suggest that MG1 is effective in inhibiting immunologic inflammation but did not affect acute inflammatory response caused by other agents.