Echinacea purpurea aerial extract alters course of influenza infection in mice.

Influenza infection is a major clinical problem and Echinacea purpurea, a widely consumed botanical product, is purported to alter the course of respiratory infections including influenza. Mice infected with WSN influenza A and treated with E. purpurea polysaccharide extract had less weight loss than untreated mice but similar pulmonary viral titers. Echinacea-treated mice had lower systemic and pulmonary KC and IL-10 levels and lower systemic IFN-gamma levels following influenza infection. These suggest that E. purpurea alters the clinical course of influenza infection in mice through modulation of cytokines and not direct antiviral activity. Copyright 2010. Published by Elsevier Ltd.