Use of Echinacea in upper respiratory tract infection.

The significant burden of upper respiratory tract infection in adults and children, coupled with a lack of specific treatment options, invites the use of alternative therapies. Echinacea is an herb widely used for the prevention or treatment of upper respiratory tract infection. This review article examines the mechanism of action, dose, and types of Echinacea used for these purposes. The principal mode of action of Echinacea is through immunostimulation. Most Echinacea studies were done in Germany, but their results are difficult to interpret because of variability of experimental parameters. Types of Echinacea commonly used are Echinacea purpurea, E pallida, and E angustifolia. Both the plant's upper parts and roots are used. For oral administration, tablets, extracts, fresh pressed juice, teas, and tinctures have been used. Though studies show a beneficial effect, clear conclusions and recommendations of Echinacea use cannot be made due to a lack of standard product, variability in dose, and variability in outcome measures. Therefore, well-designed studies with consistent standardized measures are required.