The major constituents in plantain are mucilage, iridoid glycosides (particularly aucubin), and tannins. Together these constituents are thought to give plantain mild anti-inflammatory, antimicrobial, antihemorrhagic, and expectorant actions.^{3, 4} Plantain is approved by the German Commission E for internal use to ease coughs and mucous membrane irritation associated with upper respiratory tract infections as well as topical use for skin inflammations.⁵ Two Bulgarian clinical trials have suggested that plantain may be effective in the treatment of chronic bronchitis.^{6, 7} Insufficient details were provided in these reports to determine the quality of the trials or their findings. Although plantain was thought to possess diuretic properties, one double-blind trial failed to show any diuretic effect for this plant.⁸ A preliminary trial found that topical use of a plantain ointment (10% ground plantain in a base of petroleum jelly) was helpful as part of the treatment of people with impetigo and ecthyma, two inflammatory skin disorders.⁹ Insufficient details were provided in this report, however, to determine the quality of the study or its findings.