Pleurisy Root
Asclepias tuberosa
Also known as: Butterfly Weed, Orange Swallowwort
Overview
A North American native plant traditionally used by Native American tribes and by 19th-century Eclectic physicians for pleurisy and other respiratory complaints — the condition it's named for. That reputation rests on traditional use, not modern research: no human studies have tested pleurisy root for pleurisy, pneumonia, or any other condition, and its active constituents have not been characterized. It does contain cardiac glycosides, so it can interact with heart medications and should be avoided during pregnancy.
Proposed mechanism
No human trials have tested pleurisy root for any condition, so no mechanism of action is established. Chemical analyses of the root find mainly pregnane-type steroidal glycosides along with flavonoids such as quercetin and rutin. Herbal monographs also list cardenolides — cardiac glycosides that inhibit the sodium-potassium pump, the same class of action as digoxin — but that attribution is not secure for this species: Asclepias tuberosa is among the lowest-cardenolide milkweeds, and the cardenolide most often named as its active compound was actually characterized in a different Asclepias. The safety caution stands regardless: pleurisy root is rated possibly unsafe, should not be combined with digoxin or other heart medications, and should be avoided by people with a heart condition, in pregnancy, or while nursing. Quercetin and rutin show antihistamine activity as isolated compounds in laboratory studies, but this has never been demonstrated for pleurisy root itself or in people, and no study links any of these compounds to an effect on pleural or airway tissue. Nineteenth-century Eclectic practitioners used the root as an expectorant, antispasmodic, and diaphoretic for pleurisy, bronchitis, and pneumonia-type breathing difficulty — not for obliterative bronchiolitis, a distinct and serious scarring disease of the small airways (linked to transplant rejection and to toxic inhalation exposures, including deployment-related ones) that requires medical diagnosis and for which no evidence supports this herb.
Mechanisms describe how researchers think a compound may act, often from laboratory work — a proposed mechanism is not proof of a clinical effect in people.
Traditional & studied uses
Related pathways
Pathway tags are a research aid for browsing the glossary — they are not a claim that this ingredient treats any condition.