Boneset

A principal anti-inflammatory constituent. In LPS-stimulated macrophages eupafolin inhibited inducible nitric oxide synthase (iNOS) with an IC50 near 6 µM and down-regulated inflammation-related cytokines and chemokines, providing a mechanistic basis for the herb's traditional use in feverish, inflammatory conditions.

Contribute the characteristic bitterness and are considered immunomodulatory and anti-inflammatory. A dimeric guaianolide isolated from the herb inhibited nitric oxide production (IC50 ~16 µM) in activated macrophages.

The dominant polyphenols of the hydroalcoholic extract. They inhibit attachment of influenza A virus to host cells in vitro, supporting the traditional use of boneset against colds and influenza-like illness.

Antioxidant and mild anti-inflammatory constituents typical of Asteraceae, contributing to the overall polyphenolic activity of the extract.

In vitro these polysaccharides stimulate phagocytosis and immune-cell activity, a proposed basis for the non-specific immune support attributed to boneset in minor viral infections.

A safety-relevant trace constituent. Unsaturated (1,2-dehydro) pyrrolizidine alkaloids are potentially hepatotoxic and genotoxic; their documented presence is the main reason prolonged internal use of boneset is discouraged, even though overt human hepatotoxicity from boneset itself has not been demonstrated.

Traditionally about 1-2 g of the dried flowering herb is infused in a cup of just-boiled water for 10-15 minutes and taken hot to promote sweating in feverish colds and influenza. Taken cold it acts more as a bitter tonic. Because the herb contains trace hepatotoxic pyrrolizidine alkaloids, internal use should be short-term only (not more than a few days), and it must be avoided in pregnancy, breastfeeding, in children, and in anyone with liver disease.

A hydroethanolic tincture (roughly 1:5 in ~45% alcohol) is used in small doses by Western herbalists as a diaphoretic and immune stimulant. The same pyrrolizidine-alkaloid cautions apply: reserve for acute short-term use and avoid chronic dosing.

Dichloromethane, ethanol and methanol extracts inhibited nitric oxide release from LPS-stimulated macrophages, with eupafolin (IC50 ~6 µM) and a dimeric guaianolide (IC50 ~16 µM) as the most active constituents, alongside modulation of inflammation-related cytokines and chemokines.

Hydroalcoholic aerial-part extract and its caffeoylquinic-acid constituents protected cells from influenza A virus infection by inhibiting viral attachment to the host cell surface, giving a molecular rationale for boneset's traditional use in febrile respiratory infection.

Details boneset (Eupatorium) as a diaphoretic, febrifuge and tonic used for influenza, catarrh and intermittent fevers, giving the classic distinction between the hot infusion (to induce sweating) and the cold preparation (as a bitter tonic and mild laxative).

Native American peoples used infusions of the plant for fevers, colds and body aches; the common name 'boneset' and the epithet 'feverwort' reflect its reputation for the deep bone-pains of febrile illness (later associated with dengue, 'break-bone fever').