Chinese mugwort

Chinese mugwort is an upright herbaceous perennial about 0.3–1.5 m tall with short branches and a creeping rhizome. Its stalked leaves are alternate and ovate, deeply divided into lance-shaped lobes with small marginal teeth — lower leaves are nearly bipinnate, upper leaves three-partite and bract leaves narrow and simple. The upper surface is green, pubescent and dotted with oil glands, while the lower surface is densely white-tomentose; the whole plant is strongly aromatic when crushed. Small pale-yellow tubular flowers cluster in nodding spherical heads on a narrow leafy panicle, with bisexual central florets and female marginal ones.

According to Kew's Plants of the World Online, A. argyi is native to temperate East Asia — the Russian Far East (Amur, Primorye) through China — while other records add Korea, Japan and Mongolia. It is a xerophile of dry mountain slopes, steep river banks, oak-wood margins, coastal scrub, wasteland and road or railway verges, and it grows most aromatic on poor, dry soils. In Vietnam it is naturalised and planted widely from the lowlands to lower hills; it is also cultivated commercially in China (notably the long-established Qichun 'Qi Ai' type in Hubei), Korea and Japan.

The leaf-and-stem essential oil (AAEO) contains more than 200 identified metabolites — terpenes, aldehydes and ketones, alcohols and phenols, acids and esters, and alkanes. The major constituents are 1,8-cineole (eucalyptol), camphor, thujone (α/β), borneol, α-terpineol, terpinen-4-ol, β-caryophyllene, germacrene D, camphene and linalool. The Chinese Pharmacopoeia (2020) requires Ai Ye oil to contain at least 30% 1,8-cineole and no more than 15% camphor, the two marker compounds. Besides the oil, the leaves contain flavonoids (eupatilin, jaceosidin), polysaccharides and triterpenoids, and oil content peaks in late spring and early summer before flowering.

A review by Gao and Lu (Frontiers in Pharmacology, 2026) summarises AAEO's pharmacology: antioxidant activity (DPPH IC50 ≈ 0.31 µL/mL; 91.4% ABTS scavenging at 0.45 mg/mL), anti-inflammatory action (up to 84% inhibition of TPA-induced mouse ear oedema, comparable to indomethacin, via JAK/STAT and NF-κB pathways), broad antimicrobial activity (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans), antiviral effects (inhibition of hepatitis B virus DNA replication through the TLR7–MyD88–IFN pathway) and in-vitro anticancer activity. In East Asian tradition the dried leaves are burnt for moxibustion, used in steam therapy or warm compresses, or decocted; in Vietnam mugwort is stewed with black chicken, added to soups, brewed as tea and used in herbal baths. The fine leaf fibres were historically used as a binder in Chinese seal-stamp paste.

On safety, thujone is a ketone monoterpene that can be neurotoxic at high doses; although AAEO showed no obvious acute toxicity in mice up to 3,000 mg/kg and an observational trial at the University of Freiburg (NCT01126931) examined its effect on appetite, human evidence remains limited. Essential oil should not be taken internally or used in large doses during pregnancy, as some Artemisia species stimulate the uterus. Artemisia argyi is listed as Not Evaluated (NE) by the IUCN and is not covered by CITES; it is common, easily found and widely cultivated, so it faces no significant conservation pressure.