Qing Hao
StarArtemisia annua
Synonyms: Artemisia exilis, Artemisia wadei, Artemisia hyrcana, Artemisia plumosa, Artemisia annua f. macrocephala, Artemisia stewartii, Artemisia chamomilla, Artemisia suaveolens
☯ TCM Properties
Clears Summerheat or Damp-Heat; Clears Deficiency fevers; Cools the Blood and stops bleeding; Stops malarial disorders and relieves Heat; Clears Liver Heat and brightens the eyes
Traditional Chinese Uses
Qing Hao (sweet wormwood, artemisia) is a bitter, cold, aromatic herb with its most famous application as the source of artemisinin — the compound that has revolutionized modern malaria treatment. In traditional Chinese medicine, it is used to clear deficiency Heat from the Ying-Blood level — addressing the night fever and morning coolness pattern of late-stage febrile disease — and to treat malaria with alternating chills and fever. It also clears summerheat and relieves jaundice from Damp-Heat.
Western Herbalism Properties
Gallery
Botanical Description
Artemisia annua is an aromatic annual herb in the daisy family (Asteraceae), growing 30-100 cm tall. Stems are erect, much-branched, and longitudinally grooved. Leaves are alternate, deeply 2-3 times pinnately dissected into narrow lobes, strongly aromatic with a sweet camphor-like scent. Tiny, globose, yellow flower heads are numerous and borne in loose, branched panicles. The whole plant is glandular-pubescent with a distinctive sweet-camphor fragrance. This species is the source of the antimalarial drug artemisinin.
Disturbed habitats, roadsides, rocky slopes, and waste places; native to temperate Asia (China, Russia), now widely naturalized and cultivated throughout tropical and temperate regions worldwide.
Artemisia annua is a common and widespread plant, widely cultivated for artemisinin production. High demand has led to large-scale commercial cultivation. No conservation concerns.
Active Constituents
Artemisinin (qinghaosu)
Sesquiterpene lactone (endoperoxide)Concentration: ~0.01-1.5% of dry leaf
The signature endoperoxide-bridge sesquiterpene lactone of the plant. Activated by heme/ferrous iron within Plasmodium, it generates carbon-centered free radicals and reactive oxygen species that alkylate parasite proteins, producing rapid schizonticidal activity. Its semisynthetic derivatives (artesunate, artemether, dihydroartemisinin) are the backbone of WHO-recommended artemisinin-based combination therapy.
Artemisinic acid (arteannuic acid)
Amorphane sesquiterpenoidConcentration: Often exceeds artemisinin in leaf
A biosynthetic precursor to artemisinin and a target for semisynthetic and fermentation-based artemisinin production. It contributes to the antiplasmodial activity of whole-plant preparations and shows anti-inflammatory activity in vitro.
Dihydroartemisinic acid
SesquiterpenoidConcentration: Variable, chemotype-dependent
The immediate precursor that is oxidised (partly non-enzymatically, driven by singlet oxygen and light) to artemisinin. Its abundance largely determines a chemotype's artemisinin yield.
Arteannuin B
Sesquiterpene lactoneConcentration: Minor
A co-occurring sesquiterpene lactone reported to act synergistically with artemisinin against Plasmodium in whole-plant extracts, contributing to the enhanced parasite clearance seen with plant matrix preparations versus pure artemisinin.
Scopoletin
CoumarinConcentration: Minor
A hydroxycoumarin with anti-inflammatory and antioxidant activity that is proposed to enhance the pharmacokinetics/bioavailability of artemisinin in tea and extract preparations.
Casticin / chrysosplenol D / artemetin
Polymethoxylated flavonoidsConcentration: Trace to minor
Methoxylated flavones that potentiate the antimalarial action of artemisinin in vitro and contribute anti-inflammatory and antioxidant effects to the whole herb.
Essential oil (artemisia ketone, camphor, 1,8-cineole, caryophyllene)
Volatile terpenoidsConcentration: ~0.2-0.5% (v/w)
The aromatic fraction responsible for the herb's characteristic smell; shows antimicrobial and antipyretic activity and, being heat-labile, informs the traditional caution against prolonged boiling.
⚠ Drug Interactions
CYP2C19 substrates (e.g., omeprazole, clopidogrel)
Artemisinin and its derivatives reversibly inhibit CYP2C19 (and CYP1A2) in human liver microsomes and in healthy volunteers, which can slow the clearance of drugs metabolised by these enzymes.
Clinical note: Monitor for exaggerated effect of narrow-therapeutic-index CYP2C19 substrates during concurrent use of concentrated Artemisia annua or artemisinin products.
CYP3A4 substrates (e.g., midazolam, some statins, oral contraceptives)
Artemisinin activates the xenosensors PXR and CAR and induces CYP3A4, CYP2B6 and MDR1, and displays autoinduction of its own metabolism on repeated dosing, potentially lowering exposure to CYP3A4 substrates.
Clinical note: Consider reduced effect of CYP3A4-dependent medicines (including hormonal contraceptives) with prolonged high-dose use; time-separation and monitoring advised.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6-12g | daily | — | adult | Add near end of decoction; do not cook long as active constituents are heat-labile |
Preparation Methods
Late-added decoction (hou xia)
Parts: aerial parts, leaf
Typical adult dose 6-12 g. Because the active endoperoxide and volatile constituents are heat-labile, Qing Hao is added near the end of cooking and only briefly simmered, or steeped, rather than boiled at length with other herbs.
Fresh juice / cold-water maceration
Parts: fresh aerial parts
Following Ge Hong's classical method for intermittent fevers, fresh herb is soaked in water and wrung out to express the juice, taken cold. This cold-extraction approach, which preserves artemisinin, famously guided Tu Youyou's isolation of the compound.
Powder or granule/tablet
Parts: dried aerial parts
Dried herb is milled to powder or made into standardized extracts/tablets for consistent dosing in modern clinical use; concentrated extracts are used in the rheumatology trials described above.
Clinical Studies
Effect of Artemisia annua extract on treating active rheumatoid arthritis: A randomized controlled trial
159 patients with active rheumatoid arthritis received leflunomide plus methotrexate with or without Artemisia annua extract (30 g/day) for 48 weeks. The extract group showed significantly greater improvement in pain, tender-joint count and ESR from as early as 12 weeks, with greater overall efficacy at 24 and 48 weeks and no increase in adverse events.
A pilot randomized, placebo-controlled clinical trial to investigate the efficacy and safety of an extract of Artemisia annua administered over 12 weeks, for managing pain, stiffness, and functional limitation associated with osteoarthritis of the hip and knee
42 patients with hip or knee osteoarthritis were randomised to low-dose (150 mg twice daily) or high-dose (300 mg twice daily) Artemisia annua extract or placebo for 12 weeks. The low-dose group showed a significant improvement in WOMAC total score versus placebo, with the extract generally well tolerated.
Artemisinin antimalarials moderately affect cytochrome P450 enzyme activity in healthy subjects
In healthy volunteers, artemisinin drugs modestly modulated cytochrome P450 activity: artemisinin inhibited CYP1A2 and CYP2C19 while inducing CYP3A4, supporting a genuine potential for herb-drug interactions with agents cleared by these pathways.
Historical Texts
Wushi'er Bing Fang (Prescriptions for Fifty-Two Ailments)
Western Han (unearthed at Mawangdui, c. 168 BCE)Zhou Hou Bei Ji Fang (Handbook of Prescriptions for Emergencies), Ge Hong
Eastern Jin (c. 340 CE)Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming (1596)References
- Tu Y. The discovery of artemisinin (qinghaosu) and gifts from Chinese medicine . Nature Medicine (2011) [DOI]
- Klayman DL. Qinghaosu (artemisinin): an antimalarial drug from China . Science (1985) [DOI]
- Yang M, Guo MY, Luo Y, et al.. Effect of Artemisia annua extract on treating active rheumatoid arthritis: A randomized controlled trial . Chinese Journal of Integrative Medicine (2017) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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