Parthenolide: A Comprehensive Reference
1. Identity: Chemical Names, Botanical Origin, and Preparations
Chemical Identity
Parthenolide is a sesquiterpene lactone of the germacranolide class, which occurs naturally in the plant feverfew (Tanacetum parthenium), after which it is named, and in the closely related tansy (Tanacetum vulgare). Its systematic IUPAC chemical name, as determined by spectroscopic characterization, is 4α,5β-epoxy-germacra-1-(10),11(13)-dien-12,6α-olide.
Sesquiterpene lactones (SLs) are secondary metabolites common in several families of plants, most prevalent in the Asteraceae, but also found in fungi and invertebrates. These compounds have a 15-carbon skeleton biogenetically formed from three isoprenoid units and present a lactone moiety. Parthenolide-like compounds belong to the germacranolide subclass of SLs and are chemically characterized by a 10-membered ring with a 5-membered fused lactone; the presence of an α-methylene group and a C4–C5 epoxide ring are also characteristic in their structure. These two reactive features — the exocyclic methylene and the epoxide — are central to parthenolide's reactivity with biological nucleophiles.
Parthenolide is found in highest concentration in the flowers and fruit of the feverfew plant. Lack of solubility in water and bioavailability limits the potential of parthenolide as a drug.
Botanical Source and Distribution
Tanacetum parthenium L. (Asteraceae) is a medicinal plant traditionally used for the treatment of fevers, migraine headaches, rheumatoid arthritis, stomach aches, toothaches, insect bites, infertility, and problems with menstruation and labor during childbirth. Native to the Balkan Peninsula, feverfew is now found in Australia, Europe, China, Japan, and North Africa. In the mid-19th century, feverfew was introduced in the United States.
Parthenolide is a germacrane sesquiterpene lactone with a unique structure. It has been isolated from several different species in the Asteraceae (Compositae) family, with feverfew (Tanacetum parthenium) being the most prominent source.
Common Names and Synonyms
Synonyms and common names associated with the plant and its preparations include: Chrysanthemum parthenium, feverfew, featherfew, altamisa, bachelor's button, featherfoil, febrifuge plant, midsummer daisy, nosebleed, Santa Maria, wild chamomile, wild quinine, chamomile grande, Matricaria parthenium L., MIG-99, mother herb, and mutterkraut.
Forms and Preparations
The plant contains a large number of natural products, but the active principles probably include one or more sesquiterpene lactones, including parthenolide. Other potentially active constituents include flavonoid glycosides and pinenes. The chemistry of feverfew is now well defined. Phytochemicals found in feverfew include parthenolide, camphor, and the flavonoids luteolin and apigenin.
Feverfew supplements are available in various forms, including tablets, capsules, and liquid extracts, standardised to contain at least 0.2% parthenolide. However, the parthenolide content of commercially available feverfew supplements varies substantially — by more than 40-fold — despite labeling claims of "standardization."
A more stable feverfew CO₂-extract preparation known as MIG-99 has also been developed for use in clinical trials (see §4 below). Additionally, researchers have previously demonstrated that parthenolide (PTL) can induce death of human leukemia stem cells in vitro while sparing normal hematopoietic cells; however, PTL has relatively poor pharmacologic properties that limit its potential clinical use. Consequently, a family of PTL analogs was generated to improve solubility and bioavailability. These studies identified an analog, dimethylamino-parthenolide (DMAPT), which induces rapid death of primary human leukemia stem cells from both myeloid and lymphoid leukemias.
2. Traditional and Historical Use
The feverfew herb has a long history of use in traditional and folk medicine, especially among Greek and early European herbalists. Although its earliest use is unknown, it was documented in the 1st century CE by the Greek herbalist physician Dioscorides.
Feverfew has been used for centuries as a febrifuge to treat colds and febrile diseases, and for the treatment of migraines and arthritis. The species Tanacetum parthenium, popularly known as feverfew, has been used in folk medicine for the treatment of migraines, tinnitus, giddiness, arthritis, fever, menstrual disorders, difficulty during labor, stomachaches, toothaches, and insect bites.
Feverfew has also been used for psoriasis, allergies, asthma, tinnitus, dizziness, nausea, and vomiting. Feverfew also has a long history of use for fever, menstrual irregularities, arthritis, psoriasis, allergies, asthma, dyspepsia including indigestion and flatulence, as a general intestinal stimulant and tonic, and to expel worms and intestinal parasites.
Eclectic physicians used feverfew as a gastrointestinal tonic, to increase appetite, improve digestion and secretion, and to cleanse the kidneys.
Feverfew has been used in traditional medicine, particularly in Europe, where it is mentioned in an herbal monograph as a safe compound. The plant's early modern use is documented in the herbalist tradition: it may well have been introduced into England from central Europe by the Romans, who used it for these medicinal properties.
3. Key Constituents and Active Compounds
Parthenolide as the Principal Bioactive
Parthenolide, a germacranolide-type sesquiterpene lactone, is the major constituent of feverfew leaves. Parthenolide is the most important active component of feverfew and is used for the treatment of a wide variety of diseases such as fever, migraine headache, and rheumatoid arthritis. However, it may not be the sole active constituent: an alcoholic extract of feverfew standardized to 0.35% parthenolide was found ineffective for preventing migraine in one Dutch study, suggesting that parthenolide may not be the only important active ingredient and that other constituents are necessary for migraine prevention. Chrysanthenyl acetate, an essential oil of feverfew, has been suggested as one active component in the prevention of migraine, as it inhibits prostaglandin synthetase and might have analgesic properties.
Other Constituents
Phytochemicals found in feverfew include parthenolide, camphor, and the flavonoids luteolin and apigenin. The plant contains a large number of natural products, but the active principles probably include one or more of the sesquiterpene lactones known to be present, including parthenolide.
4. Established Mechanisms of Action
NF-κB Pathway Inhibition
The most thoroughly studied mechanism of parthenolide is its inhibition of nuclear factor-kappa B (NF-κB), a central regulator of inflammation, immunity, and cell survival. Parthenolide inhibits IκB kinase (IKK), resulting in stabilization of cytoplasmic IκBα, which in turn leads to inhibition of NF-κB translocation and attenuation of subsequent inflammatory responses. Although the mechanisms mediating the various effects of parthenolide in different diseases are not entirely clear, several studies have shown that an important part of the anti-inflammatory action of this compound appears to be related to its activity in inhibiting the NF-κB signal pathway through preventing the degradation of IκBα. NF-κB is a dimeric transcription factor, and genes activated by NF-κB play central roles in cell differentiation, proliferation, inflammation, and apoptosis.
Mechanistic analyses identify several concurrent pathways: (1) inhibition of NF-κB signaling either through interaction with IκB kinase (IKK) or directly with the p65 subunit, resulting in the downregulation of antiapoptotic gene transcription; (2) degradation of MDM2 and depletion of histone deacetylase 1 (HDAC1), regulating p53 activity and increasing cancer cell sensitivity to therapy; (3) inhibition of STAT3 phosphorylation, preventing its dimerization, nuclear translocation and STAT3-dependent gene expression; and (4) reduction of cellular glutathione (GSH) and reactive oxygen species (ROS) accumulation, inducing oxidative stress.
Platelet Aggregation, Serotonin and Histamine Release
An increasing number of studies have indicated that parthenolide could interfere with a number of cellular processes including oxidative phosphorylation, platelet aggregation, and histamine and serotonin release, as well as neutrophil chemotaxis. Its parthenolide component has been shown to produce a tonic effect on vascular smooth muscle, inhibiting the contraction of smooth muscle normally caused by serotonin and phenylephrine.
It is known that parthenolide interacts with transient receptor potential ankyrin 1 (TRPA1) nucleophilic sites, which leads to the inhibition of nociception and neurogenic vasodilatation in the trigeminovascular system. Moreover, parthenolide and the related sesquiterpene lactones have been shown to inhibit the activation of the pro-inflammatory transcription factor NF-κB by different stimuli, such as phorbol esters, tumour necrosis factor-α and hydrogen peroxide.
Reactive Oxygen Species (ROS) Generation and Glutathione Depletion
The pro-apoptotic activity of parthenolide in hepatic stellate cells is associated with increased intracellular oxidative stress, as evidenced by increased intracellular ROS levels and depleted intracellular GSH levels. Parthenolide-induced ROS-mediated apoptosis of tumor cells proceeds via the intrinsic apoptotic signaling pathway. This GSH depletion mechanism is context-dependent: while it drives death in cancer cells, it serves as the foundation for exploring parthenolide's differential toxicity toward malignant versus normal cells.
STAT Inhibition
Parthenolide shows strong NF-κB- and STAT-inhibition-mediated transcriptional suppression of pro-apoptotic genes. This compound acts both at the transcriptional level and by direct inhibition of associated kinases (IKK-β). Parthenolide, a naturally occurring sesquiterpene lactone derived from feverfew, exhibits exceptional anti-cancer and anti-inflammatory properties. Its molecular targets include cytochrome c, NF-κB, STAT, reactive oxygen species (ROS), HDACs, microtubules, and inflammasomes.
HDAC Inhibition and Epigenetic Effects
A recent report demonstrated that parthenolide is a potent inhibitor of HDAC1, which validates the concept that parthenolide-based drugs may be epigenetic modifiers and thereby function via mechanisms that include differentiation induction.
Radioprotection / Radiosensitization via the Nrf2 Pathway
Parthenolide has been described to increase radiosensitivity in malignant cells. This differential radioprotection is attributed to redox-mediated modification of the KEAP1/Nrf2 pathway, a prominent cellular defence mechanism against oxidative stress. Thus, parthenolide activates NADPH oxidase in malignant cells, driving further oxidative stress, whilst preserving redox homeostasis in healthy tissue through KEAP1/Nrf2-mediated adaptive oxidative responses.
5. Scientific Evidence by Area of Use
5.1 Migraine Prevention
Evidence Overview
Feverfew (Tanacetum parthenium L.) extract is a herbal remedy that has been used for preventing attacks of migraine. The most rigorous synthesis of this evidence comes from the Cochrane Collaboration: six trials involving 561 patients met inclusion criteria for the Cochrane systematic review, and five of the six trials reported on the main outcome of migraine frequency.
Since the last version of the Cochrane review, one larger rigorous study was included, reporting a difference in effect between feverfew and placebo of 0.6 attacks per month. This adds some positive evidence to the mixed and inconclusive findings of the previous review. However, this constitutes low-quality evidence, which needs to be confirmed in larger rigorous trials with stable feverfew extracts and clearly defined migraine populations before firm conclusions can be drawn.
A 2025 updated systematic review and meta-analysis extending through August 2025 provided more current data: a comprehensive search of PubMed, EMBASE, and Google Scholar identified nine double-masked, placebo-controlled RCTs involving 899 participants. Feverfew significantly reduced migraine attack frequency, and showed a statistically significant reduction in migraine duration; however, it showed a non-significant trend towards reduced pain severity, and no significant effects were observed on migraine-associated symptoms such as nausea, vomiting, photophobia, and phonophobia.
Study Design Limitations
The small sample sizes in the clinical trials, ranging from 17 to 170 participants, limit the statistical power to detect subtle treatment effects. There was variability in the formulations of feverfew used, including freeze-dried powder, parthenolide-specific formulations, and CO₂-extracts. There was an inconsistency in the preparation and a lack of standardization of the parthenolide concentration, which contributed to variable findings.
Clinical trials of feverfew for the prevention of migraine attacks published in the 1980s and 1990s produced inconsistent results, with wide variations in the strength of parthenolides. One trial using an extract of feverfew with a standardized and constant concentration of parthenolide to treat migraine did not show any beneficial effect; this lack of efficacy might have been due to the absence of essential therapeutic components of the granulated feverfew leaves, which were either not sufficiently extracted, or perhaps degraded during the preparation. Subsequently, a new, more stable feverfew extract (MIG-99) was developed.
Overall Evidence Assessment
It appears from the data reviewed that feverfew is not associated with any major safety concerns. However, the clinical effectiveness of feverfew in the prevention of migraine has not been established beyond reasonable doubt. Evidence remains mixed and is of low to moderate quality, constrained by heterogeneous preparations, small sample sizes, and inconsistent parthenolide content.
5.2 Anti-Inflammatory Effects and Arthritis
Preclinical Evidence
Extracts of the plant inhibit the release of enzymes from white cells found in inflamed joints, and a similar anti-inflammatory effect may occur in the skin, providing a rationale for the traditional use of feverfew in psoriasis.
Research established that parthenolide, as a prototype compound, suppressed LPS- and TNF-α-induced increases in matrix metalloproteinase (MMP)-1, MMP-3, inducible nitric oxide synthase (iNOS), and interleukin (IL)-1β mRNA in chondrocytes. These data indicate a protective effect of parthenolide on the catabolic insults of pro-inflammatory cytokines on chondrocyte metabolism and GAG release in vitro and in collagen-induced arthritis (CIA) models. Parthenolide had anti-inflammatory and structure-modifying effects on experimental arthritis.
In animal models of collagen antibody-induced arthritis, parthenolide at 1 mg/kg and 4 mg/kg reduced local paw inflammation, but with no change in overall bone volume in either front or hind paws.
Clinical Evidence
There are no substantial published randomized controlled trials of isolated parthenolide as a treatment for human arthritis. The evidence base for arthritis is confined to in vitro cell studies and animal models. There is insufficient clinical evidence to support using feverfew as a pharmacological treatment, and further research and human studies are necessary to determine if the plant is safe and effective at treating medical conditions.
5.3 Anticancer Activity
Leukemia and Leukemia Stem Cells — Preclinical
Parthenolide emerges as a promising candidate, being the first small molecule identified for its selective action against leukemic stem cells. Studies demonstrate that parthenolide, a naturally occurring small molecule, induces robust apoptosis in primary human AML cells and blast crisis CML (bcCML) cells while sparing normal hematopoietic cells. Furthermore, analysis of progenitor cells using in vitro colony assays, as well as stem cells using the NOD/SCID xenograft model, show that PTL also preferentially targets AML progenitor and stem cell populations.
Leukemia cell death was associated with inhibition of NF-κB and proapoptotic activation of p53. Leukemia stem cell (LSC) survival is extensively dependent on constitutively active NF-κB. Preclinical agents such as parthenolide (PTL) that potently suppress NF-κB can eliminate LSCs in vitro while preserving normal hematopoietic stem cell (HSC) function.
Breast Cancer — Preclinical
Parthenolide and DMAPT markedly inhibited viability of stem-like cells derived from three lines of triple-negative breast cancers (TNBCs) by inducing ROS generation, mitochondrial dysfunction, and cell necrosis. Parthenolide exerts selective toxicity against a wide range of tumors but is ineffective in normal cells.
Combination Therapy — Preclinical
The parthenolide, 2-deoxyglucose, temsirolimus (PDT) regimen is a potent means of targeting AML stem cells but has little to no effect on normal stem cells, illustrating a comprehensive approach to designing combination anticancer drug regimens. Using proteomic, genomic, and metabolomic methods, researchers determined that treatment with parthenolide leads to induction of compensatory mechanisms that include up-regulated NADPH production via the pentose phosphate pathway as well as activation of the Nrf2-mediated oxidative stress response pathway, leading to the identification of 2-deoxyglucose and temsirolimus as complementary agents.
Clinical Evidence — Phase I Trial
Human clinical trial data for parthenolide itself remain limited. A Phase I trial was conducted to evaluate the pharmacokinetics and toxicity of parthenolide given as a component of "feverfew." Feverfew (Tanacet™) was administered as a daily oral tablet in a 28-day cycle, with a starting dose of 1 mg per day explored with subsequent dose escalations to 2, 3, and 4 mg. Feverfew given on this schedule had no significant toxicity, and the maximum tolerated dose was not reached. When parthenolide was administered at doses up to 4 mg as a daily oral capsule in the feverfew preparation, there was no detectable concentration in the plasma, so parthenolide pharmacokinetics could not be completed. Conclusion: feverfew, with up to 4 mg of parthenolide, given daily as an oral tablet is well tolerated without dose-limiting toxicity, but does not provide detectable plasma concentrations.
The critical implication is that parthenolide has poor pharmaceutical properties and cannot be detected in plasma when humans have been given it as part of the herbal supplement "feverfew," and has been shown to have limited in vivo activity due to poor bioavailability.
DMAPT Analog — Preclinical and Early Development
To address bioavailability limitations, the amino-analogue dimethylaminoparthenolide (DMAPT) was developed and entered Phase I clinical trials after documenting 70% oral bioavailability, plasma concentrations in excess of 40 µM after oral administration, and an acceptable toxicology profile in animal studies. DMAPT, a more hydrophilic form of parthenolide with greater bioavailability, was identified. Oral administration of DMAPT has been found to be safe and resulted in increased plasma concentrations in an animal model. More studies are warranted.
There are, as of current evidence, no published Phase II or Phase III randomized controlled trials of parthenolide or DMAPT in human cancer populations. All anticancer evidence in humans is limited to the single Phase I pharmacokinetic/toxicity study described above. Evidence for anticancer effects remains predominantly preclinical (in vitro and animal models).
5.4 Vascular Smooth Muscle and Cardiovascular Effects
Studies have indicated that parthenolide can exert beneficial effects in myocardial reperfusion injury and interfere with a number of cellular processes including oxidative phosphorylation, platelet aggregation, and histamine and serotonin release, as well as neutrophil chemotaxis. Studies have been conducted to determine the effects of parthenolide on the proliferation and cell cycle dynamics of vascular smooth muscle cells (VSMCs). These remain preclinical findings without clinical translation.
5.5 Hepatic Fibrosis — Preclinical
Parthenolide induced growth inhibition and apoptosis in hepatic stellate cells (HSCs), as evidenced by cell growth inhibition and apoptosis assays. It increased the expression of Bax proteins during apoptosis, but decreased the expression of Bcl-2 and Bcl-XL proteins. Parthenolide also induced a reduction in mitochondrial membrane potential, poly(ADP-ribose) polymerase cleavage, and caspase-3 activation. These are in vitro and animal model findings; no human trials have been conducted for hepatic fibrosis.
5.6 Anti-Parasitic Activity — Preclinical
In one study, parthenolide had an IC₅₀ of 0.37 µg/ml against Leishmania amazonensis and inhibited parasite growth in macrophages. This represents in vitro antileishmanial activity without clinical evidence in humans.
5.7 Radioprotection of Normal Tissue — Early Phase Clinical
Parthenolide has emerged as a promising candidate for radioprotection, with its analogue DMAPT exhibiting preclinical radioprotective efficacy. A Phase 0, prospective, non-randomised, double-blind, interventional pilot study (N=10 participants) with internal controls has been designed to investigate this application. This is a very early-stage, small pilot study; no efficacy conclusions can yet be drawn.
6. Body Systems and Health Areas
- Neurological / Vascular Headache: Migraine prophylaxis via effects on serotonin release from platelets, TRPA1 interaction, and vascular smooth muscle tone.
- Immune / Inflammatory: NF-κB-mediated suppression of pro-inflammatory cytokines (IL-1β, TNF-α), inhibition of neutrophil chemotaxis and histamine release.
- Musculoskeletal: Preclinical evidence in arthritis models involving suppression of matrix metalloproteinases and protection of chondrocyte integrity.
- Hematological / Oncological: Preferential induction of apoptosis in AML and CML leukemia stem cells, and in vitro activity against multiple solid tumor lines, mediated via NF-κB, ROS, HDAC1, p53, and STAT3 pathways.
- Hepatic: Preclinical anti-fibrotic effects via apoptosis of hepatic stellate cells.
- Dermatological: Parthenolide is recognized as a sensitizing allergen in Compositae allergy and has been studied as a contact allergen; separately, parthenolide-depleted feverfew extracts have been developed for cosmetic anti-inflammatory applications.
- Cardiovascular: Inhibition of platelet aggregation, serotonin-induced smooth muscle contraction, and preclinical evidence in myocardial reperfusion injury.
- Parasitological: Antileishmanial activity demonstrated in vitro.
7. Dosage Forms and Dosages Reported in Studies
In the Phase I cancer trial, feverfew (Tanacet™) was administered as a daily oral tablet in a 28-day cycle. A starting dose of 1 mg per day of parthenolide was explored with subsequent dose escalations to 2, 3, and 4 mg. Assessment of plasma pharmacokinetics was performed on patients accrued to the trial.
The conclusion of this trial was that feverfew, with up to 4 mg of parthenolide given daily as an oral tablet, is well tolerated without dose-limiting toxicity, but does not provide detectable plasma concentrations.
In the arthritis mouse model, CAIA was induced in BALB/c mice and treated daily with 1 mg/kg or 4 mg/kg of parthenolide.
Feverfew supplements are available in various forms, including tablets, capsules, and liquid extracts, standardised to contain at least 0.2% parthenolide. No formally established human therapeutic dose for isolated parthenolide has been defined, as clinical pharmacokinetics have not been completable with currently available oral feverfew preparations.
For the DMAPT analog, Phase I clinical trials were entered after documenting 70% oral bioavailability and plasma concentrations in excess of 40 µM after oral administration in animal studies. Human dose-finding results for DMAPT have not been fully reported in the published literature as of the available evidence.
8. Safety Considerations and Interactions
Contact Allergy and Dermatitis
Feverfew (Tanacetum parthenium) is a European Compositae plant suspected of causing airborne contact allergy, and its most important allergen is the sesquiterpene lactone parthenolide. A case of specific, delayed hypersensitivity induced by repeated contact with a wild form of feverfew has been reported. In the flowers investigated, the content of the responsible contact allergen parthenolide appeared to be 10 times greater (0.6–0.9%) than in earlier-studied material.
Parthenolide detects 75% of sesquiterpene lactone-allergic patients in patch testing. Cross-reactions were elicited with 11 of 21 mostly Compositae plants containing chemically related sesquiterpene lactones. The strongest reactions were elicited by tansy, yarrow (milfoil), marguerite, aster, sunflower, laurel, and Frullania.
Some feverfew-allergic patients are sensitive to airborne particles released from the plant, and isolation of parthenolide from the particle-containing extract in allergenic amounts is strong evidence of parthenolide as the responsible allergen.
Oral and Systemic Side Effects
Feverfew may cause allergic reactions in those allergic to the daisy family, including contact dermatitis or swelling and numbness of the mouth. Other side effects have included gastrointestinal upset such as mild nausea, vomiting, abdominal pain, diarrhea, and flatulence, which are, fortunately, mild and transient.
Withdrawal Effects
Long-term use of feverfew followed by abrupt discontinuation may induce a withdrawal syndrome featuring rebound headaches and muscle and joint pains.
Bioavailability and Plasma Concentrations
Lack of solubility in water and bioavailability limits the potential of parthenolide as a drug. Parthenolide has poor pharmaceutical properties and cannot be detected in plasma when humans have been given it as part of the herbal supplement "feverfew," and has been shown to have limited in vivo activity due to the poor bioavailability. This bioavailability deficit is a critical safety and efficacy consideration: the doses used in in vitro cell culture experiments that demonstrate anticancer effects are unlikely to be achievable in human plasma through standard oral feverfew supplementation.
Platelet Function
In addition to its extensive anti-inflammatory properties, feverfew also exerts other physiological effects including the inhibition of platelet aggregation and secretion of allergic mediators, e.g., histamine and serotonin. This mechanism, relevant to its postulated anti-migraine activity, also implies a theoretical interaction with anticoagulant and antiplatelet drugs, though this has not been formally evaluated in published clinical interaction studies.
Overall Safety in Clinical Trials
No major adverse effects were associated with feverfew in the included studies in the Cochrane systematic review. Feverfew given on the Phase I schedule had no significant toxicity, and the maximum tolerated dose was not reached. DMAPT has been shown to be non-toxic to normal hematopoietic cells and has no severe, systemic side effects in available preclinical data.
Supplement Standardization Concerns
The parthenolide content of commercially available feverfew supplements varies substantially — by more than 40-fold — despite labeling claims of "standardization." This variation makes it impossible to reliably reproduce effective doses across commercial products.
References
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