The Sunlight Experiment

Compound Monograph

Taraxasterol

Taraxasterol is a taraxastane-type pentacyclic triterpene of dandelion and other Asteraceae, with a coherent preclinical anti-inflammatory literature (NF-κB/MAPK suppression across arthritis, colitis, lung-injury and dermatitis models) but no human trials; as a highly lipophilic triterpene its poor oral bioavailability is a key limitation.

Work in progress

Classification

Taraxasterol is a triterpene (taraxastane-type), part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.

Terpenoids Triterpenes

Where Does It Come From? (4)

Taraxasterol is a naturally occurring triterpene (taraxastane-type), found in Dandelion, Calendula, Wild lettuce and 1 other source. It is well tolerated orally (low toxicity).

Calendula Calendula officinalis Dandelion Taraxacum officinale Globe Artichoke Cynara scolymus Wild Lettuce Lactuca virosa

Pharmacology & Research

Taraxasterol is a taraxastane-type pentacyclic triterpene, a characterising constituent of the dandelion (Taraxacum officinale) triterpene fraction where it co-occurs with lupeol. Its literature has a clear, consistent shape: a well-replicated preclinical anti-inflammatory signal — NF-κB and MAPK suppression across rodent arthritis, colitis, lung-injury and dermatitis models 1,2,3Reference 1Wang S et al. · 2016AnimalAnti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in ratsView study →Reference 2Che X et al. · 2019In vitroAnti-inflammatory and anti-apoptotic activity of taraxasterol in ulcerative colitis in vitro and in vivoView study →Reference 3Zhang X et al. · 2014AnimalProtective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in miceView study → — and no human trials of any kind. Like its sibling lupeol, it is a highly lipophilic triterpene with poor oral bioavailability, so the in-vitro and rodent potencies are not demonstrated to be reachable from ordinary intake, and dandelion delivers only trace amounts. (Keep it distinct from the separate relatives taraxerol and ψ-taraxasterol.)

What the evidence supports
  • A coherent anti-inflammatory mechanism: NF-κB (p65) and MAPK suppression, lowering TNF-α/IL-1β/IL-6, COX-2 and iNOS, replicated across several independent rodent models 1,2,3Reference 1Wang S et al. · 2016AnimalAnti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in ratsView study →Reference 2Che X et al. · 2019In vitroAnti-inflammatory and anti-apoptotic activity of taraxasterol in ulcerative colitis in vitro and in vivoView study →Reference 3Zhang X et al. · 2014AnimalProtective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in miceView study →.
  • Consistent but narrow: the immunomodulatory, hepatoprotective and anti-allergic effects are all downstream of the same anti-inflammatory/antioxidant mechanism 6,10Reference 6San Z et al. · 2013AnimalEffects of taraxasterol on ovalbumin-induced allergic asthma in miceView study →Reference 10Ge W et al. · 2023Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in-vitro and in-vivo experimentsView study →.
  • The honest headline: entirely preclinical — no human data — and poor oral bioavailability (inferred from the lipophilic triterpene class and lupeol) is the key translational limitation.
Evidence by indicationStrength of support
Anti-InflammatoryShaky
42%
ImmunomodulatoryShaky
30%
HepatoprotectiveShaky
28%
AnticancerShaky
22%
Anti-AllergicShaky
20%
1. Anti-inflammatory

The marquee, and the most replicated. Taraxasterol reduced paw swelling and cytokines in rat adjuvant-induced arthritis 1Reference 1Wang S et al. · 2016AnimalAnti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in ratsView study →, limited inflammation and apoptosis in ulcerative colitis 2Reference 2Che X et al. · 2019In vitroAnti-inflammatory and anti-apoptotic activity of taraxasterol in ulcerative colitis in vitro and in vivoView study →, protected against LPS acute lung injury 3Reference 3Zhang X et al. · 2014AnimalProtective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in miceView study →, and suppressed macrophage hyperactivation in sepsis-induced ARDS 4Reference 42022AnimalTaraxasterol inhibits hyperactivation of macrophages to alleviate the sepsis-induced inflammatory response of ARDS ratsView study → — converging on NF-κB p65, MAPK, COX-2 and iNOS.

Gap: every model is rodent or cell-based, with no human inflammatory-disease data and no head-to-head against a standard anti-inflammatory at an achievable oral exposure 1,3Reference 1Wang S et al. · 2016AnimalAnti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in ratsView study →Reference 3Zhang X et al. · 2014AnimalProtective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in miceView study →.

2. Immunomodulatory

Taraxasterol dampened Th2 cytokines and eosinophilia in an ovalbumin allergic-asthma model 6Reference 6San Z et al. · 2013AnimalEffects of taraxasterol on ovalbumin-induced allergic asthma in miceView study → and suppressed macrophage hyperactivation in sepsis/ARDS 4Reference 42022AnimalTaraxasterol inhibits hyperactivation of macrophages to alleviate the sepsis-induced inflammatory response of ARDS ratsView study → — reading as broad innate plus Th2-axis damping.

Gap: no adaptive-immunity dose-response or immune-competence data, entirely preclinical, with mechanism inferred from downstream cytokines 6,4Reference 6San Z et al. · 2013AnimalEffects of taraxasterol on ovalbumin-induced allergic asthma in miceView study →Reference 42022AnimalTaraxasterol inhibits hyperactivation of macrophages to alleviate the sepsis-induced inflammatory response of ARDS ratsView study →.

3. Hepatoprotective

Taraxasterol protected against acetaminophen-induced liver injury via Nrf2/HO-1 with JNK and Bax/Bcl-2 modulation 10,11Reference 10Ge W et al. · 2023Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in-vitro and in-vivo experimentsView study →Reference 112024AnimalTaraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammation and ameliorating oxidative stress in miceView study → and attenuated D-galactosamine/LPS fulminant hepatitis through JAK/STAT and TNF signalling 12Reference 122025Taraxasterol attenuated D-galactosamine/LPS-induced fulminant hepatitis by modulating JAK/STAT and TNF signallingView study →.

Gap: all acute chemical-injury models, with no chronic-liver-disease or human data, and the effect is largely secondary to the general anti-inflammatory/antioxidant mechanism 10,12Reference 10Ge W et al. · 2023Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in-vitro and in-vivo experimentsView study →Reference 122025Taraxasterol attenuated D-galactosamine/LPS-induced fulminant hepatitis by modulating JAK/STAT and TNF signallingView study →.

4. Anticancer

Taraxasterol stabilised p53 via MDM2 degradation in pancreatic cancer 7Reference 72025Taraxasterol regulates p53 transcriptional activity to inhibit pancreatic cancer by inducing MDM2 ubiquitination degradationView study →, enhanced bladder-cancer radiosensitivity through COX-2/PGE2/JAK2/STAT3 inhibition 8Reference 82024Taraxasterol enhanced bladder-cancer cell radiosensitivity via inhibiting the COX-2/PGE2/JAK2/STAT3/MMP pathwayView study →, and showed a dual anti-aging/anti-cancer effect in lung cells 9Reference 92024Taraxasterol exhibits dual biological effects on anti-aging and anti-cancer in lung cellsView study →.

Gap: heterogeneous, mostly single-lab cell-line/xenograft studies with non-overlapping mechanisms, no consistent signalling story and no clinical signal — the weakest ranked set despite the volume 7,8Reference 72025Taraxasterol regulates p53 transcriptional activity to inhibit pancreatic cancer by inducing MDM2 ubiquitination degradationView study →Reference 82024Taraxasterol enhanced bladder-cancer cell radiosensitivity via inhibiting the COX-2/PGE2/JAK2/STAT3/MMP pathwayView study →.

5. Anti-allergic

Taraxasterol attenuated a 2,4-dinitrochlorobenzene atopic-dermatitis model via MAPK and NF-κB inactivation 5Reference 52025AnimalTaraxasterol attenuates inflammatory responses in a 2,4-dinitrochlorobenzene-induced atopic-dermatitis mouse model via inactivation of MAPK and NF-κBView study → and reduced ovalbumin-induced allergic asthma 6Reference 6San Z et al. · 2013AnimalEffects of taraxasterol on ovalbumin-induced allergic asthma in miceView study →.

Gap: two models only, and the “anti-allergic” label is a re-framing of the same anti-inflammatory/Th2 mechanism rather than an independent evidence stream 5,6Reference 52025AnimalTaraxasterol attenuates inflammatory responses in a 2,4-dinitrochlorobenzene-induced atopic-dermatitis mouse model via inactivation of MAPK and NF-κBView study →Reference 6San Z et al. · 2013AnimalEffects of taraxasterol on ovalbumin-induced allergic asthma in miceView study →.

Mechanisms

Target / pathwayEffectRelevant to
NF-κB (p65)↓ activation / nuclear translocationanti-inflammatory, hepatoprotective, anti-allergic
MAPK (ERK/JNK/p38)↓ phosphorylationanti-inflammatory, atopic dermatitis
COX-2 / iNOS↓ expressionarthritis, lung injury, bladder-cancer radiosensitisation
Th2 cytokines (IL-4/5/13), IgE, eosinophils↓allergic asthma, atopic dermatitis
Nrf2 / HO-1↑ (antioxidant)hepatoprotection
JAK2/STAT3↓bladder cancer, fulminant hepatitis
p53 / MDM2p53 stabilisationpancreatic cancer

Pharmacokinetics

No dedicated human or in-vivo pharmacokinetic study of taraxasterol was located, so the profile is inferred from its structure and its sibling. Taraxasterol is a highly lipophilic pentacyclic triterpene monool (a single hydroxyl, no solubilising sugar), so poor aqueous solubility and low oral bioavailability are the predicted, limiting property — the same constraint documented for lupeol (log P ≈ 7.7, poor oral absorption). The implication is that the in-vitro and rodent potencies above are not demonstrated to be reachable from ordinary oral intake, and dandelion delivers only trace amounts — treat all pharmacokinetics as inferred, not measured.

Clinical trials

There are no human trials of taraxasterol of any kind, interventional or observational. The entire evidence base is in-vitro and rodent, consistent with its Tier-B classification.

CompletedPlannedTerminatedPreclinical
—(none)——Extensive

Last checked: July 2026.

Toxicity & Safety

Taraxasterol shows low apparent toxicity in animal studies: across the anti-inflammatory, hepatoprotective, colitis and asthma models it was administered to rodents at therapeutic doses without reported overt toxicity, and in the liver-injury models it was net protective 10,11Reference 10Ge W et al. · 2023Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in-vitro and in-vivo experimentsView study →Reference 112024AnimalTaraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammation and ameliorating oxidative stress in miceView study →. That said, there is no dedicated toxicology package — no formal LD50, repeat-dose, genotoxicity or safety-pharmacology study — so “low toxicity” is inferred from the absence of adverse findings in efficacy studies, not from a study designed to find harm, and there is no human exposure data (dandelion, the dietary source, is a whole-herb trace-level exposure, not isolated taraxasterol).

Pregnancy & lactation

Avoid. There is no reproductive, developmental or lactation data for isolated taraxasterol, and its documented apoptosis- and immune-modulating activity — plus an uncharacterised hormone/proliferation signal in an endometriosis model — means it should not be used in pregnancy or lactation.

Dosage

There is no established human dose, and nothing here is a recommendation. All figures in the literature are preclinical research doses — typically oral or intraperitoneal rodent dosing in the single-digit-to-tens-of-mg/kg range — that do not translate to a human dose, and dietary dandelion supplies only trace taraxasterol.

References

  1. Wang S, et al. (2016). Anti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in rats. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/27109342/
  2. Che X, et al. (2019). Anti-inflammatory and anti-apoptotic activity of taraxasterol in ulcerative colitis in vitro and in vivo. Experimental and Therapeutic Medicine. https://pubmed.ncbi.nlm.nih.gov/31410133/
  3. Zhang X, et al. (2014). Protective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in mice. International Immunopharmacology. https://pubmed.ncbi.nlm.nih.gov/24548765/
  4. (2022). Taraxasterol inhibits hyperactivation of macrophages to alleviate the sepsis-induced inflammatory response of ARDS rats. Cell Biochemistry and Biophysics. https://pubmed.ncbi.nlm.nih.gov/36070121/
  5. (2025). Taraxasterol attenuates inflammatory responses in a 2,4-dinitrochlorobenzene-induced atopic-dermatitis mouse model via inactivation of MAPK and NF-κB. Journal of ethnopharmacology / immunopharmacology. https://pubmed.ncbi.nlm.nih.gov/40119084/
  6. San Z, et al. (2013). Effects of taraxasterol on ovalbumin-induced allergic asthma in mice. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/23727181/
  7. (2025). Taraxasterol regulates p53 transcriptional activity to inhibit pancreatic cancer by inducing MDM2 ubiquitination degradation. Journal (2025). https://pubmed.ncbi.nlm.nih.gov/39671783/
  8. (2024). Taraxasterol enhanced bladder-cancer cell radiosensitivity via inhibiting the COX-2/PGE2/JAK2/STAT3/MMP pathway. Journal (2024). https://pubmed.ncbi.nlm.nih.gov/38442139/
  9. (2024). Taraxasterol exhibits dual biological effects on anti-aging and anti-cancer in lung cells. Journal (2024). https://pubmed.ncbi.nlm.nih.gov/39005687/
  10. Ge W, et al. (2023). Protection of taraxasterol against acetaminophen-induced liver injury elucidated through network pharmacology and in-vitro and in-vivo experiments. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/37209606/
  11. (2024). Taraxasterol protects against acetaminophen-induced hepatotoxicity by reducing liver inflammation and ameliorating oxidative stress in mice. Journal (2024). https://pubmed.ncbi.nlm.nih.gov/38943970/
  12. (2025). Taraxasterol attenuated D-galactosamine/LPS-induced fulminant hepatitis by modulating JAK/STAT and TNF signalling. Journal (2025). https://pubmed.ncbi.nlm.nih.gov/39701218/