Chrysoeriol

Chrysoeriol at a Glance

Chrysoeriol is a monomethoxy flavone — structurally, it is luteolin with a single methyl group added to the 3’-hydroxyl of the B-ring (hence its common name, luteolin 3’-methyl ether). Equivalently, it is apigenin carrying a 3’-methoxy group. It occurs widely: as a signature intermediate of the tricin pathway in grasses and cereals (rice, wheat, maize, sorghum) and as a minor constituent of many herbs, usually stored as glycosides rather than the free aglycone ^{1,5Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →Reference 5Lam PY et al. · 2015Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-HydroxylaseView study →}.

The molecule has an active preclinical literature — anti-inflammatory, anticancer, antioxidant, antidiabetic and aromatase-modulating effects have all been reported ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}. Two threads recur: signalling that suppresses NF-κB and JAK2/STAT3-driven inflammation ^{2,3Reference 2Wu JY et al. · 2020AnimalChrysoeriol ameliorates TPA-induced acute skin inflammation in mice and inhibits NF-κB and STAT3 pathwaysView study →Reference 3Wu JY et al. · 2022Chrysoeriol suppresses hyperproliferation of rheumatoid arthritis fibroblast-like synoviocytes and inhibits JAK2/STAT3 signalingView study →}, and modulation of aromatase (CYP19) in breast-cancer cells ^{4Reference 4Min DY et al. · 2020Chrysoeriol Prevents TNFα-Induced CYP19 Gene Expression via EGR-1 Downregulation in MCF7 Breast Cancer CellsView study →}.

The honest headline is the same one that applies to most dietary flavones: there are no human trials of isolated chrysoeriol, so its interest rests on mechanism and animal models. Where it differs from luteolin is the methyl cap — O-methylation tends to make a flavone more membrane-permeable and more resistant to rapid phase-II conjugation, so chrysoeriol is often described as the more metabolically stable of the pair ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}.

Chrysoeriol vs. Luteolin & Diosmetin

The point is the methyl group. Chrysoeriol, diosmetin and luteolin are the same flavone skeleton differing only in B-ring substitution:

• Luteolin — free hydroxyls at both 3’ and 4’ (a catechol).
• Chrysoeriol — luteolin methylated at 3’ (3’-OMe, 4’-OH).
• Diosmetin — luteolin methylated at 4’ (3’-OH, 4’-OMe) — the positional isomer.

That single O-methylation matters for two reasons. First, metabolism: the exposed catechol of luteolin is a fast target for phase-II conjugation (glucuronidation, sulfation) and catechol-O-methyltransferase, which is a major reason luteolin is poorly bioavailable. Capping one hydroxyl removes a conjugation site, so methylated flavones like chrysoeriol generally cross membranes more readily and survive first-pass metabolism better ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}. Second, selectivity: the 3’-vs-4’ distinction changes how each molecule fits an enzyme pocket — chrysoeriol and diosmetin are not interchangeable, and their reported activities (e.g. aromatase modulation, enzyme inhibition) differ even though they share a parent.

In plants, chrysoeriol is quite literally made from luteolin — a luteolin O-methyltransferase installs the 3’-methyl group (see Its Role in Plants) ^{1,5Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →Reference 5Lam PY et al. · 2015Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-HydroxylaseView study →}.

What It's Used For

Chrysoeriol’s evidence is entirely preclinical. It is best read as a mechanistically interesting flavone with consistent anti-inflammatory signalling data and scattered anticancer/metabolic findings — not as a validated therapeutic.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. There is no human evidence here; scores rank strength within an all-preclinical field, so read each row’s basis.

01Anti-Inflammatory (NF-κB / JAK2-STAT3)Promising46%Mouse ear-oedema model + macrophage and synoviocyte studies ^{2,3Reference 2Wu JY et al. · 2020AnimalChrysoeriol ameliorates TPA-induced acute skin inflammation in mice and inhibits NF-κB and STAT3 pathwaysView study →Reference 3Wu JY et al. · 2022Chrysoeriol suppresses hyperproliferation of rheumatoid arthritis fibroblast-like synoviocytes and inhibits JAK2/STAT3 signalingView study →}

02Anticancer & AromataseShaky34%MCF-7 aromatase downregulation + lung-carcinoma cell/xenograft work ^{4,6Reference 4Min DY et al. · 2020Chrysoeriol Prevents TNFα-Induced CYP19 Gene Expression via EGR-1 Downregulation in MCF7 Breast Cancer CellsView study →Reference 6Wei W et al. · 2019In vitroIn vitro and in vivo cytotoxic effects of chrysoeriol in human lung carcinoma are facilitated through activation of autophagy, sub-G1/G0 cell cycle arrest, cell migration and invasion inhibition and modulation of MAPK/ERK signalling pathwayView study →}

03Antidiabetic & AntioxidantShaky24%In-vitro enzyme inhibition and radical scavenging, largely via review synthesis ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}

Mechanisms

The load-bearing point is that the anti-inflammatory NF-κB/STAT3 signalling is the most reproduced and the only strand with an in-vivo model; the aromatase and anticancer findings are mechanistically specific but confined to cell lines.

Pharmacokinetics

There is no dedicated human pharmacokinetic dataset for chrysoeriol — no measured oral bioavailability, half-life or plasma-concentration figure for the isolate. What can be said is structural: O-methylation of a flavone’s catechol tends to raise membrane permeability and blunt the rapid phase-II conjugation (glucuronidation/sulfation) that limits parent luteolin, so chrysoeriol is generally regarded as the more metabolically stable and better-absorbed of the two ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}. In real diets it is encountered mostly as glycosides (e.g. citrus chrysoeriol-6,8-di-C-glucoside), which must be deglycosylated before the aglycone is available, and overall dietary intake is low ^{7Reference 7Posadino AM et al. · 2024ReviewCitrus limon var. pompia Camarda var. nova: A Comprehensive Review of Its Botanical Characteristics, Traditional Uses, Phytochemical Profile, and Potential Health BenefitsView study →}. Any in-vitro potency should therefore be read against the fact that achievable tissue concentrations in a person are unknown.

Clinical Trials

There are no clinical trials of isolated chrysoeriol. All evidence is in-vitro or in animal models; where the molecule reaches humans it is only as a minor constituent of foods and botanical extracts.

Last checked: July 2026.

Isolate vs. Plant Studies

Chrysoeriol’s mechanistic work is reassuringly isolate-based — the mouse anti-inflammatory study, the synoviocyte study, the MCF-7 aromatase screen and the lung-carcinoma work all used the purified compound, so the effects are genuinely attributable to this molecule rather than to a crude extract ^{2,3,4,6Reference 2Wu JY et al. · 2020AnimalChrysoeriol ameliorates TPA-induced acute skin inflammation in mice and inhibits NF-κB and STAT3 pathwaysView study →Reference 3Wu JY et al. · 2022Chrysoeriol suppresses hyperproliferation of rheumatoid arthritis fibroblast-like synoviocytes and inhibits JAK2/STAT3 signalingView study →Reference 4Min DY et al. · 2020Chrysoeriol Prevents TNFα-Induced CYP19 Gene Expression via EGR-1 Downregulation in MCF7 Breast Cancer CellsView study →Reference 6Wei W et al. · 2019In vitroIn vitro and in vivo cytotoxic effects of chrysoeriol in human lung carcinoma are facilitated through activation of autophagy, sub-G1/G0 cell cycle arrest, cell migration and invasion inhibition and modulation of MAPK/ERK signalling pathwayView study →}. The weaker strand is the antioxidant/antidiabetic material, where chrysoeriol is frequently one flavonoid among many in a plant extract and is not always tested alone ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}. The transferability caveat runs the other way from the usual one: the isolate data are clean, but because there are no human studies and no chrysoeriol-specific bioavailability figure, we cannot say whether the concentrations that work in a dish are reachable through diet or supplementation.

Its Role in Plants

Chrysoeriol sits at a branch point of flavone biosynthesis in grasses. It is made from luteolin by a luteolin O-methyltransferase that adds the 3’-methyl group ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}, and in cereals it is then a committed intermediate toward tricin, the grass-signature flavone: in rice, a dedicated cytochrome P450, CYP75B4, acts as a chrysoeriol 5’-hydroxylase that converts chrysoeriol to selgin en route to tricin ^{5Reference 5Lam PY et al. · 2015Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-HydroxylaseView study →}. The recruitment of this chrysoeriol-processing activity is thought to underlie the prevalence of tricin-type metabolites across grasses and other monocots ^{5Reference 5Lam PY et al. · 2015Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-HydroxylaseView study →}.

Functionally, flavones of this class contribute to the plant’s UV protection, antioxidant defence and antimicrobial/anti-herbivore chemistry, and tricin-pathway flavones are also incorporated into grass lignin, making chrysoeriol part of both the defensive metabolome and cell-wall chemistry of cereals. As always, a molecule’s role as a plant metabolite does not predict what it does as a medicine.

Prevalence in Nature

Chrysoeriol is widely distributed but rarely abundant. Its most systematic occurrence is in the grasses and cereals — rice (Oryza sativa), wheat (Triticum aestivum), maize, sorghum and related monocots — where it is a normal intermediate of the tricin pathway ^{1,5Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →Reference 5Lam PY et al. · 2015Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-HydroxylaseView study →}. Among eudicots it has been reported from yerba santa (Eriodictyon californicum, the plant its name references), shepherd’s purse (Capsella bursa-pastoris), Digitaria and Coronopus species, chrysanthemum flower (Chrysanthemi Indici Flos) and many other herbs, typically as a minor flavone stored in glycosylated form ^{1Reference 1Aboulaghras S et al. · 2022Health Benefits and Pharmacological Aspects of ChrysoeriolView study →}.

A well-quantified example of the glycoside is in pompia (Citrus limon var. pompia) juice, whose predominant flavonoid is chrysoeriol-6,8-di-C-glucoside (stellarin-2) at about 109 mg/L — notably, a chrysoeriol glycoside that is essentially absent from other citrus juices studied ^{7Reference 7Posadino AM et al. · 2024ReviewCitrus limon var. pompia Camarda var. nova: A Comprehensive Review of Its Botanical Characteristics, Traditional Uses, Phytochemical Profile, and Potential Health BenefitsView study →}. Free-aglycone concentrations across most sources are not well quantified, which is the main hole in the occurrence picture.

Discovery & Synthesis

Chrysoeriol was recognised as a natural flavone of several plants (the name couples chrys-, gold/yellow, with the genus Eriodictyon — yerba santa — an early source). Its structure as the 3’-methyl ether of luteolin was confirmed by total synthesis reported in 1959, alongside the related flavanone homoeriodictyol. Today the compound is obtained the way most research-grade minor flavones are: isolated from plant material or prepared semi-synthetically by selective O-methylation of luteolin, rather than manufactured at scale — there is no bulk commercial demand for it as a drug.

Patents: not yet researched.

Toxicity & Safety

Chrysoeriol carries a low toxicity flag. It is a dietary flavone consumed in small amounts within cereals, citrus and culinary/medicinal herbs, with no signal of acute toxicity in the preclinical literature. The caveats are the ordinary ones for an under-studied isolate rather than specific hazards.

Safety at a Glance

✅ Low / no toxicity

• Dietary flavone with a low-risk profile. Long-standing incidental intake from cereals, citrus and herbs; no toxicity signal in the available preclinical work.
• Isolated-compound safety is uncharacterised. No formal repeat-dose, genotoxicity or human-tolerability data exist for concentrated chrysoeriol.
• Endocrine and enzyme activity is real in vitro. Aromatase (CYP19) downregulation and other enzyme effects mean high-dose supplemental use (should it ever exist) is not automatically inert; no interaction data are available.

No isolate-specific reproductive or developmental toxicity dataset exists for chrysoeriol; any pregnancy/lactation decision belongs to the specific herb or product a person is actually taking, not to this molecule-level page. Drug-interaction data (CYP isoforms, transporters) have not been characterised for the isolate, so absence of reported interactions should not be read as proof of safety.

Dosage

There is no established human dose for chrysoeriol. Every published study uses the isolated molecule in cells or animals, so there is no clinically validated intake to cite, and no supplement standardised to it in routine use. Dietary exposure is indirect and low — largely as glycosides in cereals, citrus and herbs — and is not something a person meaningfully “doses.” Any figure encountered in the literature is a research concentration, not a recommendation.

References

1. Aboulaghras S, Sahib N, Bakrim S, et al. (2022). Health Benefits and Pharmacological Aspects of Chrysoeriol. Pharmaceuticals (Basel). https://pubmed.ncbi.nlm.nih.gov/36015121/
2. Wu JY, Chen YJ, Bai L, et al. (2020). Chrysoeriol ameliorates TPA-induced acute skin inflammation in mice and inhibits NF-κB and STAT3 pathways. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/31999977/
3. Wu JY, Chen YJ, Fu XQ, et al. (2022). Chrysoeriol suppresses hyperproliferation of rheumatoid arthritis fibroblast-like synoviocytes and inhibits JAK2/STAT3 signaling. BMC Complementary Medicine and Therapies. https://pubmed.ncbi.nlm.nih.gov/35296317/
4. Min DY, Jung E, Ahn SS, Lee YH, Lim Y, Shin SY (2020). Chrysoeriol Prevents TNFα-Induced CYP19 Gene Expression via EGR-1 Downregulation in MCF7 Breast Cancer Cells. International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/33053908/
5. Lam PY, Liu H, Lo C (2015). Completion of Tricin Biosynthesis Pathway in Rice: Cytochrome P450 75B4 Is a Unique Chrysoeriol 5′-Hydroxylase. Plant Physiology. https://pubmed.ncbi.nlm.nih.gov/26082402/
6. Wei W, et al. (2019). In vitro and in vivo cytotoxic effects of chrysoeriol in human lung carcinoma are facilitated through activation of autophagy, sub-G1/G0 cell cycle arrest, cell migration and invasion inhibition and modulation of MAPK/ERK signalling pathway. Journal of BUON. https://pubmed.ncbi.nlm.nih.gov/31424645/
7. Posadino AM, et al. (2024). Citrus limon var. pompia Camarda var. nova: A Comprehensive Review of Its Botanical Characteristics, Traditional Uses, Phytochemical Profile, and Potential Health Benefits. Nutrients. https://pubmed.ncbi.nlm.nih.gov/39203756/

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