Santin

Santin at a Glance

Santin is a lipophilic O-methylated flavonol — systematically 5,7-dihydroxy-3,6,4′-trimethoxyflavone, or equivalently 6-hydroxykaempferol 3,6,4′-trimethyl ether. It is one of the small family of methylated flavonols that characterise the aerial parts of feverfew (Tanacetum parthenium), where it co-occurs with sibling flavonols such as tanetin and jaceidin ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}. It is also found in the related Tanacetum microphyllum ^{3Reference 3Guerra JA et al. · 2006Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllumView study →} and in birch (Betula) buds ^{4Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →}.

In laboratory studies the isolated molecule shows three overlapping activities: anti-inflammatory (it suppresses inducible nitric-oxide synthase and cyclo-oxygenase-2 in stimulated macrophages) ^{3Reference 3Guerra JA et al. · 2006Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllumView study →}, antiproliferative / pro-apoptotic in several cancer cell lines ^{4,5Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →Reference 5Kłósek M et al. · 2023Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cellsView study →}, and anti-influenza ^{6Reference 6Zhong M et al. · 2019Santin inhibits influenza A virus replication through regulating MAPKs and NF-κB pathwaysView study →}. These are genuine signals, but the honest headline is that all of them are in-vitro work on the isolated compound — there are no human or animal santin studies, and in feverfew santin is a minor constituent dwarfed by the sesquiterpene lactone parthenolide.

Because santin is a trace flavonol tested only at high in-vitro concentrations, its safety profile is best read as “no dedicated toxicology and no meaningful human exposure,” rather than as an established safe or active substance.

Structure: A Methylated Flavonol

Santin is the point where the entry earns its keep, because its methylation pattern is the whole story. A parent flavonol like kaempferol or quercetin carries free hydroxyl groups that make it relatively polar and prone to rapid phase-II conjugation. Santin is built on 6-hydroxykaempferol with three of those positions — the 3-, 6- and 4′-hydroxyls — capped as methyl ethers, leaving only the 5- and 7-hydroxyls free ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}.

That O-methylation has two consequences that recur throughout the pharmacology below:

• Higher lipophilicity / membrane permeability. Methylating the hydroxyls removes hydrogen-bond donors and raises log P, so santin partitions into lipid membranes more readily than its unmethylated parents — the reason it is grouped with the “lipophilic flavonoids” of feverfew rather than the water-soluble flavone glycosides ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}.
• A distinct, easily-confused identity. Santin sits in a cluster of feverfew methylated flavonols that differ only in which positions are hydroxylated versus methylated — tanetin (a 6-hydroxykaempferol methyl ether) and the quercetagetin-derived jaceidin and centaureidin ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}. These closely-related isomers form hard-to-resolve mixtures, which has caused real confusion in the older literature about which one is present and active. Santin itself is the fixed compound CAS 27782-63-4 (C₁₈H₁₆O₇, MW 344.3).

Note that santin is not the same molecule as jaceidin: jaceidin carries an extra 3′-hydroxyl (it is a quercetagetin, not a kaempferol, derivative). The two are siblings, not synonyms.

What It's Used For

Santin’s research base is small and uniform in kind: isolated-compound, in-vitro assays, spread across inflammation, cancer cell lines and influenza. There is no whole-animal or human work.

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. Every santin application rests on isolated-compound in-vitro data only, so scores stay low by design.

01Anti-InflammatoryShaky36%Isolate ↓ iNOS/COX-2, NO, PGE₂ in RAW 264.7 macrophages; feverfew methylated-flavonol arachidonate data ^{2,3Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →Reference 3Guerra JA et al. · 2006Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllumView study →}

02Antiproliferative / Pro-ApoptoticShaky30%Isolate TRAIL synergy (colon) + caspase apoptosis (gastric/colon/liver) — all in-vitro ^{4,5Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →Reference 5Kłósek M et al. · 2023Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cellsView study →}

03Antiviral (Anti-Influenza)Shaky24%Single in-vitro study; MAPK/NF-κB damping in MDCK/THP-1 ^{6Reference 6Zhong M et al. · 2019Santin inhibits influenza A virus replication through regulating MAPKs and NF-κB pathwaysView study →}

Mechanisms

The recurring theme is transcriptional/enzyme-expression damping — iNOS/COX-2 and NF-κB/MAPK — rather than one receptor. All of it is cell-based.

Pharmacokinetics

There is essentially no pharmacokinetic data on santin. What can be said is structural rather than measured: as a trimethylated flavonol it is more lipophilic and metabolically more stable than free-hydroxyl flavonols like quercetin, which in principle favours membrane permeation and slower phase-II conjugation. But no santin-specific absorption, oral bioavailability, distribution, metabolism or half-life figures exist, and the in-vitro active concentrations (25–100 µM) are far above anything a person would plausibly reach from dietary feverfew or birch exposure. This missing ADME layer is the single biggest caveat on every in-vitro claim above.

Clinical Trials

There are no clinical trials of santin, and no animal studies. The entire evidence base is isolated-compound cell culture.

Last checked: July 2026.

Isolate vs. Plant Studies

Unusually, every santin result is the isolated molecule — the RAW 264.7 anti-inflammatory assays ^{3Reference 3Guerra JA et al. · 2006Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllumView study →}, the SW480/SW620 TRAIL work ^{5Reference 5Kłósek M et al. · 2023Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cellsView study →}, the AGS/DLD-1/HepG2 birch-bud apoptosis study ^{4Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →} and the MDCK/THP-1 influenza study ^{6Reference 6Zhong M et al. · 2019Santin inhibits influenza A virus replication through regulating MAPKs and NF-κB pathwaysView study →} all test purified santin, not a whole extract. That removes the usual “which constituent did it?” ambiguity for the in-vitro claims.

The catch is the reverse: no whole-plant study isolates santin’s own contribution to a therapeutic effect. In feverfew, the herb’s documented anti-migraine and anti-inflammatory reputation rests on the sesquiterpene lactone parthenolide and the broader flavonoid fraction collectively ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →} — santin is a minor methylated flavonol within that fraction, and no feverfew clinical outcome has been attributed to it. So santin has clean isolate mechanism data and zero plant-level efficacy evidence of its own.

Prevalence in Nature

Santin is a minor lipophilic flavonol of the Asteraceae. It is characterised in feverfew (Tanacetum parthenium) leaf, flower and seed, within the group of methylated 6-hydroxykaempferol / quercetagetin flavonols that also includes tanetin, jaceidin and centaureidin ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}; it occurs in the related Tanacetum microphyllum ^{3Reference 3Guerra JA et al. · 2006Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllumView study →}; and it is found in the buds of birch, Betula pubescens and B. pendula ^{4Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →}, with reports across other Asteraceae including Achillea species ^{5Reference 5Kłósek M et al. · 2023Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cellsView study →}. Its concentration is low and, in the accessible literature, not quantified in units comparable across sources, so no reliable “richest source” ranking can be given — that hole is logged in the compound’s gaps tracker rather than guessed at here.

Discovery & Synthesis

Santin is a defined single compound (CAS 27782-63-4; C₁₈H₁₆O₇; molecular weight 344.3) corresponding to 6-hydroxykaempferol 3,6,4′-trimethyl ether. Its first-isolation history is not well documented in the readily accessible literature; it enters the record as one of the catalogued methylated flavonols of the Asteraceae, and its feverfew context was established through the Williams group’s characterisation of the herb’s lipophilic flavonols — the same work that named its sibling tanetin — in leaf, flower and seed ^{1,2Reference 1Williams CA et al. · 1995A biologically active lipophilic flavonol from Tanacetum partheniumView study →Reference 2Williams CA et al. · 1999The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory propertiesView study →}. Preparation today is by extraction and chromatographic isolation from plant material (feverfew, Tanacetum microphyllum, birch buds) for research use; there is no notable commercial or synthetic-manufacture story, as santin is a research-scale phytochemical rather than an article of commerce.

Patents: not yet researched.

Toxicity & Safety

Santin carries a low flag, but that flag means “no toxicological signal because there is essentially no toxicological data,” not a demonstrated clean safety record. It is a trace dietary methylated flavonol, and human exposure from feverfew or birch is negligible compared with the 25–100 µM used in cell culture.

Safety at a Glance

✅ Low / no toxicity

• Trace dietary flavonol. Real-world exposure from feverfew or birch is very low; there is no evidence of harm at dietary levels.
• A hint of cancer-cell selectivity. In one birch-bud study santin was cytotoxic to cancer lines while a normal-fibroblast control was included as comparison ^{4Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →} — suggestive, not conclusive.
• No toxicology package. No repeat-dose, genotoxicity, reproductive or pharmacokinetic data exist for isolated santin; safety is unknown at the high concentrations used in vitro.
• In-vitro concentrations are not achievable from food. The active 25–100 µM levels far exceed plausible human exposure, so the cell-based activities do not translate to a dietary or supplemental effect.
• Pregnancy/lactation is a per-herb decision. Any caution belongs on the feverfew monograph (feverfew itself is traditionally avoided in pregnancy), not on this molecule page; there are no santin-specific reproductive data.

Dosage

There is no established or recommended human dose for santin. It has never been dosed in people or animals; the only figures in the literature are the 25–100 µM in-vitro concentrations used in cell-culture assays ^{4,5Reference 4Szoka Ł et al. · 2021Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cellsView study →Reference 5Kłósek M et al. · 2023Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cellsView study →}, which are not convertible to human intake and are far above anything reachable through diet or feverfew supplementation. Human exposure is incidental — as one minor flavonol among many in whole feverfew or birch preparations. These are research concentrations, not a personal recommendation.

References

1. Williams CA, Hoult JR, Harborne JB, Greenham J, Eagles J (1995). A biologically active lipophilic flavonol from Tanacetum parthenium. Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/7766058/
2. Williams CA, Harborne JB, Geiger H, Hoult JR (1999). The flavonoids of Tanacetum parthenium and T. vulgare and their anti-inflammatory properties. Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/10382317/
3. Guerra JA, Molina M, Abad MJ, Villar AM, Paulina B (2006). Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 expression by flavonoids isolated from Tanacetum microphyllum. International Immunopharmacology. https://pubmed.ncbi.nlm.nih.gov/16979127/
4. Szoka Ł, Nazaruk J, Stocki M, Isidorov V (2021). Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cells. Journal of Cellular and Molecular Medicine. https://pubmed.ncbi.nlm.nih.gov/34755444/
5. Kłósek M, Jaworska D, Pietsz G, Szliszka E (2023). Santin (5,7-dihydroxy-3,6,4′-trimethoxyflavone) enhances TRAIL-mediated apoptosis in colon cancer cells. Life (Basel). https://pubmed.ncbi.nlm.nih.gov/36836951/
6. Zhong M, Wang HQ, Yan HY, Wu S, Gu ZY, Li YH (2019). Santin inhibits influenza A virus replication through regulating MAPKs and NF-κB pathways. Journal of Asian Natural Products Research. https://pubmed.ncbi.nlm.nih.gov/30417663/

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