Chrysophanol

Pharmacology & Research

Chrysophanol (chrysophanic acid; 1,8-dihydroxy-3-methylanthraquinone) is one of the simplest hydroxyanthraquinones — the same anthraquinone-laxative family as emodin, rhein and physcion — and it turns up across rhubarb, yellow dock, cascara sagrada and, as a minor non-characteristic marker, dagga ^{1,2Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →Reference 2Prateeksha et al. · 2019ReviewChrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential — reviewView study →}. In those plants it is usually a smaller share of the anthraquinone pool than emodin or rhein — roughly 1.5% of a representative rhubarb free-anthraquinone extract, versus ~27% emodin and ~43% rhein ^{15Reference 15Li P et al. · 2017AnimalPharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease rats — rat pharmacokinetic modelView study →}. Two framing points carry through every claim. First, oral bioavailability is poor: chrysophanol is lipophilic and poorly water-soluble, absorbed and conjugated so extensively that most of the applied literature reaches for liposomes, nanoparticles or drug combinations to raise exposure, and its movement across the blood–brain barrier is limited ^{1,2Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →Reference 2Prateeksha et al. · 2019ReviewChrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential — reviewView study →}. Second, all of it is preclinical — there is no human efficacy trial of the isolated molecule, and the whole-herb use of its source plants is a multi-constituent, laxative-dominated exposure, not a chrysophanol result. Against that backdrop it has a broad in-vitro/in-vivo signal (neuroprotective, anti-inflammatory, anticancer, metabolic) ^{1,2Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →Reference 2Prateeksha et al. · 2019ReviewChrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential — reviewView study →} and a materially heavier safety profile than most dietary constituents (see Toxicity).

1. Neuroprotection

The most-developed signal. Isolated chrysophanol is protective across cerebral ischaemia–reperfusion models: in mice it reduced hippocampal damage and modulated mitochondrial autophagy (NIX/LC3B), limiting neuronal loss after reperfusion ^{3Reference 3Cui WH et al. · 2022AnimalEffects of chrysophanol on hippocampal damage and mitochondrial autophagy in mice with cerebral ischemia reperfusion — mouse modelView study →}. Reviews catalogue parallel antioxidant, anti-apoptotic and anti-inflammatory actions in stroke, Alzheimer’s-type and other CNS models ^{1,2Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →Reference 2Prateeksha et al. · 2019ReviewChrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential — reviewView study →}.

Gap: all rodent/cell; and chrysophanol’s poor blood–brain-barrier penetration is the recurring obstacle the reviews flag ^{1Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →} — much of this work therefore depends on formulation tricks rather than plain oral dosing. No human neuro data.

2. Anti-inflammatory

Isolated chrysophanol suppresses NF-κB signalling. In a sepsis-associated acute-kidney-injury model it inhibited LPS-induced p65 phosphorylation/translocation, shifted macrophages from pro-inflammatory M1 toward anti-inflammatory M2 (↓TNF-α/IL-6, ↑TGF-β), and attenuated renal injury in both cells and mice ^{4Reference 4Gou X et al. · 2025In vitroChrysophanol promotes M2 polarization and inhibits M1 polarization through the NF-κB signaling pathway to attenuate sepsis-associated acute kidney injury — in vitro and mouse modelView study →}. Anthraquinone-rich Rumex crispus (yellow dock) root fractions containing chrysophanol also show anti-inflammatory and antioxidant activity in vitro, though that is a fraction, not the pure molecule ^{5Reference 5Eom TJ et al. · 2020In vitroIn-vitro antioxidant, anti-inflammation and anticancer activities and anthraquinone content from Rumex crispus root extract and fractions — in vitroView study →}.

Gap: cell and rodent only, and the yellow-dock evidence is a whole-fraction effect that cannot be pinned to chrysophanol specifically ^{5Reference 5Eom TJ et al. · 2020In vitroIn-vitro antioxidant, anti-inflammation and anticancer activities and anthraquinone content from Rumex crispus root extract and fractions — in vitroView study →}. No human data.

3. Metabolic / antidiabetic

Isolated chrysophanol has several converging metabolic mechanisms in preclinical work: it inhibited protein-tyrosine-phosphatase-1B (PTP1B) and mildly stimulated insulin-signalling glucose transport with increased GLUT4 expression in vitro ^{8Reference 8Lee MS et al. · 2008In vitroAnti-diabetic properties of chrysophanol and its glucoside from rhubarb rhizome — in vitroView study →}; it reduced body weight, improved insulin sensitivity and drove brown-fat energy expenditure via the SIRT6/AMPK pathway in high-fat-diet obese mice ^{9Reference 9Liu X et al. · 2020In vitroChrysophanol Alleviates Metabolic Syndrome by Activating the SIRT6/AMPK Signaling Pathway in Brown Adipocytes — in vitro and obese-mouse modelView study →}; and it is a comparatively potent α-glucosidase inhibitor (IC₅₀ ≈ 4.9 µg/mL, below acarbose) identified in Leonotis nepetifolia (dagga) aerial parts ^{10Reference 10Nguyen TK et al. · 2023In vitroNepetifoliol — a new glutinane-triterpenoid from Leonotis nepetifolia (with α-glucosidase inhibition data for chrysophanol) — in vitroView study →}.

Gap: cell and mouse models; the α-glucosidase result is an isolated enzyme assay from a minor herb constituent, and none of these effects has human dosing ^{8,9,10Reference 8Lee MS et al. · 2008In vitroAnti-diabetic properties of chrysophanol and its glucoside from rhubarb rhizome — in vitroView study →Reference 9Liu X et al. · 2020In vitroChrysophanol Alleviates Metabolic Syndrome by Activating the SIRT6/AMPK Signaling Pathway in Brown Adipocytes — in vitro and obese-mouse modelView study →Reference 10Nguyen TK et al. · 2023In vitroNepetifoliol — a new glutinane-triterpenoid from Leonotis nepetifolia (with α-glucosidase inhibition data for chrysophanol) — in vitroView study →}.

4. Anticancer

Isolated chrysophanol is cytotoxic to cultured tumour lines: in human lung-cancer A549 cells it triggered cell death (described as necrosis) by raising reactive oxygen species and collapsing mitochondrial membrane potential ^{6Reference 6Ni CH et al. · 2014In vitroChrysophanol-induced cell death (necrosis) in human lung cancer A549 cells is mediated through increasing reactive oxygen species and decreasing the level of mitochondrial membrane potential — in vitroView study →}. In a structure–activity comparison of anthranoids, however, chrysophanol was less cytotoxic than emodin or aloe-emodin — its 3-methyl/1,8-dihydroxy pattern is a weaker cytotoxic scaffold ^{7Reference 7Demarque DP et al. · 2018In vitroCytotoxicity of Structurally Diverse Anthranoids and Correlation with Mechanism of Action and Side Effects — in vitro structure–activity studyView study →}.

Gap: in-vitro at micromolar concentrations that poor oral bioavailability makes hard to reach systemically; sparse in-vivo tumour work and no human oncology data ^{6,7Reference 6Ni CH et al. · 2014In vitroChrysophanol-induced cell death (necrosis) in human lung cancer A549 cells is mediated through increasing reactive oxygen species and decreasing the level of mitochondrial membrane potential — in vitroView study →Reference 7Demarque DP et al. · 2018In vitroCytotoxicity of Structurally Diverse Anthranoids and Correlation with Mechanism of Action and Side Effects — in vitro structure–activity studyView study →}.

5. Laxative (class effect)

Chrysophanol belongs to the anthraquinone/anthranoid laxative class, but it is a weak, minor contributor to laxation — the purgative action of rhubarb, cascara and yellow dock is driven by the anthraquinone glycosides and dianthrones (sennosides, cascarosides) that survive to the colon, where flora liberate active anthrones ^{14Reference 14EFSA ANS Panel · 2018ReviewSafety of hydroxyanthracene derivatives for use in food — reviewView study →}. Chrysophanol is the aglycone parent of the cascara C-glycosides cascaroside C and D ^{7Reference 7Demarque DP et al. · 2018In vitroCytotoxicity of Structurally Diverse Anthranoids and Correlation with Mechanism of Action and Side Effects — in vitro structure–activity studyView study →}.

Gap: this is a herb/glycoside indication, not a chrysophanol-isolate one, and it sits under the EU restriction of hydroxyanthracene derivatives ^{14Reference 14EFSA ANS Panel · 2018ReviewSafety of hydroxyanthracene derivatives for use in food — reviewView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
Mitochondrial autophagy (NIX/LC3B), anti-apoptotic	↓ neuronal loss after ischaemia–reperfusion	Neuroprotection
NF-κB (p65) signalling	↓ pro-inflammatory transcription; M1→M2 macrophage shift	Anti-inflammatory, sepsis-AKI
PTP1B inhibition → insulin receptor	↑ insulin signalling, GLUT4 expression, glucose transport	Metabolic / antidiabetic
SIRT6/AMPK	Activates → brown-fat energy expenditure, ↓ weight/insulin resistance	Metabolic / antidiabetic
α-Glucosidase	Inhibits (IC₅₀ ≈ 4.9 µg/mL) → ↓ carbohydrate digestion	Metabolic / antidiabetic
ROS ↑ / mitochondrial membrane potential ↓	Pro-death (necrosis/apoptosis) in tumour cells	Anticancer
CYP1A2 oxidation → aloe-emodin	Bioactivation to a more genotoxic metabolite	Toxicity

Pharmacokinetics

Bioavailability is the load-bearing caveat for the whole chrysophanol literature. It is highly lipophilic and poorly water-soluble, and although its absorption rate is reported as higher than some other anthraquinones, systemic exposure is constrained by extensive conjugation and it distributes unevenly (kidney > liver > heart > brain), with poor blood–brain-barrier penetration despite the neuroprotective signals ^{1,2Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →Reference 2Prateeksha et al. · 2019ReviewChrysophanol: A Natural Anthraquinone with Multifaceted Biotherapeutic Potential — reviewView study →}. Metabolically it is a substrate for cytochrome-P450 oxidation — CYP1A2 converts chrysophanol to aloe-emodin (a hydroxymethyl anthraquinone that is itself more genotoxic than the parent), so a fraction of an oral dose is bioactivated rather than simply cleared ^{12Reference 12Mueller SO et al. · 1998In vitroBiotransformation of the anthraquinones emodin and chrysophanol by cytochrome P450 enzymes: bioactivation to genotoxic metabolites — in vitroView study →}. This is why the applied literature leans heavily on liposomes, gold nanoparticles and drug combinations to raise exposure and blunt toxicity ^{1Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →}. The practical upshot mirrors emodin’s: potent in-vitro concentrations are not trivially reachable from an oral dose, which tempers every downstream claim.

Clinical trials

There are no human efficacy trials of isolated chrysophanol. The only human exposure is incidental, via anthraquinone-containing herbs (rhubarb, cascara, yellow dock) used as laxatives — multi-constituent, glycoside-driven preparations whose effect cannot be attributed to this molecule. Everything on this page is preclinical.

Last checked: July 2026.

Toxicity & Safety

Chrysophanol carries a moderate flag — heavier than most dietary constituents, though the case is more equivocal than emodin’s, and the low-vs-moderate call is a genuine judgement (see below).

• Direct genotoxicity — weaker than emodin. In the assay panel that flagged emodin as genotoxic (comet, micronucleus, mouse-lymphoma), chrysophanol and physcion showed no genotoxic effect ^{11Reference 11Mueller SO et al. · 1999In vitroOccurrence of emodin, chrysophanol and physcion in vegetables, herbs and liquors; genotoxicity and anti-genotoxicity of the anthraquinones and of the whole plants — in vitroView study →}, and across a structure–activity series chrysophanol is less cytotoxic than emodin or aloe-emodin ^{7Reference 7Demarque DP et al. · 2018In vitroCytotoxicity of Structurally Diverse Anthranoids and Correlation with Mechanism of Action and Side Effects — in vitro structure–activity studyView study →}. So the “hydroxyanthraquinone = genotoxic” story is not straightforwardly chrysophanol’s.
• But it is metabolically bioactivated. CYP1A2 oxidises chrysophanol to aloe-emodin, and aloe-emodin induced significantly higher micronucleus frequencies than chrysophanol — i.e. part of chrysophanol’s genotoxic risk is carried by a downstream metabolite rather than the parent ^{12Reference 12Mueller SO et al. · 1998In vitroBiotransformation of the anthraquinones emodin and chrysophanol by cytochrome P450 enzymes: bioactivation to genotoxic metabolites — in vitroView study →}. This is the pathway that keeps it inside the class concern.
• Hepatotoxicity is documented. The pharmacology reviews describe chrysophanol as having “obvious” hepatotoxicity and nephrotoxicity ^{1Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →}, and its glycoside chrysophanol-8-O-glucoside is strongly hepatotoxic in vitro — inhibiting mitochondrial respiratory-chain complexes, collapsing membrane potential, raising ROS, depleting glutathione and driving hepatocyte apoptosis ^{13Reference 13Lin L et al. · 2019In vitroHepatotoxicity and mechanism study of chrysophanol-8-O-glucoside in vitro — in vitroView study →}.
• Regulatory context. Chrysophanol is a hydroxyanthracene derivative, the class EFSA (2018) concluded raises a genotoxicity/safety concern in food, underpinning the EU/EMA restriction on hydroxyanthracene derivatives in food and supplements ^{14Reference 14EFSA ANS Panel · 2018ReviewSafety of hydroxyanthracene derivatives for use in food — reviewView study →}. It is regulated with the class even where its own direct genotoxicity is weak.
• Interactions / class effect. As an anthraquinone-laxative-class molecule, chronic exposure via the source herbs carries the class’s potassium-loss risk (compounding digoxin, diuretic and antiarrhythmic effects); the reviews note chrysophanol is often combined with other drugs specifically to reduce toxicity and modulate exposure ^{1Reference 1Xie L et al. · 2019ReviewChrysophanol: a review of its pharmacology, toxicity and pharmacokinetics — reviewView study →}. Human interaction data for the isolated molecule are absent.

Overall: the metabolic bioactivation to aloe-emodin, the documented hepatotoxicity, and the EU class restriction justify treating chrysophanol as moderate rather than a plain dietary low, even though its own direct genotoxicity signal is weaker than emodin’s.

Dosage

There is no established or safe human dose for isolated chrysophanol, and nothing here is a recommendation. Preclinical work spans oral/intraperitoneal rodent dosing in the tens of milligrams per kilogram and micromolar-to-low-microgram-per-millilitre concentrations in cell culture (e.g. the α-glucosidase IC₅₀ ≈ 4.9 µg/mL) ^{3,9,10Reference 3Cui WH et al. · 2022AnimalEffects of chrysophanol on hippocampal damage and mitochondrial autophagy in mice with cerebral ischemia reperfusion — mouse modelView study →Reference 9Liu X et al. · 2020In vitroChrysophanol Alleviates Metabolic Syndrome by Activating the SIRT6/AMPK Signaling Pathway in Brown Adipocytes — in vitro and obese-mouse modelView study →Reference 10Nguyen TK et al. · 2023In vitroNepetifoliol — a new glutinane-triterpenoid from Leonotis nepetifolia (with α-glucosidase inhibition data for chrysophanol) — in vitroView study →} — figures inflated to compensate for poor absorption. Human intake occurs only incidentally through anthraquinone-containing laxative herbs, dosed to the herb’s hydroxyanthracene-glycoside content rather than to free chrysophanol; given poor oral bioavailability, oral chrysophanol doses do not translate to meaningful, sustained systemic exposure. These are doses studied in research and are not a personal recommendation.

References