Matairesinol

Pharmacology & Research

Matairesinol is a dibenzylbutyrolactone plant lignan of flaxseed, sesame, whole grains and burdock seed — a sibling of arctigenin and arctiin (the same burdock lignan complex) and structurally kin to sesamin ^{2Reference 2Ferracane R et al. · 2010Metabolic profile of the bioactive compounds of burdock (Arctium lappa) seeds, roots and leavesView study →}. Its defining property is that it is a precursor: gut microbiota convert it (via enterodiol) to the mammalian lignan enterolactone. That matters throughout — the “phytoestrogen” and hormone-cancer literature is measured on circulating enterolactone from mixed dietary lignan intake, not on the matairesinol isolate, and there are no human trials of matairesinol itself.

1. Mammalian-lignan precursor / phytoestrogen

This is the defining role. Intestinal bacteria transform matairesinol directly to enterolactone (via enterodiol) ^{1Reference 1Heinonen S et al. · 2001In-vitro metabolism of plant lignans: new precursors of the mammalian lignans enterolactone and enterodiolView study →}; the hormone-related signal in the literature is on circulating enterolactone, whose breast-cancer epidemiology is genuinely mixed — a large prospective study found no protective association ^{4Reference 4Zeleniuch-Jacquotte A et al. · 2004Circulating enterolactone and risk of breast cancer: a prospective study in New YorkView study →}, while a prognosis meta-analysis tied higher lignan intake/enterolactone to lower all-cause mortality in postmenopausal but higher mortality in premenopausal patients ^{5Reference 5Liu Z et al. · 2021Meta-analysisLignan intake and enterolactone concentration and prognosis of breast cancer: a systematic review and meta-analysisView study →}. Matairesinol/enterolactone bind estrogen receptors weakly (SERM-like) ^{3Reference 3Rietjens IMCM et al. · 2017The potential health effects of dietary phytoestrogensView study →}.

Gap: essentially all hormone/cancer data are on the metabolite enterolactone from mixed dietary lignans, not the isolate; conversion yield varies widely with gut flora and antibiotics; and the epidemiology is associational and inconsistent by menopausal status ^{4,5Reference 4Zeleniuch-Jacquotte A et al. · 2004Circulating enterolactone and risk of breast cancer: a prospective study in New YorkView study →Reference 5Liu Z et al. · 2021Meta-analysisLignan intake and enterolactone concentration and prognosis of breast cancer: a systematic review and meta-analysisView study →}.

2. Antioxidant

Matairesinol is a polyphenolic lignan with expected in-vitro radical scavenging ^{3Reference 3Rietjens IMCM et al. · 2017The potential health effects of dietary phytoestrogensView study →}, and it drives ROS-linked mitochondrial effects in tumour cells ^{6Reference 6Lee W et al. · 2022Matairesinol induces mitochondrial dysfunction and exerts synergistic anticancer effects with 5-fluorouracil in pancreatic cancer cellsView study →}; the enterolactone metabolite is reported as a stronger antioxidant than the parent.

Gap: in-vitro/cell-level only, with no human antioxidant-outcome data for the isolate ^{3,6Reference 3Rietjens IMCM et al. · 2017The potential health effects of dietary phytoestrogensView study →Reference 6Lee W et al. · 2022Matairesinol induces mitochondrial dysfunction and exerts synergistic anticancer effects with 5-fluorouracil in pancreatic cancer cellsView study →}.

3. Anticancer (preclinical)

Direct isolate work exists: matairesinol induces mitochondrial depolarisation, ROS accumulation and apoptosis and synergises with 5-fluorouracil in pancreatic cancer cell lines ^{6Reference 6Lee W et al. · 2022Matairesinol induces mitochondrial dysfunction and exerts synergistic anticancer effects with 5-fluorouracil in pancreatic cancer cellsView study →}.

Gap: all in-vitro/animal, at supraphysiologic concentrations, with no clinical anticancer evidence for matairesinol ^{6Reference 6Lee W et al. · 2022Matairesinol induces mitochondrial dysfunction and exerts synergistic anticancer effects with 5-fluorouracil in pancreatic cancer cellsView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
Gut microbiota (dehydroxylation/demethylation)	matairesinol → enterodiol → enterolactone	precursor role — the systemically active species is the enterolignan
Estrogen receptors ERα / ERβ	weak, SERM-like binding	phytoestrogen / hormone epidemiology
ROS / mitochondrial membrane potential	ROS accumulation, depolarisation → apoptosis (cancer cells)	preclinical anticancer; antioxidant/pro-oxidant duality
Radical scavenging (phenolic H-donation)	antioxidant in vitro	antioxidant

Pharmacokinetics

Matairesinol is not active as an intact isolate systemically. Ingested matairesinol is largely converted by colonic bacteria to enterolactone (via enterodiol); the enterolignans are absorbed, undergo enterohepatic recirculation and glucuronidation, and appear in serum/urine ^{1Reference 1Heinonen S et al. · 2001In-vitro metabolism of plant lignans: new precursors of the mammalian lignans enterolactone and enterodiolView study →}. Intact bioavailability is low, and the measurable systemic exposure and biomarker of dietary-lignan intake is serum/urinary enterolactone, not matairesinol. This conversion is highly variable between individuals — it depends on gut-microbiota composition, and broad-spectrum antibiotics sharply reduce enterolactone production, which is central to interpreting any “matairesinol effect.”

Clinical trials

There are no human interventional trials of the matairesinol isolate. Human evidence is observational and measured on enterolactone (a downstream metabolite of matairesinol and secoisolariciresinol and other dietary lignans): a prospective serum-enterolactone breast-cancer study (no protective association) ^{4Reference 4Zeleniuch-Jacquotte A et al. · 2004Circulating enterolactone and risk of breast cancer: a prospective study in New YorkView study →} and a lignan-intake/enterolactone breast-cancer prognosis meta-analysis (direction differs by menopausal status) ^{5Reference 5Liu Z et al. · 2021Meta-analysisLignan intake and enterolactone concentration and prognosis of breast cancer: a systematic review and meta-analysisView study →}. Neither isolates matairesinol’s contribution.

Last checked: July 2026.

Toxicity & Safety

Matairesinol is a dietary lignan, consumed in flaxseed, sesame, whole grains and burdock seed with a long history of ordinary dietary exposure and no signal of toxicity at food levels — hence [low]. There is no established toxicity for concentrated/supplemental matairesinol (no human isolate data). The phytoestrogen caution is theoretical: weak ER activity means hormone-sensitive conditions (estrogen-receptor-positive breast cancer, endometrial issues) warrant caution with supplemental/isolated phytoestrogen use, and the premenopausal prognosis signal ^{5Reference 5Liu Z et al. · 2021Meta-analysisLignan intake and enterolactone concentration and prognosis of breast cancer: a systematic review and meta-analysisView study →} is a reason not to over-encourage high-dose supplementation — but this is precautionary, not evidence of harm at dietary intakes. Note a microbiome interaction rather than a toxicity: antibiotics markedly reduce enterolactone formation, which affects any expected benefit.

Pregnancy & lactation

Dietary lignans fine; avoid the isolated phytoestrogen. Dietary lignans from ordinary foods (flax, sesame, whole grains) are generally considered fine in pregnancy and lactation, but isolated or supplemental matairesinol/phytoestrogen is not recommended — avoid — given its weak estrogenic activity and the absence of safety data.

Dosage

There is no established therapeutic dose and no validated human dose for matairesinol, as no isolate trials exist. Relevant exposure is dietary lignan intake (flaxseed is by far the richest common source; sesame, whole grains and burdock seed also contribute), which the body converts to enterolactone at a rate set by the individual’s gut flora. Any supplement figures would be research references, not recommendations.

References