Sennoside A

Sennoside A at a Glance

Sennoside A is the principal laxative glycoside of senna and one of the stimulant-laxative components of rhubarb. Chemically it is a rhein dianthrone diglucoside — two rhein-anthrone units joined at their central carbons, each capped with a glucose sugar. That structure is the key to how it works: the sugars make it polar and poorly absorbed, so a swallowed dose survives the stomach and small intestine and travels to the colon essentially unchanged ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}.

It is a prodrug. Sennoside A itself does very little; the active molecule is what colonic bacteria make from it. In the large intestine, bacterial enzymes strip the sugars and reduce the freed dianthrone to the reactive anthrone rhein-anthrone, which is the species that actually drives laxation — speeding colonic motility and turning the colon from a net absorber of water into a net secretor of it ^{1,4Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 4Van Hoestenberghe A et al. · 1992AnimalThe effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free ratsView study →}. Onset is typically 6–12 hours, which is why senna is a classic overnight laxative ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.

With its diastereomer sennoside B, sennoside A is the standardised active of senna — one of the most widely used over-the-counter laxatives in the world, with a genuine human trial record for constipation ^{3Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →}. Almost all of that human evidence, though, is for standardised senna extract (sennosides A + B together), not for the purified isomer. As a member of the hydroxyanthracene family it also carries that class’s stimulant-laxative safety story: electrolyte loss with overuse, melanosis coli with chronic use, and an EU regulatory caution built on the genotoxic potential of the released free anthrones — set against reassuring direct genotoxicity and carcinogenicity testing of senna itself ^{10,11,12,13,14Reference 10Heidemann A et al. · 1993The genotoxicity status of sennaView study →Reference 11Brusick D · 1997Assessment of the genotoxic risk from laxative senna productsView study →Reference 12Mitchell JM et al. · 2006AnimalAn oral carcinogenicity and toxicity study of senna (Tinnevelly senna fruits) in the ratView study →Reference 13Zhang R et al. · 2023ReviewReview on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coliView study →Reference 14EFSA ANS Panel · 2018Safety of hydroxyanthracene derivatives for use in foodView study →}.

The Principal Senna Laxative

This is the point of the molecule, so it is worth stating precisely. Sennoside A is the compound that makes senna a laxative, and it does so through a defined prodrug cascade:

1. The plant delivers an inert glycoside. Sennoside A is a dianthrone diglucoside — pharmacologically inactive as swallowed, polar, and poorly absorbed. It is stored in senna leaf and pod (and in rhubarb rhizome) as the stable, storable form of the reactive anthrone ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.
2. It reaches the colon intact. Because it is a glycoside, the stomach and small intestine neither absorb nor transform it; it arrives in the large intestine unchanged ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}.
3. Colonic bacteria activate it. Bacterial β-glucosidase removes the two glucose units to give the aglycone sennidin A, and bacterial reductase reduces and cleaves the central bond to yield the active metabolite rhein-anthrone ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}. This step is obligatory — in germ-free rats, sennosides are not converted and the laxative effect does not appear ^{4Reference 4Van Hoestenberghe A et al. · 1992AnimalThe effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free ratsView study →}.
4. Rhein-anthrone stimulates the colon. The anthrone acts locally on the colonic wall, producing the two effects that together define stimulant laxation.

The two colonic actions. Rhein-anthrone is prokinetic — it stimulates colonic smooth muscle and the peristaltic reflex, accelerating transit so there is less time for water to be reabsorbed; in guinea-pig ileum it produced a dose-dependent, prostaglandin-mediated rise in muscle tension and peristalsis ^{8Reference 8Nijs G et al. · 1993Influence of rhein anthrone on peristaltic reflex of guinea-pig isolated ileum: involvement of prostaglandinsView study →}. It is simultaneously antiabsorptive/secretory — it reduces net absorption of sodium and chloride and enhances potassium and water secretion, shifting net water movement toward secretion ^{1,4Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 4Van Hoestenberghe A et al. · 1992AnimalThe effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free ratsView study →}. Part of this is prostaglandin-E2-mediated (rhein-anthrone raises luminal PGE2, and indomethacin blunts but does not abolish its purgative action) ^{6,7Reference 6Yagi T et al. · 1990AnimalProstaglandin E2-mediated stimulation of mucus synthesis and secretion by rhein anthrone, the active metabolite of sennosides A and B, in the mouse colonView study →Reference 7Yagi T et al. · 1991AnimalSuppression of the purgative action of rhein anthrone, the active metabolite of sennosides A and B, by indomethacin in ratsView study →}, and a downstream step involves colonic macrophage activation lowering aquaporin-3 water-channel expression, cutting water reabsorption from the lumen ^{5Reference 5Kon R et al. · 2014Rheinanthrone, a metabolite of sennoside A, triggers macrophage activation to decrease aquaporin-3 expression in the colon, causing the laxative effect of rhubarb extractView study →}. Co-occurring anthrones can potentiate the effect: a minor aloe-emodin dianthrone diglucoside from senna, inactive on its own, increased sennoside A’s purgative activity in mice ^{9Reference 9Nakajima K et al. · 1985AnimalIsolation of a new aloe-emodin dianthrone diglucoside from senna and its potentiating effect on the purgative activity of sennoside A in miceView study →}.

The clinical laxative evidence. Unlike most of the molecules in this class, senna has a modern randomised trial. In a double-blind, placebo-controlled RCT in chronic idiopathic constipation, standardised senna produced an overall response in ~69% of patients versus ~12% on placebo (statistically indistinguishable from magnesium oxide), with significant gains in spontaneous bowel movements and quality of life ^{3Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →}. That trial — and centuries of pharmacopoeial use — is the real human footprint. The mechanism above is sennoside A’s; the trial is standardised senna’s (sennosides A + B), a distinction the page keeps throughout.

Sennoside A vs. Sennoside B

Senna’s two principal actives are a stereochemical pair, and the distinction explains why they are always quantified together:

• Sennoside A yields, on hydrolysis, the aglycone sennidin A, which is optically active (dextrorotatory) — its two anthrone halves are joined in a chiral, trans configuration at the central C10–C10′ carbons.
• Sennoside B yields sennidin B, the meso form — the same two halves joined so that the molecule is internally compensated and optically inactive.

They are therefore diastereomers, and the C10 centres can epimerise, so the two isomers interconvert and co-occur in the plant. For this reason pharmacopoeial senna is not standardised to sennoside A alone but to total hydroxyanthracene glycosides, conventionally expressed as sennoside B ^{1,14Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 14EFSA ANS Panel · 2018Safety of hydroxyanthracene derivatives for use in foodView study →}. The practical upshot: sennoside A is the optically-active isomer of the standardised pair, but the number on a senna monograph is a combined sennoside figure, and the two isomers converge on the same active metabolite — rhein-anthrone — in the colon ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.

What It's Used For

The pharmacology is dominated by one well-mapped action — stimulant laxation via the bacterial metabolite — with a scatter of preclinical activities reported for the intact glycoside. The evidence splits sharply by whether the endpoint is the established human laxative use or a cell/rodent finding for isolated sennoside A.

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. The laxative score reflects genuine human trial evidence (for standardised senna); the other rows are isolated-molecule preclinical signals. Each application links to its write-up.

01Laxative — constipationPromising64%Established OTC use + placebo-controlled RCT (standardised senna) + mapped anthrone mechanism ^{1,3,4,8Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →Reference 4Van Hoestenberghe A et al. · 1992AnimalThe effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free ratsView study →Reference 8Nijs G et al. · 1993Influence of rhein anthrone on peristaltic reflex of guinea-pig isolated ileum: involvement of prostaglandinsView study →}

02Metabolic / hepatoprotective (preclinical)Shaky22%Isolated-molecule anti-obesity, hypoglycaemic, anti-fibrotic, hepatoprotective signals in cell/animal models ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}

03Antimicrobial / antiviral (preclinical)Shaky18%In-vitro antibacterial, antifungal and antiviral reports for isolated sennoside A ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}

Mechanisms

The load-bearing point: sennoside A is a delivery vehicle. Every therapeutic action in the table is really rhein-anthrone’s — the glycoside’s job is to survive the upper gut and release the reactive anthrone exactly where laxation is wanted.

Pharmacokinetics

Sennoside A’s pharmacokinetics are the pharmacokinetics of a colon-targeted prodrug. Because it is a polar diglucoside, oral absorption of the intact molecule is minimal — it is not meaningfully taken up in the small intestine, which is precisely what lets it reach the colon ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}. There, gut bacteria convert it to rhein-anthrone, which acts locally; the anthrone is short-lived and oxidises to rhein, and it is rhein — not sennoside A or the anthrone — that is absorbed into enterohepatic circulation and detected in plasma, urine and breast milk after a senna dose ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}. The practical consequences are clean: there is no useful “oral bioavailability of sennoside A” to quote (its low absorption is the mechanism, not a limitation), the active exposure is generated in situ and is microbiota-dependent, and the controllable input is the administered glycoside dose, not any circulating sennoside A level ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}.

Clinical Trials

Human evidence is for standardised senna, not the isolated isomer. Senna is an established OTC laxative with a modern double-blind, placebo-controlled RCT in chronic idiopathic constipation ^{3Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →} on top of pharmacopoeial recognition and long use; the preclinical (metabolic, antimicrobial, antitumour) activities of isolated sennoside A remain cell/animal-stage ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.

Last checked: July 2026.

Isolate vs. Plant Studies

Sennoside A shows the usual two-layer split, but with a strong human core. The efficacy evidence is at the whole-herb / standardised-extract level: senna is dosed and trialled by its combined sennoside content, and the randomised laxative data are for standardised senna (sennosides A + B), not the purified isomer ^{3Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →}. The mechanism is genuinely sennoside A’s — the prodrug-to-rhein-anthrone cascade is well mapped — but it is shared with sennoside B, which converges on the same metabolite ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}. Where the isolated molecule has been studied directly (the metabolic, hepatoprotective and antimicrobial reports), the work is preclinical, and even the authoritative review is candid that it is unclear whether sennoside A or a metabolite is responsible ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}. So the honest framing: take the laxative efficacy from the standardised plant, take the mechanism from the molecule, and treat the isolated-molecule pharmacology as a preclinical frontier.

Prevalence in Nature

Sennoside A is a stored dianthrone glycoside of a small set of anthraquinone-bearing medicinal plants — unlike its metabolite rhein-anthrone, which is not stored pre-formed. Its principal sources are:

• Senna (Senna alexandrina, syn. Cassia angustifolia / Cassia senna) — leaf and pod, its defining source. Senna leaf and pod store sennosides A and B as their principal actives alongside minor sennosides C and D (rhein–aloe-emodin heterodianthrones); pharmacopoeial material is standardised to total hydroxyanthracene glycosides expressed as sennoside B, typically ~2–3% in leaf and ~3–4% in pod ^{1,14Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 14EFSA ANS Panel · 2018Safety of hydroxyanthracene derivatives for use in foodView study →}.
• Rhubarb (Rheum spp., e.g. R. palmatum) — rhizome, where sennoside A occurs alongside the free anthraquinones rhein, emodin, aloe-emodin, chrysophanol and physcion; it is a minor share (~3.9%) of a representative rhubarb free-anthraquinone extract ^{16Reference 16Li P et al. · 2017AnimalPharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease ratsView study →}.

Content in both plants swings with species, plant part and processing — leaf is more potent (and more griping) than pod, and raw rhubarb is more purgative than steamed or charred forms ^{1,16Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 16Li P et al. · 2017AnimalPharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease ratsView study →}.

Major Natural Sources

Source (Botanical)	Part	Sennoside content	Note
Senna (Senna alexandrina)	Pod	~3–4% total sennosides (as sennoside B)	The standardised laxative drug; milder/less griping than leaf 1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →
Senna (Senna alexandrina)	Leaf	~2–3% total sennosides (as sennoside B)	More potent but more cramping than pod 1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →
Rhubarb (Rheum palmatum)	Rhizome	~3.9% of the anthraquinone extract	One anthraquinone among many; raw > processed 16Reference 16Li P et al. · 2017AnimalPharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease ratsView study →

Discovery & Synthesis

Sennoside A entered the literature as one of the two crystalline active glycosides that finally explained senna’s laxative action. Stoll, Becker and Kussmaul, working at Sandoz in Basel, isolated and named sennosides A and B from senna in 1949, showing that each hydrolyses to two molecules of glucose and a sennidin aglycone — sennidin A dextrorotatory, sennidin B its meso form. That work converted senna from a crude drug of variable strength into a standardisable one, since the sennoside content could now be measured. The molecule is a rhein homodianthrone diglucoside: two rhein-anthrone units linked at C10–C10′ and glucosylated. There is no meaningful “total synthesis” story of practical importance — sennoside A is obtained by extraction and purification from senna, and the article of commerce is standardised senna extract itself rather than the pure isomer, because the two isomers interconvert and converge on the same colonic metabolite. Where pure sennoside A is wanted as a reference standard, it is isolated chromatographically from senna material ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.

Patents: not yet researched.

Toxicity & Safety

Sennoside A carries a moderate flag — heavier than an inert dietary glycoside would warrant — because it is an active stimulant laxative and a member of the hydroxyanthracene-derivative class that sits under regulatory scrutiny. The caveats are the stimulant-laxative / anthranoid cautions, applied to senna’s principal active.

Safety at a Glance

⚠️ Moderate toxicity

• An established laxative with human evidence. Senna standardised to its sennosides is an OTC stimulant laxative with a placebo-controlled RCT behind its use for constipation ^{3Reference 3Morishita D et al. · 2021RCTSenna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled TrialView study →}.
• Direct testing of senna is reassuring. Standard genotoxicity batteries on senna, the sennosides and rhein were negative, and a 2-year oral carcinogenicity study of senna in rats found no carcinogenic effect ^{10,11,12Reference 10Heidemann A et al. · 1993The genotoxicity status of sennaView study →Reference 11Brusick D · 1997Assessment of the genotoxic risk from laxative senna productsView study →Reference 12Mitchell JM et al. · 2006AnimalAn oral carcinogenicity and toxicity study of senna (Tinnevelly senna fruits) in the ratView study →}.
• Stimulant-laxative class risks. Electrolyte loss (especially potassium) with overuse — which can compound digoxin, diuretic and antiarrhythmic effects — plus cramping/griping, and dependence with reduced bowel tone on chronic daily use.
• Melanosis coli with chronic use. Long-term use pigments the colonic mucosa (lipofuscin in macrophages) from laxative-induced epithelial apoptosis — benign and reversible, not linked to increased colon-cancer risk, but a marker of sustained use ^{13Reference 13Zhang R et al. · 2023ReviewReview on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coliView study →}.
• Regulatory context — short-term use. Hydroxyanthracene derivatives sit under EU/EFSA scrutiny because the released free anthrones are the structural basis for the class genotoxicity concern; senna laxatives are intended for occasional, short-term use ^{1,14Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 14EFSA ANS Panel · 2018Safety of hydroxyanthracene derivatives for use in foodView study →}.

Full Safety & Interactions Detail

Genotoxicity — the class concern vs the direct data. The EU restriction on hydroxyanthracene derivatives rests on the reactive free anthrones (the aglycone end-products), which are the structural basis for a class genotoxicity flag ^{14Reference 14EFSA ANS Panel · 2018Safety of hydroxyanthracene derivatives for use in foodView study →}. Against that structural concern, the direct testing of senna itself has been largely reassuring: senna, the sennosides and rhein did not increase mutation frequencies across bacterial and mammalian assays (aloe-emodin was the class member showing in-vitro mutagenicity, without an in-vivo effect) ^{10Reference 10Heidemann A et al. · 1993The genotoxicity status of sennaView study →}, and a formal assessment concluded the genotoxic risk to patients using senna laxatives is not established ^{11Reference 11Brusick D · 1997Assessment of the genotoxic risk from laxative senna productsView study →}.

Carcinogenicity — negative in the pivotal study. A 2-year oral carcinogenicity and toxicity study of Tinnevelly senna fruits in rats found no treatment-related carcinogenic effect at daily doses up to the high range, with only minor non-neoplastic intestinal and renal changes ^{12Reference 12Mitchell JM et al. · 2006AnimalAn oral carcinogenicity and toxicity study of senna (Tinnevelly senna fruits) in the ratView study →}. Chronic use produces melanosis coli — dark colonic pigmentation from laxative-induced epithelial apoptosis and lipofuscin-laden macrophages — which is benign, reversible on stopping, and not associated with increased colorectal-cancer risk ^{13Reference 13Zhang R et al. · 2023ReviewReview on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coliView study →}. A comprehensive review of isolated sennoside A does, however, note that long-term high-dose exposure has been linked in some contexts to aberrant crypt foci and colonic changes, keeping the “short-term use” framing appropriate ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}.

Class laxative cautions. As an active stimulant laxative, sennoside A underlies the familiar anthranoid concerns: potassium and fluid loss with excessive use, abdominal cramping/griping (worse with leaf than pod), and — with habitual daily use — laxative dependence and diminished spontaneous bowel function. These are dose- and duration-driven, tied to the very motility/secretion mechanism that makes it work.

Pregnancy and lactation (prose only). Senna is one of the better-characterised laxatives in pregnancy and is generally regarded as acceptable for short-term use where a stimulant laxative is needed. A large population-based case-control study (Hungarian Case-Control Surveillance System) found no association between maternal senna treatment and congenital abnormalities in offspring (adjusted OR ~1.0), and concluded senna is not contraindicated when constipation requires drug treatment in pregnancy ^{15Reference 15Acs N et al. · 2009ObservationalSenna treatment in pregnant women and congenital abnormalities in their offspring—a population-based case-control studyView study →}. In lactation, systemic exposure is largely to the oxidation product rhein (sennoside A and the anthrone act locally and are poorly absorbed) ^{1,2Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 2Wang D et al. · 2021Pharmacokinetics of Anthraquinones from Medicinal PlantsView study →}. Consistent with house policy, the pregnancy/lactation decision belongs on the herb or product page where intake is chosen, not on this molecule page; stated here only as the cited finding.

Dosage

There is no dose for isolated sennoside A as a stand-alone drug — it is not administered as the pure isomer. Human dosing is entirely of senna preparations standardised to their sennoside / hydroxyanthracene-glycoside content ^{1Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →}:

The amount of active rhein-anthrone actually generated depends on the individual’s colonic microbiota, not on a fixed conversion, so response varies between people ^{1,4Reference 1Le J et al. · 2021Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural CompoundView study →Reference 4Van Hoestenberghe A et al. · 1992AnimalThe effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free ratsView study →}. Senna is intended for occasional, short-term use; chronic daily use raises the electrolyte-loss, dependence and melanosis-coli concerns above ^{13Reference 13Zhang R et al. · 2023ReviewReview on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coliView study →}. These are parent-preparation figures and research doses, not a personal recommendation.

References

1. Le J, et al. (2021). Pharmacology, Toxicology, and Metabolism of Sennoside A, A Medicinal Plant-Derived Natural Compound. Frontiers in Pharmacology. https://pubmed.ncbi.nlm.nih.gov/34764866/
2. Wang D, et al. (2021). Pharmacokinetics of Anthraquinones from Medicinal Plants. Frontiers in Pharmacology. https://pubmed.ncbi.nlm.nih.gov/33935728/
3. Morishita D, et al. (2021). Senna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled Trial. The American Journal of Gastroenterology. https://pubmed.ncbi.nlm.nih.gov/32969946/
4. Van Hoestenberghe A, et al. (1992). The effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free rats. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/1555634/
5. Kon R, et al. (2014). Rheinanthrone, a metabolite of sennoside A, triggers macrophage activation to decrease aquaporin-3 expression in the colon, causing the laxative effect of rhubarb extract. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/24412547/
6. Yagi T, et al. (1990). Prostaglandin E2-mediated stimulation of mucus synthesis and secretion by rhein anthrone, the active metabolite of sennosides A and B, in the mouse colon. Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/1981580/
7. Yagi T, et al. (1991). Suppression of the purgative action of rhein anthrone, the active metabolite of sennosides A and B, by indomethacin in rats. Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/1680171/
8. Nijs G, et al. (1993). Influence of rhein anthrone on peristaltic reflex of guinea-pig isolated ileum: involvement of prostaglandins. British Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/8094026/
9. Nakajima K, Yamauchi K, Kuwano S (1985). Isolation of a new aloe-emodin dianthrone diglucoside from senna and its potentiating effect on the purgative activity of sennoside A in mice. Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/2867138/
10. Heidemann A, Miltenburger HG, Mengs U (1993). The genotoxicity status of senna. Pharmacology. https://pubmed.ncbi.nlm.nih.gov/8234427/
11. Brusick D, Mengs U (1997). Assessment of the genotoxic risk from laxative senna products. Environmental and Molecular Mutagenesis. https://pubmed.ncbi.nlm.nih.gov/9020301/
12. Mitchell JM, et al. (2006). An oral carcinogenicity and toxicity study of senna (Tinnevelly senna fruits) in the rat. Archives of Toxicology. https://pubmed.ncbi.nlm.nih.gov/16205914/
13. Zhang R, et al. (2023). Review on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coli. Frontiers in Pharmacology. https://pubmed.ncbi.nlm.nih.gov/37214441/
14. EFSA ANS Panel (2018). Safety of hydroxyanthracene derivatives for use in food. EFSA Journal. https://pubmed.ncbi.nlm.nih.gov/32625659/
15. Acs N, et al. (2009). Senna treatment in pregnant women and congenital abnormalities in their offspring—a population-based case-control study. Reproductive Toxicology. https://pubmed.ncbi.nlm.nih.gov/19491001/
16. Li P, et al. (2017). Pharmacokinetics and pharmacodynamics of rhubarb anthraquinones extract in normal and disease rats. Biomedicine & Pharmacotherapy. https://pubmed.ncbi.nlm.nih.gov/28475921/

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