Bacopaside II

Bacopaside II at a Glance

Bacopaside II is a pseudojujubogenin dammarane-triterpene saponin of Bacopa monnieri (Brahmi, water hyssop) — the classical Ayurvedic nootropic. It is not a fringe constituent: it is one of the four saponins that together make up bacoside A, the standardisation marker for Bacopa’s memory extracts, alongside bacoside A3, the jujubogenin isomer of bacopasaponin C, and bacopasaponin C ^{7Reference 7Sekhar VC et al. · 2019Insights into the molecular aspects of neuroprotective bacoside A and bacopaside IView study →}.

Its most distinctive and best-characterised property has nothing to do with memory directly. Bacopaside II is a selective inhibitor of the aquaporin-1 (AQP1) water channel, and that single mechanism drives a coherent preclinical anticancer, anti-migratory and anti-angiogenic literature, largely from one Australian group ^{2,3,4,5Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →Reference 3Palethorpe HM et al. · 2018The aquaporin 1 inhibitor bacopaside II reduces endothelial cell migration and tubulogenesis and induces apoptosisView study →Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →Reference 5De Ieso ML et al. · 2019Combined pharmacological administration of AQP1 ion channel blocker AqB011 and water channel blocker bacopaside II amplifies inhibition of colon cancer cell migrationView study →}. Separately, as a bacoside A component it contributes to Bacopa’s neuroprotective / antioxidant action and shows antidepressant-like activity as an isolate in mouse models ^{1,6Reference 1Zhou Y et al. · 2007AnimalTriterpene saponins from Bacopa monnieri and their antidepressant effects in two mice modelsView study →Reference 6Bhardwaj P et al. · 2018Comparative evaluation of four triterpenoid glycoside saponins of bacoside A in alleviating sub-cellular oxidative stress of N2a neuroblastoma cellsView study →}.

The honest headline: all of this is preclinical. There are no human trials of isolated bacopaside II, the anticancer data are in-vitro at µM concentrations, and — like all large saponins — its oral bioavailability is expected to be poor. It carries a low toxicity flag as an ordinary dietary constituent of a widely consumed, well-tolerated nootropic herb.

Bacopaside II as an Aquaporin-1 Channel Blocker

The compound-defining finding is that bacopaside II blocks the water-conducting function of aquaporin-1 (AQP1). AQP1 is a membrane channel that moves water (and, gated by cGMP, cations) across cell membranes; when over-expressed in tumours it accelerates cell migration and invasion, making it a cancer-relevant drug target ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}.

Screened in the Xenopus oocyte expression system, bacopaside II selectively blocked the AQP1 water channel (IC₅₀ ≈ 18 µM) without impairing its ionic conductance, matching predictions from in-silico modelling ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}. That selectivity is the whole point of the molecule pharmacologically, and it separates it cleanly from its sibling (see below).

From this one mechanism, three preclinical signals follow:

Anti-migratory in cancer cells. Bacopaside II impaired migration of AQP1-high HT29 colon-cancer cells (IC₅₀ ≈ 14 µM) while barely touching AQP1-low SW480 cells — a target-dependent effect ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}.
Anti-angiogenic. In human endothelial cells it reduced migration and tubulogenesis (the cell behaviours that build new blood vessels) and induced apoptosis ^{3Reference 3Palethorpe HM et al. · 2018The aquaporin 1 inhibitor bacopaside II reduces endothelial cell migration and tubulogenesis and induces apoptosisView study →}.
Direct anticancer. In colon-cancer cells it caused cell-cycle arrest and apoptosis, slowing growth in vitro ^{4Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →}.

Bacopaside II vs. Bacopaside I

Bacopaside II is almost always discussed next to bacopaside I, which was isolated and named in the same 2001 paper; both are pseudojujubogenin glycosides, differing in their sugar chain ^{9Reference 9Chakravarty AK et al. · 2001Bacopaside I and II: two pseudojujubogenin glycosides from Bacopa monnieraView study →}. That small structural difference produces two genuinely different pharmacological profiles, which is why the pair is so instructive:

Property	Bacopaside II	Bacopaside I
AQP1 water channel	Blocked, selectively (IC₅₀ ≈ 18 µM)	Blocked (IC₅₀ ≈ 117 µM)
AQP1 ion (cation) channel	Not impaired	Also blocked
AQP4 water channel	Not the focus of these studies	Not altered ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}
Human recombinant MAO-A/B	Not among the active inhibitors	Selective MAO-A inhibitor (IC₅₀ ≈ 17 µg/mL) ^{8Reference 8Singh R et al. · 2014In vitroIn vitro evaluation of Bacopa monniera extract and individual constituents on human recombinant monoamine oxidase enzymesView study →}

The take-home: bacopaside II is the cleaner, more potent, water-channel-selective AQP1 blocker, while bacopaside I is the weaker, less selective AQP1 modulator that carries the monoamine-oxidase activity relevant to mood ^{2,8Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →Reference 8Singh R et al. · 2014In vitroIn vitro evaluation of Bacopa monniera extract and individual constituents on human recombinant monoamine oxidase enzymesView study →}. They are not interchangeable, and reviews that lump them under “bacosides” obscure a real functional split.

What It's Used For

Bacopaside II’s evidence divides into its AQP1-driven oncology preclinical work (the largest and most mechanistically defined body) and its CNS role as a bacoside A component (neuroprotection, antidepressant-like activity). Both are preclinical; the isolate has never been given to humans.

A selective AQP1 water-channel blocker — the marquee mechanism:at low-µM concentrations it shuts the AQP1 water pore without touching its ion conductance, the basis for its anti-migratory, anti-angiogenic and direct anticancer effects in cell models ^{2,3,4Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →Reference 3Palethorpe HM et al. · 2018The aquaporin 1 inhibitor bacopaside II reduces endothelial cell migration and tubulogenesis and induces apoptosisView study →Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →}.

A genuine bacoside A component with CNS activity:among the four bacoside A saponins it was one of the two best neuroprotectants against oxidative stress in neuronal cells, and it shows antidepressant-like activity as an isolate in mice ^{1,6Reference 1Zhou Y et al. · 2007AnimalTriterpene saponins from Bacopa monnieri and their antidepressant effects in two mice modelsView study →Reference 6Bhardwaj P et al. · 2018Comparative evaluation of four triterpenoid glycoside saponins of bacoside A in alleviating sub-cellular oxidative stress of N2a neuroblastoma cellsView study →}.

The honest headline:every result is preclinical (in-vitro / cell-line, µM), there are no human trials of the isolate, and as a large saponin its oral bioavailability is expected to be poor — so the in-vitro concentrations may not be reachable from oral herb intake ^{2,4Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →}.

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. No human isolate data exist, so every score stays modest by design.

The largest and most mechanistically defined signal, and the reason this molecule is studied outside the nootropic context. Bacopaside II selectively blocks the AQP1 water channel (IC₅₀ ≈ 18 µM) without impairing ion conductance ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}, and this translates into function: it impaired migration of AQP1-high HT29 colon-cancer cells (IC₅₀ ≈ 14 µM) but not AQP1-low SW480 cells, a target-dependent result ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →}; as a purified isolate it induced cell-cycle arrest and apoptosis in colon-cancer cells, slowing growth in vitro ^{4Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →}; and combining it with the AQP1 ion-channel blocker AqB011 amplified the block on cancer-cell migration, consistent with the two agents hitting complementary AQP1 functions ^{5Reference 5De Ieso ML et al. · 2019Combined pharmacological administration of AQP1 ion channel blocker AqB011 and water channel blocker bacopaside II amplifies inhibition of colon cancer cell migrationView study →}.

Gap: entirely in-vitro on cell lines at µM concentrations — there is no in-vivo tumour model or human oncology data for the isolate, and the saponin bioavailability caveat applies to any oral route ^{4,5Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →Reference 5De Ieso ML et al. · 2019Combined pharmacological administration of AQP1 ion channel blocker AqB011 and water channel blocker bacopaside II amplifies inhibition of colon cancer cell migrationView study →}.

Mechanisms

Target / pathway	Effect	Relevant to
Aquaporin-1 (AQP1) water channel	selectively blocked (IC₅₀ ≈ 18 µM), ion conductance spared	anticancer / anti-migratory / anti-angiogenic
AQP1-dependent cancer-cell migration (HT29)	inhibited (IC₅₀ ≈ 14 µM), target-dependent	anticancer / anti-migratory
Cell cycle & apoptosis (colon-cancer cells)	arrest + apoptosis induction	anticancer
Endothelial migration & tubulogenesis	reduced + apoptosis	anti-angiogenic
Intracellular ROS / neuronal viability (N2a)	oxidative stress alleviated, viability preserved	neuroprotective / antioxidant
Monoamine oxidase A/B	not inhibited (contrast with bacopaside I)	mood (negative finding)

Pharmacokinetics

No dedicated pharmacokinetic study of isolated bacopaside II has been published, so its human absorption, bioavailability and half-life are not established. What can be said follows from its chemical class: bacopaside II is a large, highly glycosylated triterpenoid saponin, the structural type that characteristically shows poor passive membrane permeability, extensive gut/microbial hydrolysis of the sugar chains, and low oral bioavailability. The practical implication is the standard saponin caveat — the low-µM concentrations that block AQP1 or protect neurons in vitro may not be reached in target tissue after oral intake of Bacopa. Any human exposure is as a minor fraction of a standardised whole-herb extract, not as the purified compound, and those extracts are standardised to total bacosides rather than to bacopaside II. Filling this PK gap is the single most valuable next step for interpreting the in-vitro literature.

Clinical Trials

There are no human trials of isolated bacopaside II. All clinical evidence for Bacopa monnieri is for standardised whole-herb extracts (e.g. CDRI 08, BacoMind), whose cognitive effects cannot be attributed to this single saponin.

Completed	Planned	Terminated	Preclinical
—(none, isolate)	—	—	Substantial(AQP1/anticancer-led, plus CNS component data)

Last checked: July 2026.

Isolate vs. Plant Studies

Bacopaside II sits at an unusual midpoint. Its oncology / AQP1 evidence is genuinely isolate-based — the Adelaide group tested the purified compound in channel-expression and cancer-cell systems, so those mechanistic conclusions are about bacopaside II itself, not a whole extract ^{2,3,4Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →Reference 3Palethorpe HM et al. · 2018The aquaporin 1 inhibitor bacopaside II reduces endothelial cell migration and tubulogenesis and induces apoptosisView study →Reference 4Smith E et al. · 2018In vitroThe purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosisView study →}. Its CNS evidence is mixed: the neuroprotection comparison and the antidepressant screen used the isolated saponin ^{1,6Reference 1Zhou Y et al. · 2007AnimalTriterpene saponins from Bacopa monnieri and their antidepressant effects in two mice modelsView study →Reference 6Bhardwaj P et al. · 2018Comparative evaluation of four triterpenoid glycoside saponins of bacoside A in alleviating sub-cellular oxidative stress of N2a neuroblastoma cellsView study →}, but the human nootropic record belongs entirely to standardised Bacopa extracts, where bacopaside II is one of several active bacosides. Because the human trials use extracts standardised to total bacosides — not to bacopaside II — no clinical benefit can be assigned to this molecule alone. The transferability caveat is therefore the reverse of the usual one: the isolate mechanism is well defined, but whether it operates at achievable human exposures is unknown.

Prevalence in Nature

Bacopaside II is, on current evidence, effectively specific to Bacopa monnieri (Brahmi, water hyssop) and its close relatives in the genus. Within the plant it is a minor, sub-percent constituent of the dried herb, but its importance is out of proportion to its abundance: it is one of the four saponins that constitute bacoside A, the mixture used to standardise Bacopa’s memory extracts ^{7Reference 7Sekhar VC et al. · 2019Insights into the molecular aspects of neuroprotective bacoside A and bacopaside IView study →}. It was first isolated from the whole plant along with the wider family of Bacopa saponins — bacopasides I–III, bacopasaponins and related jujubogenin/pseudojujubogenin glycosides — that make the genus chemically distinctive ^{9,10Reference 9Chakravarty AK et al. · 2001Bacopaside I and II: two pseudojujubogenin glycosides from Bacopa monnieraView study →Reference 10Hou CC et al. · 2002Bacopaside III, bacopasaponin G, and bacopasides A, B, and C from Bacopa monnieraView study →}. Reported content varies severalfold with genotype, growing region and extraction method, which is exactly why commercial products are standardised to total bacosides rather than sold as raw powder.

Discovery & Synthesis

Bacopaside II was first isolated and named in 2001 by A. K. Chakravarty and colleagues at the Indian Institute of Chemical Biology, reported together with bacopaside I as “two pseudojujubogenin glycosides from Bacopa monniera” ^{9Reference 9Chakravarty AK et al. · 2001Bacopaside I and II: two pseudojujubogenin glycosides from Bacopa monnieraView study →}. It arrived amid a burst of early-2000s Bacopa saponin chemistry — the same groups described bacopaside III, bacopasaponin G and bacopasides A–C over the following year ^{10Reference 10Hou CC et al. · 2002Bacopaside III, bacopasaponin G, and bacopasides A, B, and C from Bacopa monnieraView study →} — that mapped out the pseudojujubogenin/jujubogenin glycoside family underlying the herb’s bacoside markers.

No total synthesis of bacopaside II is well documented; its structural complexity (a dammarane triterpene aglycone bearing a multi-sugar, sulfonylated glycoside chain) makes extraction and chromatographic isolation from Bacopa monnieri the only practical source, and research-grade material is obtained that way rather than by synthesis. There is no commercial-scale isolated production — the compound reaches people only inside standardised whole-herb extracts.

Patents: not yet researched.

Toxicity & Safety

Bacopaside II carries a low flag. It is an ordinary dietary constituent of Bacopa monnieri, a nootropic herb with a long record of human use and a good safety profile for its standardised extracts (CDRI 08, BacoMind) at studied doses — and bacopaside II is one of the very bacosides those extracts are standardised on. No isolate-specific toxicity signal has been reported; the entire literature is in-vitro or cell-based, and the anticancer work relies on the compound being cytotoxic to tumour cells, not on any documented harm to the whole organism. Unlike the Bupleurum saponin saikosaponin A (moderate), bacopaside II has no SERCA-inhibition or organ-toxicity finding attached to it.

Safety at a Glance

Low / no toxicity

Dietary constituent of a well-tolerated nootropic herb. Present in standardised Bacopa monnieri extracts with an established human-use safety record.
No isolate-specific toxicity signal reported. All data are preclinical; no organ-toxicity, genotoxicity or reproductive finding is attached to the pure compound.
Saponins are hemolytic at high concentration. A generic class property, not a bacopaside II-specific finding.
Safety context is the whole extract, not the isolate. Bacopa’s known effects (e.g. GI upset, cholinergic effects, thyroid-hormone interaction) belong to the herb and are decided on the herb/product page, not here.

Reproductive and developmental safety has not been characterised for isolated bacopaside II; pregnancy and lactation decisions belong to the Bacopa monnieri herb page and any product page, where intake is actually decided, not to this molecule page. No comprehensive isolate genotoxicity or repeat-dose package is characterised here beyond the general saponin toxicology above — silence is not evidence of safety.

Dosage

There is no established or safe human dose for isolated bacopaside II. Every figure in the literature is a preclinical in-vitro concentration — AQP1 block at ~18 µM, colon-cancer anti-migration at ~14 µM ^{2Reference 2Pei JV et al. · 2016Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieriView study →} — or a cell-assay dose, none of which is a recommendation. Real-world human exposure occurs only as a fraction of standardised Bacopa monnieri extracts (e.g. CDRI 08 / KeenMind, BacoMind), which are dosed to a fixed total-bacoside content, not to bacopaside II specifically; typical research doses of those extracts are 300–450 mg/day. These are research concentrations and extract doses, not a personal recommendation.

References

Zhou Y, et al. (2007). Triterpene saponins from Bacopa monnieri and their antidepressant effects in two mice models. Journal of Natural Products. https://pubmed.ncbi.nlm.nih.gov/17343408/
Pei JV, et al. (2016). Differential inhibition of water and ion channel activities of mammalian aquaporin-1 by two structurally related bacoside compounds derived from the medicinal plant Bacopa monnieri. Molecular Pharmacology. https://pubmed.ncbi.nlm.nih.gov/27474162/
Palethorpe HM, et al. (2018). The aquaporin 1 inhibitor bacopaside II reduces endothelial cell migration and tubulogenesis and induces apoptosis. International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/29495367/
Smith E, et al. (2018). The purified extract from the medicinal plant Bacopa monnieri, bacopaside II, inhibits growth of colon cancer cells in vitro by inducing cell cycle arrest and apoptosis. Cells. https://pubmed.ncbi.nlm.nih.gov/30037060/
De Ieso ML, et al. (2019). Combined pharmacological administration of AQP1 ion channel blocker AqB011 and water channel blocker bacopaside II amplifies inhibition of colon cancer cell migration. Scientific Reports. https://pubmed.ncbi.nlm.nih.gov/31477744/
Bhardwaj P, et al. (2018). Comparative evaluation of four triterpenoid glycoside saponins of bacoside A in alleviating sub-cellular oxidative stress of N2a neuroblastoma cells. Journal of Pharmacy and Pharmacology. https://pubmed.ncbi.nlm.nih.gov/30073654/
Sekhar VC, Viswanathan G, Baby S (2019). Insights into the molecular aspects of neuroprotective bacoside A and bacopaside I. Current Neuropharmacology. https://pubmed.ncbi.nlm.nih.gov/29676230/
Singh R, et al. (2014). In vitro evaluation of Bacopa monniera extract and individual constituents on human recombinant monoamine oxidase enzymes. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/24449518/
Chakravarty AK, et al. (2001). Bacopaside I and II: two pseudojujubogenin glycosides from Bacopa monniera. Phytochemistry. https://pubmed.ncbi.nlm.nih.gov/11576596/
Hou CC, et al. (2002). Bacopaside III, bacopasaponin G, and bacopasides A, B, and C from Bacopa monniera. Journal of Natural Products. https://pubmed.ncbi.nlm.nih.gov/12502309/