Cryptolepine

Cryptolepine at a Glance

Cryptolepine is the principal indoloquinoline alkaloid of Cryptolepis sanguinolenta — the Ghanaian root variously called Ghana quinine, yellow-dye root or nibima and brewed as a traditional water decoction for fever and malaria. It is a flat, aromatic, DNA-binding molecule (5-methyl-5H-indolo[3,2-b]quinoline) and the compound that gives the root much of its deep colour and most of its measured activity ^{1,3Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 3Bierer DE et al. · 1998In vitroEthnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activitiesView study →}.

Its best-studied action is antiplasmodial: cryptolepine kills the malaria parasite in vitro, including chloroquine-resistant strains, and suppresses parasitaemia in infected mice ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}. It does this through a striking double mechanism — it both intercalates into DNA and poisons topoisomerase II (a broadly cytotoxic property) and inhibits beta-haematin/haemozoin formation the way chloroquine does (a malaria-selective property) ^{2,5Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}. The same alkaloid also shows anticancer, antibacterial, anti-inflammatory and antihyperglycaemic activity in preclinical models, and is the antiplasmodial constituent behind wireweed (Sida acuta) as well ^{8,16,18Reference 8Banzouzi JT et al. · 2004In vitroStudies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituentView study →Reference 16Zhang Y et al. · 2021Botanical medicines Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Polygonum cuspidatum, and Alchornea cordifolia demonstrate inhibitory activity against Babesia duncaniView study →Reference 18Kamdoum BC et al. · 2022Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activityView study →}.

The catch is written into the mechanism. The DNA intercalation that makes cryptolepine active also makes the isolated molecule potently cytotoxic and genotoxic in vitro, and teratogenic in zebrafish embryos ^{6,10,15Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →Reference 10Ansah C et al. · 2005In vitroIn vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepineView study →Reference 15Mensah KB et al. · 2019Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryosView study →}. That is why cryptolepine is a genuine antimalarial lead and a rich mechanistic tool, but not a finished, self-dosed medicine — and why it is graded moderate for toxicity.

Traditional & Ethnomedical Use

The one context in which Cryptolepis has real human history is the traditional Ghanaian and West African treatment of malaria and febrile illness: the dried root is decocted in water and drunk, and a standardised tea-bag/aqueous root preparation has been used clinically in Ghana for uncomplicated malaria. That established use, however, belongs to the whole-root decoction, not to isolated cryptolepine — and the traditional preparation is an aqueous one, whereas most of the potency (and most of the toxicity) data below come from ethanol extracts or the purified alkaloid ^{1,6Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}. The mismatch between “what people drink” and “what the lab tests” is the single most important caveat on this molecule.

Cryptolepine vs. Chloroquine

Cryptolepine is often described as a natural, chloroquine-like antimalarial, and the comparison is genuinely informative — but only half-right.

Where it resembles chloroquine. Like chloroquine, cryptolepine accumulates in the parasite’s acidic digestive vacuole and inhibits the formation of beta-haematin (haemozoin, “malaria pigment”) — the crystalline detoxification product the parasite makes from the toxic free haem released as it digests haemoglobin. Blocking that detoxification lets free haem poison the parasite. This beta-haematin inhibition, not DNA binding, is thought to carry the bulk of cryptolepine’s antiplasmodial selectivity, and it is retained against chloroquine-resistant strains ^{1,5Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}.

Where it does not. Chloroquine is (at therapeutic doses) a fairly clean haem-detoxification blocker. Cryptolepine adds a second, non-selective mechanism on top — it intercalates host and parasite DNA and poisons topoisomerase II ^{2Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →}. That extra mechanism widens its activity to cancer cells and bacteria, but it is also why cryptolepine is cytotoxic to mammalian cells at concentrations not far above its antiplasmodial ones, giving it a much narrower therapeutic window than chloroquine ^{4,6Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}. The drug-discovery programmes built on cryptolepine have largely tried to engineer the DNA-intercalation (toxicity) out while keeping the antiplasmodial action in.

Cryptolepine vs. Quindoline

Quindoline is cryptolepine’s des-N-methyl congener — the same indoloquinoline skeleton without the 5-methyl group, and its biosynthetic precursor in the plant. The comparison is a clean natural structure–activity lesson: quindoline is a markedly weaker antiplasmodial than cryptolepine, so the quaternisable 5-methyl indoloquinolinium system of cryptolepine is important for both DNA binding and antiplasmodial potency ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}. Several sibling alkaloids of the same root — neocryptolepine (an indolo[2,3-b] isomer), isocryptolepine and hydroxycryptolepine — repeat the theme: small changes to the ring system or substitution shift the balance between antiplasmodial potency and general cytotoxicity ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}.

What It's Used For

Cryptolepine has an unusually broad preclinical activity profile for a single alkaloid, but the load-bearing discipline is blunt: almost all of it is in-vitro or rodent work on the isolated molecule (or ethanol extracts), the human evidence belongs to the whole-root decoction, and the same DNA intercalation that produces the activity is also the toxicity ^{1,6Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView 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. Human efficacy data are the whole-root preparation, not the isolate, so isolate scores stay preclinical by design.

01Antiplasmodial / AntimalarialPromising58%In-vitro (incl. CQ-resistant) + P. berghei mouse chemosuppression; dual haematin/DNA mechanism ^{1,5,7,8,18Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →Reference 7Karou D et al. · 2003Antimalarial activity of Sida acuta Burm. f. (Malvaceae) and Pterocarpus erinaceus Poir. (Fabaceae)View study →Reference 8Banzouzi JT et al. · 2004In vitroStudies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituentView study →Reference 18Kamdoum BC et al. · 2022Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activityView study →}

02Anticancer / CytotoxicPromising48%Multiple cell lines + mouse xenografts; topoisomerase II, WNT, STAT3, HIF-1, AMPK ^{2,4,9,11,12,14,17,20Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →Reference 9Sawer IK et al. · 2005The killing effect of cryptolepine on Staphylococcus aureusView study →Reference 11Olajide OA et al. · 2009Anti-inflammatory properties of cryptolepineView study →Reference 12Ahmed F et al. · 2011Cryptolepine, isolated from Sida acuta, sensitizes human gastric adenocarcinoma cells to TRAIL-induced apoptosisView study →Reference 14Pal HC et al. · 2017Cryptolepine inhibits melanoma cell growth through coordinated changes in mitochondrial biogenesis, dynamics and metabolic tumor suppressor AMPKα1/2-LKB1View study →Reference 17Domfeh SA et al. · 2021Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signallingView study →Reference 20Quarshie JT et al. · 2023Cryptolepine suppresses colorectal cancer cell proliferation, stemness, and metastatic processes by inhibiting WNT/β-catenin signalingView study →}

03Antibacterial / AntifungalShaky34%In-vitro bactericidal vs S. aureus (membrane + DNA effects) ^{5Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}

04Anti-InflammatoryShaky32%Rodent + in-vitro NF-κB / COX-2 / iNOS / microglia ^{11,13Reference 11Olajide OA et al. · 2009Anti-inflammatory properties of cryptolepineView study →Reference 13Olajide OA et al. · 2013Inhibition of neuroinflammation in LPS-activated microglia by cryptolepineView study →}

05AntihyperglycaemicShaky28%Rodent models; the ethnobotanical antidiabetic lead that first isolated it ^{3Reference 3Bierer DE et al. · 1998In vitroEthnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activitiesView study →}

06Anti-Babesia / AntiprotozoalShaky24%In-vitro vs Babesia duncani (and the whole Cryptolepis extract) ^{16Reference 16Zhang Y et al. · 2021Botanical medicines Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Polygonum cuspidatum, and Alchornea cordifolia demonstrate inhibitory activity against Babesia duncaniView study →}

Mechanisms

The load-bearing point is that DNA intercalation is one property doing several jobs: it underlies the antiplasmodial, anticancer and antibacterial activity and, simultaneously, the genotoxicity. The beta-haematin mechanism is the one action that is malaria-selective rather than generically cytotoxic ^{2,5Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}.

Clinical Trials

There are no controlled clinical trials of isolated cryptolepine. Human experience is with the whole Cryptolepis sanguinolenta root preparation (traditional decoction and a Ghanaian aqueous/tea-bag antimalarial product), not the purified alkaloid; the isolate’s entire evidence base is in-vitro and animal.

Last checked: July 2026.

How Cryptolepine Works

Cryptolepine’s many reported activities collapse onto a small number of physical facts about the molecule: it is flat, aromatic, positively chargeable and DNA-avid, and it concentrates in acidic compartments.

DNA Intercalation

The defining interaction. Cryptolepine’s planar indoloquinoline ring intercalates between DNA base pairs, the property from which nearly everything else follows ^{2Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →}. Intercalation preferentially interferes with DNA synthesis and, in tumour cells, arrests the cycle at G2/M ^{2,4Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →}.

Topoisomerase II Poisoning

On top of simple intercalation, cryptolepine interferes with topoisomerase II — it stabilises the enzyme–DNA “cleavable complex” so that the transient double-strand breaks the enzyme makes are not resealed, converting a housekeeping enzyme into a source of DNA damage ^{2Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →}. This is the classic mechanism of several cytotoxic anticancer drugs, and it is also the basis of cryptolepine’s genotoxicity.

Beta-Haematin / Haemozoin Inhibition

The malaria-selective mechanism. In the Plasmodium digestive vacuole cryptolepine inhibits the crystallisation of toxic free haem into inert haemozoin (beta-haematin) — the same detoxification-blocking strategy as chloroquine — which is thought to carry most of its antiplasmodial selectivity and its activity against chloroquine-resistant parasites ^{5Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}.

Mitochondrial Apoptosis

Downstream of DNA damage, cryptolepine drives intrinsic (mitochondrial) apoptosis: cytochrome-c release and caspase activation, partly independent of the topoisomerase-II effect ^{4Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →}.

Inflammatory Signalling

Separately from its DNA chemistry, cryptolepine suppresses NF-κB-driven transcription and downstream COX-2, iNOS and p38 MAPK signalling, the basis of its anti-inflammatory and anti-neuroinflammatory activity ^{11,13Reference 11Olajide OA et al. · 2009Anti-inflammatory properties of cryptolepineView study →Reference 13Olajide OA et al. · 2013Inhibition of neuroinflammation in LPS-activated microglia by cryptolepineView study →}.

Tumour-Specific Pathways

In particular tumour types cryptolepine additionally hits WNT/β-catenin (colorectal) ^{20Reference 20Quarshie JT et al. · 2023Cryptolepine suppresses colorectal cancer cell proliferation, stemness, and metastatic processes by inhibiting WNT/β-catenin signalingView study →}, IL-6/STAT3 (hepatocellular) ^{17Reference 17Domfeh SA et al. · 2021Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signallingView study →}, HIF-1α-driven glycolysis (breast) ^{19Reference 19Zheng Z et al. · 2022Cryptolepine suppresses breast adenocarcinoma via inhibition of HIF-1 mediated glycolysisView study →} and AMPKα-LKB1 / mitochondrial biogenesis (melanoma) ^{14Reference 14Pal HC et al. · 2017Cryptolepine inhibits melanoma cell growth through coordinated changes in mitochondrial biogenesis, dynamics and metabolic tumor suppressor AMPKα1/2-LKB1View study →}. Whether these are primary actions or downstream consequences of DNA-damage/cell-stress is not always resolved.

A Unifying Interpretation

Almost all of cryptolepine reduces to one sentence: it is a DNA-intercalating, topoisomerase-II-poisoning alkaloid that also happens to block haem detoxification. That single physical description explains the antiplasmodial, anticancer and antibacterial activity, the cell-cycle arrest and apoptosis, and the genotoxicity — they are not separate discoveries but the same molecular property seen against different cells. The one genuinely selective trick is the beta-haematin inhibition, which acts on a target parasites have and human cells do not, and it is therefore the mechanism medicinal chemists have tried to keep while breeding the DNA intercalation (and its toxicity) out of cryptolepine-derived leads ^{2,5Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}. Read this way, the molecule is best understood not as a gentle herbal antimalarial but as a naturally occurring cytotoxic lead whose interest is precisely its potency.

Pharmacokinetics

Human pharmacokinetics for isolated cryptolepine are not established — there are no clinical ADME data, only the animal and in-vitro pharmacology above ^{1,3Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 3Bierer DE et al. · 1998In vitroEthnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activitiesView study →}. Two structural facts shape what is known. First, cryptolepine is a lipophilic, weakly basic alkaloid that becomes protonated and trapped in acidic compartments (the parasite digestive vacuole, lysosomes), which is central to both its haemozoin-inhibiting antimalarial action and its tissue accumulation ^{5Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}. Second, as a DNA-binding intercalator it distributes to nucleic-acid-rich tissue rather than staying free in plasma ^{2Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →}. The practical consequence is a familiar compound-page caveat: potent in-vitro concentrations cannot be assumed to translate to safe, achievable plasma levels, and the isolate’s oral bioavailability, metabolism (CYP involvement), active metabolites and half-life in humans are all uncharacterised — a first-order gap for any therapeutic development.

Isolate vs. Plant Studies

This distinction is unusually consequential for cryptolepine. The efficacy and mechanism literature is overwhelmingly the isolated alkaloid (or ethanol extracts enriched in it): the Cimanga antiplasmodial series ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}, the Bonjean/Dassonneville DNA-intercalation and topoisomerase work ^{2,4Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →}, the Sawer antibacterial study ^{5Reference 5Wright CW et al. · 2001Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agentsView study →}, the multiple anticancer mechanism papers ^{14,17,19,20Reference 14Pal HC et al. · 2017Cryptolepine inhibits melanoma cell growth through coordinated changes in mitochondrial biogenesis, dynamics and metabolic tumor suppressor AMPKα1/2-LKB1View study →Reference 17Domfeh SA et al. · 2021Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signallingView study →Reference 19Zheng Z et al. · 2022Cryptolepine suppresses breast adenocarcinoma via inhibition of HIF-1 mediated glycolysisView study →Reference 20Quarshie JT et al. · 2023Cryptolepine suppresses colorectal cancer cell proliferation, stemness, and metastatic processes by inhibiting WNT/β-catenin signalingView study →} and the genotoxicity/teratogenicity studies ^{10,15Reference 10Ansah C et al. · 2005In vitroIn vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepineView study →Reference 15Mensah KB et al. · 2019Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryosView study →} all test purified cryptolepine or a defined extract. Human use, by contrast, is the whole aqueous root decoction — the traditional Ghanaian antimalarial preparation and its tea-bag product ^{1,6Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}. Two things follow. (1) The whole root is a complex mixture of indoloquinolines (neocryptolepine, isocryptolepine, quindoline and others), so its behaviour cannot be reduced to cryptolepine alone. (2) The aqueous traditional preparation may extract and deliver the alkaloids differently from the ethanol extracts that generate most potency and toxicity data — so both the benefit and the risk numbers should be read as isolate/ethanol figures, flagged as such on every claim ^{6Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}.

Its Role in the Plant

In Cryptolepis sanguinolenta, cryptolepine is the dominant member of a family of indoloquinoline alkaloids and the pigment responsible for much of the root’s colour. Biosynthetically it is an indole-derived alkaloid; quindoline, its des-N-methyl relative, is regarded as a precursor, with N-methylation giving the more DNA-avid, more potent cryptolepine ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}. Ecologically these alkaloids fit the classic profile of antimicrobial/antifeedant chemical defences — the same DNA- and membrane-directed activity that makes the root antibacterial and antiplasmodial in the lab is a plausible deterrent to microbial and herbivore attack in the soil. The alkaloids partition to the root far more than the aerial parts, and their content is strongly cultivation-dependent (accession, planting density and growth duration), so “how much cryptolepine” is as much an agronomy question as a botany one ^{21Reference 21Amissah JN et al. · 2024Increasing the planting density of Cryptolepis sanguinolenta (Lindl.) Schlt increased root biomass and cryptolepine yieldView study →}.

Prevalence in Nature

Cryptolepine is taxonomically narrow compared with a ubiquitous terpene. Its principal source by far is Cryptolepis sanguinolenta (Apocynaceae), the West African root where it is the major alkaloid, reaching up to roughly 2% of dry root weight under favourable, high-density cultivation (a cultivation-dependent maximum, not a typical assay) ^{21Reference 21Amissah JN et al. · 2024Increasing the planting density of Cryptolepis sanguinolenta (Lindl.) Schlt increased root biomass and cryptolepine yieldView study →}. Its only other well-documented plant source is common wireweed (Sida acuta, Malvaceae), where cryptolepine is the differentiating antiplasmodial alkaloid of the aerial parts but occurs only in trace amounts ^{8,16,18Reference 8Banzouzi JT et al. · 2004In vitroStudies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituentView study →Reference 16Zhang Y et al. · 2021Botanical medicines Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Polygonum cuspidatum, and Alchornea cordifolia demonstrate inhibitory activity against Babesia duncaniView study →Reference 18Kamdoum BC et al. · 2022Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activityView study →}.

A discipline note the source material insists on: keep Cryptolepis sanguinolenta (West African) distinct from Cryptolepis buchanani (the Asian species used in Thailand and India), which has a different alkaloid profile — findings should not be merged across the two species.

Major Natural Sources

Source	Family	Plant part	Reported cryptolepine content
Cryptolepis (Cryptolepis sanguinolenta)	Apocynaceae	dried root	up to ~2.08% dry wt (cultivation-dependent) 21Reference 21Amissah JN et al. · 2024Increasing the planting density of Cryptolepis sanguinolenta (Lindl.) Schlt increased root biomass and cryptolepine yieldView study →
Common wireweed (Sida acuta)	Malvaceae	aerial parts	trace (differentiating antiplasmodial alkaloid) 8,18Reference 8Banzouzi JT et al. · 2004In vitroStudies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituentView study →Reference 18Kamdoum BC et al. · 2022Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activityView study →

The root figure is an upper bound recorded at the highest planting density in a controlled agronomy trial, not a typical wild-root value; provenance, cultivation density and growth duration are the main drivers ^{21Reference 21Amissah JN et al. · 2024Increasing the planting density of Cryptolepis sanguinolenta (Lindl.) Schlt increased root biomass and cryptolepine yieldView study →}.

Discovery & Synthesis

Cryptolepine has an unusual place in natural-product history: the compound was known to synthetic chemistry before it was recognised as a natural product, having been prepared in the laboratory in the early 1900s and only subsequently identified as the alkaloid pigment of Cryptolepis root. Its modern re-isolation and characterisation were ethnobotanically driven: working from the plant’s traditional use, Bierer and colleagues isolated cryptolepine from Cryptolepis sanguinolenta, confirmed its structure, synthesised it, and documented its antihyperglycaemic activity in a single 1998 programme ^{3Reference 3Bierer DE et al. · 1998In vitroEthnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activitiesView study →}. That study is also the anchor for its confirmed chemical synthesis. Manufacture today is by chemical synthesis rather than plant extraction for research supply — the indoloquinoline core is synthetically accessible, and a large medicinal-chemistry literature has produced cryptolepine analogues aimed at separating antiplasmodial potency from cytotoxicity ^{1,3Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 3Bierer DE et al. · 1998In vitroEthnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activitiesView study →}.

Patents: not yet researched.

Toxicity & Safety

Cryptolepine carries a moderate flag — heavier than a typical dietary plant constituent — because the isolated alkaloid’s core mechanism is a toxicity mechanism. This is not a molecule with a reassuring safety margin waiting to be quantified; its potency and its hazard are the same property.

Cytotoxicity

The West African antimalarial extract of Cryptolepis sanguinolenta, and cryptolepine as its major alkaloid, are potently cytotoxic to mammalian cells in vitro ^{6Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}. Because the antiplasmodial and cytotoxic concentrations are not widely separated, cryptolepine has a narrow therapeutic window — the central problem every cryptolepine-based drug-discovery effort has tried to solve ^{4,6Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}.

Genotoxicity

As a DNA intercalator and topoisomerase-II poison, cryptolepine is genotoxic in vitro: the alkaloid and the parent herbal extract induce DNA damage (including micronucleus formation) in cultured cells ^{10Reference 10Ansah C et al. · 2005In vitroIn vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepineView study →}. This is the expected, mechanism-based consequence of stabilising topoisomerase-II cleavable complexes ^{2Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →}.

Developmental Toxicity

Cryptolepine — explicitly identified as the main alkaloid of Cryptolepis sanguinolenta — induces malformations in zebrafish embryos, a signal of developmental/teratogenic toxicity for the isolated molecule ^{15Reference 15Mensah KB et al. · 2019Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryosView study →}. Reproductive and developmental safety in mammals is not established.

Whole Root vs. Isolate

The traditional aqueous whole-root decoction has a long ethnomedical history, whereas most of the toxicity data are for the isolated alkaloid or ethanol extracts — so the hazard figures, like the efficacy figures, are isolate/ethanol values and may not map directly onto the traditional water preparation ^{6Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}. “Traditional” does not mean “non-toxic”: the concentrated or purified forms are a different, more hazardous exposure than the brewed root.

Pregnancy/lactation is a per-herb / per-supplement decision and is not adjudicated on this molecule page; note only that isolated cryptolepine is teratogenic in a zebrafish model ^{15Reference 15Mensah KB et al. · 2019Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryosView study →} and that mammalian reproductive data are lacking — any intake decision belongs on the Cryptolepis herb page.

Safety at a Glance

⚠️ Moderate toxicity

• Long ethnomedical history as the whole root. Cryptolepis sanguinolenta root decoction has traditional and clinical use for malaria in Ghana ^{1Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →}.
• The isolated alkaloid is potently cytotoxic and genotoxic. Cryptolepine intercalates DNA and poisons topoisomerase II, damaging DNA — a lead-compound liability, not a supplement safety margin ^{2,6,10Reference 2Bonjean K et al. · 1998The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cellsView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →Reference 10Ansah C et al. · 2005In vitroIn vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepineView study →}.
• Developmental toxicity signal. Cryptolepine induces malformations in zebrafish embryos; mammalian reproductive safety is not established ^{15Reference 15Mensah KB et al. · 2019Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryosView study →}.
• Narrow therapeutic window. Antiplasmodial/anticancer and cytotoxic concentrations are close, so in-vitro potency does not imply a safe achievable dose ^{4,6Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}.
• Isolate/ethanol data ≠ the traditional water decoction. Most potency and toxicity figures come from the purified alkaloid or ethanol extracts, not the aqueous preparation people actually drink ^{6Reference 6Ansah C · 2002The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxicView study →}.

Dosage

There is no established or recommended human dose for isolated cryptolepine, and — given its cytotoxicity and genotoxicity — it is not an appropriate self-dosed supplement. The figures in the research literature are in-vitro concentrations (antiplasmodial and cytotoxic assays in the low-µg/mL to low-µM range) and rodent doses, neither of which converts to human self-dosing ^{1,4,8Reference 1Cimanga K et al. · 1997In vitroIn vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolentaView study →Reference 4Dassonneville L et al. · 2000Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosisView study →Reference 8Banzouzi JT et al. · 2004In vitroStudies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituentView study →}. The only human exposure with any history is the traditional aqueous decoction of the whole Cryptolepis sanguinolenta root, standardised at the level of the plant preparation, not the alkaloid — and any decision about using the herb belongs on the Cryptolepis herb page, not here. These are research figures, not a personal recommendation.

References

1. Cimanga K, et al. (1997). In vitro and in vivo antiplasmodial activity of cryptolepine and related alkaloids from Cryptolepis sanguinolenta. Journal of Natural Products. https://pubmed.ncbi.nlm.nih.gov/9249972/
2. Bonjean K, et al. (1998). The DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cells. Biochemistry. https://pubmed.ncbi.nlm.nih.gov/9548744/
3. Bierer DE, et al. (1998). Ethnobotanical-directed discovery of the antihyperglycemic properties of cryptolepine: its isolation from Cryptolepis sanguinolenta, synthesis, and in vitro and in vivo activities. Journal of Medicinal Chemistry. https://pubmed.ncbi.nlm.nih.gov/9526563/
4. Dassonneville L, et al. (2000). Cytotoxicity and cell cycle effects of the plant alkaloids cryptolepine and neocryptolepine: relation to drug-induced apoptosis. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/11099695/
5. Wright CW, et al. (2001). Synthesis and evaluation of cryptolepine analogues for their potential as new antimalarial agents. Journal of Medicinal Chemistry. https://pubmed.ncbi.nlm.nih.gov/11543688/
6. Ansah C, Gooderham NJ (2002). The popular herbal antimalarial, extract of Cryptolepis sanguinolenta, is potently cytotoxic. Toxicological Sciences. https://pubmed.ncbi.nlm.nih.gov/12441369/
7. Karou D, et al. (2003). Antimalarial activity of Sida acuta Burm. f. (Malvaceae) and Pterocarpus erinaceus Poir. (Fabaceae). Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/14611894/
8. Banzouzi JT, et al. (2004). Studies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituent. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/15185848/
9. Sawer IK, et al. (2005). The killing effect of cryptolepine on Staphylococcus aureus. Letters in Applied Microbiology. https://pubmed.ncbi.nlm.nih.gov/15612998/
10. Ansah C, et al. (2005). In vitro genotoxicity of the West African anti-malarial herbal Cryptolepis sanguinolenta and its major alkaloid cryptolepine. Toxicology. https://pubmed.ncbi.nlm.nih.gov/15664441/
11. Olajide OA, et al. (2009). Anti-inflammatory properties of cryptolepine. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/19288476/
12. Ahmed F, et al. (2011). Cryptolepine, isolated from Sida acuta, sensitizes human gastric adenocarcinoma cells to TRAIL-induced apoptosis. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/20623717/
13. Olajide OA, et al. (2013). Inhibition of neuroinflammation in LPS-activated microglia by cryptolepine. Evidence-Based Complementary and Alternative Medicine. https://pubmed.ncbi.nlm.nih.gov/23737832/
14. Pal HC, et al. (2017). Cryptolepine inhibits melanoma cell growth through coordinated changes in mitochondrial biogenesis, dynamics and metabolic tumor suppressor AMPKα1/2-LKB1. Scientific Reports. https://pubmed.ncbi.nlm.nih.gov/28473727/
15. Mensah KB, et al. (2019). Cryptolepine, the main alkaloid of the antimalarial Cryptolepis sanguinolenta (Lindl.) Schlechter, induces malformations in zebrafish embryos. Biochemistry Research International. https://pubmed.ncbi.nlm.nih.gov/31360547/
16. Zhang Y, et al. (2021). Botanical medicines Cryptolepis sanguinolenta, Artemisia annua, Scutellaria baicalensis, Polygonum cuspidatum, and Alchornea cordifolia demonstrate inhibitory activity against Babesia duncani. Frontiers in Cellular and Infection Microbiology. https://pubmed.ncbi.nlm.nih.gov/33763384/
17. Domfeh SA, et al. (2021). Cryptolepine inhibits hepatocellular carcinoma growth through inhibiting interleukin-6/STAT3 signalling. BMC Complementary Medicine and Therapies. https://pubmed.ncbi.nlm.nih.gov/34078370/
18. Kamdoum BC, et al. (2022). Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activity. Natural Product Research. https://pubmed.ncbi.nlm.nih.gov/34121522/
19. Zheng Z, et al. (2022). Cryptolepine suppresses breast adenocarcinoma via inhibition of HIF-1 mediated glycolysis. Biomedicine & Pharmacotherapy. https://pubmed.ncbi.nlm.nih.gov/35753261/
20. Quarshie JT, et al. (2023). Cryptolepine suppresses colorectal cancer cell proliferation, stemness, and metastatic processes by inhibiting WNT/β-catenin signaling. Pharmaceuticals (Basel). https://pubmed.ncbi.nlm.nih.gov/37513937/
21. Amissah JN, et al. (2024). Increasing the planting density of Cryptolepis sanguinolenta (Lindl.) Schlt increased root biomass and cryptolepine yield. Heliyon. https://pubmed.ncbi.nlm.nih.gov/38770341/

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