Vincetoxicum: A Comprehensive Encyclopedic Reference
1. Identity, Taxonomy, and Botanical Description
1.1 Genus and Family
Vincetoxicum is a genus of plants in the family Apocynaceae. Although the species in Vincetoxicum have sometimes been included in Cynanchum, chemical and molecular evidence shows that Vincetoxicum is more closely related to Tylophora, now included in Vincetoxicum. The genus Vincetoxicum, of the family Apocynaceae, comprising over 100 species, has drawn appreciable attention and interest due to its diversity in terms of species richness and potential therapeutic applications.
Vincetoxicum comes from the Latin vinco (to conquer or subdue) + toxicum (poison), for the supposed use of these plants as an antidote for poison. The specific epithet rossicum is a Latinized reference to the presumed origin of V. rossicum in Russia, whereas nigrum is Latin for "black" in reference to the flower color of V. nigrum.
1.2 Taxonomic Complexity and Key Species
These species are assigned to the genus Cynanchum by the USDA (2000), the New York State Museum (Mitchell and Tucker 1997) and some other taxonomists in the United States, while Gleason and Cronquist (1991), Canadian and European workers assign these species to the genus Vincetoxicum. Generic and specific taxonomic considerations are addressed by Sheeley and Raynal (1996), who have used Vincetoxicum.
The medically and pharmacologically most studied species within the genus include:
- Vincetoxicum hirundinaria Medik. (syn. Cynanchum vincetoxicum (L.) Pers.; Vincetoxicum officinale Moench; Asclepias vincetoxicum L.) — the historically central European species, commonly called white swallow-wort.
- Vincetoxicum nigrum (L.) Moench (syn. Cynanchum nigrum (L.) Pers.) — commonly known as black swallow-wort.
- Vincetoxicum rossicum (Kleopow) Barbarich (syn. Cynanchum rossicum) — commonly known as pale swallow-wort or dog-strangling vine.
- Vincetoxicum arnottianum (Wight) Wight — a South Asian species used in traditional medicine.
- Vincetoxicum pumilum Decne. — studied for its alkaloid content and cytotoxic properties.
Among the many synonyms documented for Vincetoxicum hirundinaria alone are: Alexitoxicon officinale St.-Lag.; Alexitoxicon vincetoxicum (L.) H.P.Fuchs; Antitoxicum officinale Pobed.; Asclepias toxicaria Salisb.; Asclepias vincetoxicum L.; Cynanchum kenowiense K.Schum.; Cynanchum vincetoxicum (L.) Pers.; Vincetoxicum officinale Moench; and Vincetoxicum vincetoxicum (L.) H.Karst. This extensive synonymy reflects the historically contested placement of these plants between the genera Asclepias, Cynanchum, and Vincetoxicum.
1.3 Morphology
Vincetoxicum hirundinaria, commonly named white swallow-wort, is a long-lived herbaceous perennial of the genus Vincetoxicum in the family Apocynaceae. The Latin species name hirundinaria (from hirundo, meaning swallow) and the common name white swallow-wort refer to its seedpods, which are reminiscent of a swallow's wing, or tail.
Vincetoxicum hirundinaria can reach a height of 30–70 centimetres. The stem is erect, stout and glabrous. Flowers in whorls form a raceme; they have a diameter of about 1 centimetre. The corolla has five white petals, and the calyx is composed of five fused, sharp-pointed sepals. Leaves are opposite, ovate to lanceolate and short-stalked. Fruits reach a length of about 5 cm and contain many seeds showing a tuft of white hairs.
This species is native to cliffs and slopes, especially in calcareous soils, of continental Eurasia (including some Baltic islands). The Vincetoxicum species can be encountered in several countries including Afghanistan, Belgium, Cambodia, Germany, India, and Japan. Various species of this genus have been found to grow in varied environments, spanning woodlands, desert grasslands, and alpine meadows.
1.4 Common Preparations and Forms
Across different traditions and research contexts, Vincetoxicum has been prepared and used in several forms. Historically the rhizome and root were the parts most employed. Research has focused on analyzing ethanol-based extracts from various anatomical parts of V. hirundinaria, including flowers, leaves, seeds, and seed pods, to assess their phenolic and flavonoid compound levels, antioxidant activities, and cytotoxic profile. In the context of phytochemical research, alkaloids have been isolated from aerial parts of Cynanchum vincetoxicum. In more recent cosmetic and dermatological contexts, the process of creating Vincetoxicum atratum extract involves harvesting the entire plant, followed by drying and grinding it into a fine powder, which is then subjected to a solvent extraction process, typically using water or alcohol, to isolate the beneficial compounds.
2. Traditional and Historical Use
2.1 Etymology and Earliest Records
The genus name Vincetoxicum comes from the Latin verb vinco ("I win") and from toxicum ("poison"), and therefore literally means "wins the poison," with reference to the use of species of this genus as emetics in the treatment of poisonings.
Vincetoxicum hirundinaria is a poisonous plant traditionally used in treating diseases and in magic. The generic name Vincetoxicum, in Latin meaning "conqueror of poison," derives from the traditional use of this plant as an antidote to poisons.
The plant is mentioned by Dioscorides as a traditional plant utilized by Dacians and known as "herb of animals," which it was thought to open any locked door. This reference places the documented history of the plant's use at least as far back as the 1st century CE, when Dioscorides compiled his encyclopedic De materia medica.
2.2 European Folk and Popular Medicine
From an ethnobotanical point of view, Vincetoxicum hirundinaria is a poisonous plant traditionally utilized in the treatment of diseases and in magical practices. In popular medicine it was used as an antidote against snake bites and for its presumed diuretic, depurative and sudorific properties.
Specifically, Vincetoxicum officinale was noted in treatments of "diseases of the pryvytes" (Turner, 1551), which may have included diseases of microbial origin. This early 16th-century English herbalist reference illustrates the plant's integration into Renaissance-era European medical practice.
The genus Vincetoxicum was used, with reference to its emetic properties, in the treatment of poisonings. European herbalists thus employed the plant both as a direct antidote — leveraging its capacity to induce vomiting and thereby expel ingested toxins — and as a treatment for bites from venomous creatures.
2.3 Traditional Use in South and Central Asia
Vincetoxicum arnottianum (Wight) Wight is a perennial undershrub distributed in different areas of Pakistan, covering Swat and Hazara districts of Khyber Pakhtunkhwa and also in Kashmir. It is characterized by purple flowers with bearded corolla and rhomboid corona.
Vincetoxicum arnottianum is locally used for the treatment of injuries, wounds, swelling, and bruising. It has also been reported that urticaria (a skin disease) is treated with juice of V. arnottianum leaves in northern areas of Pakistan.
2.4 Traditional Use in East Asia
In the Chinese folk medicine system, utilization of different parts of V. arnottianum (Wight) Wight and V. mongolicum Maxim., such as leaves, seeds, and rhizomes, have been evidenced in traditional preparations. Historically, Vincetoxicum atratum has been used in traditional medicine, particularly in East Asia, for its purported health benefits.
2.5 Magical and Ritual Dimensions
Beyond strictly medicinal applications, Vincetoxicum hirundinaria is a poisonous plant traditionally utilized in the treatment of diseases and in magical practices. In popular medicine it was used as an antidote against snake bites and for its presumed diuretic, depurative and sudorific properties. The reference in Dioscorides to the plant as known among the Dacians as the "herb of animals" with the belief that it could "open any locked door" reflects the deep integration of the plant into ritual and folk-magical practice in addition to its medicinal roles.
3. Key Constituents and Active Compounds
3.1 Phenanthroindolizidine Alkaloids
Alkaloids play a cardinal role in both human physiology and an organism's natural defense. The majority of Vincetoxicum species encompass phenanthroindolizidine alkaloids, which have been proven to have varied biological activities.
Phenanthroindolizidine alkaloids have a basic skeleton comprising a phenanthrene ring and an indolizidine ring together in a pentacyclic structure.
Alkaloid compounds such as antofine, tylophorine, vincetene, (−)-10β,13aα-14β-hydroxyantofine N-oxide, (−)-10β,13aα-secoantofine N-oxide, (−)-(R)-13aα-6-O-desmethylantofine, (−)-(R)-13aα-secoantofine, (−)-(R)-13aα-6-O-desmethylsecoantofine, and (−)-10β-antofine N-oxide have been evidenced in V. hirundinaria Medik.
Two known phenanthroindolizidine alkaloids, (−)-(R)-13aα-antofine (1) and (−)-(R)-13aα-6-O-desmethylantofine (2), and two new natural products, (−)-(R)-13aα-secoantofine (3) and (−)-(R)-13aα-6-O-desmethylsecoantofine (4), were isolated from Cynanchum vincetoxicum.
Several phenanthroindolizidine alkaloids, including (−)-13a-α-antofine, (−)-10β,13a-α-antofine N-oxide, and (−)-14β-hydroxy-10β,13a-α-antofine N-oxides, were previously identified as major components of V. pumilum.
Antofine, a phenanthroindolizidine alkaloid, is known to be mainly distributed in Asclepiadaceae family plants, such as Vincetoxicum nigrum, Cynanchum vincetoxicum, and C. paniculatum.
3.2 Glycosides (Including Vincetoxin)
All parts of the plant, especially the root, contain glycosides, including a toxic compound vincetoxin, which is also called asclepiadin or cynanchin and may affect kidneys. The rhizome of V. hirundinaria, which is the most thoroughly studied Vincetoxicum species, contains monoamine alkaloid phenylethylenamine, triterpenes, natural rubber, mucus, resins, and acetophenones.
The herb contains mostly glycosides, saponins, and a small amount of volatile oils, whereas the seeds contain vincetoxisterin.
The main chemical compounds present in V. hirundinaria are various glycosides, vincetoxin, vincetoxicosides A and B, and alkaloids, whilst only in the seeds is present a cardiologically active ingredient.
3.3 Flavonoids and Phenolic Compounds
An extensive examination of Vincetoxicum's phytochemical profile provides substantial knowledge on the secondary metabolites that these plants contain, majorly phenanthroindolizidine alkaloids as well as flavonoids and how they contribute to their therapeutic qualities.
Total phenolics and flavonoids were detected within the ranges of 8.26–5.34 mg GAE/g and 5.36–2.40 mg QE/g, respectively, across different plant parts of V. hirundinaria in one comparative study using ethanol-based extracts.
3.4 Triterpenoids and Steroids
Nowak and Kisiel (2000) reported the isolation of the triterpenoid hancokinol from aerial portions of pale swallow-wort (Vincetoxicum rossicum), and determined that this structure possessed antitumor activity.
Glycosides of V. hirundinaria Medik., flavonoid heterosides of V. officinale Moench, heterosides of quercetin from V. officinale, phenanthroindolizidine alkaloids from V. pumilum, and phenanthroindolizidine alkaloids and N-oxide alkaloids from V. hirundinaria Medik. are among the multiple classes of compounds associated with species of the genus Vincetoxicum.
4. Mechanisms of Action
4.1 Inhibition of Protein and Nucleic Acid Synthesis
As noted by Staerk et al. (2005), "it has been shown that the toxicity of phenanthroindolizidine alkaloids is due to inhibition of protein and nucleic acid synthesis." Among the various agents in the methanol extract and the n-hexane/CH₂Cl₂ fractions, it is likely that the alkaloids (−)-13a-α-antofine, (−)-10β,13a-α-antofine N-oxide, and (−)-14β-hydroxy-10β,13a-α-antofine N-oxide were the major components responsible for the effects observed on cell viability in general and apoptosis induction in particular.
4.2 Cell Cycle Arrest
With respect to its mode of action, antofine moderately induced cell cycle arrest at G0/G1 phase and inhibited the expression of cyclin D1, cyclin E, and CDK4. Separately, the effect of Vincetoxicum arnottianum (VSM) is achieved primarily by inducing a G2/M arrest in the cell cycle and the stabilization of the actin stress fibers, leading to reduced cell motility.
4.3 Anti-Angiogenic Signaling
Although antofine, a natural phenanthroindolizidine alkaloid, exerts potential biological activities including anticancer effect and anti-angiogenic activity, the underlying mechanisms were investigated by determining the inhibitory effect of antofine on angiogenesis in cultured mouse embryonic stem (mES)/embryoid body (EB)-derived endothelial cells and vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cells (HUVECs). Research has documented antofine's suppression of angiogenesis via regulation of the AKT/mTOR and AMPK pathways.
4.4 Anti-Inflammatory Signaling
The mechanistic action of Vincetoxicum extracts in animal inflammatory models could be through COX-2, TNF-α, and NF-κB signaling pathway inhibition, boosting of the antioxidant defense system, and modulation of immunological parameters.
In a whole blood assay, Vincetoxicum hirundinaria showed inhibitory or stimulatory activities. In the PBMC assay, the root of Vincetoxicum hirundinaria revealed a distinct inhibitory effect on IL-6 release (IC50 of 3.6 µg/mL).
4.5 Anti-Adipogenic Activity
Anti-adipogenic activity was demonstrated by alkaloids isolated from root extracts of V. mukdenense Kitag. when studied in vitro on preadipocyte 3T3-L1 cells, which resulted in the repression of PPARγ protein as well as inhibition of lipid formation.
4.6 Antimicrobial and Antifeedant Activity via Antofine
Bioassay-guided fractionation identified (−)-antofine as the principal inhibitor of bacteria and fungi in root extracts of V. rossicum. This compound had especially pronounced antifungal activity, inhibiting the growth of diverse taxa including yeast-like and filamentous fungi and, notably, broad-host-range plant pathogens. A second compound, as yet uncharacterized but distinct from (−)-antofine, was detected as having antifeedant activity against a larval hymenopteran, rose sawfly (Allantus cinctus), and toxicity to two larval lepidopterans.
The chemical ecology of V. rossicum is not well characterized, but other species of Vincetoxicum as well as members of the related genus Tylophora are known to produce phenanthroindolizidine alkaloids. These compounds are reported to have pronounced antibiotic activities towards insects, tobacco mosaic virus, and bacteria.
5. Scientific Evidence by Area of Use
5.1 Cytotoxic and Anticancer Activity
Strength of evidence: Preliminary; in vitro and limited in vivo (preclinical) only. No human clinical trials identified.
Some of these agents have been thought responsible for the observed cytotoxic properties. In vitro studies revealed that both phenanthroindolizidine alkaloids and N-oxide alkaloids from V. hirundinaria (Cynanchum vincetoxicum Pers.) were responsible for the cytotoxic effects observed against cancer cells.
Cytotoxic activity of isolated alkaloids from Cynanchum vincetoxicum, and of three other alkaloids previously isolated from Tylophora tanakae — (−)-(R)-13aα-tylophorine, (−)-(R)-13aα-7-O-desmethyltylophorine, and (+)-(S)-13aβ-isotylocrebrine — was assessed in vitro using a drug-sensitive KB-3-1 and a multidrug-resistant KB-V1 cancer cell line.
Antofine derivatives (1 and 2) showed pronounced cytotoxicity against the drug-sensitive cell line (IC50 values about 100 nM), whereas the secoantofine derivative (3) was considerably less active. Cytotoxic activity of the alkaloids was assessed in vitro using both a drug-sensitive KB-3-1 and a multidrug-resistant KB-V1 cancer cell line. The KB-V1 cell line showed a marginal resistance against all alkaloids, demonstrating that these compounds are poor substrates for the P-glycoprotein (P-170) efflux pump.
The studies pertaining to the anticancer properties of the alkaloids revealed that two alkaloids, antofine and dehydroantofine, showed cytotoxic activity against four cancer cell lines: mouse lymphocytic leukemia cell line (L1210), Menogaril-resistant mouse leukemia cells (P388), human lung adenocarcinoma epithelial cell line (A549), and human colon carcinoma cell lines (HCT-8). Antofine was found to be most effective against human lung adenocarcinoma epithelial cell line A549 and human colon carcinoma cell lines HCT-8 at an EC50 concentration of 0.002 and 0.001 µg/ml, respectively.
Antofine, a representative phenanthroindolizidine alkaloid, has been used as a cytotoxicity agent that has low IC50 values in the nanomolar range in multidrug-resistant and drug-sensitive cancer cells. Alkaloids extracted from plants exhibit potential antitumor activity. However, most natural alkaloids are not useful for humans owing to their poor stability and dissolubility, and the potential adverse side effects.
Regarding leukemic cell lines: the inhibition of cell viability by different extracts of V. pumilum was measured in vitro in HL-60 and K562 human leukemic cancer cell lines and in freshly-isolated peripheral blood lymphocytes as a normal cell line. Using resazurin staining, cell viability was measured. In addition, the presence of apoptotic cells was determined using propidium iodide (PI) staining of DNA fragments (sub-G1 peak).
For the South Asian species V. arnottianum: the antitumor evaluation identified the methanolic extract of Vincetoxicum arnottianum as a promising source for exhibiting antitumor activity. Therefore, the indigenous use of the herbal remedies for the treatment of cancer and cancer-related diseases has a scientific basis. This was an in vitro study on human bone and breast cancer cell lines, and no human clinical data are available.
Antofine exhibits profound anti-proliferative activities in a variety of cancer cells. Nonetheless, all of this evidence remains in vitro or preclinical, and no controlled human clinical trials of Vincetoxicum-derived alkaloids as anticancer agents have been identified in the published literature.
5.2 Anti-Inflammatory Activity
Strength of evidence: Preliminary; in vitro and animal studies only. No human clinical trials identified.
Potential in vivo anti-inflammatory activity against carrageenan-, formalin-, and croton oil-induced inflammation (oedema) in rats was disclosed by extracts of V. arnottianum Wight.
Root extracts showed commendable in vitro anti-inflammatory activity when tested using a human mast cell line from female BALB/c mice. In addition, enhanced in vivo anti-inflammatory activity was demonstrated by inhibiting development of atopic dermatitis in 2,4-dinitrochlorobenzene-induced mice.
In the PBMC assay, the root of Vincetoxicum hirundinaria revealed a distinct inhibitory effect on IL-6 release (IC50 of 3.6 µg/mL). IL-6 is a pro-inflammatory cytokine, and inhibition at this concentration level in human peripheral blood cells represents a moderately potent in vitro effect, though this has not been translated to any human clinical investigation.
5.3 Antioxidant Activity
Strength of evidence: Preliminary; in vitro only.
Extracts isolated from Vincetoxicum luteum and Vincetoxicum hirundinaria demonstrated strong antioxidant potential. Research focused on analyzing ethanol-based extracts from various anatomical parts of V. hirundinaria, including flowers, leaves, seeds, and seed pods, to assess their phenolic and flavonoid compound levels and antioxidant activities. Quantitative assessment of total phenolics and flavonoids was carried out using the Folin–Ciocalteu procedure and the AlCl₃ colorimetric assay. For antioxidant activity, the DPPH radical scavenging assay was used. Recent investigations on the stem extracts of V. subramanii (A.N. Henry) Meve & Liede disclosed potential antioxidant activity in vitro.
5.4 Antimicrobial and Antifungal Activity
Strength of evidence: Preliminary; in vitro only. No clinical trials available.
Extracts of Vincetoxicum rossicum were tested for inhibition of bacterial and fungal growth. Bioassay-guided fractionation identified (−)-antofine as the principal inhibitor of bacteria and fungi in root extracts. This compound had especially pronounced antifungal activity, inhibiting the growth of diverse taxa that include yeast-like and filamentous fungi and, notably, broad-host-range plant pathogens.
Numerous authors have reported that (−)-antofine, a phenanthroindolizidine alkaloid isolated from roots, fruits, and leaves of swallowwort species, has pronounced antifungal, antibacterial, and antifeedant properties.
5.5 Anti-Angiogenic Activity
Strength of evidence: Preliminary; in vitro and cell culture only.
Although antofine exhibits antitumor activity against various cancer cells, the anti-angiogenic activity of antofine in endothelial cells has been investigated in vitro. Studies have evaluated the inhibitory effect of antofine on VEGF-induced angiogenesis via the AKT/mTOR and AMPK pathways in mouse embryonic stem cell-derived and human umbilical vein endothelial cells. This mechanism may theoretically reduce tumor vasculature, but no human evidence exists.
5.6 Anti-Adipogenic / Metabolic Activity
Strength of evidence: Very preliminary; single in vitro study.
Anti-adipogenic activity was demonstrated by alkaloids isolated from root extracts of V. mukdenense when studied in vitro on preadipocyte 3T3-L1 cells, which resulted in the repression of PPARγ protein as well as inhibition of lipid formation. This is a single in vitro observation with no follow-up animal or human investigation identified in the published literature.
5.7 Genotoxicity and Mutagenicity (Safety-Relevant Studies)
Strength of evidence: In vitro genotoxicity testing; important for safety characterization.
Genotoxicity of V. luteum and V. hirundinaria extracts, which demonstrated strong antioxidant capacity, was tested using chromosome aberration, sister chromatid exchange (SCE), cytokinesis-block micronucleus, and alkaline single-cell gel electrophoresis (comet) assays in human lymphocytes in vitro and the Ames Salmonella/microsome test. All tested extracts were not mutagenic in S. typhimurium strains TA98 and TA100 with and without metabolic activation and did not induce chromosome aberrations in human lymphocytes in vitro. Extract from G. officinalis was the only one which induced a significant increase in micronuclei, indicating a possible aneugenic effect.
All investigated plant extracts induced DNA damage evaluated by the comet assay, while B. officinalis and V. luteum extracts induced a slight increase in SCE values. The determined variation in response might be due to the plant extract tested and donor susceptibility.
6. Body Systems and Health Areas Associated with Vincetoxicum
- Oncology / Cellular Proliferation: Phenanthroindolizidine alkaloids isolated from many species of Vincetoxicum show promising anti-cancer activity and are a current topic of interest.
- Immune System and Inflammation: Extracts of multiple species, particularly V. hirundinaria and V. arnottianum, have shown inhibitory effects on pro-inflammatory cytokines (including IL-6) and inflammatory enzymes (COX-2, NF-κB) in preclinical models. Alkaloids from Vincetoxicum isolated from the same genus reported in vitro immunomodulatory potential towards Con A lymphoproliferation that resulted by stimulating macrophages and blocking the release of IL-2.
- Renal System (Toxicological Concern): All parts of the plant, especially the root, contain glycosides including the toxic compound vincetoxin, which may affect kidneys.
- Skin and Dermatology: Leaf juice preparations are employed in traditional Pakistani practice for urticaria, and at tested concentrations (0.25–1 mg/mL) no toxic effects were observed on HaCaT (human keratinocyte) cells, indicating the plant's potential for cosmetic, dermatological, and pharmaceutical use.
- Vascular and Angiogenic Systems: Antofine has been investigated as a potential suppressor of VEGF-driven angiogenesis via the AKT/mTOR and AMPK signaling axis in preclinical cell models.
- Metabolic / Adipose Tissue: Alkaloids from V. mukdenense have been studied in vitro for suppression of adipogenesis via PPARγ repression.
- Excretory / Emetic Function (Historical): The traditional use of the plant as an emetic and as a diuretic and depurative positions it historically in the context of excretory system support.
7. Dosage Forms Reported in Studies
No standardized human clinical dosages for Vincetoxicum or its isolated alkaloids have been established in published clinical trials. The following dosage information reflects what has been described in experimental and research contexts only:
- In vitro cytotoxicity (antofine derivatives): Antofine derivatives (−)-10β-antofine N-oxide and (−)-10β,13α-14β-hydroxyantofine N-oxide, isolated from aerial parts of Cynanchum vincetoxicum, showed cytotoxic activity at an IC50 concentration of about 100 nM when tested in vitro against drug-sensitive human KB carcinoma cells (KB-3-1) and a multi-drug-resistant human KB carcinoma cell line (KB-V1).
- In vitro cytotoxicity (antofine, human colon and lung cancer): Antofine was found to be most effective against human lung adenocarcinoma epithelial cell line A549 and human colon carcinoma cell lines HCT-8 at an EC50 concentration of 0.002 and 0.001 µg/ml, respectively.
- In vitro anti-inflammatory (V. hirundinaria root, IL-6 inhibition): The root of Vincetoxicum hirundinaria revealed a distinct inhibitory effect on IL-6 release (IC50 of 3.6 µg/mL).
- In vitro skin safety (V. hirundinaria): In all experiments involving plant extracts and at all tested concentrations (0.25–1 mg/mL), no toxic effects were observed on HaCaT cells.
- Cell incubation time for leukemic cell lines (V. pumilum): Inhibition of cell viability caused by the methanol extract of V. pumilum and its fractions was examined using an alamarBlue® assay. HL-60 and K562 cells were incubated with different concentrations for 48 hours.
No human oral, topical, or parenteral dosing regimens are supported by clinical trial data for any species or preparation of Vincetoxicum as a dietary supplement or therapeutic agent.
8. Safety Considerations
8.1 Plant Toxicity: Vincetoxin
Vincetoxin has an action similar to that of aconitine and causes abundant salivation, vomiting, diarrhea, intestinal pain, cramps, and paralysis.
All parts of Vincetoxicum hirundinaria (Apocynaceae), especially the rhizome, contain vincetoxin (a mixture of steroid glycosides), tylophorine, and amyrin, and are classified as Category II toxins, producing cytotoxic (CT), neurotoxic (NT), and gastrointestinal (GI) effects including salivation, vomiting, diarrhea, convulsions, respiratory arrest, and paralysis of muscles.
All parts of the plant are poisonous, though the species was once used for supposed medicinal virtues.
8.2 Renal Risk
All parts of the plant, especially the root, contain glycosides, including the toxic compound vincetoxin — also called asclepiadin or cynanchin — which may affect kidneys.
8.3 Cardiological Concern
Only in the seeds is present a cardiologically active ingredient. The nature and precise cardiac mechanism of this seed constituent are not fully characterized in the publicly available peer-reviewed literature.
8.4 Genotoxicity Profile
Extracts from Vincetoxicum luteum and Vincetoxicum hirundinaria were not mutagenic in S. typhimurium strains TA98 and TA100 with and without metabolic activation, and did not induce chromosome aberrations in human lymphocytes in vitro. However, all investigated plant extracts induced DNA damage as evaluated by the comet assay. This raises the possibility of DNA strand breakage at higher concentrations, warranting further investigation.
8.5 Stability and Formulation Limitations
Antofine, a representative phenanthroindolizidine alkaloid, has been used as a cytotoxicity agent that has low IC50 values in the nanomolar range. Alkaloids extracted from plants exhibit potential antitumor activity. However, most natural alkaloids are not useful for humans owing to their poor stability and dissolubility, and the potential adverse side effects. This represents a significant barrier to clinical development of Vincetoxicum-derived compounds as human therapeutic agents.
8.6 No Established Safe Dose for Human Use
No regulatory body — including the NIH Office of Dietary Supplements, the European Medicines Agency (EMA), the European Food Safety Authority (EFSA), or WHO — has established a recommended safe dosage or monograph for Vincetoxicum preparations as a human dietary supplement or botanical medicine. The plant is formally classified in toxicological literature as a poisonous plant with documented toxidrome. All pharmacological applications identified in the research literature are at the in vitro or preclinical animal stage.
9. Research Gaps and Future Directions
While providing a thorough summary of what is currently known regarding Vincetoxicum, current studies also identify research gaps that call for future investigations. Further research on the genus ought to concentrate on concluding unsolved taxonomic data, phytochemical explorations, and carrying out more accurate biological and pharmacological research.
The genus Vincetoxicum has significant diversity, ecological flexibility, and possible implication in the fields of botany, pharmacology, and medicine. An apparent understanding of the phylogenetic relationships of genus Vincetoxicum within the Apocynaceae family has illuminated its evolutionary progression. The examination of biologically effective elements of Vincetoxicum species lays the ground plan for additional research and isolation of phytochemical compounds. The genus's pertinence in drug discovery and development of molecular leads has been demonstrated by many known pharmacological actions.
To date, the entirety of the pharmacological evidence for therapeutic uses of Vincetoxicum rests on in vitro cell culture and animal models. Transition to human clinical investigation requires resolution of formulation challenges (stability, bioavailability), definition of safe dose ranges, and formal toxicological evaluation beyond the in vitro genotoxicity studies already conducted.
References
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