Cynanchum

Other Names

AdelostemmaBaekshuohBai weiBaishouwuBaiweiBinhai baishouwuBuckhornsBunburiaCyathellaCynanchi Atrati Radix et RhizomaCynanchi Paniculati Radix et RhizomaCynanchi Stauntonii Rhizoma et RadixCynoctonumDog-strangling vineEnsleniaExostegiaFlanaganiaFolotsiaGilgiaGlossonemaGraphistemmaHolostemmaKarimboleaMahafaliaMastostigmaMellichampiaMetalepisMetaplexisMonostemmaNematurisOdontantheraPaekhasuoPaeksuoPentarrhinumPetalostemmaPlatykelebaProsopostelmaPsanchumPycnoneurumPycnostelmaRaphistemmaRhodostegiellaSarcocyphulaSarcostemmaSchizocoronaSeshagiriaSichuaniaSteinheiliaSwallowwortSymphyoglossumTaishan baishouwuTelminostelmaUrostelmaVincetoxicumXu-Chang-QingZiervoglia徐长卿牛皮消属白薇鹅绒藤属

Synopsis

Cynanchum: A Comprehensive Reference

1. Identity, Taxonomy, and Botanical Overview

Cynanchum L. is a large genus of flowering plants whose taxonomic placement has evolved over time. The Cynanchum genus previously belonged to the family Asclepiadaceae, but is now classified under the family Apocynaceae. The genus comprises more than 200 species distributed worldwide. Plants of this genus are distributed worldwide, including in East Africa, the Mediterranean region, the tropical zone of Europe, and the subtropical and temperate zones of Asia. A total of 53 species and 12 varieties are native to the southwestern region of China. However, only 33 species of the genus Cynanchum have been systematically studied to date.

Cynanchum is one of the most important genera in the Asclepiadaceae family, which has long been known for its therapeutic effects; 16 species in the genus are of high medicinal value. According to available monographs and literature, 17 medicinal plants are formally recognized within the genus Cynanchum. The most pharmacologically studied and medicinally significant species include:

Cynanchum paniculatum (Bunge) Kitag. ex H. Hara — known in Chinese as Xuchangqing; source of the crude drug Cynanchi Paniculati Radix et Rhizoma
Cynanchum atratum Bunge — known as Baiwei; source of Cynanchi Atrati Radix et Rhizoma
Cynanchum wilfordii (Maxim.) Hemsl. — one of three species used as Baishouwu
Cynanchum auriculatum Royle ex Wight — also used as Baishouwu
Cynanchum bungei Decne. — also used as Baishouwu
Cynanchum stauntonii (Decne.) Schltr. ex Lévl. and C. glaucescens — sources of Baiqian
Cynanchum otophyllum C. K. Schneid. — known as Qingyangshen
Cynanchum vincetoxicum (L.) Pers. — also known as white swallowwort; European species

Definitive identification of original plant species is important for standardizing herbal medicine. Although only the dried roots of Cynanchum wilfordii are prescribed as Cynanchi Wilfordii Radix in the Korean Pharmacopoeia, the roots of C. wilfordii and C. auriculatum are often misused in the Korean herbal market due to their morphological similarity and similar name. In general, species in the same genus feature similar morphological characteristics; however, the highly similar morphological features of many Cynanchum species complicate species discrimination in this genus, resulting in herbal medicine confusion.

Common Forms and Preparations

The extracts of the root and/or rhizome parts have been applied in traditional Chinese medicines (TCM) for the prevention and treatment of various illnesses for centuries. In Chinese medical practice, numerous drugs (such as tablets and powders) containing different parts of plants of this genus are used to treat snake bites, bruises, osteoblasts, rheumatoid arthritis and tumors. C. otophyllum can be found in diverse polyherbal preparations used in cosmetic or as food supplement (detox products), and in phyto-preparations claimed to reduce hair loss. Roots and rhizomes of the relevant species are typically prepared as dried whole drug material, decoctions (water-boiled preparations), ethanolic extracts, or powdered drug formulations. Crude drugs of Cynanchi Atrati Radix used in Chinese medicine are generally horse's tail-shaped, 10–15 cm long, with a stout, tubercular rhizome; crude drugs are conventionally prepared as bitter and salty segments, characterized within the parameters of traditional Chinese herbal remedies as being cold in nature and attributive to the stomach and liver channels.

2. Traditional and Historical Use

Traditional Chinese Medicine (TCM)

In China, several species have been used to treat chronic diseases in TCM for thousands of years, and the roots and stems of these species have been used as a component of TCM or in combination with other Chinese medicinal plants. Cynanchum paniculatum has been used as folk medicine by Chinese medicine practitioners for more than two thousand years to treat various inflammatory diseases. The earliest record of Cynanchum paniculatum traces back to Shennong's Materia Medica Classic, which is the oldest Chinese pharmacopeia compiled in the Han Dynasty about 100 AD.

Ever since the first documentation of Xuchangqing as a top-grade medicine in Shennong Materia Medica, Cynanchum paniculatum was frequently cited in many other medical literatures, such as the Supplement to Recipes Worth A Thousand Gold (Tang Dynasty, AD 682), Taiping Holy Prescriptions for Universal Relief (Song Dynasty, AD 992), and Compendium of Materia Medica (Ming Dynasty, AD 1590) for the treatment of wind-damp syndrome, similar to other acute infectious diseases such as tuberculosis, malaria, fevers, acute urinary infection, and abscesses.

The anti-inflammatory property of Cynanchum paniculatum can be traced from its wind-damp removing, collaterals' obstruction relieving, and toxins counteracting effects as folk medicine in CM. Cynanchum paniculatum (also called Xuchangqing in Chinese) is the dried root and rhizome of Cynanchum paniculatum (Bge.) Kitag, commonly used as a type of traditional Chinese medicine (TCM) to treat rheumatic arthralgia, toothache, lumbago, soft tissue injury, rubella, and eczema.

The dried roots and rhizomes of Cynanchum atratum Bunge are named 'Baiwei' according to traditional Chinese medicine theory and are also named Cynanchi Atrati Radix in the Chinese Pharmacopoeia. Cynanchi Atrati Radix is famous for its medicinal value of clearing away heat, relieving drenching, detoxifying, and treating abscesses. It was commonly used in some Asian countries for the treatment of fever, vasoconstrictive syncope, lymphangitis, and other diseases, obviously due to the effect of C21 steroidal glycosides. In traditional Chinese medicine, Cynanchi Atrati Radix is known as a successful remedy for lower asthenic fever; specifically, it is regarded as curative for seasonal febrile disease involving depleted yin levels with prolonged fever or high fever at night subsiding in the morning, infantile summer fever, and postpartum fever.

Bunge Auriculate Root (Baishouwu) is an appellative name for the root tubers of Cynanchum auriculatum, Cynanchum bungei, and Cynanchum wilfordii in China, which is a famous tonic drug in TCM known for its functions in enriching vital essence and enhancing immunity.

Cynanchi Stauntonii Rhizoma et Radix (Baiqian), derived from dried rhizomes and roots of Cynanchum stauntonii or Cynanchum glaucescens, is used for descending Qi, relieving cough, and expelling phlegm. This herb is officially recognized in the 2015 Chinese Pharmacopoeia; its traditional pharmacological effects include antitussive, phlegm elimination, and descending qi.

There is a long history of use of Cynanchum paniculatum in lower back pain, joint pain, and trauma; ancient Chinese documentation in the book of simplified herbs (Jianyicaoyao, Qing Dynasty) specifically stated the major action of Cynanchum paniculatum is for the treatment of trauma and joint pain.

Other Ethnobotanical Traditions

The roots of the plant Cynanchum otophyllum C. K. Schneid (Apocynaceae), known as Qingyangshen in Chinese, are used for a long time as a traditional medicine by different ethnic communities in the Yunnan province (China). Qingyangshen is used essentially to treat epilepsy, rheumatism, and other inflammatory diseases. Traditional Yi herbal medicines are characterized by their numerous quantities of herbaceous plants and their common preparation with alcohol.

Plants belonging to genus Cynanchum have traditionally been used in folk medicine as antifebrile, antitussive, diuretic, expectorant, anticonvulsant, analgesic, and tonic agents. Cynanchum wallichii (Duanjieshen) is used in the famous Chinese prescription "Hulisan" as a primary drug to treat arthrophlogosis and injury from fall or fracture. All parts of Cynanchum chinense (Erongteng) are used to treat colds and chills.

3. Key Chemical Constituents and Classes

More than 440 compounds, including C21 steroids, steroidal saponins, alkaloids, flavonoids, and terpene, have been isolated and identified from Cynanchum plants up to now. At present, more than 400 compounds have been isolated from genus Cynanchum; these compounds include steroids, flavonoids, acetophenones, triterpenoids, alkaloids, phytosterols, polysaccharides, and other compounds.

C21 Steroids (Pregnane Glycosides)

Among these compounds, C21 steroid is the characteristic ingredient. C21 steroids, as the typical constituents of Cynanchum species, possess a variety of structures and pharmacological activities. A total of 172 newly identified C21 steroid compounds have been reviewed in a major study; their in vitro and in vivo pharmacological studies are also reviewed and discussed, focusing on antitumor, antidepressant, antifungal, anti-aging, Na⁺/K⁺-ATPase inhibitory, appetite suppressing and antiviral activities. These glycosides are characterized by a pregnane carbon skeleton with sugar moieties attached, and include named compounds such as cynanosides, wilfosides, otophyllosides, auriculosides, and cynabungosides.

Pregnane glycosides are a class of substances with steroids as the mother nucleus containing a glycosidic bond structure; modern pharmacology has shown that these compounds are a class of compounds with different structures and multiple biological activities. Until 2021, phytochemistry investigations have uncovered 232 compounds isolated from the three Baishouwu species (C. auriculatum, C. bungei, and C. wilfordii), which could be classified into C21-steroids, acetophenones, terpenoids, and alkaloids.

Paeonol and Other Acetophenone Derivatives

The chemical composition of Cynanchum paniculatum is similar to other Asclepiadaceae plants, consisting mostly of phenolic derivatives. Paeonol (C₉H₁₀O₃, CAS Number 552-41-0, PubChem CID 11092) is a phenolic compound that accounts for around 1% of the entire dry Cynanchum paniculatum and is also a major active compound in Xuchangqing. Paeonol (2'-hydroxy-4'-methoxyacetophenone) is the single most studied active compound derived from the genus and is shared with other botanical sources such as Cortex Moutan.

Phenanthroindolizidine Alkaloids

Two known phenanthroindolizidine alkaloids, (−)-(R)-13aα-antofine and (−)-(R)-13aα-6-O-desmethylantofine, and two new natural products, (−)-(R)-13aα-secoantofine and (−)-(R)-13aα-6-O-desmethylsecoantofine, were isolated from Cynanchum vincetoxicum. Antofine and related phenanthroindolizidine alkaloids are distributed across multiple Cynanchum species. Antofine has also been isolated from Cynanchum atratum Bunge, where it displays antifungal activity against Penicillium digitatum.

Other Notable Compound Classes

From Cynanchum acutum, isolation studies have identified six flavonoid compounds including rutin, quercetin-3-O-neohesperidoside, quercetin-3-O-β-galactoside, isoquercitrin, quercetin, and kaempferol 3-O-β-glucoside, in addition to the coumarin scopoletin. Volatile oils, terpenoids, and polysaccharides have also been characterized from diverse species. According to modern phytochemical results, volatile oils have been found to be the primary components in C. paniculatum; other primary chemical components include acetophenone derivatives, terpenes, saturated hydrocarbons, and phenolic compounds.

4. Established and Proposed Mechanisms of Action

Anti-Inflammatory Mechanisms

In rheumatoid arthritis, paeonol possesses protective effects on inflammatory response in IL-1β-induced human fibroblast-like synoviocytes during disease progression via modulating the NF-κB pathway. Furthermore, paeonol, by upregulating forkhead box O3 (FOXO3) through inhibition of miR-155 expression, protects against TNF-α-induced proliferation and cytokine release of rheumatoid arthritis fibroblast-like synoviocytes.

Anticancer and Cytotoxic Mechanisms

C21-steroids were found to exhibit strong anti-tumor activity mainly involving hepatoma, breast cancer, and human glioma; while acetophenones and crude extracts were revealed to exert immunomodulatory, hepatoprotection, anti-inflammatory, and anti-depressant activities. Research into C. paniculatum aqueous extract (CPAE) has explored apoptosis induction through the Caspase-dependent PARP pathway and the inhibition of epithelial-mesenchymal transition (EMT) via the TGF-β1/Smad2/3 pathway.

Na⁺/K⁺-ATPase Inhibition

C21 steroids from Cynanchum species have demonstrated Na⁺/K⁺-ATPase inhibitory activity in in vitro studies, a mechanism shared with cardiac glycosides, and one proposed mechanism by which pregnane glycosides from this genus may exert cardiovascular and appetite-related effects. Their in vitro and in vivo pharmacological studies are reviewed and discussed, focusing specifically on Na⁺/K⁺-ATPase inhibitory, appetite suppressing, and antiviral activities among others.

Anticonvulsant Mechanisms

Studies have shown that three compounds from Cynanchum otophyllum — otophylloside F, otophylloside B, and a rostratamine glycoside — exert significant anticonvulsant effect, while not promoting any neurotoxic or sedative effects or alteration on locomotor activity in a zebrafish larval model. The potential anticonvulsant properties of Otophylloside N, a steroidal glycoside isolated from C. otophyllum, have also been evaluated; this compound reduced fast swimming induced by PTZ exposure in zebrafish larvae, and Otophylloside N attenuated PTZ-induced apoptosis and neuronal activation in zebrafish.

Appetite Suppression

In the search for plant alternatives to Hoodia gordonii containing P57, a pregnane glycoside with potential appetite suppressant effect, the roots of Cynanchum auriculatum were investigated. Pregnane glycosides, present in plants of family Apocynaceae and isolated before from Hoodia gordonii, Caralluma fimbriata, and Cynanchum auriculatum, were previously reported as anti-obesity agents.

Cardiovascular Effects

Paeonol has been shown to downregulate scavenger receptor-A (SR-A) expression, suppress uptake of oxidized LDL by macrophage, and inhibit macrophage-derived foam cell formation, which plays a crucial role in the occurrence and pathogenesis of atherosclerosis. Cynanchum paniculatum has long been used as a medicinal remedy, and supporting documents indicate it can be a promising botanical remedy for cardiovascular diseases.

5. Scientific Evidence by Area of Application

5.1 Inflammation and Rheumatological Conditions

Cynanchum paniculatum Radix, known as Xuchangqing in Chinese, is commonly prescribed in Chinese Medicine for the treatment of various inflammatory diseases. The anti-inflammatory property can be traced from its wind-damp removing, collaterals' obstruction relieving, and toxins counteracting effects as folk medicine. Research has systematically reviewed pharmacological effects of C. paniculatum among a variety of human diseases, including diseases of the respiratory, circulatory, digestive, urogenital, hematopoietic, endocrine and metabolomic, neurological, skeletal, and rheumatological systems and malignant diseases.

A Cynanchum paniculatum-containing herbal capsule, the compound Fengshiding capsule (CFC), which also contains Alangium platanifolium, Angelicae dahurica, and Glycyrrhiza uralensis, has been widely used as a clinical therapy against rheumatoid arthritis. However, current evidence is quite preliminary; the specific link between Cynanchum paniculatum and LDL scavenging still needs to be thoroughly investigated.

Contemporary studies found that paeonol alleviates IL-1β-induced osteoarthritis in vivo and alleviates pain and inflammation in a murine complete Freund's adjuvant-induced arthritis model. Evidence strength: These findings are based on preclinical (in vitro cell culture and rodent) models. Human clinical trial evidence for Cynanchum species as isolated agents in rheumatic diseases is very limited. The Fengshiding capsule is a multi-herb formulation, making attribution of effect to C. paniculatum alone uncertain.

5.2 Anticancer Activity

Crude extracts and compounds have demonstrated significant activity against tumor cells, such as the SMMC-7721, MCF-7, Hela, K562, SHG44, HCT-8, A549, PC3, PLC/PRF/5, KB, T-24, SK-OV-3, SK-MEL-2, HCT-15, Col2, HepG2, and U251 cell lines in vitro.

A compound (215) was isolated from the roots of C. wilfordii and found to completely reverse the multidrug resistance of KB-V1 and MCF7/ADR cells to adriamycin, vinblastine, and colchicine at a concentration level of 1 μM. Compounds 232 and 233 isolated from the roots of C. paniculatum were evaluated against A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines in vitro by using the SRB bioassay; experimental results showed that these compounds have selective cytotoxicity on SK-MEL-2 cells with IC₅₀ values of 26.55 and 17.36 μM, respectively.

Pregnane sapogenins from C. wilfordii revealed significant cytotoxicities on HL-60 (IC₅₀ 6.72 μM) and MCF-7 (IC₅₀ 2.89 μM), and additional compounds also revealed strong inhibitory activities against K-562 (IC₅₀ 6.72 μM) or MCF-7 (IC₅₀ 2.49 μM), respectively.

Although current literature suggests an anticancer progression and metastasis role of Cynanchum paniculatum and its derivatives, no clinical experimental study has been conducted to verify the role of Cynanchum paniculatum either as a single agent or in decoction as complementary and alternative medicine in cancer patients. Evidence strength: All anticancer evidence is preclinical (in vitro cell line data and some animal studies). No human clinical trials have been conducted. This area remains exploratory.

5.3 Neurological and Anticonvulsant Effects

Pharmacological studies have suggested that Bunge Auriculate Root (Baishouwu) exhibits antidepressant and antiepileptic activities, and the root of Cynanchum otophyllum (Qingyangshen) has antifungal and antiepileptic activities. Qingyangshen is used essentially to treat epilepsy, rheumatism, and other inflammatory diseases.

The anticonvulsant investigations of C. otophyllum compounds have been conducted in zebrafish and rodent models using pentylenetetrazol (PTZ)-induced seizure paradigms. A study evaluated 19 compounds from roots of C. otophyllum in the changes in locomotor activity of 6-dpf zebrafish larvae exposed to 10 mM PTZ; results showed that three compounds exerted a significant anticonvulsant effect and did not promote any neurotoxic or sedative effects or alterations on locomotor activity. Evidence strength: Anticonvulsant evidence is restricted to animal and zebrafish models. No controlled human trials have been published.

5.4 Antidepressant Activity

Increased research attention has been focused on C. taiwanianum, C. auriculatum, C. paniculatum, C. otophyllum, and C. stauntonii because of, among other things, their anti-depressant effects in preclinical models. Acetophenone derivatives and C21 steroids from the Baishouwu group (C. auriculatum, C. bungei, C. wilfordii) have shown antidepressant activity in rodent forced swim tests and tail-suspension tests. Evidence strength: Evidence is limited to preclinical animal behavioral models. No published human clinical trials on antidepressant use have been identified.

5.5 Respiratory System: Antitussive and Expectorant Effects

Cynanchi Stauntonii Rhizoma et Radix (Baiqian), derived from dried rhizomes and roots of Cynanchum stauntonii or Cynanchum glaucescens, is used to relieve cough and expel phlegm; its anti-inflammatory, antiviral, and antitussive activities have been reported. Steroidal glycosides contained in C. stauntonii are responsible for various bioactivities; the herb has possessed airway smooth muscle relaxant, analgesic, anti-inflammatory, and anti-thrombotic effects, and induced HepG2 cell apoptosis in model systems. Evidence strength: Primarily pharmacological and preclinical. Use in clinical TCM practice is long-established, but formal randomized controlled trial evidence is not available.

5.6 Appetite Suppression and Metabolic Effects

Increased attention has been focused on certain Cynanchum species because of their anti-tumor, neuroprotective, anti-fungal, parasitic and anti-viral, anti-depressant, anti-oxidant, anti-inflammatory, and immunosuppressive effects. These plants also can suppress appetite, induce weight loss, and expand blood vessels. The appetite-suppressive effect of C. auriculatum pregnane glycosides was investigated in the context of searching for Hoodia-type alternatives. The highest significant inhibitory activity among compounds tested was found for the pregnane glycoside stemmoside C, whereas β-sitosterol showed the weakest activity. Evidence strength: Appetite suppression data comes from preclinical and biochemical studies. No human efficacy data have been published.

5.7 Antiviral Activity

The antiviral effect of Cynanchum paniculatum extract on bovine viral diarrhea (BVD) virus was tested; in the tissue culture infectious dose (TCID₅₀) assay, the BVD virus decreased when treated with ethyl acetate extracts at 18.2 μg/ml, suggesting that ethyl acetate extracts and fractions of C. paniculatum extract could be used as a potential antiviral for BVD. Evidence strength: Limited to in vitro cell culture assay; no human antiviral trial data exist.

5.8 Antifungal Activity

Numerous studies have reported that (−)-antofine, a phenanthroindolizidine alkaloid isolated from roots, fruits, and leaves of swallowwort species, has pronounced antifungal, antibacterial, and antifeedant properties. This compound has especially pronounced antifungal activity, inhibiting the growth of diverse taxa that include yeast-like and filamentous fungi and, notably, broad-host-range plant pathogens. Evidence strength: In vitro antimicrobial assays; no human clinical evidence exists.

5.9 Immunomodulatory Effects

The dry roots of C. auriculatum, C. bungei, and C. wilfordii have been revealed to exhibit immunomodulatory activities, among a range of other biological effects. Baishouwu is a famous tonic drug in TCM known for its functions in enriching vital essence and enhancing immunity. Evidence strength: Immunomodulatory activity is supported by preclinical in vitro and in vivo studies; human evidence is lacking.

5.10 Anti-aging and Hepatoprotective Effects

The traditional use of Baishouwu species for nourishing liver is closely associated with observed hepatoprotective activity in preclinical studies. Various activities of Baishouwu can be attributed to acetophenones and C21-steroids based on available literature. Evidence strength: Preclinical only; no controlled human trials have been identified for these specific endpoints.

6. Body Systems and Health Areas Associated with Cynanchum

Musculoskeletal and rheumatological: Rheumatic arthralgia, joint pain, lower back pain, osteoarthritis, traumatic injury, rheumatoid arthritis
Neurological: Epilepsy/anticonvulsant use, depression, neuroprotection
Respiratory: Cough, phlegm/expectorant, airway smooth muscle relaxation
Cardiovascular and metabolic: Atherosclerosis (preclinical), lipid reduction, appetite suppression, blood vessel dilation
Immunological: Tonic and immune enhancement, immunomodulation
Oncological (preclinical only): Diverse tumor cell lines in vitro; anti-tumor, pro-apoptotic, anti-metastatic
Dermatological: Rubella, eczema, skin infections, itching
Infectious disease: Snake bite treatment, fever, antiviral, antifungal, antibacterial
Hepatic: Hepatoprotection, lipid-lowering effects in preclinical studies
Endocrine and metabolic: Anti-obesity, anti-adipogenic properties (preclinical)

7. Dosage Forms and Reported Dosages

The clinical administration of C. paniculatum to an adult human is suggested to be 3–12 g daily. This range represents the traditionally recommended dose of the crude dried root/rhizome in TCM decoction. No standardized dosage exists for isolated constituents such as paeonol or individual C21 steroids in human use. The potential effect and interaction of Cynanchum paniculatum with chemotherapy, immunotherapy, and target therapy need to be carefully investigated in the future concerning both the efficacy and safety of future clinical applications.

Dosage forms reported across the literature include:

Dried crude root and rhizome (decoction)
Ethanol or aqueous extracts for research use
Volatile oil extraction
Compound herbal formulas (e.g., Fengshiding capsule, containing C. paniculatum as one of several herbs)
Tablets and powders as referenced in Chinese medical practice

For isolated paeonol: LD₅₀ values of paeonol from C. paniculatum were 196 mg/kg (i.v.), 781 mg/kg (i.p.), and 3430 mg/kg (p.o.) in mice. These are animal toxicological reference values and do not represent human therapeutic doses.

8. Safety Considerations

Toxicity Data (Preclinical)

Previous toxicity evaluations of Cynanchum paniculatum (Xuchangqing) revealed an LD₅₀ value of 32.9 ± 1.0 g/kg upon intraperitoneal administration to mice; these findings indicate a favorable safety margin in murine models. Intravenous administration of Xuchangqing at a dose of 5 g/kg in rabbits elicited transient convulsions, followed by complete recovery within 48 h, underscoring a manageable acute toxicity profile at this dose in animal models.

Adulteration and Misidentification

The highly similar morphological features of many Cynanchum species complicate species discrimination in this genus, resulting in herbal medicine confusion. Research using ITS2 barcode technology identified a potential safety problem with Cynanchi Atrati Radix et Rhizoma (Baiwei) samples; by employing the ITS2 barcode, researchers greatly improved the identification efficiency and accuracy of commercial herbal medicines in the Cynanchum genus. The roots of C. wilfordii and C. auriculatum are often misused in the Korean herbal market due to their morphological similarity and similar name.

Alkaloid-Related Toxicity

Phenanthroindolizidine alkaloids including antofine and related compounds isolated from Cynanchum vincetoxicum exhibit potent cytotoxic activity against both drug-sensitive and multidrug-resistant cancer cell lines in vitro. These compounds, while potentially useful as leads for anticancer research, represent a class of phytotoxins present in some Cynanchum species, and their safety profile for human consumption has not been characterized in clinical studies.

Limited Clinical Safety Data

Few reports on the clinical use and toxic effects of Cynanchum sp. are available; further attention should be focused on the study of these species to gather information on their respective toxicology data and relevant quality-control measures and clinical value of the crude extracts, active compounds, and bioactive metabolites from this genus. The proper toxicology evaluation is crucial to guarantee the safety, efficacy, and eligibility for medical use.

Potential for Drug Interactions

Chinese herbs consist of multiple compounds with complex mechanisms of action that may affect multiple targets and pathways in humans. Cynanchum paniculatum is a Chinese herb used to treat venomous snake bites with good clinical efficacy, but its therapeutic mechanism is still not well known; network pharmacology approaches have been applied to screen active compounds and analyze network pathways. The NF-κB pathway modulation, Na⁺/K⁺-ATPase inhibitory activity, and multi-target interactions documented in preclinical work theoretically suggest potential for interactions with drugs affecting these pathways (e.g., cardiac glycosides, immunosuppressants, anti-inflammatory drugs), though specific drug interaction studies in humans are absent from the published literature.

Invasive Species and Ecological Context

Vincetoxicum rossicum (syn. Cynanchum rossicum), the pale swallow-wort, is an herbaceous perennial in the Asclepiadaceae that was introduced into North America from Russia and Ukraine in the late 1800s. That V. rossicum contains potent inhibitors of plant pathogenic fungi, diverse bacteria, and herbivorous insects likely contributes to its success as an invasive species. This species, along with C. nigrum (black swallowwort), contains phytotoxic and cytotoxic alkaloids, reinforcing the distinction between the medicinally valued East Asian Cynanchum species and those that have become problematic invasive plants in North America.

9. Research Gaps and Current Status

In recent years, research reports on the chemical constituents and pharmacological activities of plants of genus Cynanchum have shown an increasing trend, and an increasing number of researchers show special interest in this genus and its therapeutic properties in the field of traditional Chinese medicine. Despite this activity, the overwhelming majority of published evidence for Cynanchum remains at the preclinical level.

However, many Cynanchum species have received little or no attention, and few reports on the clinical use and toxic effects of Cynanchum sp. are available. It is high time that more efforts should be focused on the underlying mechanisms of beneficial bioactivities and the structure-activity relationship of the constituents, as well as their potential synergistic and antagonistic effects. Translation to human clinical trials remains largely absent across all investigated therapeutic areas.

References

Health Conditions

Health conditions that Cynanchum may help support.

No conditions available.

Body Systems

Body systems that Cynanchum may help support.

No body systems available.