Erythropalum scandens

Erythropalum scandens Blume: A Comprehensive Reference

1. Identity: Botanical Classification, Nomenclature, and Common Forms

1.1 Taxonomic Identity

Erythropalum scandens Blume, 1826, is classified as a eudicot within the order Santalales, family Erythropalaceae, genus Erythropalum (NCBI Taxonomy ID: 350427). Erythropalum is a monotypic genus — that is, a genus containing the single species Erythropalum scandens — currently placed in the Erythropalaceae section of the family Olacaceae. The original species description was published by Carl Ludwig Blume in 1826 in Bijdragen tot de flora van Nederlandsch Indië (Bijdr. Fl. Ned. Ind.: 922). Pharmacognostic analyses have led some modern systematic botanists to conclude that Erythropalum may deserve independent status under the family Erythropalaceae Planchon ex Miq.

1.2 Synonyms

The species carries several botanical synonyms recorded in the GBIF Backbone Taxonomy, including Cocculus calophyllus Wall., Dactylium vagum Griff., Decastrophia inconspicua Griff., Erythropalum grandifolium Elmer, Erythropalum populifolium (Arn.) Mast., Erythropalum vagum (Griff.) Mast., Mackaya populifolia Arn., Modeccopsis vaga Griff., and Passiflora heyneana Wall.

1.3 Common Names

In Vietnam, the plant is known as dây hương or bò khai. In the Kanikkar tribal community of the Western Ghats, Tamil Nadu (India), it is commonly referred to as Vaathavallikodi. The plant is called Chicangteng in Chinese. In English, it is sometimes called the "redstake climber."

1.4 Morphological Description and Native Habitat

E. scandens, the only species in the genus Erythropalum, is a perennial and evergreen liana. The native range of this species spans southern India, the central Himalaya, south to Hainan, and extends through Malesia. It is a liana and grows primarily in the wet tropical biome. It has the function of soil and water conservation, and often grows in limestone mountains and tropical rainforests. It is widely distributed in Southeast Asian countries such as Bangladesh, Brunei, Bhutan, and Cambodia, as well as in the southern Chinese provinces of Guangdong, Guangxi, Guizhou, Hainan, Tibet, and Yunnan.

1.5 Common Forms and Preparations

The plant is used as an edible wild vegetable in tropical and subtropical areas of Southeast Asia; local peoples from Guangxi, Guangdong, Hainan, and southern Yunnan provinces in China have traditionally collected and eaten its young leaves and stems. In Vietnam, E. scandens leaves may be used as a vegetable in some soups and stir-fry dishes.

In research and traditional medicinal contexts, preparations of E. scandens include:

• Decoctions and baths: The chopped tender shoots of Erythropalum scandens are boiled with water, and a bath is taken with the warm water until relief from rheumatic complaints is obtained.
• Oral pastes: Fresh leaf paste prepared from the leaf of Erythropalum scandens is mixed with one teaspoon of honey and given orally twice a day for treating rheumatism by the Kanikkar tribals.
• Ethanol extracts: In laboratory settings, researchers have prepared ethanolic extracts from leaves and stems for pharmacological testing.
• Raw vegetable: The tender leaves and stems have a distinct taste and smell, and due to their high nutritional value and pleasing taste, they are often picked and eaten by farmers.

With its unique flavor, E. scandens is widely introduced and cultivated in Guangxi, China, including about 67 hectares in Daxin County of Chongzuo City and nearly 100 hectares in Nanning Arboretum. It commands a market price ranging from 40 to 100 yuan per kilogram, presenting a promising economic opportunity.

2. Traditional and Historical Use

2.1 India — Kanikkar Tribal Tradition

Known as Vaathavallikodi among the Kanikkar tribals of the Kalakad-Mundanthurai Tiger Reserve (KMTR), Western Ghats, Tamil Nadu, the tender shoots and leaves of this plant are used to treat rheumatic complaints. Two documented preparations exist in the ethnomedicinal record: the external bath decoction and the oral honey paste described above (Section 1.5). The Kanikkar are the predominant tribal community in the Reserve Forest, and among the 50 medicinal plants belonging to 36 families identified from this community, E. scandens has been employed for the treatment of rheumatism.

2.2 China — Zhuang Nationality and Southern Provincial Traditions

The stems and leaves of this plant have been used for centuries by the Zhuang nationality in the region. Traditionally, the rhizome of E. scandens has been employed for its medicinal properties, described in Chinese traditional medicine terms as clearing heat and moisture, expelling wind, and activating blood flow. These properties render it useful for treating conditions such as edema, jaundice, hemiplegia, rheumatic bone pain, and adverse urination.

2.3 Vietnam and Southeast Asia — Food and Medicinal Traditions

Bò khai (Erythropalum scandens), a vegetable native from tropical parts of Asia, is widely mentioned as an important medicinal plant for traditional uses in relief of rheumatic pains. In Vietnam, the plant is valued both for its nutritional properties and its medicinal applications. Communities in Thailand have also recognized the plant among edible indigenous vegetables with antioxidant properties.

2.4 Summary of Traditional Uses Across Cultures

• Rheumatism and joint pain: Documented across Indian tribal tradition (Kanikkar), Chinese Zhuang practice, and Vietnamese folk medicine, via decoctions, baths, and oral preparations.
• Edema: Documented in Chinese traditional medicine (rhizome use, Zhuang nationality).
• Jaundice: Recorded in Chinese traditional medicine applications of the rhizome.
• Hemiplegia and circulatory complaints: Recorded in Chinese traditional medicine as part of the "activating blood flow" indication.
• Food use: Young leaves and stems consumed as a vegetable across China, Vietnam, and Thailand.

3. Key Constituents and Active Compounds

3.1 Root Constituents

The roots contain resins, phenolic, and triterpene medicinal ingredients. The main components of the resin include sumaresinolic acid and coniferyl cinnamate.

3.2 Leaf Constituents — Phytochemical Screening

Preliminary phytochemical screening of ethanol extracts of the leaf powder of E. scandens shows the presence of alkaloids, terpenoids, steroids, carbohydrates, glycosides, and starch. The leaf thus contains key bioactive compound classes including alkaloids, terpenoids, and glycosides. Physicochemical constants such as a total ash value of 6.73% are recorded as critical parameters for assessing drug purity.

3.3 Leaf Constituents — GC-MS Analysis

A 2011 GC-MS study of the ethanol extract of E. scandens leaves identified 41 volatile and semi-volatile compounds. Notably identified components included: tetradecanoic acid (10,13-dimethyl-methyl ester), n-hexadecanoic acid, 9,12,15-octadecatrienoic acid methyl ester (an omega-3 fatty acid ester), and phytol. Among the identified phytochemicals, tetradecanoic acid and n-hexadecanoic acid have the property of antioxidant activity.

3.4 Stem Constituents — Isolation of Secondary Metabolites

Thirteen compounds were successfully isolated and identified from Erythropalum scandens Blume stems via ethanolic extraction. A novel aromatic glycoside (compound 1) was uncovered, not previously reported. Compounds 3–7 and 9–12 were isolated from this specific plant for the initial time. The inhibitory effect on xanthine oxidase (XOD) was examined, and compound 11 demonstrated inhibitory activity with an IC₅₀ of 706.35 ± 18.36 µM. Molecular docking studies showed that the compound binds to the XOD enzyme via hydrogen bonding and hydrophobic interactions.

3.5 Novel Dimeric Phenylpropanoids — Palumoids A and B

In a study published in Chemistry & Biodiversity (2025), E. scandens Blume — widely utilized as both a functional vegetable and herbal medicine in southern China — was found to contain two new phenylpropanoid dimers, designated palumoids A (compound 1) and B (compound 2), with distinct coupling manners. Biologically, these phenylpropanoids showed superior inhibition of interleukin-1β (IL-1β) release in monosodium urate (MSU)-stimulated THP-1 cells compared to the positive control drug colchicine. Notably, palumoid B, featuring a pyran ring linkage between the two phenylpropanoid monomers, exhibited stronger activity than palumoid A. Further mechanistic studies revealed that palumoid B acts as an NLRP3 inflammasome inhibitor by specifically blocking the activation of NLRP3 and interfering with the assembly of the NLRP3 inflammasome complex.

3.6 Flavonoid Biosynthesis — Genomic Perspective

A 2025 chromosome-level genome assembly study (BMC Plant Biology) acknowledged E. scandens as a perennial woody vine with substantial medicinal and edible applications. Through transcriptomic and metabolomic analyses of stems, leaves, and kernels, 34 genes and 12 enzymes were identified as key contributors to flavonoid biosynthesis, predominantly in stems and leaves. This finding explains, at least in part, the rich phenolic content observed in the aerial parts of the plant and provides a genomic foundation for understanding its bioactive compound profile.

3.7 Phenolic Acids Documented in Thai Context

A review of edible indigenous plants from Thailand noted that Erythropalum scandens, among other species from the north of Thailand, recorded antioxidant properties with high caffeic acid, gallic acid, chlorogenic acid (CGA), p-coumaric acid, o-coumaric acid, catechin, ferulic acid, protocatechuic acid (PCA), and quercetin content.

4. Scientific Evidence by Area of Use

4.1 Anti-Inflammatory Activity

Preclinical (Animal) Evidence:

In a study published in the International Journal of PharmTech Research (2011), E. scandens was extracted with ethanol and evaluated for anti-inflammatory activity in rats using a carrageenan-induced paw edema method. The ethanol extract exhibited potent anti-inflammatory activity at a dose of 200 mg/kg, assessed at 3 hours post-administration, compared against the reference standard indomethacin. The observed pharmacological activity was interpreted as providing scientific basis for the folkloric use of the plant in treating acute inflammation.

Evidence strength: Preliminary. This is a single animal study (albino rat model) employing a standard acute inflammation screening assay. No dose-response data across multiple doses, no mechanistic pathway identification, no human data, and no replication in independent laboratories are available for this specific finding.

4.2 Anti-Gouty and Hyperuricemia Activity

In Vitro and Mechanistic Evidence:

Two new phenylpropanoid dimers, palumoids A and B, were identified from E. scandens. These compounds showed superior inhibition of IL-1β release in MSU-stimulated THP-1 cells compared to colchicine. Palumoid B, featuring a pyran ring linkage, exhibited stronger activity and was found to act as an NLRP3 inflammasome inhibitor by specifically blocking NLRP3 activation and interfering with the assembly of the NLRP3 inflammasome complex.

Separately, E. scandens has been shown in experimental research to inhibit xanthine oxidase (XOD) activity, reduce uric acid production, and protect the neovascular endothelium and kidney. A compound isolated from the stems demonstrated XOD inhibitory activity with an IC₅₀ of 706.35 ± 18.36 µM, with molecular docking indicating binding to the XOD active site via hydrogen bonding and hydrophobic interactions. This research implies a possible beneficial role of E. scandens stems in managing hyperuricemia.

Evidence strength: Preliminary in vitro and mechanistic only. The NLRP3 inhibition data from palumoids A and B represents a significant mechanistic insight, as this pathway is well-established in the pathophysiology of gout. However, all current evidence is confined to cell culture systems and enzyme assays. No animal models of gout using E. scandens extracts or isolated compounds, and no human clinical trials, have been published.

4.3 Antioxidant Activity

In vitro studies have demonstrated that extracts of the plant may exhibit free radical scavenging abilities and moderate antimicrobial activity, supporting some of its traditional uses. The presence of phenolic acids including caffeic acid, gallic acid, chlorogenic acid, ferulic acid, and quercetin documented in Thai studies on the plant is consistent with antioxidant potential, as these compound classes are well-established free radical scavengers in the broader phytochemical literature.

Evidence strength: Preliminary. The specific antioxidant studies on E. scandens are limited to in vitro assays; no controlled human trials measuring antioxidant outcomes attributable to this plant have been published.

4.4 Overall State of Clinical Evidence

Despite promising findings in vitro and in preliminary animal models, comprehensive clinical studies in humans are limited. The available scientific literature primarily consists of laboratory and animal studies, which, while encouraging, cannot definitively establish efficacy and safety for specific health conditions. More rigorous clinical research is needed to validate the traditional claims and fully understand the potential health contributions of Erythropalum scandens.

5. Body Systems and Health Areas Associated with Erythropalum scandens

• Musculoskeletal System (Rheumatism, Joint Pain, Gout): Erythropalum scandens is widely mentioned as an important medicinal plant for traditional uses in the relief of rheumatic pains. Scientific research has extended this to potential anti-gouty activity via NLRP3 inflammasome inhibition in cell models.
• Uric Acid Metabolism and Kidney Protection: E. scandens has been shown experimentally to inhibit XOD activity, reduce uric acid production, and protect the neovascular endothelium and kidney.
• Inflammatory Pathways (NLRP3 Inflammasome): The identification of palumoids A and B as NLRP3 inflammasome inhibitors links the plant to a key molecular pathway involved in inflammatory and metabolic diseases, including gout and related conditions.
• Liver and Biliary System: Traditionally, the rhizome has been employed for clearing heat and moisture and for treating conditions such as jaundice.
• Nutritional / General Health (Functional Food): The young stems and leaves are rich in nutrition and have high edible and medicinal value. Flavonoid biosynthesis pathways elucidated via genome analysis confirm the plant's capacity to produce health-relevant secondary metabolites in its edible aerial parts.

6. Dosage Forms and Dosages Reported in Studies

No formal standardized dosage recommendations exist in international pharmacopeias, monographs, or government regulatory body publications for Erythropalum scandens as a dietary supplement or herbal medicine. The following dosages appear in the peer-reviewed research literature and should be understood strictly in their experimental context:

• Ethanol leaf extract (rat, carrageenan paw edema model): The ethanol extract exhibited potent anti-inflammatory activity at a dose of 200 mg/kg, 3 hours after administration, compared with the reference standard indomethacin. This is an animal study dose and has not been extrapolated to human dosing in any published clinical study.
• Traditional oral preparation (Kanikkar tribal practice): Fresh leaf paste from E. scandens is mixed with one teaspoon of honey and given orally twice a day for treating rheumatism. No standardized quantity of leaf paste is specified in the published ethnobotanical record.
• Traditional topical/bath preparation: Chopped tender shoots are boiled with water, and a bath is taken with the warm water until relief from rheumatic complaints. Quantities are not specified in the published record.

No human clinical trial has established a therapeutic dose, dosing frequency, or standardized extract specification for any indication.

7. Genomic and Phytochemical Research Infrastructure

A high-quality genome for E. scandens was constructed in 2025 employing PacBio, Hi-C, and Illumina sequencing technologies. The resultant genome assembly reached an approximate size of 2.03 Gb, featuring a contig N50 of 4.09 Mb, with 11 pseudochromosomes successfully established. Gene structural annotation identified 89.39% repetitive sequences and 23,346 high-quality protein-coding genes within the assembled genome. Comparative genomic analysis revealed that E. scandens shares the closest evolutionary relationship with Santalum album and Malania oleifera, with two whole-genome duplication events estimated to have occurred approximately 18 and 120 million years ago.

This investigation provides a genomic framework for E. scandens, elucidates the biosynthetic mechanisms of flavonoids in stems and leaves and fatty acids in kernels, and offers a theoretical foundation for advancing its medicinal and edible potential.

The complete plastome of E. scandens, characterized previously by PMC-published research, is 156,154 bp in length and contains the typical structure of angiosperm plastomes, including two inverted repeat (IR) regions of 26,394 bp, a large single-copy (LSC) region of 84,799 bp, and a small single-copy (SSC) region of 18,567 bp. The plastome contains 112 genes, consisting of 79 unique protein-coding genes, 29 unique tRNA genes, and four unique rRNA genes.

8. Safety Considerations

Erythropalum scandens has no entry in major international pharmacopeias (European Pharmacopoeia, USP, WHO monographs) and has not been evaluated by regulatory bodies such as the EMA, EFSA, or the NIH Office of Dietary Supplements as a standalone supplement ingredient. The following observations are drawn strictly from the published scientific record:

• Long-term food use in human populations: The plant is used as an edible wild vegetable in tropical and subtropical areas of Southeast Asia, with local peoples from Guangxi, Guangdong, Hainan, and southern Yunnan provinces in China having traditionally collected and eaten its young leaves and stems. This documented history of food consumption suggests a basic baseline of tolerability for the young aerial parts as a food, though this does not constitute a formal safety assessment.
• Absence of clinical toxicology data: Comprehensive clinical studies in humans are limited. The available scientific literature primarily consists of laboratory and animal studies, which cannot definitively establish its efficacy and safety for specific health conditions. No published human safety studies, toxicology trials, or adverse event case reports were identified in the peer-reviewed literature.
• Pharmacognostic standardization status: Since the plant is useful in traditional medicine for the treatment of rheumatism, pharmacognostic authors have noted the importance of standardizing it for use as a drug. The pharmacognostic constants for leaves, diagnostic microscopic features, and numerical standards have been proposed as useful parameters for drug monograph compilation. However, no official pharmacopoeial monograph has been finalized as of the time of writing.
• Alkaloid content: The ethanol extracts of the leaf powder have been shown to contain alkaloids. The identity, concentration, and toxicological significance of specific alkaloids in E. scandens have not been fully characterized in the published record.
• Drug interactions: No published data on herb-drug interactions, contraindications, or specific population warnings (pregnancy, lactation, pediatric use, renal or hepatic impairment) were identified in the peer-reviewed literature for this plant.
• Conservation status: The redstake climber has been declared "Vulnerable" in Singapore, where it is native. Sustainability of wild harvest is therefore a consideration for sourcing practices.

References

• NCBI Taxonomy Browser: Erythropalum scandens (Taxonomy ID: 350427)
• GBIF Backbone Taxonomy: Erythropalum scandens Blume
• Plants of the World Online (Kew Science): Erythropalum scandens Blume
• Wikipedia: Erythropalum
• Wang et al. (2021). Complete plastome sequence of Erythropalum scandens (Erythropalaceae), an edible and medicinally important liana in China. PMC / Mitochondrial DNA Part B.
• Yang T. et al. (2025). Chromosome-level genome assembly provides insights into flavonoid biosynthesis in stems and leaves and fatty acid biosynthesis in kernels of Erythropalum scandens. BMC Plant Biology, 25:1000.
• Pan Q. et al. (2025). Chemical constituents from the stems of Erythropalum scandens. Phytochemistry Letters, 69, 103015.
• Wei et al. (2025). Palumoids A and B, Two New Dimeric Phenylpropanoids With Anti-gouty Activity From Erythropalum scandens Blume. Chemistry & Biodiversity.
• Sutha S. et al. (2014–2015). Pharmacognostical Investigation of Erythropalum scandens BL., Bijdr (Erythropalaceae) – An Ethnomedicinal Plant. IJPPR, Vol-6, Issue 4, 945–952.
• Mohan V.R. et al. (2011). Anti-inflammatory activity of leaf of Erythropalum scandens Bl., Bijdr. against carrageenan induced paw edema. Int. J. PharmTech Res., 3(1): 24–26.
• GC-MS determination of bioactive components of Erythropalum scandens. Journal of Applied Pharmaceutical Science, 01(09): 170–173 (2011).
• Growth, physiological and N, P, K accumulation responses of Erythropalum scandens Bl. seedlings under different substrates. BMC Plant Biology (2024).
• Effects of the nitrate and ammonium ratio on plant characteristics and Erythropalum scandens Bl. substrates. PMC.
• Nutritional values, bioactive compounds, and biological activities of some edible indigenous plants from Thailand: A review. ResearchGate (2025).
• India Biodiversity Portal: Erythropalum scandens Bl.