Oxystelma (Oxystelma esculentum): A Comprehensive Reference
1. Identity: Botanical Classification, Names, and Forms
1.1 Accepted Scientific Name and Taxonomy
Oxystelma esculentum (L.f.) Sm. is the accepted botanical name of a plant documented across multiple authoritative botanical sources. It belongs to the family Apocynaceae, subfamily Asclepiadoideae, tribe Asclepiadeae, subtribe Asclepiadinae, genus Oxystelma. The World Checklist of Vascular Plants, facilitated by the Royal Botanic Gardens, Kew, reports this name as the accepted name in the genus Oxystelma within the family Apocynaceae.
1.2 Synonymy and Nomenclatural History
The species has accumulated a substantial number of synonyms in its taxonomic history. Notable synonyms include Asclepias rosea Roxburgh (nom. illeg.), Asclepias rosea Kunth, Oxystelma alpini Decne., Oxystelma esculentum R.Br., and Oxystelma esculentum (L.f.) Schult. Further synonyms include Oxystelma wallichii Wight, Periploca esculenta L.f., and Sarcostemma esculentum (L.f.) R.W. Holm. The basionym, Periploca esculenta L.f., was first published in Supplementum Plantarum in 1782.
1.3 Common Names and Vernacular Terms
Oxystelma esculentum R.Br., commonly known as 'Jaldudhi', is one plant that has not been studied sufficiently despite its traditional usage. Additional vernacular names include Uttamaphalini, Dugdhika, Jal-dudhi, "Edible oxystelma," Jian huai teng (Chinese), Dudhilata, Uttama, Dudhani, Yugmaphalottama, Gongamala, Dudhiyalata, Kshirai, Jaldodi, Narot, Kinikinippala, Gharot, Uttamai, and Anarsinge-laharo. In Laos, the plant is known by names meaning "silk," "silk vegetable," and "flower vegetable," derived from the silky hairs on its seeds.
1.4 Plant Description and Morphology
O. esculentum is a twining, herbaceous plant characterized by its slender, green stems that climb and coil around supporting structures. When cut, the vine releases a milky latex that is characteristic of the Apocynaceae family. Its narrow, lance-shaped leaves are opposite and dark green with light green veins. The flowers are grouped in twos or threes, bell-shaped and nodding, with five triangular petals that are white on the outside and veined with purple on the inside. The fruits are elongated follicles containing seeds to which silky hairs adhere.
1.5 Geographic Distribution and Habitat
Oxystelma esculentum is a species of flowering plant native to China, South Asia, Southeast Asia, northeastern Africa, and south-west Asia. The species is widely distributed from southern Asia to northern Africa. It has been established in Iraq and Egypt, and is also found in Pakistan, Sri Lanka, India, Bangladesh, Myanmar, Nepal, and southern China. It is distributed throughout the wild in the plains, on hedges and among bushes, usually near water and lower hills of India, Ceylon, and Java. The plant can be found in wasteland, often at the edge of water or even growing in water. O. esculentum is a perennial twiner growing near waterlogged areas of the Indian subcontinent.
1.6 Common Dosage Forms and Preparations
Fruits and leaves of the plant are used for treating burning urination and as diuretics. Decoction and infusion of the plant are used to treat sore throats, mouth ulcers, chronic fever, dysuria, and gonorrhea, and as hepatoprotective agents and blood purifiers. A decoction of the plant is used as a gargle in aphthous ulcerations of the mouth and in sore throat. The root is considered specific for jaundice, and the milk sap is used as a wash for ulcers. Scientific studies have examined methanolic, ethanolic, ethyl acetate, aqueous, and acetone extracts of various plant parts — primarily leaves, roots, and aerial parts — as experimental preparations. The plant is also edible; its shoots are eaten raw with a spicy sauce in Laos.
The medicinal usage of O. esculentum is reported in the Indian Pharmaceutical Codex and the Chinese, British, and American Pharmacopoeias, as well as in the traditional systems of medicine such as Ayurveda, Unani, and Siddha.
2. Traditional and Historical Use
2.1 Ayurvedic Tradition (Indian Subcontinent)
Oxystelma esculentum (L.f.) Sm., a lesser-known medicinal plant from the family Apocynaceae, holds significant ethnobotanical importance and has been traditionally used in various indigenous medicinal systems for its therapeutic properties. In the Ayurvedic tradition specifically, the plant is used as a diuretic, aphrodisiac, anthelmintic, for bronchitis, and is considered useful for leucoderma; the fruit is regarded as expectorant and anthelmintic; the juice is used for gonorrhea and for muscle pain. Traditional Ayurvedic use focuses on the leaves and young shoots, and sometimes the roots, though rarely the latex.
O. esculentum is a perennial twiner growing near waterlogged areas of the Indian subcontinent. It is traditionally used as a diuretic, galactagogue, anthelmintic, and antiperiodic. It is also used ethnomedicinally in throat infections, skin diseases, and jaundice.
2.2 Uses Across Multiple Traditional Systems
A wide range of species in the Apocynaceae family, including O. esculentum, are valued for their potent medicinal properties and are deeply integrated into traditional healthcare systems like Ayurveda, Siddha, and Unani. The plant is extensively used to treat many ailments such as jaundice, throat infections, skin diseases, muscle pain, gonorrhea, cough, and leucoderma, and has been reported to possess various biological activities including diuretic, laxative, antiulcer, antiseptic, anthelmintic, antiperiodic, and hepatoprotective properties.
2.3 Use in Pakistan and the Middle East
O. esculentum is widely spread in the Balochistan plains, the Indus plains, and the Cholistan Desert of Pakistan. Fruits and leaves of this plant are used for treating burning urination and as diuretics. Decoction and infusion of the plant are used to treat sore throats, mouth ulcers, chronic fever, dysuria, and gonorrhea, and as hepatoprotective agents and blood purifiers.
2.4 Food Use
This vine is edible; its shoots are eaten raw with a spicy sauce in parts of Southeast Asia. It has also been noted that the flowers and fruits can be eaten, though some sources have not confirmed this usage with certainty.
3. Key Phytochemical Constituents
3.1 Signature Compound Classes: Cardenolides and Pregnane Glycosides
O. esculentum is one of the plants known to contain cardenolides and pregnane glycosides, which are major classes of therapeutically important phytoconstituents. These cardenolides and pregnane glycosides are found in very few plants. Phytochemical analysis of O. esculentum has also revealed the presence of pregnane derivatives, triterpenoids, sterols, and flavonoids.
Several specific compounds have been isolated and characterized from different plant parts:
- Two new cardenolide diglycosides, named oxystelmoside and oxystelmine, were isolated from the dried roots of Oxystelma esculentum.
- A novel pregnane ester oligoglycoside named oxysine has been isolated from Oxystelma esculentum and characterized as calogenin-3-O-β-d-oleandropyranosyl(1→4)-O-β-d-thevetopyranosyl(1→4)-O-β-d-Cymaropyranosyl(1→4)-O-β-d-digitoxopyranoside.
- A novel pregnane triglycoside named esculentin has been isolated from Oxystelma esculentum and characterized as sarcogenin-3-O-β-d-thevetopyranosyl(1→4)-O-β-d-cymaropyranosyl(1→4)-O-β-d-oleandro-pyranoside.
- Three new glycosides named alpinoside A, alpinoside B, and alpinoside C were obtained from the chloroform-soluble portion of the methanol extract of the aerial parts of Oxystelma esculentum var. alpini. These glycosides showed positive Liebermann–Burchard and Keller–Kiliani reactions, indicating the presence of steroidal glycosides with 2-deoxy sugars.
- Earlier chemical investigations on the roots of O. esculentum also reported the presence of pregnane oligoglycosides and two cardenolide glycosides.
3.2 Flavonoids
The leaves of O. esculentum contain flavonoids, specifically isovitexin and vitexin-2''-O-beta-D-glucopyranoside. Both young and old stems have been found to contain cardenolides, flavonoids, phenolics, coumarins, steroids, and triterpenoids.
3.3 Phenolic Acids and Other Constituents
HPLC analysis of the crude ethanolic extract of O. esculentum has revealed the presence of chlorogenic acid, gallic acid, 4-hydroxybenzoic acid, ferulic acid, caffeic acid, and coumarin, which are associated with numerous pharmacological activities.
A wide range of phytochemical constituents have been isolated from the plant, including flavonoids, tannins, phytosterols, phenols, glycosides, fatty acids, galacto-glycerolipid, and volatile oil. The plant is a rich source of essential fatty acids such as palmitic acid, oleic acid, linoleic acid, linolenic acid, and stearic acid.
Secondary metabolites including proteins, alkaloids, flavonoids, tannins, carbohydrates, amino acids, phenolic compounds, and glycosides are present in ethyl acetate, ethanol, and acetone extracts of O. esculentum leaves. The highest total phenolic and flavonoid contents were detected in the ethyl acetate extract, followed by ethanol and acetone extracts.
3.4 GC-MS Profiling
Solanesol was identified as a major constituent by GC-MS analysis of the ethanol leaf extract. GC-MS screening of the ethanol leaf extract revealed the presence of 13 phytocompounds, among which 6 compounds possess potential anti-diabetic properties, namely p-Chloroamphetamine, 1-Heptadecanol, Pentadecane, Hexadecanoic acid-2-hydroxy-1-(hydroxymethyl) ethyl ester, Octadecanoic acid-2,3-dihydroxy propyl ester, and Solanesol.
4. Proposed Mechanisms of Action
The mechanistic basis for the observed biological activities of O. esculentum has been investigated primarily through in vitro and in silico methods, rather than established clinical pharmacology. The following proposed mechanisms are derived from preclinical data:
- Anti-inflammatory mechanism: Molecular docking studies have demonstrated high binding energy of the plant's phytocompounds with the lipoxygenase enzyme, which has been used to validate the anti-inflammatory potential of O. esculentum. In vitro anti-inflammatory potential of the ethanolic extract was evaluated by lipoxygenase enzyme inhibition activity and a human red blood cell (HRBC) membrane stability assay.
- Antidiabetic mechanism: Solanesol was identified as the major constituent by GC-MS and its binding affinity was assessed by in silico molecular docking analysis on human pancreatic α-amylase; solanesol showed less binding affinity with the highest docking score than the standard drug acarbose.
- Antioxidant mechanism: Total antioxidant assays have revealed that the ethyl acetate leaf extract of O. esculentum has the efficiency to inhibit oxidative agents.
- Diuretic mechanism: The diuretic activity of the methanol extract of O. esculentum aerial parts was studied in male Wistar albino rats at 5-hour and 24-hour intervals. Animals were divided into five groups: control, urea, furosemide, 200 mg/kg, and 400 mg/kg MEOE. The extract was administered intraperitoneally; urine volume and electrolytes (Na+, K+, Ca2+, Cl−) were measured. Urine output increased significantly in all treatment groups; MEOE increased urine volume and electrolyte balance in a dose-dependent manner. Results indicate that MEOE is an effective hypernatraemic, hyperkalaemic, hypercalcaemic, and hyperchloraemic diuretic, supporting the traditional claim of O. esculentum as a diuretic.
- Pregnane glycoside mechanisms: Pregnanes and pregnane glycosides are well-studied secondary metabolites; many exhibit immunomodulatory, anticancer, antidiabetic, antiarthritic, antiulcer, anti-nociceptive, hypolipidaemic, anti-inflammatory, and antibacterial properties.
5. Scientific Evidence by Area of Use
5.1 Anti-Inflammatory, Analgesic, and Antipyretic Activity
Study type and design: A 2024 study published in Frontiers in Pharmacology (DOI: 10.3389/fphar.2023.1326968) evaluated the anti-inflammatory, analgesic, and antipyretic potential of O. esculentum using different animal models. Phytochemical profiling assessed total phenolic content (TPC) and total flavonoid content (TFC) via HPLC.
Experimental models: The in vitro anti-inflammatory potential was evaluated by lipoxygenase enzyme inhibition and HRBC membrane stability assay. The in vivo anti-inflammatory potential was determined by the carrageenan-induced paw edema test, and analgesic potential by the hot plate test, tail-flick test, formalin-induced analgesia, acetic acid-induced writhing activities, and yeast-induced elevation of body temperature.
Results: Total phenolic content was measured at 212.6 ± 3.18 µg GAE/g and total flavonoid content at 37.6 ± 1.76 µg QE/g. In vitro and in vivo studies of the plant extract exhibited significant anti-inflammatory, analgesic, and antipyretic activities in a dose-dependent manner.
Evidence strength: This evidence is confined to animal and in vitro models. No human clinical trials have been conducted. The findings are preliminary and cannot be extrapolated to clinical practice without further investigation.
5.2 Antidiabetic Activity
Study type and design: In vitro and in silico antidiabetic activity of O. esculentum were studied for the first time in a 2022 publication in the South African Journal of Botany. Leaf extracts were examined for total phenolic content, total flavonoid content, antioxidant, antibacterial, and antidiabetic (in vitro and in silico) activities.
Results: Total antioxidant capacity was evaluated by DPPH, SO, FRAP, MC, and PHM assays, and antibacterial activity was determined by the minimal inhibitory concentration method against 10 pathogenic bacteria. In silico docking against the human pancreatic α-amylase target (a diabetes-relevant enzyme) identified solanesol as a candidate ligand, though its docking score did not exceed that of the reference drug acarbose.
Evidence strength: Evidence is in vitro and in silico only. No animal model studies of blood glucose reduction or insulin secretion with standardized extracts, nor any human trials, have been identified in peer-reviewed literature for this plant's antidiabetic properties as of the available sources.
5.3 Antioxidant Activity
Research has reported that the methanolic extract of O. esculentum showed increased antioxidant activity in a dose-dependent manner, scavenging several free radicals. The HPLC-detected phenolic acids — chlorogenic acid, gallic acid, ferulic acid, and caffeic acid — are known antioxidant compounds. Evidence is limited to in vitro radical scavenging assays (DPPH, FRAP, and related methods); no human clinical studies on antioxidant endpoints have been identified.
5.4 Anticancer / Antitumor Activity
Study type and design: A study published in a peer-reviewed journal investigated the antitumor effect and antioxidant role of the methanol extract of O. esculentum on tumor growth and host survival time in mice bearing Ehrlich's ascites carcinoma (EAC). MEOE was administered at doses of 200 and 400 mg/kg body weight once a day for 9 days after 24 hours of tumor inoculation.
On day 10, the parameters of tumor volume, packed cell volume, and viable and non-viable cell count were assessed. Hematological and liver biochemical parameters, and antioxidant enzymes including lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were also measured.
Cell line study: A separate study investigated the phytochemical profile, cytotoxic effects, and lactogenic activity of O. esculentum. The cytotoxic potential was evaluated against ovarian (OVCAR3), breast (T47D), and cervical (HeLa) cancer cell lines, demonstrating a concentration-dependent increase in cytotoxicity, with T47D cells exhibiting the highest sensitivity (IC50 = 42.82 μg/ml).
Evidence strength: All anticancer evidence is animal-model and in vitro (cell line) based. These are early-phase preclinical findings. No human clinical trials of O. esculentum for cancer treatment have been identified in the available literature.
5.5 Diuretic Activity
Studies on male Wistar albino rats revealed that the methanolic extract of O. esculentum significantly increased urine output and altered electrolyte balance. As described in section 4 above, the preclinical diuretic study showed dose-dependent effects at 200 mg/kg and 400 mg/kg (MEOE) administered intraperitoneally. The results supported the traditional claim, but these findings remain at the animal model stage.
5.6 Hepatoprotective Activity
The methanol extract of O. esculentum exhibited strong anticancer, diuretic, and protective properties against paracetamol-induced hepatotoxicity in preclinical studies. The plant has been reported to exhibit hepatoprotective activity, where its extracts help safeguard liver function by mitigating oxidative damage and improving liver enzyme levels in experimental models. All hepatoprotective evidence is from animal models; no human clinical data are available.
5.7 Antimicrobial Activity
Research found that leaf extracts of O. esculentum effectively inhibited the growth of both gram-positive and gram-negative bacteria, particularly in methanolic and ethyl acetate fractions. The plant is known for its antimicrobial properties, with extracts demonstrating significant activity against various bacterial and fungal pathogens, making it a potential candidate for natural antimicrobial therapies. These findings are from in vitro minimum inhibitory concentration studies and have not progressed to clinical trials.
5.8 Bone Fracture Healing
Study type and design: The bone fracture-healing properties of a flavonoid-enriched fraction of O. esculentum (designated Oxy50-60F) were investigated in Swiss mice using a drill-hole injury model. Oxy50-60F was administered orally at 1 mg/kg/day, 5 mg/kg/day, and 10 mg/kg/day after a 0.6 mm drill-hole injury in mice femur mid-diaphysis for 7 and 14 days. Parathyroid hormone (40 μg/kg, 5 times/week) was given subcutaneously as the positive control. Confocal imaging for bone regeneration, micro-architecture of femur bones, ex vivo mineralisation, haematoxylin and eosin staining, measurement of reactive oxygen species, and gene expression of osteogenic and anti-inflammatory genes were studied.
Evidence strength: Preliminary animal study only. This area of investigation is at an early stage and requires substantial further research before clinical relevance can be assessed.
5.9 Lactogenic / Galactagogue Activity
O. esculentum is traditionally used as a galactagogue. A preprint study (not yet peer-reviewed at the time of search) examined this property experimentally: in vivo studies highlighted the extract's ability to enhance milk yield and pup growth in lactating rats, correlating with increased prolactin levels. However, specific scientific studies on O. esculentum as a galactagogue are scarce in the literature, and the plant's traditional uses for various health conditions only indirectly suggest its potential in supporting lactation.
6. Body Systems and Health Areas Associated with Oxystelma
- Renal / Urinary System: Diuretic activity — traditional use for dysuria, burning urination, gonorrhea; supported by animal studies.
- Hepatic / Liver System: Hepatoprotective effects against chemically induced liver damage in animal models; traditional use for jaundice.
- Musculoskeletal System: Bone fracture healing investigated in mouse models; folk use for muscle pain.
- Immune / Oncological: Anticancer activity against EAC and cancer cell lines (OVCAR3, T47D, HeLa) in preclinical research; no clinical translation.
- Anti-infective: Antimicrobial in vitro activity against bacterial and fungal pathogens; traditional use for throat infections, gonorrhea, skin diseases.
- Anti-inflammatory / Pain: In vivo analgesic, antipyretic, and anti-inflammatory activity in rodent models; traditional use for fever, pain.
- Endocrine / Reproductive: Galactagogue (lactation support) in animal models; traditional use as aphrodisiac and emmenagogue.
- Metabolic / Glycaemic: In vitro and in silico antidiabetic activity; no clinical data.
- Dermatological: Traditional use for skin diseases and leucoderma; no systematic clinical evidence.
- Respiratory: Traditional Ayurvedic use for bronchitis and as an expectorant.
7. Dosage Forms and Doses Reported in Studies
There are no established human clinical dosages for O. esculentum. The following dosages have been reported in preclinical (animal) studies only, exactly as stated in the source literature:
- Anticancer (mice, Ehrlich's ascites carcinoma): MEOE was administered at doses of 200 and 400 mg/kg body weight once a day for 9 days after 24 hours of tumor inoculation.
- Diuretic (rats): Animals were divided into 5 groups: control, urea, furosemide, 200 mg/kg, and 400 mg/kg MEOE.
- Bone fracture healing (mice): Oxy50-60F was administered orally at 1 mg/kg/day, 5 mg/kg/day, and 10 mg/kg/day after a 0.6 mm drill-hole injury for 7 and 14 days.
The preclinical dosage range employed across studies generally falls between 200–400 mg/kg body weight for crude extracts in rodent models. These figures cannot be directly translated into human dosage recommendations.
8. Safety Considerations
8.1 Toxicological Evidence
A brine shrimp lethality assay performed on O. esculentum extract indicated low toxicity. Formal systematic toxicology studies — including subchronic, chronic, reproductive, or genotoxicity studies — have not been identified for O. esculentum in the available peer-reviewed literature. The study of this plant is recognized as important for future bioactivity-guided fractionation of medicinal phytoconstituents, and for conducting pre-clinical or clinical trials.
8.2 Cardenolide Content and Potential Cardiac Considerations
O. esculentum is one of the plants known to contain cardenolides and pregnane glycosides, which are major classes of therapeutically important phytoconstituents. Cardenolides — the compound class that includes cardiac glycosides like those found in digitalis — are biologically active at low concentrations and are associated with potent cardiovascular effects. While no formal clinical toxicity reports specific to O. esculentum have been identified in this review, the known pharmacology of cardenolides as a class is relevant to safety assessment, particularly for individuals with pre-existing cardiac conditions or those taking other cardiac medications.
8.3 Absence of Clinical Safety Data
No completed human clinical safety trials for O. esculentum as a supplement or herbal preparation have been identified. The study of this plant is recognized as important for future bioactivity-guided fractionation, pre-clinical or clinical trials, and the preparation of formulations or semi-synthetic compounds. The absence of human safety data is a significant limitation. The current body of evidence does not provide a basis for establishing safe upper limits of intake in humans.
8.4 Evidence Gaps and Research Status
While findings from phytochemical investigations are promising, more comprehensive studies are needed to fully understand the mechanisms of action and potential applications of these phytochemicals in human health. Future research on this plant will benefit bioactivity-guided fractionation of medicinal phytoconstituents, pre-clinical or clinical trials, and the production of formulations or semi-synthetic molecules.
9. Overall Evidence Assessment
The scientific evidence base for Oxystelma esculentum as a dietary supplement or therapeutic agent remains at an early, predominantly preclinical stage. It is a lesser-known medicinal plant that holds significant ethnobotanical importance and has been traditionally used in various indigenous medicinal systems for its therapeutic properties. Laboratory investigations — in vitro cell assays, animal models, and in silico docking studies — have generated a body of preliminary data suggesting anti-inflammatory, antioxidant, diuretic, antimicrobial, anticancer, hepatoprotective, and galactagogue activities. However, the translation of these findings to human health applications requires systematic pharmacokinetic studies, dose-ranging trials, and randomised controlled clinical trials, none of which have been published as peer-reviewed literature identified in this review. Claims about clinical efficacy in humans cannot currently be substantiated by the available evidence.
References
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