Gen info
- Amphineurion is a genus of plants in the family Apocynaceae, first described as a genus in 1948. It contains only one species, Amphineurion marginatum.
- Etymology: The genus name Amphineurion derives from Greek amphi meaning surrounding, and neros meaning water. The specific epithet marginatum means "having a distinct margin", referring to the leaves. (4)

Botany
• Growth form: A woody liana with greenish yellow latex, growing up to 8 m.  Foliage: Leaves are green, margin slightly wavy, leaf blade oblong, measuring up to 12 cm by 4 cm,  with acuminate or caudate apex, base acute to rounded, and has 12 - 15 lateral veins. Leaf blade is hairy on the undersides along the veins. Stems: Stems and branches are dotted with lenticels. Flowers: White to yellow, arranged in clusters called as cymes, axillary located, lobes are very narrowly elliptical. Fruit: Brownish follicles, cylindrical shape. Seeds are oblong in shape and flat. (4)

• Long-Petal Aganosma is shrub-like when young with arching stems, climber when conditions suitable. Showy flowers are borne in lax clusters, at branch-ends and in leaf-axils, hairless to sparsely finely velvet-hairy, 4-20 cm long. Flower are white or yellowish, tube 8-10 mm, densely hairy inside; petals very narrowly elliptic, 1.5-2 cm x 2-3.5 mm. Stamens inserted below middle of flower tube. Sepals are near linear, 5-7 mm, finely velvet-hairy outside. Leaf-stalks are about 1 cm; leaf blade oblong, 4.5-12 x 2-4 cm, below velvet-hairy especially along veins, base pointed to rounded, tip tapering or with a tail; lateral veins 12-15 pairs, elevated below. Seedpods are 2, cylindric, 15-40 x about 1 cm. (Flowers of India)

Distribution
- Native to the Philippines.
- In thickets and secondary forests, chiefly in seasonal areas at low and medium elevation. (2)
- Also native to

Constituents
- In a study of three Thai medicinal plants, A. marginatum showed highest total phenolic content of 106.34 mg GAE/g extract and highest antioxidant capacity against DPPH with IC50 of 11.15 mg/L. (see study below) (5)
- Two unprecedented 10-membered macrocytic dehydropyrrolizidine alkaloids were isolated from the roots. (see study below) (9)

Properties
- Toxicity concern: The presence of the pro-toxic dehydropyrrolizidine alkaloids suggest medical preparations from the plant may pose potential health risk to consumers. (see study below) (9) 
- Studies have suggested antioxidant, antibacterial, anti-inflammatory properties.

Parts used
Stems, roots, leaves.

Uses
Edibility
- In times of famine, including the Khmer Rouge regime years, the people of Cambodia ate young leaves and stems of the climber. ( )
- In northeastern Thailand, young leaves and young shoots eaten as vegetable. (10)
Folkloric
- Used for menstruation problems.
- Root decoction used for urinary disorders and as post-partum remedy.
- Roots and stems used for mental illness and schizophrenia. (4)
- In Cambodian traditional medicine, used by HBV-infected pregnant women at two time points: one month before birth and during early postpartum. (see study below) (6)
- In northeastern Thailand, roots thoroughly rubbed against a stone tool is put on drinking water to increase breast milk postpartum. Boiled stems are eaten to treat hemorrhoids. Crushed leaves are applied to hemorrhoids. (10)
Others
- Agroforestry: Useful for soil stabilization and preventing erosion; facilitates growth of surrounding flora. (3)
- Air cleaning: Known to enhance air quality, acting as a natural filter.

Studies
• Antioxidant: Study evaluated the antioxidant activity of crude extracts of three Thai medicinal plants (Amphineurion marginatum, Caryota maxima, and Markhamia stipulata).and examined cytotoxicity effect on human dermal fibroblast cells. Amphineurion marginatum showed highest total phenolic content of 106.34 mg GAE/g extract and highest antioxidant capacity against DPPH with IC50 of 11.15 mg/L. It also showed highest reducing ferric ability on FRAP assay. On cytotoxicity assay, it showed no cytotoxic effect on human dermal fibroblast cells at concentrations of 62.5 - 1,000 mg/L. (5)
• Use in HBV-Infected Pregnant Patients / Toxicity Study: In Cambodian traditional medicine, used by HBV-infected pregnant women at two time points: one month before birth and during early postpartum. TA PROHM study evaluated the consumption of traditional medicine and acute liver toxicity in 2 groups of HBV-infected pregnant women, with and without postpartum hepatocellular injury. Of 75 women enrolled, 52 (69.3%) used one traditional remedy from 123 different plants and 12 alcoholic maceration of porcupine stomach. Consuming at least one remedy with alcohol was significantly associated with hepatocellular injury (33% vs 13%, p=0.034). Of the 123 plant species identified, four were associated with hepatocellular injury: Amphineurion marginatum, Selaginella tamariscina,  Mitragyna speciosa, and Tetracera indica. Alcohol-based remedies may exacerbate risk of hepatocellular injury in HBV-infected women already exposed to immune restoration. Study suggests further evaluation of complex mixtures of herbs by invitro and invivo studies. (6)
• Antibacterial / Anti-Inflammatory: Study evaluated various extracts of five Thai medicinal plants for antibacterial and anti-inflammatory activities. Antibacterial activity was tested against Vibrio cholera (clinical), S. aureus  ATCC25923, S. epidermidis ATCC12228 and  E. coli  ATCC25922 using agar well diffusion method. Anti-inflammatory activity was evaluated using murine macrophage (RAW264.7) model. GC-MS study of ethanolic and methanolic extracts of A. marginatum revealed dominant components of phenol, 3'-acetyllycopsamine, and lupeol. Results showed A. marginatum extracts exhibited both antibacterial and anti-inflammatory activity, which has potential as supplementary agents in pharmaceutical products. (7)
• Pro-Toxic Dehydropyrrolizidine Alkaloids / Roots: Study of roots isolated two unprecedented 10-membered macrocytic dehydropyrrolizidine alkaloids. The presence of the pro-toxic dehydropyrrolizidine alkaloids suggest medical preparations from the plant may pose potential health risk to consumers. (9)

Availability
• Wild-crafted.
• Seeds in the cybermarket.

Additional Sources and Suggested Readings
(1)
Amphineurion marginatum / KEW: Plants of the World Online
(2)
Amphineurion / Co's Digital Flora of the Philippines
(3)
Amphineurion marginatum / Botanical Realm
(4)
Amphineurion marginatum / National Parks: FLORA & FAUNA WEB
(5)
Antioxidant Activity of Markhamia stipulata, Caryota maxima, Amphineurion marginatum Extracts and Cytotoxicity Effect on Human Dermal Fibroblast Cells / RMUTI Journal, 2019; 12(2): pp 138-148
(6)
Traditional medicine consumption in postpartum for HBV-infected women enrolled in the ANRS 12345 TA PROHM study in Cambodia / Sotheara Moeung, Francois Chassagne, Sophie Goyet, Sovann Nhoeung et al / PLoS One, 2023; 18(8): e0288389 / DOI: 10.1371/journal.pone.0288389
(7)
Antibacterial activity against some human pathogenic bacteria and anti-inflammatory activity of five Thai medicinal plant extracts / Nualyai Yaraksa / Creative Science, 2019; 11(1): pp 1-10 /
(8)
Amphineurion / Wikipedia
(9)
Pro-toxic 1,2-Dehydropyrrolizidine Alkaloid Esters, Including Unprecedented 10-Membered Macrocyclic Diesters, in the Medicinally-used Alafia cf. caudata and Amphineurion marginatum (Apocynaceae: Apocynoideae: Nerieae and Apocyneae) / Steven M Colegate, Dale R Gardner, Michael Boppré et al / Phytochemical Analysis, 2016; 27(5): pp 257-276 / DOI: 10.1002/pca.2624
(10)
Ethnobotanical study and utilization of plants in Khok Nhong Phok forest, Kosum Phisai District, Northeastern Thailand / Narin Saisor, Preecha Prathepha, Surapon Saensouk / BIODIVERSITAS, 2021; 22(10): pp 4336-4348 / pISSN: 1412-033X / eISSN: 2085-4722 / DOI: 10.13057/biodiv/d221026

DOI: It is not uncommon for links on studies/sources to change. Copying and pasting the information on the search window or using the DOI (if available) will often redirect to the new link page. (Citing and Using a (DOI) Digital Object Identifier)