Gen info
- Hygrophila, common known as swampweeds, is  genus of flowering plants in the acanthus family, Acanthaceae. It consists of 80 to 100 species, many of which are aquatic plants. It is one of only two genera in its family that contains aquatic plants, the other being Justicia. (2)
- Etymology: The genus name Hydrophila derives from Greek words hygro meaning "moist", and phila meaning "love", referring to the plants affinity for moist soil. The specific epithet ringens means "open-mouthed" or "gaping", referring to the shape and characteristic of the flower.

Botany
• Perennials to 80 cm tall, branched. Stems erect or decumbent at base, 4-angled, striate, slightly pubescent. Petiole 0.5-1 cm, glabrous; leaf blade narrowly lanceolate to oblanceolate, 3-10 × 0.5-1.5 cm, both surfaces with numerous cystoliths and glabrous or slightly pubescent, secondary veins 8-11 on each side of midvein, base attenuate and decurrent onto petiole, margin entire or slightly undulate, apex acute to obtuse. Flowers (solitary or)2-10 clustered in leaf axils, sessile; bracteoles narrowly ovate, 3-5 mm, margin pubescent, apex obtuse. Calyx narrowly campanulate, ca. 6 cm, 5-lobed to middle; lobes linear-lanceolate, grayish pubescent or fulvous strigose, apex acuminate. Corolla pale purple, 1-2.5 cm; tube ca. 7 mm, ca. 2 mm wide, glabrous; limb 2-liped; lower lip obovate, ca. 3 mm, 3-lobed to middle, lobes ovate with an obtuse apex; upper lip elliptic, ca. 3 mm, shallowly 2-lobed, outside puberulent. Stamens 4, included; filaments glabrous, longer pair ca. 5 mm, shorter pair ca. 3 mm; anther thecae 1-2 mm. Ovary glabrous; style filiform, ca. 8 mm, included; stigma unequally 2-lobed. Capsule narrowly oblong, 0.8-2.2 cm, ca. 1.5 mm wide, glabrous, 12-18-seeded. Seeds ca. 1 mm, pubescent. (Flora of China)

Distribution
- Native to the Philippines.
- Also native to Andaman Is., Assam, Bangladesh, Borneo, Cambodia, China South-Central, China Southeast, East Himalaya, Hainan, India, Japan, Korea, Laos, Malaya, Maldives, Myanmar, Nansei-shoto, Nepal, Nicobar Is., Pakistan, Sri Lanka, Taiwan, Thailand, Vietnam, West Himalaya. (1)

Constituents
- No studies found on phytoconstituents.

Properties
- Studies have suggested antidiabetic, anti-inflammatory, analgesic, cytotoxicity properties.

Parts used
Aerial Parts, leaves, seeds.

Uses
Edibility
- Leaves reportedly eaten as vegetable. (9)
Folkloric
- No reported folkloric medicinal use in the Philippines.
- In Manipur, India, boiled extract of whole aerial parts used long-term for treatment of diabetes. (5) In Assam,  leaves mixed with powder of P. nigrum and juice prescribed for treatment of pneumonia. (6) Roots taken orally for treatment of anemia, constipation, dropsy, dysuria, urinary calculi, gout, oliguria; also as aphrodisiac and rejuvinator. (7)
- In Peninsular Malaysia, leaves applied as poultice to treat wounds, swellings, boils, headache, and toothaches. (9)
Others
- Agroforestry: This genus of swampweeds can be integrated in moist wetlands with potential benefit for erosion control and habitat provision.

Studies
• Antidiabetic / Leaves: Study of evaluated the effect of aqueous leaf extracts of H. ringens on blood sugar and body weight changes in alloxan-induced albino mice.  Acute toxicity testing showed no mortality or abnormal behavior at dosage of 2000 mg/kbw. Results showed significant antidiabetic activity at dose of 400 mg/kg. (3)
• Anti-Inflammatory / 4-O-Methylglucuronoxylan / Seeds: Study of H. ringen seeds extracted a soluble polysaccharide, DL1, a polymer containing xylose (Xyl; 78.5%) and 4-O-methyl-D-glucuronic acid (4-O-MeGlcA 21.5%). DL1 showed inhibition of bovine serum albumin denaturation with IC50 of 0.35 mg/mL, comparable  in activity to diclofenac (NSAID). In a model of lipopolysaccharide-stimulated macrophages, DL1 (20-40 µg/mL) strongly inhibited inflammatory cytokines and reactive oxygen species without significant macrophage cytotoxicity. The inhibitory effect of DL1 on inflammatory cytokines is mediated by activation of mitogen-activated protein kinases by inhibiting phosphorylation of p38 and extracellular signal-regulated kinase. Results suggest potential for DL1 for treatment of inflammation via its cytokine suppressive activity. (4)
• Analgesic / Cytotoxicity / Leaves: A methanolic crude extract at dose of 100 and 200 mg/kbw and ethyl acetate fraction at dose of 100 and 200 mg/kbw showed promising analgesic activity of 61,58%m 67.23% and 59 .89%, 64.41% of inhibition, respectively, compared to standard. In brine shrimp lethality bioassay, the extract and fraction of leaves exhibited potent cytotoxicity with LC50s of 1.931 µg/mL, 4.454 µg/mL, and petroleum ether (9.099 µg/mL) and carbon tetrachloride (11.390 µg/mL) fractions showed moderate cytotoxicity respectively, compared to Vincristine sulphate (LC50 0.824 µg/mL). (8)

Availability
- Wild-crafted.

Additional Sources and Suggested Readings
(1)
Hygrophila ringens / KEW: Plants of the World Online
(2)
Hygrophila / Wikipedia
(3)
EXPLORING THE ANTI-DIABETIC POTENCY & ACUTE TOXICITY OF AQUEOUS LEAF EXTRACTS OF HYGROPHILA RINGENS (L.) R.BR EX (STEUD) IN EXPERIMENTAL MICE / TV Ramana, OS Rathor, G Gyananath / Internation Journal of Current Research, 2016; 8(12): pp 43450-43455 /
ISSN: 0975-833X
(4)
4-O-Methylglucuronoxylan from Hygrophila Ringens var. Ringens Seeds: Chemical Composition and Anti-Inflammatory Activity / Vo Hoai Bac, Tat Cuong Trinh, Andreas Koschella, thomas Heinze et al / Macro-Molecular Bioscience, 2025: 2400434 / DOI: 10.1002/mabi.202400434
(5)
PLANTS USED IN THE TREATMENT OF DIABETES BY THE MEITEI COMMUNITY IN IMPHAL EAST DISTRICT OF MANIPUR (INDIA) / A Radhapyari Devi, Y Sunitibala Devi, H Manoranjan Sharma / Research Journal of Life Sciences, Bioinformatics, Pharmaceutical and Chemmical Sciences, 2019; 5(1) / DOI:10.26479/2019.0501.77
(6)
ETHNOBOTANICAL STUDY OF MEDICINAL PLANTS USED BY THE DIFFERENT TRIBAL COMMUNITIES IN NILAKH- SRIPANI AREA OF DHEMAJI DISTRICT, ASSAM / Pranab Bpraj, Mousmi Saikia / International Journal of Pharmaceutical Sciences and Research,  2022; 13(11) /
DOI:10.13040/IJPSR.0975-8232.13(11).4586-07
(7)
Details for Hygrophila ringens / OSADHI: Online Structural and Analytics based Database for Herbs of India
(8)
Chemical and Biological Investigations of "Hygrophila ringens(L.)" / Mazharul Islam Chowdhury /
ASIN: 3848491540 / ISBN-10: 9783848491544 /
(9)
Hygrophila ringens / RHMJ Lemmens and N Bunyapraphatsara / PROSEA: Plant Resources of South-East Asia

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)