Family • Polygonaceae - Polygonum barbatum Linn. - KNOTWEED - Mao liao

Scientific names

Polygonum stoloniferum Blanco
Polygonum persicaria Walp.
Polygonum fissum Blume
Polygonum fissum Hassk.
Polygonum fissum Miers.
Polygonum eruthrodes Miq.
Polygonum stagnimum Miers.
Polygonum barbatum Meisn.
Polygonum barbatum Hook.
Polygonum barbatum Blume
Polygonum flaccidum Roxb.
Polygonum serrulatum Hook.
Polygonum serulatum Lagasca
Persicaria barbata Linn.
Persicaria omerostroma (Ohki.)Sasaki.
Polygonum omerostromum Ohki.

Common names

Bukakau (Bik.)
Kanubsubang (Pamp.)
Kaykayu (If.)
Saimbangan-tubig (Sul.)
Sigan-lupa (Tag.)
Subsuban (Tag.)
Bearded knotweed (Engl.)
Jointweed (Engl.)
Knotgrass (Engl.)
Smart-weed (Engl.)
Water milkwort (Engl.)
Mao liao (Chin.)

Other vernacular names

CAMBODIA: Kating he.
INDONESIA: Salah nyowo, Mengkrengan, Jukut carang.
MALAYSIA: Tebok seludang, Johong beraleh, Panchis-panchis.
VIETNAMESE: Ng[eer] tr[aws]ng, Ng[eer] r[aa]u.

Subsuban is an ascending, slightly hairy plant, growing to a height of 30 to 60 meters. Stipules are sheathing, and cut into long, filiform cilia which are longer than the tube. Leaves are lanceolate 10 to 15 centimeters long, smooth or nearly so except at the ciliate margins and midrib, and tapering at both ends. Inflorescence is terminal, and in the upper axils, sparingly branched, with erect, lax and peduncled racemes, 2 to 6 centimeters long, 5 to 7 millimeterw in diameter. Flowers are in short, slender pedicels. Perianth is white or purplish, 2 millimeters long and without glands. Fruit is a triangular, black and shining nut.


Additional Sources and Suggested Readings

(1) Phytochemical Studies on Polygonum barbatum (L.) Hara var. barbata (Polygonaceae) / M Abdul Mazid, Bidyut K Datta et al / Rec. Nat. Prod. 5:2 (2011) 143-146

(2) ANTI-ULCER EVALUATION OF POLYGONUM BARBATUM LINN LEAF EXTRACT / Queen, Rosary Sheela X; Arockiasamy, P; Jeba, Singh D; Ilavarasan, R; Alex, Ramani V / International Journal of Pharmacy & Pharmaceutical Sciences;Oct2011, Vol. 3 Issue 4, p81

(3) BIOLOGICAL ACTIVITIES OF POLYGONUM BARBATUM / Bashir Ahmad Chaudhry*, Muhammad Younas Syad, Khalid Hussain Janbaz, Altaf Ahmad Dasti and Bashir Ahmad Loothar / Journal of Research (Science), Bahauddin Zakariya University, Multan, Pakistan. Vol.14, No.2, December 2003, pp. 169-175

(4) IN-VITRO ANTIOXIDANT ACTIVITY OF POLYGONUM BARBATUM LEAF EXTRACT / QUEEN ROSARY SHEELA X*, ALEX RAMANI V / Asian Journal of Pharmaceutical and Clinical Research Vol. 4, Suppl 1, 2011

(5) Persicaria barbata / Vernacular names / GLOBinMED

– In open, usually wet places at low and medium altitudes, up to 1,400 meters in some regions, throughout the Philippines.
– Also occurs in Aftrica, India, Malaya, Bangladesh, Thailand, and in many other countries in South-East Asia.

Parts used 
Leaves, seeds, and roots.

– Study of aerial parts yielded sitosterone, viscozulenic acid, and acetophenone.
– Study isolated flavanones from chloroform and ethyl acetate extracts of leaves.

Considered astringent, carminative, parasiticide.

– Young leaves and shoots cooked as vegetable.
– Sap of pounded leaves applied to wounds is considered an effective cicatrizant.
– In Malabar and Canara seeds are used to relieve colic pains.
– Roots are used as astringent.
– In China decoction of leaves and stems used to wash wounds and ulcers.
– Sap applied to wounds as antiseptic.
– Paste of roots used for treatment of scabies.

Study Findings
• Anti-Ulcer: A study on the aqueous and methanolic leaf extracts of P barbatum showed reduction of gastric volume, total acidity, free acidity and ulcer index. The antiulcer activity may be due to the presence of flavanoids and tannins.
• Anti-Ulcer: Study evaluated the antiulcer activity of a leaf extract on aspirin-and-pylorus ligation and aspirin-induced ulcer models. Results showed antiulcer activity with significant decrease in ulcer index, acidity, volume and increase in pH of gastric content.
Subsuban4• Wound-Healing: A study of wound healing on albino rats of Wistar strain showed a significant increase in wound closure rate, tensile strength and decrease in epithelization perioe in PB treated group. Study concludes that ethanolic extract of P B had greater wound healing activity than nitrofurazone ointment.
• Phytochemical : Study of aerial parts yielded sitosterone, acetophenone, and viscozulenic acid. Acetophenone is used extensively as a food additive to create various food fragrances, and is also known to possess hypnotic and anticonvulsant property.
• Biological Activities: Study screened aerial parts of Polygonum barbatum for biological activities. A dichlormethane extract showed brine shrimp toxicity and spasmolytic activity. A methanol extract was found to possess cholinergic activity.
• Antimicrobial Screening: Study screened Polygonum barbatum for antimicrobial activity. An ethanolic leaf extract showed considerable broad spectrum activity against gram positive, gram negative and fungial oganisms.
• Wound Healing / Whole Plant: Study of whole plant extracts on two wound models (excision wound model and incision wound model) showed wound healing properties comparable with Providine iodine. The aqueous extract was found to be more effective.
• Antioxidant: Study evaluated a leaf extract for in-vitro antioxidant activity. The PBLE contained a noticeable amount of total phenols. Results showed concentration-dependent antioxidant activity. An ethanolic extract showed significant antioxidant activity and a better source of natural antioxidants.