Polygonum orientale is a branching annual, 30 to 100 centimeters in height. Leaves are long petioled, ovate or ovate-cordate, 15 to 20 centimeters long, 5 to 12 centimeters wide, and covered with soft, silky, grey hairs. Racemes are cylindric, laxly panicled, 8 to 13 centimeters long. Flowers are white. Nut is rounded, black and shining, about 3 millimeters in diameter.
A variety of the plant has rose-pink flowers.
- In open, wet places along streams at low and medium altitudes in Pampanga and Rizal Provinces in Luzon.
- Also occurs in India to Japan and southward to Australia.
- Rootstock yields oxymethyl-anthraquinone, 0.05%.
- Study yielded six compounds: myricitrin, luteolin, gallic acid, catechin, protocatechuic acid and p-hydroxycinnamic acid. (3)
- Study of aerial parts isolated three lignans: arctiin, lappaol B, orientalin.
- Study of fruits yielded 28-O-ß,7ß-dihydroxt-lup-20(29)-en-28-oate (a new triterpenoid saponin), 5,7-dihydroxychromone, and naringenin.
- Study for chemical constituents yielded seven compounds identified as ombuine-3-O-beta-D-galactopyranoside (1), ombuine-3-O-rutinoside (2), tryptophan (3), quercetin-3-O-methyl ether (4), kaempferol-3-O-(2"-O-alpha-L-rhamnopyranosyl) -beta-D-glucuronopyranoside (5), quercetin-3-O-(2"-O-alpha-L-rhamnopyranosyl)-beta-D-glucuronopyranoside (6), quercetin-3-O-beta-D-glucuronide (7). (12)
- Study for chemical constituents from flowers yielded nine compounds viz. alphitonin (1), methyl 3,4-dihydroxybenzoate (2), apocynin (3), kaempferol-3-O-β-D-glucoside (4), 1,3,5-trihydroxybenzene (5), 3,3′-dimethoxyellagic-acid-4-O-β-D-glucoside (6), kaempferol-3-O-α-L-rhamnoside (7), quercetin-3-O-α-L-rhamnoside (8), kaempferol (9). (14)
- Ethanolic extract of aerial parts yielded a new anthraquinone glucoside 1-hydroxy-8-methoxy-3-methyl-6-O-β-D-glucopyranosyl-anthraquinone (1), along with 1, 6-dihydroxy- 8-methoxy-3-methyl-anthraquinone (2), quercitrin (3), kaempferol-3-O-α-rhamnoside (4), arborinol (5), β-sitosterol (6) and β-sitosterol-D-glucoside (7).
- Nuts prescribed for flatulence and for tuberculous swellings.
- In India, whole plant is used for whooping cough and menorrhagia. Fruit and leaves are burned and prescribed for fever. Decoction of leaves used for liver and splenic diseases.
(6) In India, root juice taken orally to increase frequency of urination. (20)
• Taxifolin / Antioxidant: Study showed the taxifolin from Polygonum orientale showed very potent antioxidant activity. (1)
• Free Radical Scavenging: Study investigated the free radical scavenging potentials of P orientale extracts. Results showed the free radical-scavenging activities to be: methanol>ethanol>water>ethyl acetate>chloroform. (2)
• Cardioprotective / Antioxidant: Study evaluated the protective effect of flowers, leaves, and main stem of Polygonum orientale on H9c2 myocardial cells oxidative injury induced by H2O2. Results showed a protective effect on H9c2 myocardial cells oxidative injury. The activity showed a positive correlation with antioxidant activities. (4)
• Antihyperglycemic / Flowers: Study evaluated the antihyperglycemic effect of an aqueous extract of flowers in streptozotocin-induced diabetic mice. Results showed significant reduction of blood glucose, serum cholesterol, and increase in liver glycogen. (6)
• Cardioprotective Flavonoids: A FEE (flavonoid-enriched extract) was reported to show cardioprotective effect. Study isolated twenty-three active phenolics including ten flavonoid C-glycosides and six flavonoids O-glycosides. (7)
• Bone Healing / Osteoblastic Effects: Study showed root tubers of P. orientale could increase ALP activity and DNA synthesis by stimulating proliferation and differentiation of osteoblasts in vitro, respectively. Results partly explain the pharmacologic ways the herb promotes the healing of bone fractures and rheumatism. (8)
• New Triterpenoid Saponin / Fruits: Study of fruits yielded 28-O-ß,7ß-dihydroxt-lup-20(29)-en-28-oate (a new triterpenoid saponin), 5,7-dihydroxychromone, and naringenin. (9)
• Effects on Osteoblastic Cell Growth / Benefits for Bone Healing and Rheumatism: Study showed root tubers could increase both ALP activity and DNA synthesis by stimulating proliferation and differentiation of osteoblasts in vitro, with the potential to promote healing of bone fractures and rheumatism. . (10)
• Absorption of Basic Dyes on P. orientale Activated Carbon: Low cost activated carbon from Polygonum orientale was evaluated for its ability to remove basic dyes (malachite green and rhodamine B). Thermodynamic study showed the adsorption was a spontaneous endothermic process. (11)
• Phytoremediation of Phenol from Waste Water: Removing phenol from wastewater is a major challenge of international concern. Study evaluated the ability of P. orientale to phytoremediate phenol. Results provide a theoretical basis for the understanding of mechanisms involved in removal of phenol by P. orientale. (13)
• Antinociceptive / Leaves: Study investigated methanolic extract of Persicaria orientalis leaves for antinociceptive activity in a rodent model using hot plate and tail immersion methods for acute effect and carrageenan-induced paw edema and formalin-induced edema methods for chronic inflammatory effect. Results showed antinociceptive effect and protecting effect against inflammatory stimuli which may be due to phenolic and flavonoid compounds. (18)
• Anti-Inflammatory / Anti-Diarrheal / Thrombolytic / Cytotoxic / Leaves: Study evaluated of methanolic extract of leaves showed significant anti-inflammatory (inhibition of hypotonicity-induced human red blood cell hemolysis and albumin denaturation) and anti-diarrheal (castor oil-induced diarrhea) effects and moderate thrombolytic (33.13% clot lysis) and lower cytotoxic (LC50 58.91 µg/ml in brine shrimp lethality) activities. (19)