Tonghoy

Family • Cruciferae / Brassicaceae - Nasturtium officinale R. Br. - WATERCRESS - Xi yang cai


Scientific names

Nasturtium officinale R. Br.
Nasturium aquaticum
Roripa nasturtium Rusby
Roripa nasturtium-aquaticum Hayek
Sisymbrium nasturtium Linn.

Other vernacular names

CHINESE: Dou ban cai, Shui tian jie, Shui han cai, Shui sheng cai.

Common names

Watercress (Engl.)
Tonghoy (Ilk.)
Nasturium (Engl.)
Cress (Engl.)
Xi yang cai (Engl.)

Botany
Tonghoy is a perennial floating aquatic plant, with very branched creeping stems. The leaves are erect and pinnate; the upper ones with 3 to 7 pinnules and a terminal one, the lower ones cut into 3 repand segments. Flowers are white, borne in short racemes. Petals are longer than the sepals.

Tonghoy

Distribution
Abundant in shallow waters and small streams in the Trinidad valley, Benguet areas, at altitudes of about 1,300 meters. The pods is 1.2 to 2.5 cm long, stalked and spreading, or bent upward. Seeds are small and 2-seriate.

Watercress

Additional Sources and Suggested Readings

(1) Nasturtium officinale / Plants For A Future

(2) Effect of hydroalcoholic extracts of Nasturtium officinale leaves on lipid profile in high-fat diet rats./ Selfollah Bahramikla and Razieh Yazdanparast / J Ethnopharmacol. 2008 Jan 4;115(1):116-2 / doi:10.1016/j.jep.2007.09.015

(3) Nasturtium officinale reduces oxidative stress and enhances antioxidant capacity in hypercholesterolaemic rats / Razieh Yazdanparast et al / Chemico-Biological Interactions Vol 172, Issue 3, 15 April 2008/ doi:10.1016/j.cbi.2008.01.006

(4) Decrease of plasma and urinary oxidative metabolites of acetaminophen after consumption of watercress by human volunteers / Clinical pharmacology and therapeutics / 1996, vol. 60, no6, pp. 651-66

(5) Platelet Aggregatory Effects of Nasturtium officinale and Solanum torvum Extracts / H Moriyama et al / Nat Med • VOL.57;NO.4;PAGE.133-138(2003) /

(6) Activity against drug resistant-tuberculosis strains of plants used in Mexican traditional medicine to treat tuberculosis and other respiratory diseases / Maria del Rayo Camacho-Corona et al / Phytotherapy Research • Volume 22 Issue 1, Pages 82 – 85

(7) Antioxidant Efficacy of Nasturtium officinale Extracts Using Various In Vitro Assay Systems / Seifollah Bahramikia, Razieh Yazdanparast / Journal of Acupuncture and Meridian Studies, Volume 3, Issue 4 , Pages 283-290, December 2010

(8) Ontogenic Variations of Ascorbic Acid and Phenethyl Isothiocyanate Concentrations in Watercress (Nasturtium officinale R.Br.) Leaves / Usha R. Palaniswamy, Richard J. McAvoy, Bernard B. Bible, and James D. Stuart / J. Agric. Food Chem., 2003, 51 (18), pp 5504–5509 / DOI: 10.1021/jf034268w

Tonghoy3Parts utilized
Seeds

Constituents 
• A good source of calcium; a fair source of iron.
• Antiscorbutic; rich in vitamins A and C; fair in vitamin D.
• Contains an essential oil, the principal substance of which is phenylpropionic acid nitrite.
• It also contains a glucoside, gluconastutiin.
• Contains specific indoles that help in disposing of excess estrogen; heavy cooking destroys these indoles.
• Contains phenethyl isothiocyanate (PEITC), a compound known for cancer-preventive properties. source
• Phytochemical screening yielded alkaloids, flavonoids, glycosides, terpenoids, saponins.

Properties
• A good source of calcium; a fair source of iron.
• Improves appetite and bone health.
• Considered antiscorbutic, diuretic, expectorant, hypoglycemic, odontalgic, purgative, stimulant, stomachic.

Uses
Culinary
– Edible: leaves, seeds.
– Leaves, raw or cooked.
– Used as garnish and condiment.
– Seeds are powdered and used as mustard.
– Adding water to the powdered seed activates the enzyme, myrosin. acting on the glycoside, sinigrin, to produce a sulphur compound. Mixing hot water, vinegar, or salt inhibits the enzymatic reaction and produced a milder but bitter mustard. source

Tonghoy4Folkloric
– Bruised leaves and juice, used as a facial lotion to remove blotches, spots and blemishes.
– Used for tubercular patients.
– Used as expectorant, for asthma and coughs.
– Also used as a stimulant and aphrodisiac.
– Freshly expressed juice used for chest and kidney complaints, externally for skin irritations and inflammations.
– Used as hair tonic, believed to promote hair growth.
– Poultice of leaves used for lymphatic swellings.
– In Iran, used as a cardioprotective agent.

Study Findings
• Cardioprotective / Hypolipidemic: Study of the hydroalcoholic extract of N officinale on rats lowered total and LDL cholesterol and triglycerides while raising serum HDL levels. Results shows a cardioprotective effect and supports a basis for medical application.
• Antioxidant / Lipid Benefits: Study showed the extract of NO has notable scavenging activity against DPPH radicals and potent reducing power. It reduced Total and LDL cholesterol while increasing HDL levels. Results suggest the lipid effect could be due to its antioxidative potential.
• Hepatoprotective: Study of the alcoholic extract of N officinale showed it significantly diminished acetaminophen-induced liver damage in a rat model.
• Platelet Aggregating Effect: Study of the the plant extracted with 50% ethanol showed a more potent platelet aggregating effect than the aqueous extract suggesting the platelet aggregation activating constituent may be more ethanol soluble than water soluble.
• Anti-Tuberculosis Activity: In a study evaluating nine plants used in Mexican traditional medicine to treat tuberculosis, Nasturtium officinale showed the best activity against sensitive Mycobacterium tuberculosis.
• Antigenotoxicity: Study evaluated the aqueous juice of watercress for genotoxicity and possible protective effect against damage induced by cyclophosphamide in vivo in male and female Swiss mice. Analysis of bladder histological changes suggest a probably protective effect. Watercress juice did not induce genetic damage, exhibiting a protective activity against CP.
• Antioxidant: Study investigated the antioxidant activity of N. officinale extract using various assays. Results showed potent reducing power in a ferric reducing antioxidant power assay, nitric oxide radicals, and hydrogen peroxide, as well as chelating ability on ferrous ions.
• Hypoglycemic / Triglyceride Lowering: Study of effect of feeding plant-mixed pelleted food in STZ-induced diabetic rats showed significant hypoglycemic effect and and significant lowering of triglyceride levels.
• Glucosinolate Nasturtiin / Phenethyl Isothiocyante (PEITC) / Anti-Cancer: Watercress is the richest source of glucosinolate nasturtiin, which on hydrolysis produces phenethyl isothiocyante (PEITC). PEITC is believed to be protective against cancers associated with tobacco specific carcinogens. PEITC was highest in leaves harvested at 40 days, producing 150% higher PEITC concentrations compared to leaves at transplant.
• Wastewater Bioaccumulation of Heavy Metals: Study showed Nasturtium officinale was able to accumulate both copper and zinc at upper levels, and nickel at low levels.

Availability
Wild-crafted.
Cultivated.