Botany
Kangkong is a smooth, widely spreading
vine, with the stems trailing on mud or floating on water. Leaves are
oblong-ovate, 7 to 14 centimeters long, with a pointed tip and heart-shaped or arrow-shaped
base, long petioled, the margins entire or angular, and sublobed. Peduncles are erect, 2.5 to 5 centimeters long, with 1 or 2 flowers, borne in the
axils of the leaves. Sepals are green, oblong, about 8 millimeters long. Corolla
is narrowly bell-shaped, about 5 centimeters long, and purplish; limb nearly white or pale pink purple, about 5 centimeters in diameter, the tube
deeper purple inside. Capsules are smooth and ovoid, about 1 centimeter long.
Distribution
- Throughout the Philippines
in stagnant streams, fresh-water swamps, and pools.
- Probably introduced.
- Found throughout the tropics of the Old World.
- Extensively cultivated in southern China.
 Constituents
- Plant contains protein 1.6 %, fat 0.2%, and vitamins C3 and B2.
Properties
- Considered purgative, diuretic, antiepileptic, CNS depressant, anti-inflammatory, hypolipidemic, antimicrobial, anthelmintic, antidiabetic.
Parts
used
Young leaves and stems
Uses
Edibility / Nutritional
- Young leaves and shoots
eaten raw in salads, or steam and boiled like spinach.
- Young stems popular as achara (native pickles) ingredient.
- Good sources of iron, calcium, vitamins B and C and amino acids.
Folkloric
- Tops are mildly laxative.
-The purplish variety used for diabetes because of assumed insulin-like
principle it contains.
- Juice used as emetic.
- Dried latex is purgative.
- Poultice of buds used for ringworm.
- Used as laxative and sedative; used for piles, nervous conditions, headache, insomnia.
- In Burma, the juice is employed as an emetic in cases of arsenical or opium poisoning.
- In Cambodia, used as poultice for fever with delirium; buds applied to ringworm.
- In Ayurveda, extracts
of leaves are used for jaundice and nervous debility.
- Juice used as emetic in opium and arsenic poisoning.
- In Sri Lanka, used for
liver disease, eye problems, constipation.
Others
- Leaves used as food for gurami fish and pigs.
Studies
• Hypoglycemic / Anti-Diabetic:
(1) Study showed the boiled whole extract of I. aquatica to
exert an oral hypoglycemic effect in healthy, male, Wistar rats after
a glucose challenge. (2) An aqueous extract of the green leafy vegetable
Ipomoea aquatica is as effective as the oral hypoglycaemic drug tolbutamide
in reducing the blood sugar levels of Wistar rats.(3) Inhibitory effect
of Ipomoea aquatica extracts on glucose absorption using a perfused
rat intestinal preparation: Study showed a significant inhibitory effect
on glucose absorption. Furthermore, results suggest the inhibition of
glucose absorption is not due to the acceleration of intestinal transit.
(4) Study showed the consumption of shredded, fresh, edible portion
of IA for one week, effectively reduced the fasting blood sugar of Streptozotocin-induced
diabetic rats.
• Antioxidant / Antiproliferative: Antioxidant and antiproliferative activities of water
spinach (Ipomoea aquatica Forsk) constituents: Study showed the water
extract of stems had the highest antiproliferative activity. The ethanol
extract of the stems had the highest total phenolic compounds. The ethanol
extract of leaves had the highest amount of flavonoids.
• Diuretic: Study on the diuretic activity of the methanol extract
of Ipomoea aquatica in Swiss albino mice showed good diuretic activity.
In all cases, the excretion of electrolytes and urine volume increase
was higher than the standard diuretic, furosemide.
• Antioxidant: Study of a methanol extract yielded a compound ( 7-O-B-D-glucopyronosyl-dihydromquercetin-3-O-a-D-glucopyranoside)
that exhibited antioxidant activity with an EC50 value of 83 and showed
very strong lipid peroxidation-inhibitory activity in a liposome model
system.
• Antimicrobial: Study investigating the antimicrobial efficacy of the leaf extract of three herbs – A longifolia, I aquatica and E fluctuans – on four pathogenic bacterial strains (E coli, P aeruginosa, S aureus and M luteus). Ipomoea aquatica exerted the higher amount of antimicrobial activity against the bacterial strains, better than the two other herb extracts.
• Antiulcerogenic: Study in an aspirin-induced ulcer model in rats found Ipomoea aquatica to possess potent anti-ulcerogenic and ulcer-healing properties and can act as a potent therapeutic agent against peptic ulcer disease.
• Cytotoxicity: Study isolated a purified bioactive compound from the leaf of Ipomoea aquatica – 7-O-B-D-glucopyranosyl-dihydroquercetin-3-O-a-D-glucopyranoside (DHQG). Results showed DHQG showed cytotoxicity towards cancer cell lines tested.
• Nootropic / Memory Enhancing Potential: Study suggests that MEIA markedly improves brain Ach level. MEIA treatment may be of value in reinforcing depressed cholinergic transmission in certain age related memory disorders and to improve memory and learning in normal individuals.
• Anxiolytic: Study evaluated the anxiolytic activity of Ipomoea aquatica leaves. A methanol-ethanol extract significantly potentiated ketamine-induced sleep by reduction in latency to sleep and increased duration of sleep, suggesting the interaction of I. aquatica with CNS depressants.
• Hypoglycemic/ Antioxidant: Study evaluated the hypoglycemic and antioxidant activity of methanolic extract of leaves in Swiss albino mice. Results showed potent hypoglycemic activity compared with control. Extract also showed potent free radical scavenging activity with vitamin C as standard.
• CNS Depressant / Antiepileptic: Study on various animal models evaluated the CNS depressant and antiepileptic activities of a methanol extract of leaves of Ipomoea aquatica. Results showed dose-dependent and significant increases in onset to clonic and tonic convulsions or complete protection against seizures induced by strychnine and picrotoxin. There was also dose-dependent prolongation of pentobarbitone sleeping time and suppression of exploratory behavior.
Availability
Cultivated.
Wildcrafted.
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