- The genus name is
Greek-derived, mythology dedicating the water lily to the semi-divine
maidens, the nymphs. The genus has roughly about 40 species found in
the tropical and temperate climates of both hemispheres. There is confusing
synonymy as plants are placed in different species or species sometimes
misapplied. There are many variants and hundred of hybrids.
nouchali is the national flower of Sri Lanka where it is called Nil
Lauas is long-lived aquatic
herb, with rootstock rooting in the mud. Leaves are long-stalked
and leathery, floating on the surface of water, ovate to almost circular, prominently
toothed, slightly peltate, 12 to 15 centimeters across, with the base deeply
heart-shaped, and densely hairy beneath. Petioles are long, slender and
submerged. Flowers are fragrant, white or red, about 8 centimeters in diameter,
borne on long peduncles. Petals are linear-oblong to lanceolate. Fruits are
globular, with longitudinally numerous, striated seeds.
- In shallow
lakes and ponds, often locally abundant, from northern Luzon to Mindanao.
Usually cultivated for its attractive flowers.
- Also occurs in tropical Asia to Malaya.
- The leaves and rhizomes
contain an abundant amount of tannic acid, an alkaloid resembling nupharin,
glucose, metaarabic acid, starch, fat; and ash.
- The leaves contain myricitin, saccharose and phytosterin.
Phytochemical analysis of a methanolic extract of stems yielded flavonoids, alkaloids, saponins, and tannins. (see study below) (17)
- The juice is bitter and astringent has some narcotic properties.
- Flowers are astringent and cardiotonic.
- Juice is bitter.
- Studies have shown antioxidant, antinociceptive, antimicrobial, antidiabetic, cholinergic, antihepatotoxic, anti-inflammatory properties.
- The seeds, long stalks of flowers and rhizomes are edible; eaten boiled or roasted.
- Roots and rhizomes often eaten raw.
- The tender leaves and flower peduncles of the red and blue-water lily
are also valued as food.
- Flowers stalks considered an excellent source of iron and a fair source of calcium.
- Juice is astringent; decoction of the juice used as injection
- Plant juice considered mildly narcotic, rubbed on the forehead and temples to induce sleep.
- Powdered roots used as demulcent for piles; also for dysentery and dyspepsia.
- Powdered root prescribed for piles as demulcent; also for dysentery and dyspepsia.
- Flowers used as astringent and cardiotonic.
- In Bangladesh, the roots used by the traditional healers of the Tripura, Marma and Murong tribes to treat dysuria, urinary tract infections and leucorrhea. Also, used for indigestion, heart diseases, stomachaches, cancer, and as anti-hemorrhagic.
- In Nepal and India flowers used in treatment of diabetes.
- In Ayurveda and Siddha systems of medicines, used for diabetes, liver disorders, urinary problems, menorrhagia, blenorrhagia; also used as tonic and aphrodisiac.
Study showed high levels of non-enzymatic antioxidants like phenols, flavonoids, tannins, etc., as well as antioxidant potential in the methanol extracts of dry flowers. High levels of enzymatic antioxidants were found in the fresh flower aqueous extracts. (3)
• Antidiabetic / Flowers: Flower extract showed significant reduction of blood glucose in diabetic rats.
• Antidiabetic / ß-Cell Stimulation: Hydroalcoholic extract also showed a dose-dependent response possibly through ß-cell stimulation, release of insulin and activation of insulin receptors.
• Antihepatotoxic :
Study of alcoholic extract of N. stellata flowers showed hepatoprotective activity against CCl4-induced hepatic damage possibly through cell membrane stabilization, hepatic cell regeneration and antioxidative enzyme activation. (6)
• Cholinergic :
Study of alcohol extract of defatted fruits of N. stellata produced mild sedation and ataxia, potentiated hexobarbitone-induced hypnosis in mice. Large doses after atropinization caused a rise in blood pressure and a stimulant effect on guinea pig ileum, suggesting an unstable cholinergic principle.
• Antimicrobial :
Flower extract showed activity against P. aeruginosa, B. cereus, S. aureus.
• Analgesic . Anti-Inflammatory:
Study showed significant analgesic and antipyretic activity. The anti-inflammatory activity was comparable to hydrocortisone.
• Intestinal Alpha-Glucosidase Inhibitory Activity / Toxicological Evaluation:
Study showed potent rat intestinal alpha-glucosidase inhibitory activity for maltose hydrolysis. Genotoxicity assessment showed the extract did not cause genotoxic in Ames test. (5)
• Antihyperglycemic / Antihypolipidemic:
Study of N. stellata flower extract exhibited blood sugar lowering effect as well as an antihyperlipidemic effect on alloxan-induced diabetic rats. (7)
• Nymphayol / Antidiabetic:
Chloroform extract showed significant glucose lowering effect. Study isolated a nymphayol, found to lower blood glucose, increase insulin content, and a significant increase in beta cell mass. (8)
• Antioxidant / Analgesic / Anti-Inflammatory: A methanolic extract of flowers was evaluated for antioxidant, analgesic and anti-inflammatory activities. The extract exhibited a dose-dependent increase in pain threshold in hot plate method, significant reduced writhing cause by acetic acid and number of licks caused by formalin. There was also significant dose-dependent inhibition of carrageenan-induced paw edema. There was good antioxidant potential exhibited in DPPD, ONOO and total ROS scavenging methods. (10)
• Antimicrobial: Hexane, ethyl acetate and methanolic extracts were evaluated for antimicrobial activity against S. aureus, Pseudomonas aeruginosa, B. subtilis, E. coli, enterococcus faecalis, X. campestris, Streptococcus mutans, Lactobacillus casei, L. acidophilus, Candida albicans. The ethyl acetate extract of leaf were active against all investigated bacteria. (11)
• Lectin / Antibacterial / Antiproliferative: A lectin (termed NNTL) was purified from the extracts of Nymphaea nouchali tuber. NNTL showed toxicity against brine shrimp nauplii with an LC50 of 120±29 µg/ml and exerted strong agglutination activity against four pathogenic bacteria. In addition, it showed antiproliferative activity against EAC (Ehrlich ascites carcinoma) cells. (12)
• Antidiabetic / Antioxidant / Hypolipidemic: Study evaluated the possible antidiabetic, hypolipidemic, and antioxidant effects of an ethanol extract of N. pubescens tuber. Results showed significant reduction of blood glucose, lipids except HDL-C, serum enzymes, significant increase in HDL. The effects may be due to its potent antioxidant potential. (13)
• Antibacterial / Flower: Study evaluated the antibacterial activity of Nymphaea nouchali flower on human and plant pathogenic bacteria. A methanol extract showed better antibacterial activity against two pathogenic bacteria, B. subtilis and S. lutea than commercial antibiotic nalidixic acid. Results suggest a potential candidate for development of a novel broad spectrum antibacterial herbal formulation. (15)
• Antidiabetic / Seeds: Study evaluated the antihyperglycemic activity of a hydroalcoholic extract of Nymphaea nouchali seeds in STZ-induced diabetic rats. Results showed significant restoration of blood glucose to normal level, together with improvement of lipids, renal, and hepatic markers. Histopath exam suggests the activity is due to extrapancreatic mechanisms. (16)
• Antihyperglycemic / Antinociceptive / Stems: A methanolic extract of stems showed significant and dose-dependent reduction of blood glucose in glucose-loaded mice. In antinociceptive activity evaluation with acetic acid induced pain model in mice, there was significant and dose dependent reduction in acetic acid induced abdominal constrictions in mice. Glibenclamide and aspirin were used as standard drugs. (see constituents above) (17)
• Antihyperglycemic Mechanisms / Adipocyte Differentiation / Glucose Consumption / Seeds: Study has demonstrated the antihyperglycemic effect of a hydroalcoholic seed extract in diabetic rats, but the functional mechanisms remains unknown. This study evaluated the effect of NN extract on PPAR? activation, adipocyte differentiation, and glucose consumption in 3T3-L1 cells. Study suggests N. nouchali seed extract promotes adipocyte differentiation and glucose consumption by inducing PPAR? activation which increases mRNA GLUT-4 expression and subsequently enhances insulin responsiveness in insulin target issues. (18)