INTRODUCTION:

Enhydra fluctuans Lour. (Family: Asteraceae) is a small genus of marsh herb, distributed in tropical and subtropical regions. The plant is a prostate, spreading, annual herb. This is also an edible semi aquatic herbaceous vegetable plant with serrate leaves, grows all over India. The leaves which are slightly bitter are used to treat inflammation, skin diseases, and small pox¹. The stems are somewhat fleshy, 30 centimeters or more in length, branched, rooting at the lower nodes, and somewhat hairy. The leaves are stalkless, linear-oblong, 3 to 5 centimeters in length, pointed or blunt at the tip, usually truncate at the base, and somewhat toothed at the margins. The flowering heads are without stalks, are borne singly in the axils of the leaves, and excluding the bracts, are less than 1 centimeter in diameter. The outer pair of the involucral bracts is ovate and 1 to 1.2 centimeters long; the inner pair is somewhat smaller. The flowers are white or greenish-white. The acheness is enclosed by rigid receptacle-scales².

Figure 1: Enhydra fluctuans whole plant with flower

Classification

Kingdom: Plantae

Phylum: Magnoliophyta

Class: Magnoliopsida

Order: Asterales

Family: Asteraceae

Genus: Enhydra

Specific Epithet: fluctuans Lour

Species: Enhydra fluctuans Loureiro

Common names

Commonly known as Enhydra (Engl.), Kankong-kalabau (Tag.), Buffalo spinach (Engl.), Marsh herb (Engl.), Water cress (Engl.), Zhao ju (Chin.). Some compilations refer to Enhydra fluctuans as Enydra fluctuans³.

Synonym/s

Enydra anagallis Gardner, Meyera fluctuans (Lour.) Spreng.⁴

Other vernacular names

Bengali: Hingcha, helencha, hinche, hingcha, hincha,

India: harkuch, haruch, matsayaakshi,

Indonesia: Godobos.

Thai: Phak bung ruem.

Vietnamese: Câyraungổ, Rau ngổ, Ngổtrâu, Ngổđất, Ngổhương

Sanskrit: achari, bramhi, chakrangi, helanchi, hilamochika, himamocika, jalabramhi, mambi, matsyakshi, matsyangi, mochi, rochi, sasasrutih, shankhadhara, trinittaparni, vishaghni³.

Natural habital

Enhydra fluctuans is a tropical herb, more sensitive to cold especially when very young. The species grows in and along ditches, water courses, margins of fish ponds and rice fields in the open, from sea-level up to 1,800 m. It is able to reproduce by fragmentation and may be so abundant that it clogs water courses.

Geographic distribution

This species is an old world species, possibly of Indochinese origin, which occurs in tropical Asia and Africa. It is common to all countries of Southeast Asia.

a. Native

Bangladesh; Benin; Burkina Faso; Cambodia; Cameroon; Congo, The Democratic Republic of the; Côte d'Ivoire; Ghana; India; Indonesia; Kenya; Lao People's Democratic Republic; Malaysia; Mozambique; Myanmar; Nigeria; Philippines; Rwanda; Senegal; South Africa; Sri Lanka; Sudan; Tanzania, United Republic of; Thailand; Togo; Uganda; Viet Nam; Zambia; Zimbabwe⁴.

b. Present - origin uncertain

Australia

Edible uses

According to Burkill the young parts are used as a salad in several countries, including Malaya. Sometimes they are steamed before they are eaten.

Guerrero reports that in the Philippines the leaves are pressed and applied to the skin as a cure for certain herpetic eruptions.Inbengal it is washed,chopped and cooked as Sag fry or boiled with rice and eaten with boiled rice with boiled potato,salt and mastered oil.

Burkill reports that the young parts and the leaves of the plant are somewhat bitter and are used by the Malays as a laxative. Caius says that the leaves are useful in diseases of the skin and of the nervous system. The fresh juice of the leaves is prescribed in Calcutta as an adjunct to tonic metallic medicines, and is given in neuralgia and other nervous diseases. The leaves are antibilious. The expressed juice of the leaves is used as a demulcent in cases of gonorrhea; it is taken mixed with the milk of either a cow or a goat. As a cooling agent, the leaves are pounded and made into a paste which is applied cold to the head.

Watt quotes Forsyth, who states that the plant is useful in torpidity of the liver. An infusion should be made the previous evening. It is boiled with rice and taken with mustard oil and salt⁵.

Chemical constituents

Plant is rich in protein and is a good source of β-carotene. It also contains saponins, myricyl alcohol, kaurol, cholesterol, sitosterol, glucoside, sesquiterpene lactones including germacranolide, enhydrin, fluctuanin and fluctuandin, a number of diterpenoid acids and their isovalerate and angelate derivatives, stigmasterol, cholesterol, sitosterol, glucoside, other steroids and gibberellins A9 and A13 have been isolated from this plant.⁶

Characteristics

Climate: Tropical

Habitat: Hydrophytic

Habit: Herb

Flower colour: Beige, white⁷

Popularity of Enydra fluctuans over time

Figure 2: Popularity of Enydra fluctuans over time

Plots of numbers of papers mentioning Enydra fluctuans (filled column histogram and left hand axis scale) and line of best fit, 1926 to 2006 (complete line, with equation and % variation accounted for, in box on the left hand side); Plots of a proportional micro index, derived from numbers of papers mentioning Enydra fluctuans as a proportion (scaled by multiplying by one million) of the total number of papers published for that year (broken line frequency polygon and right hand scale) and line of best fit, 1926 to 2006 (broken line, with equation and % variation accounted for, in broken line box on the right hand side)⁸.

Recent pharmacological studies

1. Antioxidant activity

The Ethanol (EEF), Chloroform (CEF) and Pet-Ether (PEEF) extracts of Enhydra fluctuans were evaluated for reducing power, total phenolic content, the DPPH scavenging activity, NO-scavenging activity and super oxide scavenging activity by Swain et al., . In all the tests the ethanol extract was found to have higher antioxidant activity⁹.

2. Antimicrobial and cytotoxic activity

Amin et al., evaluate evaluated three medicinal plants (Enhydra fluctuans, Clerodendrum viscozum and A. peniculata) for antimicrobial and cytotoxic activities against some pathogenic organisms and Artemia salina (brine shrimp nauplii). All three showed activity against brine shrimp nauplii. A methanol leaf extract of E. fluctuans showed significant efficacy against tested bacteria and fungi¹⁰.

3. Hepatoprotective activity

Sannigrah et al.,evaluated the hepatoprotective potential of Enhydra fluctuans against carbon-tetrachloride-induced oxidative damage in rats. Results showed the flavonoid rich ethyl acetate fraction to have significant hepatoprotective activity, probably due to the extract's ability to inhibit lipid peroxidation and increase the anti-oxidant enzymatic activity¹¹.

4. CNS Depressant Activity

Roy et al., studied Neuropharmacological effects of three fractions of aerial parts of Enhydra fluctuans using mice models. Results showed significant spontaneous motility depressant, sedative, anticonvulsant and anti-stress activity¹².

5. Analgesic activity:

Rahaman et al., evaluated the analgesic activity of Enhydra fluctuans that showed promising results in both acetic acid-induced writhing and the tail-flick methods¹³.

6. Antidiarrheal activity

Uddin et al.,studied the methanol and aqueous extracts of the Enhydra fluctuans that showed antidiarrheal activity on castor-oil induced diarrhea. The methanolic extract moderately inhibited growth of S. dysenteriae, S. boydii and S. flexneri; the aqueous extract inhibited growth of S. aureus, S. dysenteriae and S. boydii¹⁴.

7. Antimicrobial activity

Bhakta et al., evaluated Antimicrobial efficacies of methanol extract of Asteracantha longifolia, Ipomoea aquatica and Enhydra fluctuans against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Micrococcus luteus. Study results showed extract variations, but the methanol extract of A. longifolia, I. aquatica and Enhydra fluctuans showed antimicrobial activity against pathogenic bacteria - S. aureus, P. aeruginosa, E coli and M. luteus¹⁵.

ACKNOWLEDGEMENTS:

The authors are thankful to the authors/editors of all those articles, journals and books from where the data for this article has been reviewed and discussed.

REFERENCES:

1. Kirtikar KR, Basu BD. Indian Medicinal Plants.Sri Satguru Publications, Delhi, 2002. Vol. VIII: pp.1360.

2. Kirtikar KR, Basu BD. Indian Medicinal Plants. International Book Distributors, Dehra Dun, 1999. Vol. II: pp. 1360.

3. Quisumbing, Eduardo. Medicinal Plants of the Philippines. Katha Publishing, Quezon City, 1978

4. Gupta AK. Enydra fluctuans. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.

5. http://findmeacure.com/2009/04/04/helanchaenhydra-fluctuans/

6. Ghani A. Medicinal plant of Bangladesh. Asiatic Society of Bangladesh, Bangladesh, 2003: pp. 3-17, 215, 323.

7. Dokosi OB. Herbs of Ghana. Ghana University Press, Accra, Ghana, 1998.

8. http://www.newcrops.uq.edu.au/listing/species_pages_E/Enydra_fluctuans.htm

9. Swain PK, Dinda1 SC, Nayak DP, Kar B, Patro VJ. Antioxidant activity of Enhydra fluctuans Lour. aerial parts. Journal of Phytotherapy and Pharmacology.1 (2); 2012: 23-34.

10. Amin R, Mondol R, Habib MR, Hossain MT. Antimicrobial and Cytotoxic Activity of Three Bitter Plants-Enhydra fluctuans, Andrographis peniculata and Clerodendrum viscosum. Advanced Pharmaceutical Bulletin. 2(2); 2012: 207-211

11. Sannigrahi S, Mazumder UK, Mondal A, Pal D, Mishra SL, Roy S. Flavonoids of Enhydra fluctuans exhibit anticancer activity against Ehrlich's ascites carcinoma in mice. Nat Prod Commun. 5 (8); 2010:1239-42.

12. Roy SK, Mazumder U, Islam A. Pharmacological evaluatio of Enhydra fluctuans aerial parts .for central nervous system depressant activity. Pharmacologyonline. 1; 2011: 632-643

13. Rahman MT, Gegum N. Analgesic activity of Enhydra fluctuans. Fitoterapia. 73(7-8); 2002: 654-660

14. Uddin SJ, Ferdous MM, Rouf R. Evaluation of Anti-diarrheal Activity of Enhydra fluctuans. Med Sc. 5 (4); 2011, 324-327.

15. Bhakta JN, Majumdar P, Munekage Y. Antimicrobial efficacies of methanol extract of Asteracantha longifolia, Ipomoea aquatica and Enhydra fluctuans against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Micrococcus luteus. The Internet Journal of Alternative Medicine.7(2); 2009: 125-135.

Received on 11.05.2013 Modified on 13.06.2013

Research J. Pharm. and Tech. 6(9): September 2013; Page 927-929