Natural Products (Professional)

Purslane

Scientific Name(s): Portulaca oleracea L. Family: Portulacaceae

Common Name(s): Purslane , garden (common) purslane , pigweed , ma chi xian (Chinese) , munyeroo , portulaca , pusley

Clinical Overview

Uses of Purslane

Purslane is beneficial in urinary and digestive problems. It has antifungal and antimicrobial effects. It is high in vitamins and minerals and has been used as a food source. It possesses marked antioxidant activity. These potential uses have not been verified by clinical studies.

Purslane Dosing

No dosing information is available on purslane. The leaves have been used widely as a potherb and, therefore, are known to be safe.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Purslane Interactions

None well documented.

Purslane Adverse Reactions

Purslane is said to be safe, even in high dosages; however, individuals with a history of kidney stones should use purslane with caution.

Toxicology

No known toxicity.

Botany

The purslane family includes several fleshy plants. P. oleracea is a herbaceous, succulent annual, cosmopolitan weed. Some consider it a weed because of its growth patterns. Purslane grows 10 to 30 cm tall and has reddish-brown stems, alternate wedge-shaped leaves, and clusters of yellow flowers containing 4 to 6 petals that bloom in summer. Its numerous seeds are black, shiny, and rough. The plant prefers sandy soil. The herb, juice, and seeds are mainly used. Golden purslane ( P. sativa ) is a similar, related species to purslane, with yellow leaves, but is a larger plant and is not weedy. 1 , 2 , 3 , 4 , 5 , 6 , 7

History

In ancient times, purslane was considered to be an anti-magic herb used to protect against evil spirits. 6 Purslane's use as a medicinal herb dates back at least 2000 years, but it was used as food well before this period. Ancient Romans used purslane to treat dysentery, intestinal worms, headache, and stomachache. 2 , 3 , 6 The Zulu used the plant as an emetic. 6 Purslane was part of the Australian aborigines' diet as a salad green. The Chinese, French, Italians, and English also used purslane in salads. A folk use of purslane includes reducing fever. 5

Chemistry

Purslane is a rich source of omega-3 fatty acids, which are beneficial in congenital heart disease (CHD) and certain cancers. 3 One report states that in spite of its genetic diversity, purslane remains one of the most abundant vegetable sources of omega-3 fatty acids. 8 Other reports confirm the high fatty acid content in the plant. 9 , 10 Purslane contained 8.5 mg fatty acid per gram (wet weight) in another study. 11 Several other articles and reviews confirm purslane's high omega-3 fatty acid content. 12 , 13 , 14 , 15 Fatty acids in purslane seeds (eg, linoleic acid, palmitic acid) have also been evaluated. 16 One report concludes that the omega-3 fatty acid concentration found in purslane is dependent on nitrogen source. 17

Purslane also contains carbohydrates, lipids, glycosides, alkaloids, sterols, triterpenes, and flavonoids. 18 Phenolic constituents of the plant include scopoletin, bergapten, isopimpinellin, lonchocarpic acid, robustin, genistein, and others. 19 Plant acids present include citric, malic, ascorbic, succinic, fumaric, and acetic acids. 20 The volatile oil of P. oleracea has also been studied and contains mainly linalool and 3,7,11,15-tetramethyl-2-hexadecen-1-ol. 21

Purslane is a rich source of vitamins, with vitamins A, B, C, and E contained in the plant. 2 Purslane is high in carotenoid content, including beta-carotene. 9 , 10 Calcium, magnesium, potassium, folate, and lithium are also present. 2 , 6 Amino acids in the leaves of Portulaca species include phenylalanine, alanine, tyrosine, and aspartate. 22 Antioxidants including glutathione and alpha-tocopherol are also found in purslane. 15 The plant's constituents include mucilage as well. 2 A gum has been found in purslane, which may be considered a food emulsifier. 23 A review is available, comparing various plant gums, including purslane. 24 The enzyme phosphoenolpyruvate carboxylase from purslane leaves has been described. 25 Chemical composition of P. oleracea at different growth stages has been evaluated. 26

Purslane Uses and Pharmacology

Purslane is a versatile herb and has several culinary uses including “cooked greens” much like spinach or collards. 5 Its nutritive quality, especially the rich source of omega-3 fatty acids purslane provides, has a beneficial effect on cholesterol and triglyceride levels, in heart disease, and in strengthening the immune system. 3 , 4 Purslane is also high in vitamin and mineral content. 3 The plant possesses marked antioxidant activity. 27

Purslane has long been considered of value in the treatment of urinary and digestive problems. The juice has diuretic effects. 2 Purslane is also considered to be a “cooling aid” and cleansing stimulant of the kidneys, helpful in the bladder for urinary tract infection. 3 , 6

The plant's mucilagenous properties make it useful in GI problems. 2

Besides having vermicidal properties, purslane has been reported to possess antifungal effects, with marked activity against the genus Trichophyton. 28 The phenolic constituents of the plant exhibit antimicrobial effects. 19

Animal data

Purslane, placed in animal feed, prevents diarrhea as well as provides immunostimulation in 1 patient. 29 Other sources mention purslane as effective in treating hookworms and amoebic dysentery. 2 , 4

Clinical data

Purslane in a combination mouthwash demonstrated antimicrobial as well as anti-inflammatory effects. 30 Skin conditions such as acne, psoriasis, or sunburn may benefit from purslane. 2 Other uses of the plant include a poultice for backache/dysmenorrhea; 1 neuropharmacological actions; 31 and in cosmetics as a gamma-linolenic acid (GLA) source. 5

Dosage

No dosing information is available on purslane. The leaves have been used widely as a potherb and, therefore, are known to be safe.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Individuals with a history of kidney stones should use purslane with caution as it may increase kidney filtration, urine production, and possibly cause a stone to move. 6 Purslane injection induces powerful contractions of the uterus, but oral purslane is said to weaken uterine contractions. Avoid use during pregnancy. 2

Toxicology

Purslane is said to be safe, even in high dosages, as it is eaten as a vegetable. 4

Bibliography

1. Hocking, G. A Dictionary of Natural Products . Medford, NJ: Plexus Publishing, Inc., 1997;625.
2. Chevallier, A. The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing, 1996;253.
3. Low T, Rodd T, eds. Magic and Medicine of Plants . Surry Hills, NSW: Reader's Digest, 1994;282.
4. Reid, D. Chinese Herbal Medicine . Boston, MA: Shambhala Publications, Inc., 1986;56.
5. D'Amelio, F. Botanicals, A Phytocosmetic Desk Reference . Boca Raton, FL: CRC Press, 1999;245-246.
6. http://www.ann.com.au/herbs/Monographs/portulac.htm
7. http://www.botanical.com/botanical/mgmh/p/prugol77.html
8. Ezekwe M, et al. Nutritive characterization of purslane accessions as influenced by planting date. Plant Foods Hum Nutr . 1999;54:183-191.
9. Guil-Guerrero J, et al. Lipids classes, fatty acids, and carotenes of the leaves of six edible wild plants. Z Lebensm Unters Forsch A . 1999;209:313-316.
10. Liu L, et al. Fatty acids and β-carotene in Australian purslane ( Portulaca oleracea ) varieties. J Chromatogr . 2000;893:207-213.
11. Simopoulos A, et al. Purslane: A terrestrial source of omega-3 fatty acids. N Engl J Med . 1986;315:833.
12. Simopoulos, A. Terrestrial sources of omega-3 fatty acids: Purslane. Epitheor Klin Farmakol Farmakokinet . 1987;:89-102.
13. Koch, H. Purslane. Omega-3 fatty acids in an old medicinal plant. Dtsch Apoth Ztg . 1988;128:2493-2495.
14. Lercker, G. Perplexity on fatty acid identification in purslane ( Portulaca oleracea ) tissues. J Am Oil Chem Soc . 1992;69:193.
15. Simopoulos A, et al. Common purslane: A source of omega-3 fatty acids and antioxidants. J Am Coll Nutr . 1992;11:374-382.
16. Liu P, et al. Comparative study of fatty acids in Portulaca oleracea L. and its seeds. Fenxi Ceshi Xuebao . 1995;14:70-72.
17. Palaniswamy U, et al. Omega-3 fatty acid concentration in Portulaca oleracea is altered by nitrogen source in hydroponic solution. J Am Soc Hortic Sci . 2000;125:190-194.
18. Sayed H, et al. Pharmacognostical study of Portulaca oleracea L. growing in Egypt. Part Ι: Botanical study of the stems, leaves, and investigation of the lipid content. Bull Pharm Sci . 1985;8:41-60.
19. Awad N. Lipid content and antimicrobial activity of phenolic constituents of cultivated Portulaca oleracea L. Bull Fac Pharm . 1994;32:137-142.
20. Gao Z, et al. Determination of low molecular carboxylic acids in Portulaca oleracea L. by ion exclusion chromatography. Sepu . 1996;14:50-52.
21. Liu P, et al. GC-MS analysis of volatile oil of Portulaca oleracea L. Ziran Kexueban 1994;14:72-74.
22. Mirajkar P, et al. Studies on leaf protein of Portulaca species and other leafy vegetables. Curr Trends Life Sci 1984;11(Prog. Leaf Protein res.):95-98.
23. Garti N, et al. Surface and emulsification properties of a new gum extracted from Portulaca oleracea L. Food Hydrocolloids . 1999;13:145-155.
24. Garti N, et al. Natural hydrocolloids as food emulsifiers. Annu Surfactants Rev . 1994;2 (Design and Selection of Performance Surfactants):104-145.
25. Wu M, et al. Molecular properties of phosphoenolpyruvate carboxylase from Portulaca oleracea leaves. Zhiwu Shengli Xuebao . 1988;14:35-41.
26. Mohamed A, et al. Chemical composition of purslane ( Portulaca oleracea ). Plant Foods Hum Nutr . 1994;45:1-9.
27. Shang S, et al. Screening antioxidants from Chinese herb medicines. Tianran Chanwu Yanjiu Yu Kaifa . 1994;6:36-39.
28. Oh K, et al. Detection of antifungal activity in Portulaca oleracea by a single-cell bioassay system. Phytother Res . 2000;14:329-332.
29. Kato S, et al. Portulaca oleracea in feeds for diarrhea prevention. Jpn Kokai Tokkyo Koho . 1994; appl. # JP 92-315865 19921030.
30. Wu W. Anti-inflammatory and antimicrobial mouthwashes for controlling oral diseases. Faming Zhuanli Shenqing Gongkai Shuomingshu . 1995; Chinese patent, appl. # CN 93-11712 19930908.
31. Radhakrishnan R, et al. Neuropharmacological actions of Portulaca oleracea v. sativa. J Pharm Pharmacol . 1998;50(suppl. British Pharm. Conf. 1998):225.