Zea mays

 

Zea mays

Synonyms

No documentation

Vernacular Name

Mother’s hair, Cornsilk, Corn Silk, Indian Corn Silk, Indian Corn

Description

Conventionally, Zea mays grows to a height of 2-3m, though some varieties have been known to grow to a height of 7m.  The stalk of Z. mays resembles bamboo, but is lighter in color and not as dense.  On average, the internodes are roughly 20cm to 30cm in length, separated by the large, flag-like leaves which reduce in size the further up the stalk they are.  The inflorescence from the female Z. mays plant is commonly referred to as the “ears” are a seeds which are wrapped tightly in the leaves.  Until the time of harvest, the seeds are not visible.  Each of the seeds are roughly 0.5cm in diameter and grow tightly around the corn cobs in a linear fashion.  The seeds are typically yellow, but can be brown, blue, black or red, depending on the variety of Z. mays.  From the top of the seed cluster, grows a tuft of silky, hair-like strings, which, in reality, are elongated stigmas.

Origin / Habitat

Z. mays is an herbaceous plant first cultivated in Central America 5,000 years ago.  Since then, it has been propagated throughout both the North and South American continents.  In North America, Z. mays has been used as food, clothing, and medicine, and traditionally, most Native American tribes leave no part of the plant unused.

Chemical Constituents

cis-alpha-terpineol, 6,11-oxidoacor-4-ene, citronellol, trans-pinocamphone, eugenol, neo-iso-3-thujanol, cis-sabinene hydrate.(2)

Plant Part Used

Kernels or seeds and stigmas of the female flowers harvested prior to the fertilization period. (6)

Traditional Use

Though often considered only for its nutritional value, many Native American tribes found numerous medicinal uses for Maize and Maize silk. Perhaps the most uniform use of Maize silk is that of a diuretic.  Most often a tea is made either from the silky hairs or the seeds in order to stimulate the bladder and ease pain in cases of cystitis.(3) The diuretic properties of Maize silk have also been used to treat urinary tract infections, gout and rheumatism.(4) The tea made from Maize silk has also been used by several Native American tribes to treat low blood sugar and high blood pressure.(5) In cases of kidney stones, a Maize infusion has been used in order to promote kidney health and treat cases of “gravel” in the kidneys,(6) specifically by those of the Cherokee tribe.(7)

Externally, some Native American tribes have found uses for Z. mays.  A poultice consisting of the meal made from the seeds has been used to treat numerous dermatological maladies and wounds.(4)  The poultice has also been used to ease the sore throats.(6) In the Native American tradition of using as much of a plant as possible, a decoction was made from the dried cobs in order to treat rashes such as poison ivy.(6) The grains of corn have also been used externally to treat and remove warts.(5)

The fresh Z. mays is an ideal habitat for the fungus Ustilago maydis, commonly known as “Corn smut”.  The fungus has been used as a salve in order to treat some dermatological complaints.(6)  U. maydis has also been used in order to both induce and ease labor,(7) and induce delivery of the afterbirth.(5)

When the grains of Z. mays are ingested for medicinal purposes, as opposed to nutritional purposes, they play a role in both the respiratory and digestive systems.  The Cherokee have used parched grains in order to increase lung capacity and improve respiratory function.(6) Either a gruel or an infusion of the grains has been used to treat diarrhea.(7)

Dosage

Dosages vary by tribe, application and preparation.

Tea: 0.5gm placed in cold water, then boiled. Several cups of tea per day may be used as a diuretic.(1)

Pharmacology

Pre-clinical

Diuretic and uricosuric properties have traditionally been attributed to Maize silk. Laboratory studies confirm that extract of cornsilk causes diuresis by increasing glomerular filtration rate and inhibiting sodium, potassium and chloride tubular reabsorption, thereby increasing their urinary excretion.(8),(9)

Maize silk also has antioxidant activity as reported in laboratory studies.(10),(11) The main constituents of Z. mays with antioxidant activity include the volatile compounds cis-alpha-terpineol (24.22%), 6,11-oxidoacor-4-ene (18.06%), citronellol (16.18%), trans-pinocamphone (5.86%), eugenol (4.37%), neo-iso-3-thujanol (2.59%), and cis-sabinene hydrate (2.28%).(2) Maize silk’s antioxidant activity may support its traditional uses in for cystitis, gout, kidney stones, nephritis, and prostatitis.(12)

Maize silk has been reported in a laboratory study to inhibit tumor necrosis factor-alpha (TNF) and E. coli lipopolysaccharide (LPS) induced adhesion molecules and leukocyte adhesion to endothelial cell surface.(13) By interfering with this leukocyte adhesion or adhesion molecule upregulation, cornsilk may be an important therapeutic target for the treatment of bacterial sepsis and various inflammatory diseases, like arthritis and autoimmune conditions. The extract did not alter the production of TNF by LPS-activated macrophages and failed to inhibit the cytotoxic activity of TNF. Further laboratory and human studies are needed to support the use of cornsilk for inflammatory diseases or bacterial sepsis.

Clinical

No documentation

Interaction and Depletions

Interaction with other Herbs

No documentation

Interaction with Drugs

Based on pharmacology, use with caution in individuals on diuretic medications or medications for blood pressure, as Maize silk may increase fluid loss and lead to electrolyte imbalances.

Precautions and Contraindications

Side effects

There are no known side effects when Maize or Maize silk is taken in recommended dosages.

Use with caution if allergic to corn or corn products.

Pregnancy

Not to be used by pregnant or nursing women.

Age limitation

Not to be used with children.

Adverse reaction

No documentation

Read More

  1) Western Herb

  2) South Africa Herbs

References

  1. Wichtl M. Herbal Drugs and Phytopharmaceuticals . Stuttgart: CRC Press MedPharm; 1994.
  2. El-Ghorab A, El-Massry KF, Shibamoto T.Chemical composition of the volatile extract and antioxidant activities of the volatile and nonvolatile extracts of Egyptian corn silk (Zea mays L.) J Agric Food Chem. 31Oct 2007;55(22):9124-9127.
  3. Morgenstern K. Plant Profiles: Corn (Zea mays), Indian Corn, Maize. Sacred Earth.  Available from: http://www.sacredearth.com/ethnobotany/plantprofiles/corn.php.  [Accessed on 27 September 2009].
  4. Miczak M. Nature's Weeds, Native Medicine: Native American Herbal Secrets. Twin Lakes, WI: Lotus Press; 1999.
  5. Heatherley AN. Healing Plants: A Medicinal Guide to Native North American Plants and Herbs. Guilford CT: Lyons Press; 1998.
  6. Moerman DE.  Native American Ethnobotany. Portland OR: Timber Press; 2009.
  7. Hatfield G. Encyclopedia of Folk Medicine: Old World and New World Traditions. Santa Barbara, CA: ABC-CLIO, Inc; 2004.
  8. Maksimović Z, Kovacevic N, Milovanovic Z. Diuretic activity of Maydis stigma extract in rats. DiePharmazie. 2004;59:12.
  9. Velazquez DV, Xavier HS, Batista JE, de Castro-Chaves C.  Zea mays L. extracts modify glomerular function and potassium urinary excretion in conscious rats. Phytomedicine. May2005;12(5):363-369.
  10. Maksimović Z, Malencić D, Kovacević N.Polyphenol contents and antioxidant activity of Maydis stigma extracts. Bioresour Technol. May2005;96(8):873-877.
  11. Maksimovi ZA, Kova N. Preliminary assay on the antioxidative activity of Maydis stigma extracts. Fitoterapia. Feb2003;74(1-2):144-147.
  12. Ebrahimzadeh MA, Pourmorad F. Hafezi S.  Antioxidant activities of Iranian corn silk. Turk J Biol. 2008;32:43-49.
  13. Habtemariam S. Extract of corn silk (stigma of Zea mays) inhibits the tumour necrosis factor-alpha- and bacterial lipopolysaccharide-induced cell adhesion and ICAM-1 expression. Planta Med. May1998;64(4):314-318.