Zea mays

 

Zea mays

Synonyms

No documentation.

Vernacular Name

Gbade, Gbadese, Gbadoda, Tchara Igbado

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 colour and not as dense. On average, the internodes are roughly measuring 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”  and are seeds which are wrapped tightly in the leaves. Until the time of harvest, the seeds are not visible. Each of the seeds is roughly measured 0.5cm in diametre and grows tightly around the corn cobs in a linear fashion. The seeds are typically yellow, but can be brown, blue, black or red in colour, 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 over 5,000 years ago. It is thought to be native to South America and Africa. It requires some rainfall to thrive but will survive temporarily in harsh conditions.  Ideal conditions are full sunlight and average rainfall.

Chemical Constituents

Cis-alpha-terpineol, 6,11-oxidoacor-4-ene, citronellol, trans-pinocamphone, eugenol, neo-iso-3-thujanol, cis-sabinene hydrate [1].

Plant Part Used

Kernals or seeds and stigmas of the female flowers harvested prior to the fertilisation period [2][3].

Traditional Use

Z. mays, though native to the American continents, has been established as a useful medicinal plant in several parts of Africa. It’s been widely used as a diuretic in some African traditional medical systems.  Typically an infusion or decoction of the styles is used in order to achieve the desired diuretic effect [2].  This use has been considered very effective as a diuretic [3]. In other cases, the dried beards of the cob are decocted and ingested [2]. This has led to the use of Z. mays to treat some urino-genital conditions [4]. The same application has also been used as a hepatoprotective, as Z. mays is thought to be very useful for treating liver maladies [4].

Z. mays has been used to treat general fever along with some bronchial conditions. Typically, the macerated leaved are either ingested directly, or dilute in order to treat both fever [4] and persistent cough [2].  Additionally, Z. mays has been thought to be useful in cases of hypertension. The liquid from boiled stigmas has been thought to be effective in lowering blood pressure [2].

Z. mays is also thought to be effective in treating open sores, wounds and general skin disorders. Perhaps most often, the plant is burned or charred and the ash applied directly to the maligned area [5]. Z. mays is thought to be not only analgesic, but anti-inflammatory [6].

Pharmacology

Pre-clinical

Diuretic and uricosuric properties have traditionally been attributed to Z. mays 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 [7][8].

Z. mays silk also has antioxidant activity as reported in laboratory studies [9][10]. 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%) [1]. Z. mays silk’s antioxidant activity may support its traditional uses in for cystitis, gout, kidney stones, nephritis, and prostatitis [11].

Z. mays 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 [12]. 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 Z. mays silk may increase fluid loss and lead to electrolyte imbalances.

Precautions and Contraindications

Side effects

There are no known side effects when Z. mays or Z. mays 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) Native American Herbs

References

  1. 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. Oct. 31, 2007;55(22):9124-9127.
  2. Neuwinger HD. African Traditional Medicine: A Dictionary of Plant Use and Applications. Stuttgart, Germany: Medpharm Gmbh Scientific Publishers; 2000.
  3. Buolos L. Medicinal Plants of North Africa.  Algonac, MI: Reference Publications; 1983:349.
  4. Schmeltzer GH, Gurib-Fakim A, AGROOH. Medicinal Plants 1. Wageningen, Netherlands: Plant Resources of Tropical Africa; 2008.
  5. Gelfand M, Mavi S, Drummond RB, Ndemera B. The Traditional Medical Practitioner in Zimbabwe.  Gweru, Zimbabwe: Mambo Press; 1985:324.
  6. Baerts-Lehmann M, Lehmann J.  Prelude Medicinal Plants Database.  Catholic University of Louvain. 2007 Available from: http://www.metafro.be/prelude.  [Accessed on  March 28, 2009].
  7. Maksimović Z, Kovacevic N, Milovanovic Z. Diuretic activity of Maydis stigma extract in rats. DiePharmazie. 2004;59:12.
  8. 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. May 2005;12(5):363-369.
  9. Maksimović Z, Malencić D, Kovacević N.Polyphenol contents and antioxidant activity of Maydis stigma extracts. Bioresour Technol. May 2005;96(8):873-877.
  10. Maksimovi ZA, Kova N. Preliminary assay on the antioxidative activity of Maydis stigma extracts. Fitoterapia. February 2003;74(1-2):144-147.
  11. Ebrahimzadeh MA, Pourmorad F. Hafezi S. Antioxidant activities of Iranian corn silk. Turk J Biol. 32;2008:43-49.
  12. 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. May 1998;64(4):314-318.