Aloe

Scientific names: Aloe vera, A. perryi Baker (Zanzibar or Socotrine aloe), A. barbadensis Miller (also called A. vera Tournefort ex Linne or A. vulgaris Lamark (Curacao or Barbados aloe), or A. ferox Miller (Cape aloe). A. vera Miller and A. vera L. may not be the same species.

Common names: Aloe also is known as aloe vera, as well as Cape, Zanzibar, Socotrine, Curacao, or Barbados aloes.

Efficacy rating:

ÒÒÒ...Positive clinical trials

Safety rating:

...No safety concerns despite wide use.

What is Aloe?

Aloes, of which there are approximately 500 species, belong to the family Liliaceae. The name, meaning “bitter and shiny substance,” derives from the Arabic alloeh. Indigenous to the Cape of Good Hope, these perennial succulents grow throughout most of Africa, southern Arabia, and Madagascar, and are cultivated in Japan, North and South America, and in the Caribbean and Mediterranean regions. Often attractive ornamental plants, their fleshy leaves are stiff and spiny along the edges and grow in a rosette. Between this layer and the colorless mucilaginous pulp containing the aloe gel are numerous vascular bundles and inner bundle sheath cells from which a bitter yellow sap exudes when the leaves are cut.

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What is it used for?

Traditional/Ethnobotanical uses

Drawings of aloe have been found in wall carvings of Egyptian temples erected in the fourth millennium BC. Called the “Plant of Immortality”, it was a traditional funerary gift for the pharaohs. The Egyptian Book of Remedies (ca. 1500 BC) notes the use of aloe in curing infections, treating the skin, and preparing drugs that were chiefly used as laxatives. The Bible says that Nicodemus brought a mixture of myrrh and aloes for the preparation of Christ's body. Alexander is said to have conquered the island of Socotra to obtain control of it. The Greek physician Dioscorides, in 74 AD, recorded its use to heal wounds, stop hair loss, treat genital ulcers, and eliminate hemorrhoids. In the 6th century AD, Arab traders carried it to Asia. From the Mediterranean region, it was carried to the New World in the 16th century by the Spaniards. In the modern era, its clinical use began in the 1930s as a treatment for roentgen dermatitis.

Topical aloe appears to inhibit infection and promote healing of minor burns and wounds, frostbite, as well as in skin affected by diseases such as psoriasis and seborrheic dermatitis, although some studies have not confirmed these results. Dried aloe latex should be ingested with caution as a drastic cathartic, but its use is not recommended. In 2002, the US Food and Drug Administration required all over-the-counter aloe laxative products to be removed from the US market or reformulated because manufacturers have not provided the necessary safety data.

What is the recommended dosage?

As a gel, A. vera may be applied externally. The resin product causes vomiting and diarrhea and not recommended for internal use.

How safe is it?

Contraindications

Ingestion is contraindicated in pregnant and breast-feeding women, children younger than 12 years of age, patients with inflammatory bowel disease, and elderly patients with suspected intestinal obstruction.

Pregnancy/nursing

Documented adverse effects; do not use. Cathartic, reputed to cause abortion.

Interactions

Potential interactions between ingested aloe resin and the following medications have been identified: digoxin, furosemide, thiazide diuretics, sevoflurane stimulant laxatives, and diabetes drugs.

Side Effects

There has been one report that using the gel as standard wound therapy delayed healing. The gel may cause burning sensations in abraded skin, and redness and itching also can occur. Use caution with cosmetic products containing A. vera gel. A case of acute liver damage after aloe vera ingestion has been reported.

Toxicities

The resin product causes vomiting and diarrhea at doses of 250 mg and is not recommended for internal use.

References

  1. Aloe. Review of Natural Products. Facts & Comparisons [database online]. St. Louis, MO: Wolters Kluwer Health Inc; October 2010.

Copyright © 2009 Wolters Kluwer Health

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