Aloe Vera

Aloe Vera

Other Names

Aloe derives from the Arabic halal, meaning a shining, bitter substance.1 Among 360 species, Aloe vera is the official name recognized by the International Rules of Botanical Nomenclature.2
Cape aloe
Aloe curacao
Barbadoes aloe
Venezuela aloe
Indian aloe
Mediterranean aloe
Star cactus

What Is It?

Native to southern and eastern Africa, aloe is a perennial succulent with numerous long, tapered fleshy leaves. The leaves contain two markedly different products, one a laxative cell sap, or juice, and the other a mucilaginous gel used widely in cosmetics.

To obtain the laxative juice, aloe leaves are cut at the base and arranged to allow the juice to run out. This fluid is collected and then cooked down to a dark brown concentrate, which solidifies into dry form upon cooling. Also known as “bitter aloes,”this product has a strong odor and a very bitter flavor. 5,6

To obtain Aloe vera gel, the thick leaves of the plant are filleted, and the light green gel tissue in the center of the leaves is preserved in its fully wet condition. In contrast to the dried sap or juice, aloe vera gel has a mild odor and flavor. 7

Medicinal History

Ancient Egyptians called aloe the “plant of immortality,” and depicted aloe in wall paintings. Cleopatra is said to have used aloe as a beauty treatment. 8 Aloe was also employed as an embalming ingredient. In the Gospel Of St. John (19: 39-40), the body of Christ was wrapped in linen and a mixture of myrrh and aloe. 9 As early as the 4th century B.C., Greeks sent by Alexander The Great to the southern Yemen island of Socotra cultivated aloe. Knowledge of aloe’s healing virtues spread.

In his 1^st century A.D “Greek Herbal,” physician Pedianus Dioscorides gave the first detailed description of aloe. Dioscorides noted that the sap, not the gel is the healing agent, equating increased bitterness of aloe with increased effectiveness. According to Dioscorides, taken internally aloe induces sleep and cleanses the stomach, heals tonsillitis and relieves diseases of the mouth; used topically aloe relieves boils, bruises, hemorrhoids, wounds, dry itchy skin and ulcerated genitals, heals foreskin, stops hair loss, and soothes the eyes. 8

Other early herbalists including Galen and Pliny employed aloe. In the 10^th century aloe’s uses were described by Arab physicians, and aloe was introduced to Europe and listed in Anglo Saxon medical texts. In China aloe was called Lu-hui, meaning "black deposit," and was first mentioned in the 11^th century. 8,9 Records from the 17^th century show that Britain’s East India Company purchased and traded aloe from Socotra and Zanzibar. The West Indies became an important commercial region for cultivated aloe sold to the European market as early as the 1600’s. There the Dutch established plantations in Barbados, Curacao, Aruba and Bonaire. 1, 6 Popular demand for an effective laxative effects and other reputed health benefits ensured aloe’s cultivation, processing and trade.

Habitat & Cultivation

From its origin in southern Africa, aloe spread to the Mediterranean, the Middle East, the Caribbean, Central, South, and North Americas. Today aloe is cultivated commercially on a large scale in the US Southwest, Venezuela, South Africa, and the Caribbean, and on a smaller scale in numerous other locations. 1,6

Though aloe is a tropical plant, it withstands extremes in temperature and moisture, as long as the roots do not freeze or sit long in standing water. 8 Aloe grows quickly and yields mature leaves up to 50 cm in length.

How It Works

Aloe contains the laxative agent alloin, also known as barbaloin, or Aloe-emodin anthrone. Alloin acts as a stimulant irritant to the digestive tract, promoting bowel movement and elimination. 4,10,11

Wound healing activity of Aloe vera gel is attributed in part to a complex carbohydrate called acemannan. The anti-inflammatory activity of Aloe vera gel is attributed to an enzyme called bradykinase. 12 Several studies show that Aloe vera gel accelerates wound healing, reduces inflammation, and promotes recovery from burns. 4

Contemporary Uses Approved by Authoritative Bodies

Germany’s Commission E

Aloe - For constipation

World Health Organization

Aloe - Short term treatment of occasional constipation
Aloe vera gel –In its monograph on Aloe vera gel, WHO describes and references its uses for the topical treatment of wounds, inflammation and burns.

Potential Risks

The following information is derived from the World Health Organization, Germany’s Commission E, ESCOP, and the AHPA Botanical Safety Handbook.

Safety issues and concerns:

Aloe may cause cramping and discomfort in the gastrointestinal tract.
Long term aloe use can cause laxative dependency and electrolyte and fluid imbalance.
Chronic abuse may lead to hepatitis.

Aloe should not be used in cases of:

Intestinal obstruction
Dehydration and/or electrolyte depletion
Inflammatory intestinal diseases including Crohn’s disease, ulcerative colitis, irritable bowel syndrome, or diverticulitis.
Cramps, colic, hemorrhoids, nephritis, or undiagnosed abdominal pain, nausea, or vomiting.
By pregnant women or nursing mothers
By children under age 10.

Potentially harmful drug interactions

Aloe may modify the effectiveness of cardiac glycosides and antiarrhythmic drugs.

Allergy precautions

Avoid topical Aloe vera gel in cases of known allergy to Liliaceae plants.

4,10,11,13

Usage Tips

The following dosage guidelines are derived from the World Health Organization, Germany’s Commission E, ESCOP, and the AHPA Botanical Safety Handbook.

Use aloe for occasional constipation only after you have tried increasing your dietary fiber intake.
To relieve occasional constipation take a dose of aloe containing 10 – 30 mg. (not more than 30 mg) of alloin in the evening. This will produce a bowel movement in 6 – 12 hours.
Consume no more than 30 mg of alloin per day without medical supervision.

4,10,11,13

Product Choosing/Buying Tips

Aloe – Look for products which specify alloin content.
Aloe vera gel – Look for products labeled 100% pure Aloe vera gel.

Note

While no world health body officially recognizes Aloe vera gel as a topical healing aid, extensive accounts of traditional use over centuries point to significant benefits. The topical healing properties of Aloe vera gel are widely described in herbal texts, pharmacopoeas, and scientific studies. Even the World Health Organization on the one hand states that there is no officially approved use of Aloe vera for topical healing, and on the other hand offers an Aloe vera gel monograph with an impressive review of significant scientific studies demonstrating topical healing activity. 4

Aloe vera gel products vary widely in actual aloe content. If a product does not state that it is 100% pure aloe vera gel, then it may be highly diluted.

Trivia

The Roman physician Pliny the Elder, stated that fake Aloe was being made and sold near Jerusalem. He called it the "bastard kind".
Between 1500-1600 Spanish conquistadors and missionaries brought aloe to the New World, and planted it around Catholic missions. Aloe quickly came to be used extensively by missionaries and native people as a universal healing agent throughout Caribbean Islands, Central and South America.

References:

1. Tyler, Varro., Brady, Lynn., Robbers, James., Pharmacognosy. 9^th ed., (Philadelphia,

Lea & Febiger, 1988) 62 – 64.

2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, 2nd ed. (New York: John Wiley & Sons, Inc. 1996), 25 – 28.

3. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. 2nd ed., (Paris: Lavoisier Publishing 1993), 363 – 364.

4. World Health Organization. WHO Monographs on Selected Medicinal Plants, Vol. 1. (Geneva, Switzerland: World Health Organization. 1999), 33 – 49.

5. Samuelsson, Gunnar., Drugs of Natural Origin. 3^rd ed., (Stockholm, Swedish

Pharmaceutical Press, 1992), 118.

6. Evans, W.C., Trease and Evans’ Pharmacognosy, 13^th ed., (Philadelphia, Bailliere

Tindall, 1989) 413 – 416.

7. Wichtl M, Bisset NG (eds.). Herbal Drugs and Phytopharmaceuticals. Trans from

2^nd German ed., (Stuttgart: Medpharm GmbH Scientific Publishers. 1994), 59 – 62.

8. “History Of Aloe vera” From History of Biomedicine-Indigenous Cultures

Karolinska Institutet. Retrieved May 3, 2002 from the World Wide Web:

http://www.mic.ki.se/Indig.html

9. Bown, Deni. The Herb Society Of America Encyclopedia of Herbs & Their Uses. 1^st ed., (New York: Dorling Kindersley. 1995), 235.

10. Blumenthal M, Busse W, Goldberg A, Gruenwald J, Hall T, Riggins CW, Rister RS (eds.). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. S. Klein, R.S. Rister (trans.). 1^st ed., (Austin, TX: American Botanical Council. 1998), 80 –81.

11. European Scientific Cooperative on Phytotherapy. ESCOP Monographs on the Medicinal Uses of Plant Drugs. 1^st ed., (Exeter, U.K.: ESCOP 1997), Fascicule 5.

12. Agricultural Research Service, Dr. Duke’s Phytochemical and Ethnobotanical

Databases. http://www.ars-grin.gov/duke/

13. McGuffin M, Hobbs C, Upton R, Goldberg A (eds.). American Herbal Products Association’s Botanical Safety Handbook. 1^st ed., (Boca Raton, FL: CRC Press. 1997), 7 - 8