{{Taxobox
| color = lightgreen
| name = ''Aloe''
| image = Koeh-007.jpg
| image_width = 240px
| image_caption = ''[[Aloe succotrina]]''
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Asphodelaceae]]
| genus = '''''Aloe'''''
| genus_authority = [[Carolus Linnaeus|L.]]
| subdivision_ranks = Species
| subdivision = See [[Aloe#Species|Species]]
}}
{{otheruses}}

'''''Aloe''''', also written ''Aloë'', is a [[genus]] containing about four hundred [[species]] of [[flowering plants|flowering]] [[succulent plant|succulent]] [[plants]].

The genus is native to [[Africa]] and is common in [[South Africa]]'s [[Cape Province]] and the mountains of tropical Africa, and neighbouring areas such as [[Madagascar]], the [[Arabian peninsula]] and the islands off Africa.

The [[APG II system]] (2003) placed the genus in the family [[Asphodelaceae]]. In the past it has also been assigned to families [[Aloaceae]] and [[Liliaceae]]. Members of the closely allied genera ''[[Gasteria]]'', ''[[Haworthia]]'' and ''[[Kniphofia]]'' which have a similar mode of growth, are also popularly known as aloes. Note that the plant sometimes called "American aloe" (''[[Agave americana]]''), belongs to [[Agavaceae]], a different family.

Most Aloes have a [[rosette (botany)|rosette]] of large, thick, fleshy [[Leaf|leaves]]. The leaves are often lance-shaped with a sharp apex and a spiny margin. Aloe [[flower]]s are tubular, frequently yellow, orange or red and are borne on densely clustered, simple or branched leafless stems.

Many species of Aloe are seemingly stemless, with the rosette growing directly at ground level; other varieties may have a branched or un-branched [[plant stem|stem]] from which the fleshy leaves spring. They vary in colour from grey to bright green and are sometimes striped or mottled.

==Uses==
{{Refimprove|date=February 2007}}
''Aloe'' species are frequently cultivated as ornamental plants both in gardens and in pots. Many ''Aloe'' species are highly decorative and are valued by collectors of succulents. Some species, in particular ''[[Aloe vera]]'' are purported to have medicinal properties.

Other use of Aloes include their role in [[alternative medicine]]s (see [[Herbalism]]) and in home first aid. Both the translucent inner pulp and the resinous yellow exudate from wounding the Aloe plant are used ''externally'' to relieve skin discomforts and ''internally'' as a laxative. To date, some research has shown that Aloe vera produces positive medicinal benefits for healing damaged skin. Conversely, other research suggests Aloe vera can negatively affect healing (Vogler and Ernst, 1999).
In [[homeopathy|homeopathic medicine]] aloe is used for hemorrhoids<ref>{{cite book
| last = money gill
| first = Roger
| title = Desktop guide to keynotes and confirmatory symptoms
| publisher =Hahnemann Clinic Publishing
|date=1993
| location =Grass Valley, CA
| ISBN =0-9635368-0-X}}
</ref>.

Some Aloe species have also been used for human consumption. For example, drinks made from or containing chunks of aloe pulp are popular in Asia as commercial beverages and as a tea additive; this is notably true in [[Korea]].

===External uses===
Aloe is used externally to treat a number of skin irritations. It has [[antiseptic]] and [[antibiotic]] properties which make it highly valuable in treating cuts and abrasions. It has also been commonly used to treat first and second degree burns, as well as [[sunburn]]s and [[poison oak]], [[poison ivy]], and [[poison sumac]] infections, and [[eczema]]. It can also be used as a hair styling gel and works especially well for curly or frizzy hair.

===Internal uses===
[[Image:Aloe vossii - plant (aka).jpg|right|thumb|200px|''[[Aloe vossii]]'']]
Aloe contains a number of medicinal substances used as a [[purgative]]. The medicinal substance is produced from various species of aloe, such as ''A. vera'', ''A. vulgaris'', ''A. socotrina'', ''A. chinensis'', and ''A. perryi''. Several kinds of aloes are commercially available: Barbadoes, Socotrine, Hepatic, Indian, and Cape aloes. Barbadoes and Socotrine are the varieties most commonly used for curative purposes {{Fact|date=February 2007}}.

Aloes are the expressed juice of the leaves of the plant. When the leaves are cut, the juice that flows out is collected and evaporated. After the juice has been removed, the leaves are sometimes boiled to yield an inferior kind of aloes. The juice of the leaves of certain species, e.g. ''Aloe venenosa'', is [[poison]]ous.

<!--Aloe's benefits include ingesting aloe juice to lower blood sugar levels in diabetes patients.{{Fact|date={{subst:CURRENTMONTHNAME}} {{subst:CURRENTYEAR}}}}-->
There have been very few properly conducted studies about possible benefits of aloe gel taken internally. One study found improved wound healing in mice. Another found a positive effect of lowering risk factors in patients with heart disease. Some research has shown decreasing fasting blood sugar in diabetic animals given aloe<ref>Ghannam N and others. The antidiabetic activity of aloes: Preliminary clinical and experimental observations. Hormone Research 24:288-294, 1986. [http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=3096865&dopt=AbstractPlus available online]</ref><ref>Ajabnoor MA. Effect of aloes on blood glucose levels in normal and alloxan diabetic mice. Journal of Ethnopharmacology 28:215-220, 1990. [http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=2109811&dopt=AbstractPlus available online]</ref><ref>Al-Awadi F, Fatania H, Shamte U. The effect of a plants mixture extract on liver gluconeogenesis in streptozotocin induced diabetic rats. Diabetes Research 18:163-168, 1991. [http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=1842751&dopt=AbstractPlus available online]</ref><ref>Roman-Ramos R and others. Experimental study of the hypoglycemic effect of some antidiabetic plants. Archivos de Investigacion Medica 22(1):87-93, 1991.[http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=1819981&dopt=AbstractPlus available online]</ref>. None of these studies can be considered to be definitive, and there are many false advertising claims for aloe.

Aloe has been marketed as a remedy for coughs, wounds, [[ulcer]]s, [[gastritis]], [[diabetes]], [[cancer]], [[headache]]s, [[arthritis]], [[immune-system deficiencies]], and many other conditions when taken internally. However, these uses are unsubstantiated; the only substantiated internal use is as a [[laxative]]. Furthermore, there is evidence of potential adverse side effects (for example, acute [[hepatitis]]<ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15633238 Acute hepatitis induced by an Aloe vera preparation: a case report]</ref>). Although some studies suggest that certain components of aloe such as aloe-emodin have genotoxic activity, human clinical trials and rodent carcinogenicity studies do not substantiate a genotoxic risk to humans when aloe products are consumed as directed{{cite journal |author=Brusick D, Mengs U |title=Assessment of the genotoxic risk from laxative senna products |journal=Environ Mol Mutagen |volume=29 |issue=1 |pages=1-9 |year=1997 |id=PMID 9020301}}.

On May 9, 2002, the U.S. Food and Drug Administration issued a final rule banning the use of aloe and [[Rhamnus purshiana|cascara sagrada]] as laxative ingredients in over-the-counter drug products.{{Fact|date=October 2007}}

===Chemical properties of aloin ===
[[Image:Split Aloe.jpg|thumb|right|200px|Split Aloe]]
According to W. A. Shenstone, two classes of [[Aloin|aloins]] are to be recognized: (1) [[nataloin]]s, which yield [[picric acid|picric]] and [[oxalic acid]]s with [[nitric acid]], and do not give a red coloration with nitric acid; and (2) [[barbaloin]]s, which yield [[aloetic acid]] (C₇H₂N₃O₅), [[chrysammic acid]] (C₇H₂N₂O₆), picric and oxalic acids with nitric acid, being reddened by the acid. This second group may be divided into a-barbaloins, obtained from Barbadoes aloes, and reddened in the cold, and b-barbaloins, obtained from Socotrine and Zanzibar aloes, reddened by ordinary nitric acid only when warmed or by fuming acid in the cold. Nataloin (2C₁₇H₁₃O₇·H₂O) forms bright yellow scales. Barbaloin (C₁₇H₁₈O₇) forms yellow [[Prism (geometry)|prism]]atic crystals. Aloes also contain a trace of volatile oil, to which its odour is due.{{Fact|date=April 2007}}

==Heraldry==
The aloe plant (''A. rubrolutea'') occurs as a charge in [[heraldry]], such as in the Civic Heraldry of Namibia [http://www.ngw.nl/int/afr/windhoek.htm]

==Species==<!-- This section is linked from [[Aloe]] -->
There are around 400 species in the genus ''Aloe''. For a full list, see [[List of species of genus Aloe]]. Species include:
*''[[Aloe arborescens]]'' - Aloe Arborescens Miller, used in healthcare
*''[[Aloe aristata]]'' - Torch Plant, Lace Aloe
*''[[Aloe dichotoma]]'' - quiver tree or kokerboom
*''[[Aloe nyeriensis]]''
*''[[Aloe variegata]]'' - Partridge-breasted Aloe, Tiger Aloe
*''[[Aloe vera]]'' Barbados Aloe, Common Aloe, Yellow Aloe, Medicinal Aloe. This is the variety used medicinally.
*''[[Aloe wildii]]''

==References==
<references/>
*Schmidt JM, Greenspoon JS (1991) Aloe vera dermal wound gel is associated with a delay in wound healing. ''Obstet Gynecol'' 1: 115-117.
*Vogler BK, Ernst E (1999) Aloe vera: a systematic review of its clinical effectiveness ''British Journal of General Practice'' 49: 823-828.
*International Aloe Science Council: http://www.iasc.org/aloe.html
*University of Maryland Medical Center: http://www.umm.edu/altmed/ConsHerbs/Aloech.html
*Craig, Winston. The All-purpose Gel. ''Vibrant Life'' July 2001.
*Farrar, Maureen Meyers. Skin Deep. ''Better Nutrition'' July 2005.
*''British Journal of General Practice'', October 1999

==Links==
[[List of Southern African indigenous trees]]

==Bibliography==
*''The Aloes of South Africa'' - Gilbert Westacott Reynolds (AA Balkema, Cape Town 1969)
*''Grass Aloes in the South African Veld'' - Charles Craib & Gillian Condy (Umdaus Press, Pretoria 2006) ISBN 1-919766-41-3

==External links==
{{commons|Aloe}}
*[http://content.herbalgram.org/abc/healthyingredients/default.asp?h=Aloe American Botanical Council Web site] Information, news, and studies about Aloe Vera from the American Botanical Council
*[http://www.aloe-vera-studies.org/aloe-vera-plant.php Aloe Vera Plant Uses and Growing Guide]
*[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=101163 Flora of North America: ''Aloe'']
*[http://www.natural-medicinal-herbs.com/herbs/aloe.htm Aloe Vera Guide] Complete Information on Aloe Vera
*[http://www.fleuraloe.com/home_in.html Fleur Aloe '''Information and Products Aloe''' Manufacturing Majoca (Mallorca)] ( Englis, Deutch and Spanish )

==Images==
<gallery>
Image:Babosa1.jpg|''[[Aloe arborescens]]''
Image:Aloe aristata.jpg|''[[Aloe aristata]]''
Image:Köcherbaum_Köcherbaumwald_01.JPG|''[[Aloe dichotoma]]''
Image:Aloe_hereroensis_Auob_C15.JPG|''[[Aloe hereroensis]]''
Image:Aloe_parvula.JPG|''[[Aloe parvula]]''
Image:Aloe peglerae01.jpg|''[[Aloe peglerae]]''
Image:Aloe_saponaria_1.jpg|''[[Aloe saponaria]]''
Image:Aloe_saponaria_3.jpg|''[[Aloe saponaria]]'' flower
Image:Aloe_striatula_1.jpg|''[[Aloe striatula]]''
Image:Aloes on N6 Route.jpg|''[[Aloe - unidentified]]''
</gallery>

[[Category:Aloe]]
[[Category:Medicinal plants]]
[[Category:Laxatives]]
[[Category:Cosmetic chemicals]]

[[ar:نبات الصبر]]
[[bs:Aloe]]
[[bg:Алое]]
[[ca:Àloe]]
[[da:Aloe]]
[[de:Aloen]]
[[et:Aaloe]]
[[es:Aloe]]
[[eo:Aloo]]
[[fr:Aloès]]
[[hsb:Wohnjowy alowej]]
[[hr:Aloe]]
[[it:Aloe (botanica)]]
[[kn:ಲೋಳೆ ಸರ]]
[[ka:ალოე]]
[[lt:Alavijas]]
[[nl:Aloë]]
[[ja:アロエ]]
[[no:Aloe]]
[[pl:Aloes]]
[[pt:Aloe]]
[[ru:Алоэ]]
[[sr:Алоје]]
[[fi:Aaloet]]
[[sv:Aloe]]
[[uk:Алое]]
[[ur:صَبِر]]
[[zh:芦荟]]