''Aloe vera'' () is a
succulent plant
In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meanin ...
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Aloe
''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering plant, flowering succulent plant, succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Acc ...
''.
It is widely distributed, and is considered an
invasive species
An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...
in many world regions.
[
An ]evergreen
In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...
perennial
In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...
, it originates from the Arabian Peninsula
The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world.
Geographically, the ...
, but also grows wild in tropical, semi-tropical, and arid climates around the world.[ It is cultivated for commercial products, mainly as a topical treatment used over centuries.][ The species is considered attractive for decorative purposes, and is often used indoors as a potted plant.
The leaves of ''Aloe vera'' contain significant amounts of the polysaccharide gel acemannan, which can be used for topical purposes. The leaves also contain aloin, which is a toxic compound. ''Aloe vera'' products are typically made from the gel.
''Aloe vera'' acemannan may be used in skin lotions, ]cosmetics
Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...
, ointments and gels for minor burns, skin abrasions, insect bites, and windburn.
Oral ingestion of aloe vera extract
An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures or absolutes or dried and powdered.
The aromatic principles of ma ...
s may cause acute abdominal pain and cramps, and hepatitis
Hepatitis is inflammation of the liver parenchyma, liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), Anorexia (symptom), poor appetite ...
if consumed chronically.[ It should not be used during pregnancy. Some people have allergic reactions to aloe when used on skin.]
Etymology
The genus name ''Aloe
''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering plant, flowering succulent plant, succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Acc ...
'' is derived from the Arabic
Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...
word ''alloeh'', meaning "bitter and shiny substance" or from Hebrew
Hebrew (; ''ʿÎbrit'') is a Northwest Semitic languages, Northwest Semitic language within the Afroasiatic languages, Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and ...
''ahalim'', plural of ''ahal''. The specific epithet
In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
''vera'' comes from ''verus'' meaning "true" in Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
.[
]
Common names
Common names use ''aloe'' with a region of its distribution, such as ''Chinese aloe'', ''Cape aloe'' or ''Barbados
Barbados, officially the Republic of Barbados, is an island country in the Atlantic Ocean. It is part of the Lesser Antilles of the West Indies and the easternmost island of the Caribbean region. It lies on the boundary of the South American ...
aloe''.
Taxonomy
The species has several synonyms
A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...
: ''Aloe barbadensis'' Mill., ''Aloe indica'' Royle, ''Aloe perfoliata'' L. var. ''vera'' and ''Aloe vulgaris'' Lam. Some literature identifies the white-spotted form of ''Aloe vera'' as ''Aloe vera'' var. ''chinensis''; and the spotted form of ''Aloe vera'' may be conspecific with ''A. massawana''. The species was first described by Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
in 1753 as ''Aloe perfoliata'' var. ''vera'', and was described again in 1768 by Nicolaas Laurens Burman
Nicolaas Laurens Burman (27 December 1734 – 11 September 1793) was a Dutch botanist.
He was the son of Johannes Burman (1707–1780). He succeeded his father to the chair of botany at the Athenaeum Illustre of Amsterdam., and at the Hortus Bot ...
as ''Aloe vera'' in ''Flora Indica'' on 6 April and by Philip Miller
Philip Miller Royal Society, FRS (1691 – 18 December 1771) was an English botany, botanist and gardener of Scottish descent. Miller was chief gardener at the Chelsea Physic Garden for nearly 50 years from 1722, and wrote the highly popular ...
as ''Aloe barbadensis'' some ten days after Burman in the ''Gardener's Dictionary''.
Techniques based on DNA comparison suggest ''Aloe vera'' is relatively closely related to '' Aloe perryi'', a species endemic to Yemen. Similar techniques, using chloroplast
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...
DNA sequence comparison and inter simple sequence repeat profiling have also suggested it is closely related to '' Aloe forbesii'', '' Aloe inermis'', '' Aloe scobinifolia'', '' Aloe sinkatana'', and '' Aloe striata''. With the exception of the South African species ''A. striata'', these ''Aloe'' species are native to Socotra
Socotra, locally known as Saqatri, is a Yemeni island in the Indian Ocean. Situated between the Guardafui Channel and the Arabian Sea, it lies near major shipping routes. Socotra is the largest of the six islands in the Socotra archipelago as ...
(Yemen), Somalia, and Sudan. The lack of obvious natural populations of the species has led some authors to suggest ''Aloe vera'' may be of hybrid origin.
Description
''Aloe vera'' is a stemless or very short-stemmed plant growing to tall, spreading by offsets.[
]
Leaves
The leaves are thick and fleshy, green to grey-green, with some varieties showing white flecks on their upper and lower stem surfaces.[Yates A. (2002) ''Yates Garden Guide''. Harper Collins Australia] The margin of the leaf is serrated and has small white teeth.
''Aloe vera'' leaves contain phytochemicals under study for possible bioactivity, such as lignans, phytosterol
Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanol ester, stanols. More than 250 sterols and related compounds have been identified ...
s, polyphenol
Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...
s, acetylated mannans, polymannans, anthraquinones C-glycoside
In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...
s, anthrones, and other anthraquinones, such as emodin and various lectin
Lectins are carbohydrate-binding proteins that are highly specific for sugar Moiety (chemistry), groups that are part of other molecules, so cause agglutination (biology), agglutination of particular cells or precipitation of glycoconjugates an ...
s.
Flowers
The flowers are produced in summer on a spike up to tall, each flower being pendulous, with a yellow tubular corolla long.[ Random House Australia/]
Roots
Like other ''Aloe'' species, ''Aloe vera'' forms arbuscular mycorrhiza, a root symbiosis
Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...
that allows the plant better access to mineral nutrients from the soil.
Distribution
''Aloe vera'' is considered to be native only to the south-east Arabian Peninsula
The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world.
Geographically, the ...
in the Hajar Mountains in north-eastern Oman
Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...
and eastern U.A.E. However, it has been widely cultivated around the world, and has become naturalized in North Africa, as well as Sudan and neighboring countries, along with the Canary Islands
The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...
, Cape Verde
Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...
, and Madeira Islands. It has also naturalized in the Algarve
The Algarve (, , ) is the southernmost NUTS statistical regions of Portugal, NUTS II region of continental Portugal. It has an area of with 467,495 permanent inhabitants and incorporates 16 municipalities (concelho, ''concelhos'' or ''município ...
region of Portugal, and in wild areas across Spain, especially in the region of Murcia.
The species was introduced to China and various parts of southern Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
in the 17th century. It is widely naturalized elsewhere, occurring in arid, temperate, and tropical regions of temperate continents. The current distribution may be the result of cultivation.[
]
Cultivation
''Aloe vera'' has been widely grown as an ornamental plant. The species is popular with modern gardeners as a topical medicinal plant[ and for its interesting flowers, form, and succulence. This succulence enables the species to survive in areas of low natural rainfall, making it ideal for rockeries and other low water-use gardens.] The species is hardy in zones 8–11, and is intolerant of heavy frost and snow. The species is relatively resistant to most insect pests, though spider mites, mealy bugs, scale insects, and aphid
Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...
species may cause a decline in plant health. This plant has gained the Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...
's Award of Garden Merit
The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions.
It includes the full range of cultivated p ...
.
In pots, the species requires well-drained, sandy potting soil, and bright, sunny conditions. Aloe plants can turn red from sunburn under too much direct sun, though gradual acclimation may help. The use of a good-quality commercial propagation mix or packaged "cacti and succulent mix" is recommended, as they allow good drainage. Terra cotta pots are preferable as they are porous. Potted plants should be allowed to completely dry before rewatering. When potted, aloes can become crowded with "pups" growing from the sides of the "mother plant". Plants that have become crowded can be divided and repotted to allow room for further growth, or the pups can be left with the mother plant. During winter, ''Aloe vera'' may become dormant, during which little moisture is required. In areas that receive frost or snow, the species is best kept indoors or in heated glasshouses. Houseplants requiring similar care include haworthia and agave.
There is large-scale agricultural production of ''Aloe vera'' in Australia, Cuba, the Dominican Republic, China, Mexico, India, Jamaica, Kenya, Tanzania, South Africa, Spain, and the United States, with much of the output going toward the cosmetics industry.[
]
Uses
Two substances from ''Aloe vera'' – a clear gel and its yellow latex
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well.
In nature, latex is found as a wikt:milky, milky fluid, which is present in 10% of all floweri ...
– are used to manufacture commercial products.[ Aloe gel typically is used to make ]topical medication
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surface area, body surfaces such as the skin or mucous membranes to treat ailments via a large ...
s for skin conditions, such as burns, wounds, frostbite, rashes, psoriasis, cold sores, and dry skin.[ Aloe latex is used individually or manufactured as a product with other ingredients to be ingested for relief of ]constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The Human feces, stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the ...
.[ Aloe latex may be obtained in a dried form called ''resin'' or as "aloe dried juice".]
There is conflicting evidence regarding whether ''Aloe vera'' is effective as a treatment for wounds or burns.[ There is some evidence that topical use of aloe products might relieve symptoms of certain skin disorders, such as psoriasis, ]acne
Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...
, or rashes,[ but topical application may cause an ]allergic reaction
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...
in some people.[
''Aloe vera'' gel is used commercially as an ingredient in ]yogurt
Yogurt (; , from , ; also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial Fermentation (food), fermentation of milk. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to ...
s, beverages, and some desserts, but at high or prolonged doses, ingesting aloe latex or whole leaf extract can be toxic. Use of topical aloe vera in small amounts is likely to be safe.[
]
Topical medication and potential side effects
''Aloe vera'' may be prepared as a lotion
Lotion is a low-viscosity topical preparation intended for application to the skin. By contrast, creams and gels have higher viscosity, typically due to lower water content. Lotions are applied to external skin with bare hands, a brush, a clea ...
, gel, soap or cosmetics
Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...
product for use on skin as a topical medication.[ For people with ]allergies
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...
to ''Aloe vera'', skin reactions may include contact dermatitis
Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes ...
with mild redness and itching, difficulty with breathing, or swelling of the face, lips, tongue, or throat.
Dietary supplement
Aloin, a compound found in the semi-liquid latex of some ''Aloe'' species, was a common ingredient in over-the-counter (OTC) laxative products in the United States until 2002 when the Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...
banned it because manufacturers failed to provide the necessary safety data.[ ''Aloe vera'' has potential toxicity, with ]side effects
In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects.
A drug or procedure usually used ...
occurring at some dose levels both when ingested and when applied topically. Although toxicity may be less when aloin is removed by processing, ''Aloe vera'' ingested in high amounts may induce side effects, such as abdominal pain, diarrhea or hepatitis
Hepatitis is inflammation of the liver parenchyma, liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), Anorexia (symptom), poor appetite ...
. Chronic ingestion of aloe (dose of 1 gram per day) may cause adverse effects, including hematuria, weight loss, and cardiac or kidney disorders.[
''Aloe vera'' juice is marketed to support the health of the digestive system, but there is neither scientific evidence nor regulatory approval for this claim.] The extracts and quantities typically used for such purposes are associated with toxicity in a dose-dependent way.
Traditional medicine
''Aloe vera'' is used in traditional medicine as a skin treatment. Early records of its use appear from the fourth millennium BCE.[ It is also written of in the '' Juliana Anicia Codex'' of 512 CE.][Reynolds, Tom (Ed.) (2004) ''Aloes: The genus Aloe (Medicinal and Aromatic Plants - Industrial Profiles''. CRC Press. ]
Commodities
''Aloe vera'' is used on facial tissue
Facial tissue and paper handkerchief refers to a class of soft, absorbent, disposable papers that are suitable for use on the face. They are disposable alternatives for cloth handkerchiefs. The terms are commonly used to refer to the type of tis ...
s where it is promoted as a moisturizer and anti-irritant to reduce chafing of the nose. Cosmetic companies commonly add sap or other derivatives from ''Aloe vera'' to products such as makeup, tissues, moisturizers, soaps, sunscreens, incense, shaving cream, or shampoos. A review of academic literature notes that its inclusion in many hygiene products is due to its "moisturizing emollient effect".
Toxicity
Orally ingested non-decolorized aloe vera leaf extract was listed by the California Office of Environmental Health Hazard Assessment among "chemicals known to the state to cause cancer or reproductive toxicity", possibly resulting from the anthraquinones.[
Since 2016, aloe vera whole leaf extract is classified as a possible human carcinogen ( group 2B) by the ]International Agency for Research on Cancer
The International Agency for Research on Cancer (IARC; ) is an intergovernmental agency forming part of the World Health Organization of the United Nations.
Its role is to conduct and coordinate research into the causes of cancer. It also cance ...
.
Use of aloe vera on the skin is generally not associated with significant side effects.[ Oral ingestion of aloe vera is potentially toxic,][ and may cause abdominal cramps and diarrhea which in turn can decrease the absorption of drugs.][
]
Interactions with prescribed drugs
Ingested aloe products may have adverse interactions with prescription drugs, such as those used to treat blood clots, diabetes
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...
, heart disease
Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina pectoris, angina, myocardial infarction, heart attack), heart failure, ...
and potassium
Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...
-lowering agents (such as Digoxin
Digoxin (better known as digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart disease, heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. ...
), and diuretics, among others.[
]
Gallery
File:Aloe vera leaf showing the gel (1).JPG, Leaf and inner gel
File:Aloe vera gel.jpg, Gel used for desserts
File:Es Lidah Buaya.JPG, ''Es lidah buaya'', an Indonesian ''Aloe vera'' iced drink
File:Gelaloevera.JPG, Juice
File:Cut Aloe Vera Leaf.jpg, Cut leaf
File:Aloe vera cut leaf drawing1.jpg, Diagram of leaf: 1 Cuticle, 2 Chloroplast parenchym, 3 Inner tissue, 4 Vascular bundles
File:Aloe Vera Buds.jpg, Buds
File:Aloe Vera flower.jpg, Flower buds
File:Aloe vera flower 2.jpg, Flowers
File:AloeBluhendD2.JPG, Plants of different sizes
File:A potted aloe vera plant.jpg, A potted plant
File:Aloe plant bud.jpg, Basal shoots (root sprouts)
References
External links
*
{{DEFAULTSORT:Aloe vera
vera
Drought-tolerant plants
Flora of the Arabian Peninsula
Garden plants of Africa