Aloe vera, pronounced ˈ, also known as the
true aloe or
medicinal aloe, is a species of
succulent plantSucculent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climates or soil conditions. Succulent plants store water in their leaves, stems, and also in roots...
in the genus
AloeAloe , also Aloë, is a genus containing about 500 species of flowering succulent plants. The most common and well known of these is Aloe vera, or "true aloe"....
that is believed to have originated in the
SudanSudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
. Aloe vera grows in arid climates and is widely distributed in Africa, India, Nepal and other arid areas.
The species is frequently cited as being used in herbal medicine. Many scientific studies on the use of extracts of Aloe vera have been undertaken, some of them conflicting.
Despite these limitations, there is some preliminary evidence that Aloe vera extracts may be useful in the treatment of wound and burn healing, minor skin infections,
sebaceous cystA sebaceous cyst is a term that loosely refers to either epidermoid cysts or pilar cysts . Because an epidermoid cyst originates in the epidermis and a pilar cyst originates from hair follicles, by definition, neither type of cyst is strictly a sebaceous cyst...
s, diabetes, and elevated
blood lipidsBlood lipids are lipids in the blood, either free or bound to other molecules. They are mostly transported in a protein capsule, and the density of the lipids and type of protein determines the fate of the particle and its influence on metabolism. The concentration of blood lipids depends on...
in humans. These positive effects are thought to be due to the presence of compounds such as polysaccharides, mannans, anthraquinones, and lectins.
Description
Aloe vera is a stemless or very short-stemmed succulent plant growing to 60–100 cm (24–39 in) tall,spreading by
offsetsIn botany and horticulture Offset is a term used to describe a small virtually complete daughter plant that has been naturally asexually produced on the mother plant. They are clones , meaning that they are genetically identical to the mother plant. In the plant nursery business and gardens they...
. The leaves are thick and fleshy, green to grey-green, with some varieties showing white flecks on the upper and lower stem surfaces. The margin of the leaf is serrated and has small white teeth. The
flowerA flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are produced in summer on a spike up to 90 cm (35.4 in) tall, each flower pendulous, with a yellow tubular corolla 2–3 cm (0.8–1.2 in) long. Like other Aloe species, Aloe vera forms
arbuscular mycorrhizaAn arbuscular mycorrhiza is a type of mycorrhiza in which the fungus penetrates the cortical cells of the roots of a vascular plant....
, a
symbiosisSymbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
that allows the plant better access to
mineralA mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
nutrients in soil.
Taxonomy and etymology
The species has a number of
synonymsIn scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
: A. barbadensis Mill., Aloe indica Royle, Aloe perfoliata L. var. vera and A. vulgaris Lam., and common names including Chinese Aloe, Indian Aloe, true Aloe, Barbados Aloe, burn Aloe, first aid plant. The species name vera means "true" or "genuine." Some literature identifies the white spotted form of Aloe vera as Aloe vera var. chinensis, however, the species varies widely with regard to leaf spots and it has been suggested that the spotted form of Aloe vera may be conspecific with A. massawana. The species was first described by Carl Linnaeus in 1753 as Aloe perfoliata var. vera, and was described again in 1768 by
Nicolaas Laurens BurmanNicolaas Laurens Burman was a Dutch botanist.He was the son of Johannes Burman . He succeeded his father to the chair of botany at the University of Amsterdam., and at the Hortus Botanicus. He continued the correspondence with Carolus Linnaeus, joining him at the University of Uppsala in 1760...
as Aloe vera in Flora Indica on the 6th of April and by
Philip MillerPhilip Miller FRS was a Scottish botanist.Miller was chief gardener at the Chelsea Physic Garden from 1722 until he was pressured to retire shortly before his death...
as Aloe barbadensis some ten days after Burman in the Gardener's Dictionary.
Techniques based on
DNADeoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
comparison suggest that Aloe vera is relatively closely related to
Aloe perryiAloe perryi is a species of plant in the genus Aloe. It is endemic to Socotra in Yemen. Its natural habitat is rocky areas.-References:* Miller, A. 2004. . Downloaded 20 August 2007....
, a species that is endemic to
YemenThe Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....
. Similar techniques, using
chloroplastChloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
DNA sequence comparison and ISSR profiling have also suggested that Aloe vera is closely related to
Aloe forbesiiAloe forbesii is a small stemless Aloe native to Socotra, Yemen....
,
Aloe inermisAloe inermis is a small, stemless Aloe native to Yemen.-References:*...
,
Aloe scobinifoliaAloe scobinifolia is a small, stemless Aloe from Somalia....
,
Aloe sinkatanaAloe sinkatana is a small, stemless Aloe native to Sudan....
, and
Aloe striataAloe striata is a small, stemless South African Aloe....
. With the exception of South African species A. striata, these Aloe species are native to
SocotraSocotra , also spelt Soqotra, is a small archipelago of four islands in the Indian Ocean. The largest island, also called Socotra, is about 95% of the landmass of the archipelago. It lies some east of the Horn of Africa and south of the Arabian Peninsula. The island is very isolated and through...
(
YemenThe Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....
),
SomaliaSomalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
, and
SudanSudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
. The lack of obvious natural populations of the species have led some authors to suggest that Aloe vera may be of hybrid origin.
Distribution
The natural range of Aloe vera is unclear, as the species has been widely cultivated throughout the world. Naturalised stands of the species occur in the southern half of the
Arabian peninsulaThe Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
, through North Africa (
MoroccoMorocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
,
MauritaniaMauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
,
EgyptEgypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
) as well as
SudanSudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
and neighbouring countries, along with the
CanaryThe Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
,
Cape VerdeThe Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
, and Madeira Islands. This distribution is somewhat similar to the one of
Euphorbia balsamiferaEuphorbia balsamifera is a plant in the Euphorbia genus. It is distributed from Arabian Peninsula to Sahara and Canary Islands....
,
Pistacia atlanticaPistacia atlantica is a species of pistachio tree known by the English common name Mt. Atlas mastic tree and as the Persian turpentine tree. In Iran it is called baneh. In the Canary Islands is known as Almacigo. Betoum is called in Arabic.- Overview :It is a tree of the genus Pistacia. It is a...
, and a few others, suggesting that a dry sclerophyl forest once covered large areas, but has been dramatically reduced due to desertification in the
SaharaThe Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
, leaving these few patches isolated. Several closely related species (or sometimes identical) can be found on the two extreme sides of the Sahara: Dragon trees and
AeoniumAeonium is a genus of about 35 species of succulent, subtropical plants of the family Crassulaceae.The name comes from the ancient Greek "aionos" ....
being some of the most representative examples.
The species was introduced to
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and various parts of southern Europe in the 17th century. The species is widely naturalised elsewhere, occurring in temperate and tropical regions of
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
,
BarbadosBarbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...
,
BelizeBelize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
,
NigeriaNigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
,
ParaguayParaguay , officially the Republic of Paraguay , is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Paraguay lies on both banks of the Paraguay River, which runs through the center of the...
and the
USThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
It has been suggested that the actual species' distribution is the result of human cultivation and that the taxonomy could be doubtful too.
Cultivation
Aloe vera has been widely grown as an ornamental plant. The species is popular with modern gardeners as a putatively medicinal plant and due to 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
zonesA hardiness zone is a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone...
8–11, although it is intolerant of very heavy frost or snow. The species is relatively resistant to most insect pests, though spider mites, mealy bugs, scale insects, and
aphidAphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
species may cause a decline in plant health. In pots, the species requires well-drained sandy potting soil and bright sunny conditions; however, in very hot and humid tropical or subtropical climates, aloe plants should be protected from direct sun and rain, as they will burn and/or turn mushy easily under these conditions. The use of a good-quality commercial propagation mix or pre-packaged "cacti and succulent mix" is recommended, as they allow good drainage. Terracotta pots are preferable as they are porous. Potted plants should be allowed to completely dry prior to re-watering. When potted aloes become crowded with "pups" growing from the sides of the "mother plant," they should be divided and re-potted to allow room for further growth and help prevent pest infestations. 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. Large scale agricultural production of Aloe vera is undertaken in
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
,
BangladeshBangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
,
CubaThe Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
, the
Dominican RepublicThe Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
,
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
,
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
,
JamaicaJamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
,
KenyaKenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
and
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, along with the USA to supply the cosmetics industry with Aloe vera
gelA gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state...
.
Claims of medical properties
Scientific evidence for the cosmetic and therapeutic effectiveness of aloe vera is limited and when present is frequently contradictory. Despite this, the cosmetic and alternative medicine industries regularly make claims regarding the soothing, moisturizing, and healing properties of aloe vera, especially via Internet advertising. Aloe vera gel is used as an ingredient in commercially available
lotionA lotion is a low- to medium-viscosity, topical preparation intended for application to unbroken skin. By contrast, creams and gels have higher viscosity.Lotions are usually applied to external skin with bare hands, a clean cloth, cotton wool or gauze...
s, yogurt, beverages, and some
dessertIn cultures around the world, dessert is a course that typically comes at the end of a meal, usually consisting of sweet food. The word comes from the French language as dessert and this from Old French desservir, "to clear the table" and "to serve." Common Western desserts include cakes, biscuits,...
s.
Aloe vera juice is used for consumption and relief of digestive issues such as
heartburnHeartburn, also known as pyrosis or acid indigestion is a burning sensation in the chest, just behind the breastbone or in the epigastrium...
and
irritable bowel syndromeIrritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
. The extracts and quantities typically used for these purposes appear to be free from any serious toxicity. It is common practice for cosmetic companies to add sap or other derivatives from Aloe vera to products such as makeup,
tissuesFacial tissue and paper handkerchief refers to a class of soft, absorbent, disposable papers that is suitable for use on the face. They are disposable alternatives for cloth handkerchiefs...
,
moisturizerMoisturizers or emollients are complex mixtures of chemical agents specially designed to make the external layers of the skin softer and more pliable, by increasing its hydration by reducing evaporation. Naturally occurring skin lipids and sterols as well as artificial or natural oils,...
s,
soapIn chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
s,
sunscreenSunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...
s,
incenseIncense is composed of aromatic biotic materials, which release fragrant smoke when burned. The term "incense" refers to the substance itself, rather than to the odor that it produces. It is used in religious ceremonies, ritual purification, aromatherapy, meditation, for creating a mood, and for...
,
shaving creamShaving cream is a substance that is applied to the face or wherever else hair grows, to provide lubrication and avoid razor burn during shaving. Shaving cream is often bought in a spray can, but can also be purchased in tubs or tubes. Shaving cream in a can is commonly dispensed as a foam or a gel...
, and
shampooShampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair...
s. Other uses for extracts of aloe vera include the dilution of
semenSemen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
for the artificial fertilization of sheep, use as fresh food preservative, and use in
water conservationWater conservation refers to reducing the usage of water and recycling of waste water for different purposes such as cleaning, manufacturing, and agricultural irrigation.- Water conservation :Water conservation can be defined as:...
in small farms. The supposed therapeutic uses of Aloe vera are not exclusive to the species and may be found to a lesser or greater degree in the gels of all aloes, and indeed are shared with large numbers of plants belonging to the family
AsphodelaceaeAsphodeloideae is a subfamily of the monocot family Xanthorrhoeaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae. The subfamily name is derived from the generic name of the type genus, Asphodelus...
. Bulbine frutescens, for example, is used widely for the treatment of burns and a host of skin afflictions.
Aloe vera has a long association with herbal medicine, although it is not known when its medical applications were first suspected. Early records of Aloe vera use appear in the
Ebers PapyrusThe Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor, in the winter of 1873–74 by Georg Ebers...
from 16th century BC, in both Dioscorides' De Materia Medica and
Pliny the Elder'sGaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
Natural History written in the mid-first century CE along with the Juliana Anicia Codex produced in 512 AD. Aloe vera is non-toxic, with no known side effects, provided the
aloinAloin, also known as Barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 Aloe species at levels from 0.1 to 6.6% of leaf dry weight , and in another 17 species at indeterminate levels [Reynolds, 1995b]...
has been removed by processing. Taking aloe vera that contains
aloinAloin, also known as Barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 Aloe species at levels from 0.1 to 6.6% of leaf dry weight , and in another 17 species at indeterminate levels [Reynolds, 1995b]...
in excess amounts has been associated with various side-effects. However, the species is used widely in the traditional herbal medicine of
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
,
JapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
RussiaRussia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
,
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Jamaica, Latin America and
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
.
Aloe vera may be effective in treatment of wounds. Evidence on the effects of its sap on wound healing, however, is limited and contradictory. Some studies, for example, show that aloe vera promotes the rates of healing, while, in contrast, other studies show that wounds to which aloe vera gel was applied were significantly slower to heal than those treated with conventional medical preparations. A more recent review (2007) concludes that the cumulative evidence supports the use of aloe vera for the healing of first to second degree burns.
In addition to topical use in wound or burn healing, internal intake of aloe vera has been linked in preliminary research with improved blood
glucoseGlucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
levels in diabetics, and with lower blood
lipidLipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
s in hyperlipidaemic patients, but also with acute hepatitis (liver disease). In other diseases, preliminary studies have suggested oral aloe vera gel may reduce symptoms and inflammation in patients with
ulcerative colitisUlcerative colitis is a form of inflammatory bowel disease . Ulcerative colitis is a form of colitis, a disease of the colon , that includes characteristic ulcers, or open sores. The main symptom of active disease is usually constant diarrhea mixed with blood, of gradual onset...
. Compounds extracted from aloe vera have been used as an immunostimulant that aids in fighting cancers in cats and dogs; however, this treatment has not been scientifically tested in humans.
Topical application of aloe vera may be effective for genital herpes and
psoriasisPsoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
. However, it is not effective for the prevention of radiation-induced injuries. Although anecdotally useful, it has not been proven to offer protection from sunburn or suntan. In a double-blind clinical trial, both the group using an aloe vera containing
dentifriceDentifrice is a paste, liquid or powder used to help maintain oral hygiene. There have been many dentifrices produced over the years, many focusing on marketing strategies to sell products, such as offering whitening capabilities. The most essential dentifrice recommended by dentists is toothpaste...
and the group using a fluoridated dentifrice had a reduction of gingivitis and plaque, but no statistically significant difference was found between the two.
Aloe vera extracts might have antibacterial and antifungal activities, which possibly could help treat minor skin infections, such as boils and benign skin cysts and may inhibit growth of fungi causing
tineaTinea is a general term used to describe skin mycoses. The term ringworm is even less precise, but is usually considered a synonym.It is sometimes equated with dermatophytosis, and it is true that most conditions identified as "tinea" are members of the imperfect fungi that make up the dermatophytes...
. For bacteria, inner-leaf gel from aloe vera was shown in one study to inhibit growth of
StreptococcusStreptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
and
ShigellaShigella is a genus of Gram-negative, nonspore forming, non-motile, rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella causes disease in primates, but not in other mammals. It is only naturally found in humans and apes. During...
species in vitro. In contrast, aloe vera extracts failed to show antibiotic properties against
XanthomonasXanthomonas is a genus of Proteobacteria, many of which cause plant diseases. Most varieties of Xanthomonas are available from the National Collection of Plant Pathogenic Bacteria in the United Kingdom and other international culture collections such as ICMP in New Zealand, CFBP in France, and...
species.
Commodity uses
Aloe vera is now widely used on facial tissues, where it is promoted as a moisturiser and/or anti-irritant to reduce chafing of the nose of users suffering hay-fever or cold. It has also been suggested that biofuels could be obtained from Aloe vera seeds. It can also be used to retwist dreadlocked hair, a favourite agent for vegans and those preferring natural products.
Aloe vera is also used for soothing the skin, and keeping the skin moist to help avoid flaky scalp and skin in harsh and dry weather. Aloe vera may also be used as a moisturizer for oily skin.
Historical uses
AloinAloin, also known as Barbaloin, is a bitter, yellow-brown colored compound noted in the exudate of at least 68 Aloe species at levels from 0.1 to 6.6% of leaf dry weight , and in another 17 species at indeterminate levels [Reynolds, 1995b]...
was the common ingredient in
over-the-counterOver-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
(OTC) laxative products in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
prior to 2003, when the
Food and Drug AdministrationThe Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
ruled that aloin was a
class III ingredientThe UNique Ingredient Identifier is a non-proprietary, free, unique, unambiguous, non-semantic, alphanumeric identifier linked to a substance’s molecular structure and/or descriptive information by the Substance Registration System of the Food and Drug Administration...
, thereby banning its use. It should be noted that unprocessed aloe that contains aloin is used primarily as a laxative, whereas processed Aloe vera juice that does not contain significant amounts of aloin is used as a digestive healer. Manufacturers commonly remove aloin in processing due to the FDA ruling.
Culinary uses
Aloe is also used as a food substance. Some
molecular gastronomistsMolecular gastronomy is a subdiscipline of food science that seeks to investigate, explain and make practical use of the physical and chemical transformations of ingredients that occur while cooking, as well as the social, artistic and technical components of culinary and gastronomic phenomena in...
have begun to take advantage of its gelling properties. Perhaps the most notable among these is Chef Quique Dacosta's "Oysters Guggenheim," created at El Poblet in Spain.
Side Effects and Cautions
Use of topical aloe vera is not associated with significant side effects. A 2-year National Toxicology Program (NTP) study on oral consumption of non-decolorized whole leaf extract of aloe vera found clear evidence of carcinogenic activity in male and female rats, based on tumors of the large intestine. According to the NTP, from what is known right now there is nothing that would lead them to believe that these findings are not relevant to humans. However, more information, including how individuals use different types of aloe vera products, is needed to determine the potential risks to humans. Abdominal cramps and diarrhea have been reported with oral use of aloe vera. Diarrhea, caused by the laxative effect of oral aloe vera, can decrease the absorption of many drugs. People with diabetes who use glucose-lowering medication should be cautious if also taking aloe by mouth because preliminary studies suggest aloe may lower blood glucose levels. There have been a few case reports of acute hepatitis from aloe vera taken orally. However, the evidence is not definitive.
Biologically active compounds
Aloe vera leaves contain a range of biologically active compounds, the best-studied being acetylated mannans, polymannans,
anthraquinoneAnthraquinone, also called anthracenedione or dioxoanthracene is an aromatic organic compound with formula . Several isomers are possible, each of which can be viewed as a quinone derivative...
C-glycosides, anthrones and anthraquinones, and various lectins.
See also
- Aloe
Aloe , also Aloë, is a genus containing about 500 species of flowering succulent plants. The most common and well known of these is Aloe vera, or "true aloe"....
- Asphodelaceae
Asphodeloideae is a subfamily of the monocot family Xanthorrhoeaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae. The subfamily name is derived from the generic name of the type genus, Asphodelus...
- Herbal medicine
- Succulent plants
- Medicinal plants