Aloe vera, also known as the Medicinal Aloe, is a species of succulent plant that probably originated in northern Africa. The species does not have any naturally occurring populations, although closely related Aloes do occur in northern Africa The species is frequently cited as being used in herbal medicine since the beginning of the first century AD, because it is mentioned in the New Testament (John 19:39–40 And there came also Nicodemus, which at the first came to Jesus by night, and brought a mixture of myrrh and aloes...). However, it is unclear whether the aloes described in the Bible are derived from A. vera. Extracts from A. vera are widely used in the cosmetics and alternative medicine industries, being marketed as variously having rejuvenating, healing or soothing properties.
There is, however, little scientific evidence of the effectiveness or safety of A. vera extracts for either cosmetic or medicinal purposes, and what positive evidence is available is frequently contradicted by other studies. Despite these limitations, there is some preliminary evidence that A. vera extracts may be useful in the treatment of diabetes and elevated blood lipids in humans. These positive effects are thought to be due to the presence of compounds such as mannans, anthraquinones and lectins.
Aloe vera is a stemless or very short-stemmed succulent plant growing to 60–100 cm (24–39 in) tall, spreading by offsets. The leaves are lanceolate, thick and fleshy, green to grey-green, with some varieties showing white flecks on the upper and lower leaf surfaces. The margin of the leaf is serrated and has small white teeth. The flowers are produced in summer on a spike up to 90 cm (35 in) tall, each flower pendulous, with a yellow tubular corolla 2–3 cm (0.8–1.2 in) long. Like other Aloe species, A. vera forms arbuscular mycorrhiza, a symbiosis that allows the plant better access to mineral nutrients in soil.
The natural range of A. vera is unclear, as the species has been widely cultivated throughout the world. It has been suggested that naturalised stands of the species occur through North Africa in Algeria, Morocco, and Tunisia, along with the Canary and Madeira Islands. The species was introduced to China, India, Pakistan and various parts of southern Europe in the 17th century. The species is widely naturalised elsewhere, occurring in temperate and tropical regions of Australia, Barbados, Belize, Nigeria, Paraguay and the USA. It has been suggested that, like many Aloes, the species is originally from Southern Africa and that populations that occur elsewhere are the result of human cultivation.