Aloevera

Aloe vera is a succulent plant species that probably originated in northern Africa. The species does not have any naturally occurring populations, although closely related aloes do occur in northern Africa.^[1] The species is frequently cited as being used in herbal medicine since the beginning of the first century AD. 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.

Uses

Preparations made from the plant Aloe vera are often referred to as "aloe vera".^[37] Scientific evidence for the cosmetic and therapeutic effectiveness of aloe vera is limited and when present is frequently contradictory.^[2][3] Despite this, the cosmetic and alternative medicine industries regularly make claims regarding the soothing, moisturizing, and healing properties of aloe vera.^[4][38] Aloe vera gel is used as an ingredient in commercially available lotions, yogurt, beverages, and some desserts,^[39][40][41] although at certain doses, it has toxic properties when used either for ingested or topical applications.^[42]

Folk medicine

Early records of Aloe vera use appear in the Ebers Papyrus from 16th century BC,^[14] in both Dioscorides' De Materia Medica and Pliny the Elder's Natural History written in the mid-first century AD^[14] along with the Juliana Anicia Codex produced in 512 AD.^[39] The species is used widely in the traditional herbal medicine of many countries.^[4] Aloe vera, called kathalai in Ayurvedic medicine, is used as a multipurpose skin treatment. This may be partly due to the presence of saponin, a chemical compound that acts as an anti-microbial agent.^[43]

Dietary supplement

Aloin, a compound found in the exudate of some Aloe species, was the common ingredient in over-the-counter (OTC) laxative products in the United States prior to 2003, when the Food and Drug Administration ruled that aloin was a class III ingredient, thereby banning its use.^[44] Aloe vera has potential toxicity, with side-effects occurring at some dose levels both when ingested or applied topically.^[42] Although toxicity may be less when aloin is removed by processing, aloe vera that contains aloin in excess amounts may induce side-effects.^[4][5][45] A 2-year National Toxicology Program (NTP) study on oral consumption of non-decolorized whole leaf extract of Aloe vera found evidence of carcinogenic activity in male and female rats. The NTP says more information is needed to determine the potential risks to humans.^[46][47][48]

Aloe vera juice is marketed to support the health of the digestive system, but there is neither scientific evidence nor regulatory approval to support this claim.^[49] The extracts and quantities typically used for such purposes appear to be dose-dependent for toxic effects.