Aloe vera is a stemless or very short-stemmed succulent plant growing to 24–39 in tall,spreading by offsets. 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 flowers are produced in summer on a spike up to 35 in tall, each flower pendulous, with a yellow tubular corolla 0.8–1.2 in long. Like other Aloe species, Aloe vera forms arbuscular mycorrhiza, a symbiosis that allows the plant better access to mineral nutrients in soil.
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 lotions, yogurt, beverages, and some desserts.
Aloe vera juice is used for consumption and relief of digestive issues such as heartburn and irritable bowel syndrome, although it bears significant potential to be toxic when taken orally. It is common practice for cosmetic companies to add sap or other derivatives from Aloe vera to products such as makeup, tissues, moisturizers, soaps, sunscreens, incense, shaving cream, and shampoos. Other uses for extracts of aloe vera include the dilution of semen for the artificial fertilization of sheep,use as fresh food preservative, and use in water conservation 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 Asphodelaceae. 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 Papyrus from 16th century BC, in both Dioscorides' De Materia Medica and Pliny the Elder's 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 aloin has been removed by processing. Taking aloe vera that contains aloin in excess amounts has been associated with various side-effects. However, the species is used widely in the traditional herbal medicine of China, Japan, Russia, South Africa, the United States, Jamaica, Latin America and India.
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 glucose levels in diabetics, and with lower blood lipids 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 colitis. 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 psoriasis.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 dentifrice 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 tinea. For bacteria, inner-leaf gel from aloe vera was shown in one study to inhibit growth of Streptococcus and Shigella species in vitro. In contrast, aloe vera extracts failed to show antibiotic properties against Xanthomonas species.