Aloe vera, a member of the lily family, is a spiky, succulent, perennial plant. It is indigenous to eastern and southern Africa, but has been spread throughout many of the warmer regions of the world, and is also popularly grown indoors. There are about 300 identified species, but Aloe vera ("true aloe") is the most popular for medical applications. It has also been known as Aloe vulgaris ("common aloe") and Aloe barbadensis. The plant has yellow flowers and triangular, fleshy leaves with serrated edges that arise from a central base and may grow to nearly 2 ft (0.6 m) long. Each leaf is composed of three layers. A clear gel, that is the part of the plant used for topical application is contained within the cells of the generous inner portion. Anthraquinones, which exert a marked laxative effect, are contained in the bitter yellow sap of the middle leaf layer. The fibrous outer part of the leaf serves a protective function.
Aloe vera has been in use for thousands of years, and is mentioned in records as long ago as 1750 B.C. Use of the plant is thought to have originated in Egypt or the Middle East. It was reputedly used in Egyptian embalming procedures, as drawings of Aloe vera have been found on cave walls in the region. Legend has it that Aloe vera was one of Cleopatra's secrets for keeping her skin soft. Pliny and Dioscorides of ancient Greece wrote of the healing effects of this plant. Additionally, Alexander the Great is said to have acquired Madagascar so that he could utilize the Aloe vera growing there to treat soldiers' wounds. It is also a remedy which has long been used in the Indian practice of Ayurvedic medicine.
In the United States, Aloe vera was in use by the early 1800s, but primarily as a laxative. A turning point occurred in the mid-1930s, when a woman with chronic and severe dermatitis resulting from x-ray treatments was healed by an application of Aloe vera leaf gel. Success with this patient encouraged trials with others suffering from radiation burns. Evidence of the effectiveness remained anecdotal until 1953, when Lushbaugh and Hale produced a convincing study, using Aloe vera to treat beta radiation lesions in rats. Other experimental protocols have been carried out using animals since that time, but there is little human research data to describe the degree of effectiveness of Aloe vera treatment. Some evidence suggests that it is especially helpful in the elderly and other people with impaired health or failing immune systems.
Judith Turner, The Gale Group Inc., Gale, Detroit,