Реферат на тему:
Aloe is a genus of succulent, flowering plants in the family Asphodelaceae, which contains about 400 different species. They are native to the drier parts of Africa, especially South Africa's Cape Province and the mountains of tropical Africa.
Members of the closely allied genera Gasteria and Haworthia, which have a similar mode of growth, are also sometimes popularly known as aloes. Note that the plant sometimes called "American aloe", Agave americana, belongs to a different family, namely Agavaceae.
Aloe plants are stiff and rugged, consisting mainly of a rosette of large, thick, fleshy leaves. Many common varieties of Aloe are seemingly stemless, with the rosette growing directly at ground level; Other varieties may mave a branched or un-branched stem from which the fleshy leaves spring. The leaves are generally lance-shaped with a sharp apex and a spiny margin. They vary in color from grey to bright green and are sometimes striped or mottled.
Aloe flowers are small, tubular, and yellow or red and are borne on densely clustered, simple or branched leafless stems. The plants are cultivated as ornamental plants, especially in public buildings and gardens.
Human use of Aloes is primarily as an herbal in alternative medicines and "home first aid". Both the translucent inner plup as well as the resinous yellow exudate from wounding the Aloe plant is used externally to relieve skin discomforts and internally as purgatives. To date, research has show in certain cases that Aloes produce positive medicinal benefits for healing damaged skin, however there is still much debate regarding the effectiveness and safety for using Aloes medicinally in other manners.
Some Aloes have been used for human consumption. For example drinks made from or containing chunks of aloe pulp are popular in Asia as commercial beverages, and as a tea additive. This is notably true in Korea. As well, the yellow exudate from the leaves were once used on children's fingers to stop nail-biting.
The most common uses of aloe vera have been from topical use on human skin to treat various conditions. Aloe vera is also often used to treat skin from burns. Not only does it soothe the skin, ease pain and reduce inflammation, studies have been done to show that using aloe as a topical treatment to burns will help speed up the healing recovery process. A study performed in the 1990s showed that the healing of a moderate severe burn was sped up by six days when covering the wound on a regular basis with aloe vera gel, compared to the healing of the wound covered in a gauze bandage (Farrar, 2005). Aloe vera not only helps burns of various degrees, it also has become a common relief aid in treating sunburns. This is often the most common known use of the plant and the rubbing of aloe vera leaves onto sun-burned skin dates back to civilizations such as the Mayas and the Incas (http://www.newstarget.com/001560-02.html). Today this relief product is still used for the same purpose, yet can be found in drugstores in a gel form. When rubbed over over-exposed skin, the redness will disappear within a couple of days and helps to preserve moisture so that the skin will not become dry and peel.
Aloe vera can also be used to treat minor cuts and scrapes. Using an aloe vera leaf and rubbing it over a cut will help prevent infection and will speed up the healing response from the body. The aloe vera acts as a sealant and pulls the skin back together like a bandage or a suture (http://www.newstarget.com/001560-02.html). Although aloe should not be used as a substitute for medical treatment, its many uses are beneficial and should be considered for anything such as an everyday moisturizer to a first-aid antiseptic. In addition to the above-mentioned benefits, continueous research is being done to learn how else the aloe vera plant can play an important part in human lives.
Many cosmetic companies are now adding this plant to every product possible including makeup, soaps, sunscreens, shampoos and lotions, as well as any product that is created to soothe, protect and moisturize the skin. This is due partiall to fact that Aloe extract is full of vitamins, nutrients and minerals, as well as, the perception of the general public of Aloe as a healing ingrediant. The International Aloe Science Council advises choosing products that contain between twenty-five and forty percent aloe in them to receive the ultimate aloe vera benefits to the skin (http://www.iasc.org/aloe.html).
Aloe gel is also useful for any dry skin condition, especially eczema around the eyes and sensitive facial skin. and catreating fungal infections such as ringworm. In Ayurvedic medicine, the gel is usually applied fresh and can even be converted into an ointment for long-term use.
Aloe contains a number of medicinal substances used as a purgative. The medicinal substance is produced from various species of aloe, such as A. vera, A. vulgaris, A. socotrina, A. chinensis, and A. perryi. Several kinds of aloes are commercially available: Barbadoes, Socotrine, Hepatic, Indian, and Cape aloes. Barbadoes and Socotrine are the varieties most commonly used for curative purposes.
Aloes is the expressed juice of the leaves of the plant. When the leaves are cut, the juice that flows out is collected and evaporated. After the juice has been removed, the leaves are sometimes boiled, to yield an inferior kind of aloes. The juice of the leaves of certain species, e.g. Aloe venenosa, is poisonous.
Aloe vera has been widely marketed as having a number of benefits when taken internally. For example, Aloe has been marketed as a remedy for coughs, wounds, ulcers, gastritis, diabetes, cancer, headaches, arthritis, immune-system deficiencies, and many other conditions. However, these uses are unproven. The only