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Aloe is a of , in the family , which contains about 400 different . They are native to the drier parts of , especially 's and the mountains of tropical Africa.
Members of the closely allied genera and , 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 .
Aloe plants are stiff and rugged, consisting mainly of a rosette of large, thick, fleshy . 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 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 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 . 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 (). 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 (). 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 ().
Aloe gel is also useful for any dry skin condition, especially around the eyes and sensitive facial skin. and catreating fungal infections such as ringworm. In 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 . 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 .
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, , , , , , , , and many other conditions. However, these uses are unproven. The only substantiated internal use is as a . Furthermore, there is evidence of significant adverse side effects (see for example ). Consult your doctor when contemplating taking Aloe internally. Avoid use during pregnancy because the are strongly . High doses of the leaves can cause vomiting.
Aloe's benefits include ingesting aloe juice to lower blood sugar levels in diabetes patients, aloe as a strong laxative, may have some anti-cancer effects on humans and is even being tested to treat asthma
Compounds in Aloes
Aloe vera contains over seventy-five nutrients and twenty minerals, nineteen amino acids including all eight essential amino acids and eleven secondary amino acids as well and twelve vitamins. These vitamins include: A, B1, B6, B12, C and E (). It has even been referred to as “a pharmacy in a plant” (Farrar, 2005).
Aloes also contain , , , , , and . It is also a source of a class of chemicals called Aloins.
Aloe vera (flowers)
Chemical properties of Aloin
Aloins are soluable and easily extracted by water. 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. According to W. A. Shenstone, two classes of Aloins are to be recognized: (1) , which yield and with , and do not give a red coloration with nitric acid; and (2) , which yield (C7H2N3O5), (C7H2N2O6), picric and oxalic acids with nitric acid, being reddened by the acid. This second group may be divided into a-barbaloins, obtained from Barbadoes aloes, and reddened in the cold, and b-barbaloins, obtained from Socotrine and Zanzibar aloes, reddened by ordinary nitric acid only when warmed or by fuming acid in the cold. Nataloin (2C17H13O7·H2O) forms bright yellow scales. Barbaloin (C17H18O7) forms yellow crystals. Aloes also contain a trace of volatile oil, to which its odour is due.
Medicinal use of Aloin
The dose is 130-320 mg, that of aloin being 30-130 mg. Aloes can be absorbed from a broken surface and will then cause purging. When given internally it increases the actual amount as well as the rate of flow of the . It hardly affects the , but markedly stimulates the muscular coat of the , causing purging in about fifteen hours. There is hardly any increase in the intestinal secretion, the drug being emphatically not a hydragogue cathartic. There is no doubt that its habitual use may be a factor in the formation of haemorrhoids; as in the case of all drugs that act powerfully on the lower part of the intestine, without simultaneously lowering the venous pressure by causing increase of secretion from the bowel. Aloes also tends to increase the menstrual flow and therefore belongs to the group of emmenagogues. Aloin is preferable to aloes for therapeutic purposes, as it causes less, if any, pain. It is a valuable drug in many forms of constipation, as its continual use does not, as a rule, lead to the necessity of enlarging the dose. Its combined action on the bowel and the is of especial value in chlorosis, of which amenorrhoea is an almost constant symptom. The drug is obviously contraindicated in pregnancy and when haemorrhoids are already present. Many well-known patent medicines consist essentially of aloes.
Lign-aloes and Agarwood
The lign-aloes are quite different from plants of the Aloe genus. The term "Aloes" is used in the (Numbers 24:6), but as the trees usually supposed to be meant by this word are not native in , it has been suggested that the reading in which the word does not occur is to be preferred. Lign-aloe is a corruption of the Latin lignum-aloe, a wood, not a resin. refers to it as agallochon, a wood brought from or , which was odoriferous but with an astringent and bitter taste. This may be , a native of East India, , and , which supplies the so-called eagle-wood or aloes-wood, which contains much resin and oil.
There are around 400 species in the genus Aloe. For a full list, see . Common species include:
- Wylliespoort Aloe
- Candelabra Aloe, Tree Aloe, Krantz Aloe
Candelabra Aloe (Aloe arborescens)
- Torch Plant, Lace Aloe
- Tree Aloe
- Shortleaf Aloe
- Cat's Tail Aloe
- Climbing Aloe
- Clanwilliam's Aloe
- Namibian Partridge Breast Aloe
- Jeweled Aloe
- Noble Aloe, Zimbabwe Aloe
- Cape Aloe, Tap Aloe, Bitter Aloe
- Blue Aloe
- Spider Aloe
- Namaqua Aloe
- Karoo Aloe, Ramenas
- Soap Aloe, Zebra Aloe
- Gold Tooth Aloe
- Gold Tooth Aloe
- Perry's Aloe
- Kouga Aloe
- Bastard Quiver Tree
- Fan Aloe
- Spiral Aloe
- Rosette Aloe
- Maidens Quiver Tree
- African Aloe
- Tilt-head Aloe
- Coral Aloe
- Bullocks Bottle Brush Aloe
- Partridge-breasted Aloe, Tiger Aloe
- True Aloe, Barbados Aloe, Common Aloe, Yellow Aloe, Medicinal Aloe
- Zebra Aloe