Aloe vera
Aloe vera, called aloe, acíbar or Barbados aloe, among others, it is a succulent species of the Asphodelaceae family. With some 500 species, aloe is widely distributed and is considered an invasive species in many regions of the world.
It is an evergreen plant, probably originating in the Arabian Peninsula, but growing wild in tropical, semi-tropical, and arid climates throughout the world. It is cultivated for commercial products, primarily as a topical treatment used for centuries. The species is attractive for decorative purposes and is successful indoors as a pot plant.
It is used in many consumer products, including beverages, skin lotions, cosmetics, ointments, or in gel form for minor burns and sunburns. There is little clinical evidence for the effectiveness or safety of Aloe vera extract as a cosmetic or topical drug.
Etymology and common name
The botanical name derives from the Latin, alóe, from the Greek άλς, άλός (als, alós), 'salt' (giving άλόη, ης, ή —aloe, aloes, aloe—, which designated both the plant and its juice), due to its flavor, reminiscent of seawater. From there it would have passed to the Latin ălŏē, ēs with the same meaning, and which, in a figurative sense, also meant 'bitter'. The Greek word comes from the Hebrew אֲהָלִים (ʾăhālîm) or ohel (אהל), frequently quoted in biblical texts. The Hebrew word probably derives from the Tamil அகில் (akil). For its part, the word vera ("true& #34;) comes from Latin. Until the XIX century, its most popular name was acibar (gum resin), it was It is known as aloe, alovera, aloe vera, azabila, slug, gamonite, pita perfoliada, pita zabila, pitazabila, pitazábila, sabila, yerba slug, zabida, zabila, zabin, zabira, zadiba, zadiva, zambana, zavida, aloes (gum resin).
Description
Acaule shrub or with a short stem up to 30 cm, erect, without lateral shoots. The leaves, which can measure up to 40-50 cm long by 10-15 cm wide in adult specimens, are arranged in the form of a basal rosette. They are narrowly triangular-lanceolate, canaliculate, straight, erect-patent, herbaceous, greyish-green, glaucous, lightly covered with bloom and without spots —except for a few elongated pale specks on the suckers and at the base of some older leaves. —, dentate only on the margin, with teeth about 2 mm long, thick, hard, retroverse, lighter in color than the blade.
The plant has triangular fleshy leaves with jagged edges, yellow tubular flowers, and fruits containing numerous seeds. Each leaf is composed of three layers: 1) A transparent inner gel that contains 99% water and the rest is composed of by glucomannans, amino acids, lipids, sterols and vitamins. 2) The middle layer of latex which is the bitter yellow sap and contains anthraquinones and glucosides. 3) The thick outer layer of 15 to 20 cells called the cortex which has a protective function and synthesizes carbohydrates and proteins. Within the cortex there are vascular bundles responsible for the transport of substances such as water (xylem) and starch (phloem)
The inflorescence, about 70-100 cm tall, ends in a simple raceme of about 30-50 by 5-6 cm, compact in the anthesis and in fructification. The floral bracts —already scattered and scarce on the floral stem below the inflorescence— are 8-11 by 5-6 mm and triangular, acuminate, membranaceous and with light brown parallel ridges. The flowers are sub-erect in the preanthesis, patent in the anthesis and then pendulous when ripe and in fructification; the peduncles are 4-5 mm, somewhat accrescent, reaching 7 mm at fruiting. The 25-30 mm perianth is tubular, slightly narrowed at the base, and yellow in color; the outer tepals are welded along the lower half of their length. The stamens, exserted, measure 30-35 mm.
Flowering does not occur until three or four years of age. The fruit is a capsule of 20-25 by 6-8 mm, with seeds of about 5 mm, not counting the wings. These plants present cross-pollination and ornithophilia in their natural habitat, being very prone to hybridization; which is why the flowers are removed from crops for commercial purposes.[citation required]
Taxonomy
The botanical name of Aloe vera is Aloe barbadensis miller and it belongs to the Asphodelaceae (Liliaceae) family. The species has several synonyms: A. barbadensis Mill., Aloe indica Royle, Aloe perfoliata L. var. vera and A. vulgaris Lam. The spotted form of Aloe vera may be conspecific with A. massawana. The species was described by Charles Linnaeus in 1753 and later by Nicolaas Laurens Burman and published in Flora Indica... nec non Prodromus Florae Capensis, 83, in 1768 and by Philip Miller as Aloe barbadensis about ten days after Burman in the Gardener's Dictionary
Techniques based on DNA comparison suggest that Aloe vera is relatively related to Aloe perryi, a species endemic to Yemen. Similar techniques, using DNA comparison Chloroplast DNA sequences and ISSR profiles have also suggested that it is closely related to Aloe forbesii, Aloe inermis, Aloe scobinifolia, Aloe sinkatana and Aloe striata. With the exception of the South African species A. striata, these Aloe species are native to Socotra (Yemen), Somalia, and Sudan. The lack of obvious natural populations of the species has led some authors to suggest that the Aloe vera may be of hybrid origin.
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Distribution and habitat
It is probably native to Arabia and was naturalized in subtropical and temperate regions of both hemispheres, including the Mediterranean. It has been widely cultivated throughout the world and has been naturalized in North Africa, as well as in Sudan and the countries neighbors, along with the Canary Islands, Cape Verde and the Madeira Islands.
The species was introduced to China and various parts of southern Europe in the 17th century. It is widely naturalized elsewhere, occurring in arid, temperate, and tropical regions of temperate continents. Aloe vera can be found in altered, nitrified sandbanks and coastal crags from sea level to 200 ms. no. m..
Cultivation
Aloe vera has been widely cultivated as an ornamental plant and is popular among modern gardeners as a topical medicinal plant, and because of its interesting flowers, shape, and succulence, this succulence allows the species to survive. in areas of low natural rainfall, making it ideal for rockeries and other low-water use gardens. The species is relatively resistant to most insect pests, although mites, mealybugs, and aphid species can cause a decline in plant health.
Because Aloe vera comes from hot and desert places, its cultivation requires that the minimum temperatures do not fall below 0 °C. Intense frosts or weak but repeated frosts cause damage, since it is not cold tolerant; neither does it tolerate humidity, neither in the soil nor on the plant. It can be located in full sun or semi-shade.
The cultivation of these plants in pots and as decorative plants has spread enormously in recent years. Terracotta pots are preferable to any other material, since they are porous, which prevents excess moisture. An also porous substrate, such as the one used for cacti and succulents, is suitable; it is convenient to let it dry completely before watering again.
When plants become full of suckers that emerge around the "mother plant," they should be divided to allow for more growth of the parent plant and to help prevent infestations of pests such as spider mites, mealybugs and species of aphids. During the winter, this species can go into a state of dormancy, so watering should be suspended, especially if it is outdoors. In very cold areas it is better to keep it indoors or in greenhouses with heating.
This species is cultivated on a large scale in Australia, Bangladesh, Cuba, the Dominican Republic, China, Mexico, India, Jamaica, Colombia, Venezuela, Kenya, Peru, Tanzania, and South Africa, along with the United States to supply the cosmetics industry.. In Spain, its cultivation is increasingly common, with Córdoba being the main producing area, while in the Canary Islands it is completely wild.
Uses
Aloe vera is cultivated as a decorative plant, for medicinal uses, in cosmetics and even for food in some countries. Two substances from Aloe vera, a clear gel and its yellow latex, are used to make commercial products. Aloe gel is typically used to make topical medications for skin conditions, such as burns, wounds, frostbite, rashes, psoriasis, cold sores, or dry skin. Aloe latex is used individually or made as a product with other ingredients that is taken by mouth to relieve constipation.
Clinical use of aloe vera is supported primarily by anecdotal data. Evidence-based uses have been tested in humans or animals and safety and efficacy have not always been proven. There is conflicting evidence regarding the whether aloe vera is effective as a treatment for wounds or burns. There is some evidence that topical use of aloe products might relieve symptoms of certain skin disorders, such as psoriasis, herpes, acne, or skin rashes. Aloe vera gel is used commercially as an ingredient in yogurts, beverages, and some desserts.
Based on tradition and some scientific theories, Aloe vera is often used to treat alopecia, bacterial and fungal skin infections, chronic leg wounds, parasitic infections, systemic lupus erythematosus, arthritis and tic douloure. However, they have not been extensively tested in humans, and safety and efficacy have not always been proven.
In some places, the varieties Aloe chinensis and Aloe maculata are often called Aloe vera. Although the last two may have similar medicinal properties, at the pharmaceutical level it is important to correctly identify the species since they are different.
Currently, there are over two hundred and fifty recognized varieties of Aloe, of which only four have significant curative or medicinal properties. Although the varieties Arborescens, Maculata and Chinensis are different varieties, many people refer to them as Aloe Vera.
Historical use
The use of aloe vera as a medicinal plant has a very long history, it has been used for medicinal purposes in various cultures for millennia: Greece, Egypt, India, Mexico, Japan and China. It dates back to the time of ancient Egypt 6,000 years ago, from where their representations have been preserved on the stone walls of the Valley of the Kings. Traditionally, aloe vera has been used to empirically treat a wide list of disorders and ailments, such as skin problems (wounds, burns, and psoriasis), constipation, external and internal ulcers, hyperlipidemia, diabetes, and lupus erythematosus.
One of the earliest recorded pharmaceutical applications can be found on a 21st century BC Sumerian clay tablet. C., but there are reports of drawings of the plant on the walls of Egyptian temples from the 4th millennium BC. C.[citation needed] Egyptian queens Nefertiti and Cleopatra used it as part of their regular beauty regimens. Aloe vera is also quoted in the Bible, being a of the most significant that of John 19.39. It is also written in the Codex Juliana Anicia of 512 CE. I d. C. Alexander the Great and Christopher Columbus used it to treat the wounds of soldiers.
The first reference to aloe vera in English was a translation by John Goodyer in AD 1655. from the medical treatise De Materia Medica by Dioscorides. Barbaloin, a compound of aloe vera, was isolated in 1851 by T. and H. Smith of the Blandfield Chemical Works in Edinburgh. span style="font-variant:small-caps;text-transform:lowercase">XIX, aloe vera was used as a laxative in the United States, but in the mid-1930s there was a point of inflection when used successfully to treat chronic and severe radiation dermatitis.
Use as cosmetic and medicinal
In cosmetics it is used more and more. Most responsible manufacturers extract and purify the extracts, avoiding the latex of the plant, known as aloin. Currently, its direct use is widespread through very rudimentary domestic procedures, giving rise to irritation (dermatitis, eczema) or allergic reactions (urticaria), when the Aloe gel has not been cleaned properly.
This species has been cultivated since ancient times for its medicinal use.
Two products are obtained from it:
- Gel, which is the mucilaginous portion of the tissue or mesophilic parenchyma located in the center of the leaves. From this pulp a bright and bitter gel is extracted. The skin should be removed to prevent oxidation, which would give it a dark color. To keep it in good condition, the newly obtained material should be stabilized and preserved from bacterial and fungal contamination.
- Cheer up, is the juice that results from the incision of the leaves, is a crystalline solid of brown and very bitter. It is located in the pericyclic cells located near the leading beams immediately below the epidermis, between chlorophilic parenchyma and mucillaginous. In general, it is obtained by letting the fluid flow out of the sheets cut transversally in a container. The smell is characteristic and strong.
The leaves should be cut at the base, near the stem. To cut them, it is enough to make a small incision at the beginning of the leaf and make a circular turn around the stem, without causing any damage to the plant. Once collected, the leaves are washed and filleted. The epidermis must be removed, as it contains aloin, a toxic substance.
Aloe vera is used in facial tissues where it is promoted as a moisturizer and anti-irritant to reduce nose rubbing. Cosmetic companies often add sap or other derivatives of aloe vera to products such as makeup, tissues, moisturizers, soaps, sunscreens, incense, shaving cream, or shampoos. A review of the academic literature notes that its inclusion in many hygiene products is due to its "moisturizing emollient effect".
Toxicity
The use of topical aloe vera gel is not associated with significant side effects. Unprocessed gel may contain impurities, acids, or substances that used for long periods of time could cause skin lesions. Most of manufacturers process the Aloe gel avoiding irritating extracts (mainly latex), however, at home or in alternative therapies, the gel is used directly from the plant, unprocessed or poorly processed, producing sometimes a significant allergic reaction on the skin.
For people with allergies to aloe vera, skin reactions may include contact dermatitis with mild redness and itching, photosensitivity, difficulty breathing, or swelling of the face, lips, throat tongue or throat. Unprocessed aloe vera gel used on broken skin, in inaccurate doses, could be counterproductive, as well as its use in children under 12 years of age.
Oral ingestion of aloe vera is potentially toxic, and can cause abdominal cramps and diarrhea, which in turn can decrease the absorption of medications. Aloin, a compound found in the semi-liquid latex of some species of aloe, was the common ingredient in over-the-counter laxative products in the United States until 2002, when the Food and Drug Administration banned it because manufacturers failed to provide necessary safety data.
Although toxicity may be less when aloin is removed through processing, aloe vera ingested in large quantities may induce side effects, such as abdominal pain, diarrhea, or hepatitis. Chronic ingestion of aloe (dose of 1 gram per day) can cause adverse effects, including hematuria, weight loss, and cardiac or renal disorders. Oral aloe is not recommended during pregnancy due to the theoretical stimulation of uterine contractions, and in women nursing mothers, it can sometimes cause gastrointestinal upset in the nursing infant. Raw aloe latex contains chemicals that appear to cause cancer, and processed aloe latex may contain cancer-causing compounds. Leaf extract Whole aloe vera has been classified by the International Agency for Research on Cancer as a possible human carcinogen (Group 2B), along with other natural products.
Orally ingested unbleached aloe vera leaf extract has been listed by the US State of California Office of Environmental Health Hazard Assessment as a "chemical substance known to the state as causing cancer or reproductive toxicity". Ingested aloe products may have adverse interactions with prescription medications, such as those used to treat blood clots, diabetes, heart disease, and potassium-lowering agents (such as digoxin), and diuretics, among others.
