Botanical Name: Aloe Perryi, Aloe vaera (LINN)
Species: A. perryi
Common Name: Socotrine aloe.
Habitat: –Aloes are indigenous to East and South Africa, but have been introduced into the West Indies (where they are extensively cultivated) and into tropical countries, and will even flourish in the countries bordering on the Mediterranean. These plants are mainly found in dry areas; on flat or gentle slopes, primarily on limestone pavement but occasionally on sandy plains or granite mountains; at elevations from sea-level to 900 metres.
Aloe Perryi or Aloveras are succulent plants belonging to the Lily family, with perennial, strong and fibrous roots and numerous, persistent, fleshy leaves, proceeding from the upper part of the root, narrow, tapering, thick and fleshy, usually beset at the edges with spiney teeth. Many of the species are woody and branching. In the remote districts of S.W. Africa and in Natal, Aloes have been discovered 30 to 60 feet in height, with stems as much as 10 feet in circumference.
The flowers are produced in erect, terminal spikes. There is no calyx, the corolla is tubular, divided into six narrow segments at the mouth and of a red, yellow or purplish colour. The capsules contain numerous angular seeds.
The true Aloe is in flower during the greater part of the year and is not to be confounded with another plant, the Agave or American Aloe (Agave Americana), which is remarkable for the long interval between its periods of flowering. This is a succulent plant, without stem, the leaves being radical, spiney, and toothed. There is a variety with variegated foliage. The flower-stalk rises to many feet in height, bearing a number of large and handsome flowers. In cold climates there is usually a very long interval between the times of its flowering, though it is a popular error to suppose that it happens only once in a hundred years for when it obtains sufficient heat and receives a culture similar to that of the pineapple, it is found to flower much more frequently. Various species of Agave, all of which closely resemble each other, have been largely grown as ornamental plants since the first half of the sixteenth century in the south of Europe, and are completely acclimatized in Spain, Portugal and Southern Italy, but though often popularly called Aloes all of them are plants of the New World whereas the true Aloes are natives of the Old World. From a chemical point of view there is also no analogy at all between Aloes and Agaves.
Although the Agave is not employed medicinally, the leaves have been used in Jamaica as a substitute for soap, the expressed juice (a gallon of the juice yields about 1 lb. of the soft extract), dried in the sun, being made into balls with wood ash. This soap lathers with salt water as well as fresh. The leaves have also been used for scouring pewter and kitchen utensils. The inner spongy substance of the leaves in a decayed state has been employed as tinder and the fibres may be spun into a strong, useful thread.
The fleshy leaves of the true Aloe contain near the epidermis or outer skin, a row of fibrovascular bundles, the cells of which are much enlarged and filled with a yellow juice which exudes when the leaf is cut. When it is desired to collect the juice, the leaves are cut off close to the stem and so placed that the juice is drained off into tubs. This juice thus collected is concentrated either by spontaneous evaporation, or more generally by boiling until it becomes of the consistency of thick honey. On cooling, it is then poured into gourds, boxes, or other convenient receptacles, and solidifies.
Aloes require two or three years’ standing before they yield their juice. In the West Indian Aloe plantations they are set out in rows like cabbages and cutting takes place in March or April, but in Africa the drug is collected from the wild plants.
A plant of mainly arid and semi-arid lowland areas in the tropics. It grows best in areas where annual daytime temperatures are within the range 22 – 27°c, but can tolerate 12 – 31°c. It can be killed by temperatures of 5°c or lower It prefers a mean annual rainfall in the range 400 – 700mm, but tolerates 250 – 1,400mm. Tolerant of poor soils. Requires a well-drained, light to medium soil and a position in full sun. Prefers a pH in the range 6.5 – 7, tolerating 6 – 7.5.
Aloe species follow the Crassulacean acid metabolism (CAM). CAM plants can fix carbon dioxide at night and photosynthesize with closed stomata during the day, thus minimizing water loss. This, plus their succulent leaves and stems, and the presence of a thick cuticle, makes them well adapted to dry conditions.
Seed – we have no specific information on this species – in general Aloes are sown in a sandy, well-drained potting soil in a warm, shady position in standard seed trays. Germination takes about three weeks. Cover the seed with a thin layer of sand (1 – 2mm), keep moist. The seedlings can be planted out in individual bags or containers as soon as they are large enough to handle.
The most important constituents of Aloes are the two Aloins, Barbaloin and Isobarbaloin, which constitute the so-called ‘crystalline’ Aloin, present in the drug at from 10 to 30 per cent. Other constituents are amorphous Aloin, resin and Aloe-emodin. The proportion in which the Aloins are present in the respective Aloes is not accurately known.
The manner in which the evaporation is conducted has a marked effect on the appearance of the Aloes, slow and moderate concentration tending to induce crystallization of the Aloin, thus causing the drug to appear opaque. Such Aloes is termed ‘livery’ or hepatic, and splinters of it exhibit minute crystals of Aloin when examined under the microscope. If, on the other hand, the evaporation is carried as far as possible, the Aloin does not crystallize and small fragments of the drug appear transparent; it is then termed ‘glassy,’ ‘vitreous,’ or ‘lucid’ Aloes and exhibits no crystals of Aloin under the microscope.
Used medicinally in the same ways as Aloe vera Aloe vera is used in the following ways:-
The clear gel contained within the leaf makes an excellent treatment for wounds, burns and a host of other skin disorders, placing a protective coat over the affected area, speeding up the rate of healing and reducing the risk of infection. The gel is also applied externally to cure haemorrhoids. These actions are in part due to the presence of aloectin B, which stimulates the immune system. To obtain this gel, the leaves can be cut in half along their length and the inner pulp rubbed over the affected area of skin. This has an immediate soothing effect on all sorts of burns and other skin problems.
The use of the gel has been approved in the United States for the treatment of leukaemia in cats, of fibrosarcoma in dogs, for wound healing in humans and to prevent dry socket (‘alveolar osteitis’) in humans.
The peeled leaves are eaten to relieve sore throat and coughs and as a mild laxative. As a food supplement, the leaf gel is said to facilitate digestion, and to improve blood and lymphatic circulation, as well as kidney, liver and gall bladder functions. There are claims of beneficial activity of Aloe vera products in cases of AIDS, arthritis, or other chronic and debilitating conditions. However, these claims have not been substantiated by scientific studies. There is also no evidence that topical Aloe vera gel is effective in preventing or minimizing radiation-induced skin reactions in cancer patients. In large amounts, the gel has anti-irritant properties.
A bitter substance is obtained from the yellow sap at the base of the leaf. Known as ‘bitter aloes’, it contains anthraquinones which are a useful digestive stimulant and a strong laxative. It also has vermicidal properties. It is taken internally in the treatment of chronic constipation, poor appetite, digestive problems etc. Mixed with other ingredients to mask its bitter taste, it is taken against asthma and to treat coughs. Similar mixtures are taken to cure dysentery, kidney problems or against dyspepsia. It should be administered preferably in combination with an antispasmodic to moderate its griping action.
It is applied externally as a refrigerant to treat acne or cuts.
‘Curaçao aloe’ should contain at least 28% hydroxy-anthraquinone derivatives; it is almost entirely soluble in 60% alcohol and for more than 70% in water. It should not contain more than 12% moisture and 3% ash.The plant is strongly purgative so great care should be taken over the dosage.
Anthraquinone-based laxatives, such as bitter aloes, should not be used longer than 8 – 10 days, nor by children younger than 12 years. Contra-indications include pregnancy, breastfeeding, intestinal inflammations and haemorrhoids.
When plants are grown in pots the anthraquinone content is greatly reduced.
The word Aloes, in Latin Lignum Aloes, is used in the Bible and in many ancient writings to designate a substance totally distinct from the modern Aloes, namely the resinous wood of Aquilaria agallocha, a large tree growing in the Malayan Peninsula. Its wood constituted a drug which was, down to the beginning of the present century, generally valued for use as incense, but now is esteemed only in the East.
A beautiful violet colour is afforded by the leaves of the Socotrine Aloe, and it does not require a mordant to fix it.
Known Hazards: The sap of Aloe species contains anthraquinones. These compounds have several beneficial medicinal actions, particularly as a laxative, and many species of Aloe are thus employed in traditional medicine. Whilst safe in small doses and for short periods of time, anthraquinones do have potential problems if used in excess. These include congestion and irritation of the pelvic organs.
Long term use of anthraquinone laxatives may also play a role in development of colorectal cancer as they have genotoxic potential, and tumorigenic potential.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.