Dr Vikas Sharma & Proloy Sankar
Aloe-vera is a succulent plant, belonging to the family Alliaceae, grows to a height of 60 – 100 cm, matures in 4-6 years and survives for a period of nearly 50 years under favorable conditions. Many countries like India, South Africa, the United States of America, Venezuela Aruba, Bonaire, Haitin etc. commercially cultivate this plant. The leaves of this wonderful medicinal plant are flooded with numerous vitamins, minerals, enzymes, natural sugars, amino acids etc. They are as well rich in various phytochemicals that exhibit emollient, purgative, antioxidant, anti-inflammatory, anti-helmenthic, antimicrobial, aphrodisiac, antiseptic and cosmetic values. The leaves of Aloe-vera are succulent, erect and form a dense rosette. The gel made from the leaves have innumerable applications and the plant is mainly cultivated worldwide, primarily as a crop for ‘Aloe gel’. These days, Aloe-vera is widely used in food. It is also approved by the FDA as a flavoring agent & as a food supplement. It is also a main ingredient in many herbal remedies. Even many cosmetic products that are prepared are based on Aloe products. Aloe-vera is known to contain around 75 potentially active constituents: vitamins, enzymes, minerals, sugars, lignin, saponins, salicylic acids and amino acids.
In Aloe-vera, potentially active chemical constituents from the gel includes polysaccharides, glucomannan and acemannan and other comprises of carboxypeptidase, magnesium, zinc, calcium, glucose, cholesterol, salicylic acid, prostaglandin precursors, vitamins A, C, E, lignins, saponins, plant sterols and amino acids . The gel or mucilage obtained from the flesh of the leaf contains quite different compounds from the bitter latex extracted from the leaf lining. The emollient polysaccharide, glucomannan is a good moisturizer, which accounts for its use in many cosmetics. Acemannan, the major carbohydrate fraction in the gel, is a water soluble long chain mannose polymer which accelerates wound healing, modulates immune function (particularly macrophage activation and production of cytokines) and demonstrates anti-neoplastic and antiviral effects. The leaf lining’s (latex, resin or sap) anthraquinone glycosides (aloin, aloe-emodin and barbaloin) are potent stimulant laxatives. These water soluble glycosides are split by intestinal bacteria into aglycones which effect the laxative action.
Immune system: Alprogen, an anti-allergic compound of Aloe-vera inhibits calcium influx into mast cells, thereby inhibiting the antigen-antibody-mediated release of various mediators like histamine, serotonin, etc from mast cells.
Digestion: Drinking Aloe-vera juice naturally allows the body to cleanse the digestive system. It encourages the bowels to move and helps with elimination if a person is constipated and if one have diarrhea, it will help slow it down. The anthraquinones present in latex acts as potent laxatives. They do so by increasing intestinal water content, by stimulating mucus secretion and as well by increasing intestinal peristalsis.
Healing: Aloe gel has got healing properties too as it not only increases the collagen content of the wound, but also changes the collagen composition and the degree of collagen cross linking. Due to this, it accelerates wound contraction and increases the breaking strength of resulting scar tissue.
Antimicrobial: Six antiseptic agents namely lupeol, salicyclic acid, urea nitrogen, cinnamonic acid, phenols, sulfur, all of them exhibit inhibitory action on fungi, bacteria and viruses demonstrating its antimicrobial activity. Another compound, acemannan acts both alone and synergistically with azidothymidine (AZT) and acyclovir to block reproduction of both Herpes and the AIDS virus .
Anti diabetic: Aloe-vera gel is an effective anti hyperglycemic agent against type 2 diabetes. It lowers the blood glucose level without disturbing the normal blood lipid level and liver / kidney function. It has been proposed that blood glucose level is lowered due to its increased metabolism.
Anti-aging: Aloe-vera is rich in mucopolysaccharides which help in binding moisture to the skin as it stimulates fibroblasts to produce collagen and elastin fibers thereby making the skin more elastic and less wrinkled. Moreover, the amino acids present in Aloe gel also soften hardened skin cells and zinc present in the gel acts as an astringent & tightens the pores. It has also anti-acne effect.
Anti-inflammatory: Aloe-vera by inhibiting the cyclooxygenase pathway reduces the production of prostaglandin E2 from arachidonic acid. A novel anti-inflammatory compound called C-glucosyl chromone had been isolated from Aloe gel extracts recently.
Aloe-vera is a medicinal plant and due to its extensive medicinal, nutraceutical and other uses, it enjoy a great demand in the market across the globe mainly, Australia, US and the entire Europe. Due to the exponentially growing demand for it in the international market, Aloe-vera presents the finest commercial opportunity among the various medicinal plants and India is among the few countries gifted with the unique geographical features essential for cultivation of Aloe-vera and other high potential medicinal plants.
(The authors are from Division of Biochemistry, FBSc., SKUAST-J).
