PHARMACOGNOSTIC AND PHYTOCHEMICAL PROPERTIES OF ALOE VERA LINN -AN OVERVIEW

Aloe vera is a perennial, drought-resisting, succulent plant belonging to the Asphodelaceae family which, historically has been used for a variety of medicinal purposes. It has a vast traditional role in indigenious system of medicine like ayurveda, siddha, unani and homoeopathy. Clinical evaluations have revealed that the pharmacological active ingredients are concentrated in both the gel and rind of the aloe vera leaves. Bioactive compounds from aloe vera are very effective in various treatments, such as burns, allergic reactions, rheumatoid arthritis, rheumatic fever, acid indigestion, ulcers, diabetes, skin diseases, dysentry, diarrohoea, piles and inflammatory conditions of the digestive system and other internal organs, including the stomach, small intestine, liver, kidney, and pancreas. The active ingredients have been shown to have analgesic, anti-inflammatory, antioxidant and anticancer agent. The present review is therefore, an effort to give a detailed survey of the literature on its traditional, phytochemical and pharmacological properties. 1 . Natural antimicrobials can be derived from barks, stems, leaves, flowers and fruits of plants, various animal tissues or from microorganisms 2 . Genus Aloe is a perennial succulent herb have grown in temperate and subtropical parts of the world. This plant genus is originated in Africa. The genus includes 200 or more species. Some of them are cultivated for the resinous latex contained in their thick, fleshy leaves. Since biblical times, aloe plants have figured among folkloric remedies as purgatives and as treatments for skin disorders. Aloe vera is a member of liliaceae family. It is commonly called aloe, burn plant, lily of the desert, elephant's gall. Alove vera (L.) in synonym A. brobadensis is a cactus (leaves) like plant with green, dagger- shaped leaves that are fleshy, tapering, spiny, marginated and filled with a clear viscous gel 3 . The name, aloe, is derived from the Arabic "alloeh" or Hebrew "halal" meaning bitter shiny substance. Two types of exudates are secreted by aloe leaves. One is a bitter reddish-yellow juice contained in the pericyclic cells located under the strongly cutinized epidermis of the leaves. This "juice" has been generally used for laxative purposes and in dried form. Its bitterness is due to the presence of aloin, aloe-emodin and related compounds. The other exudate is a transparent, slippery mucilage or gel produced by the thin-walled tubular cells in the inner central zone (parenchyma) of the leaf. The raw "gel" resembles colorless gelatin with hair-like connective matrices and is also sometimes called "juice. " In antiquity, this mucilage was applied to inflamed skin and during the 20th century it was used on radiation burns. The bio active compounds are used as astringent, haemostatic, antidiabetic 4,5 , antiulcer, anti-septic 6 , antibacterial 7 . antiinflammatory, antioxidant and anticancer agent and also, effective in treating stomach ailments, gastrointestinal problems, skin diseases, constipation, radiation injury, wound healing, burns, dysentery, diarrhoea and in the treatment of skin diseases. Currently the plant is widely used in skin care, cosmetics and as