Chemical Constituents, Biological Activity and Agricultural Cultivation of Aloe vera

Aloe vera is a perennial, drought-resisting and succulent plant belonging to the Liliaceal family, which historically has been used for a variety of medicinal purposes. Scientific investigations on A. vera have gained more attention the last several decades due to its reputable medicinal properties. After describing Aloe in a botanical point of view, the papers relating with the chemical composition of skin and gel of Aloe, particularly describes the gel of Aloe. The chemical analysis reveals that A. vera contains various carbohydrate polymers, notably glucomannans, along with a range of other organic and inorganic components. The heterogeneous nature of Aloe products may contribute to the diverse biological and therapeutic activities that have been observed including promotion of wound healing, antifungal activity, hypoglycemic or antidiabetic effects, antiinflammatory, anticancer, immunomodulatory and gastroprotective properties etc. On the other hand, different factors also affecting the chemical composition of the gel, such as species and variety, climatic and soil conditions, cultivation methods and stress adaptation are enumerated and discussed. In this review, the historical uses, the botany, the chemistry, pharmacological activity and clinical trial, adverse effects and agricultural cultivation of A. vera will be described. This paper concludes that it still remains uncertain as to which of the component(s) is responsible for these physiological properties, more researches are needed to confirm the therapeutic and beneficial effects and to definitively clarify the myth surrounding Aloe vera. In addition, promoting its large-scale cultivation such as beach planting and seawater irrigation is also a meaty theme to study and debate.