Phytochemical and Pharmacological Importance of Stevia: A Calorie Free Natural Sweetener

Stevia, a natural sweetener, comprises of 200 species of herbs and shrubs from the family Asteraceae (Composite). Among the different species of Stevia, S. rebaudiana exhibits the highest level of sweetness. Stevia contains entkaurene, a diterpene glycoside commonly known as stevioside which is 150-300 times more sweeter than sugar. In addition to its interesting sweetening property, Stevia plant shows many other pharmacological properties. Its’ leaves also contains good amount of protein, amino acid, lipids, vitamins and minerals. Phyto-chemical screening showed that tannins are also present in higher concentrations followed by alkaloids, glycosides, saponins, sterols, and triterpenes, anthraquinones, and other reducing compounds. Stevia glycosides possess many pharmaceutical properties viz; anti-hyperglycaemic, antihypertensive, antioxidant, antimicrobial activity, anticancer effect, anti-inflammatory and immune-modulatory effect etc. Stevia has potential qualities of a sweetener and also constituting a source of many substances with a nutritional effect on the human beings. Among different chemical constituents, stevioside has a potential mode of actions in controlling type 2 diabetes. Stevia enriched food products brings several benefits to human society. Commercial marketing of products stevia in different form such as leaf powder, liquid and fresh leaves has become a potential adventure for many biotechnological companies because of its large demand.