Preliminary Phytochemical Screening And Evaluation of Free Radical Scavenging Activity Of Stevia rebaudiana Bertoni From Different Geographical Sources

Abstract

Stevia rebaudiana Bertoni, a natural non-caloric substitute to conventional sugar, is also popular as the “sweet herb of Paraguay”. It is a storehouse of various bioactive constituents mainly, the ent-kaurene diterpene glycosides namely stevioside, rebaudioside A, B, C, D and E. The plant is known to exhibit a wide range of biological activities like hypoglycemic, anti-oxidant, anticancer, antibacterial activities. The present research is based on a preliminary phytochemical screening and comparative evaluation of in vitro antioxidant activity of the dried leaves of five varieties of Stevia rebaudiana procured from five different geographical locations of India viz., Delhi, Surat, Kangra, Bangalore and Indore. Total phenolic and total flavonoid content was also determined using Folin-Ciocalteu reagent method and aluminum chloride colorimetric. The result showed that the variety from Kangra showed the highest phenolic and flavonoid content of 5.87 and 62.22 mg GAE/L respectively.