5.

Scavenging Effect of Various Extracts of the Gymnema sylvestre R. Br. and Antioxidant Activity of the Isolated Triterpenes

 Valeria Romanucci, Piero Porcaro, Cinzia Di Marino and Anna De Marco

Department of Chemical Sciences, University of Federico II, Via Cinthia 4, 80126 Napoli, Italy

Consorzio Sannio Tech, Piazza San G. Moscati, 82030 Apollosa (BN), Italy

Department of Biology, University Federico II, Complesso Universitario Monte S. Angelo,

IT-80126 Napoli, Italy

Abstract:Gymnema sylvestre has been used in Asian traditional medicine for its anti-microbial, anti-hypercholesterolemic, hepatoprotective and sweet suppressing properties and activities. G. sylvestre has also been used extensively in chewing gum, as a health food for preventing obesity and diabetes, and as a tea. This study has evaluated the total phenolic content and antioxidant activity of the aqueous and organic G. sylvestre extracts and their sub-fractions for the initial characterization of the biological properties of the isolated compounds. An in vivo cell model was used to calculate the concentration inhibiting cell growth by 50% and the ability to exert antioxidant activity. All compounds inhibit cell growth in a dose-dependent manner, with an IC 50 value ranging between 29 and 1462 μM. The effects on intracellular ROS levels are extremely variable, but it is of interest that some of the compounds appear to display an antioxidant effect.