HPLC method to assay total saponins in Ilex paraguariensis aqueous extract

Ilex paraguariensis St. Hilaire is a South American tree from which leaves and twigs are used to prepare a commonly consumed tea in several South American countries. The plant is known as erva-mate in Portuguese or yerba mate in Spanish. Considering the potential use of the saponins as surfactant as well as its therapeutic potential, the present work was designed to propose extraction and quantitation methods for the saponins present in Ilex paraguariensis. The saponins were extracted by decoction, hydrolyzed and quantified by a HPLC method with UV detection. The saponins concentration was expressed in ursolic acid (total saponins). The method showed linearity for ursolic acid in the range of 13.5 to 135 mu g mL(-1). The aqueous extract presented total saponins concentration of 352 mu g mL(-1). The results also suggest the possibility of use of similar method for assaying triterpenoid saponins in other plants.