Biochemistry & Pharmacology: Open Access
Open Access

Isolation of a trypanocidal sesquiterpene lactone from Stevia gilliesii by chromatographic techniques

Joint Event on 10^th World Congress on Pharmacology & 6^th International Conference and Exhibition on Advances in Chromatography & HPLC Techniques

August 02-03, 2018 | Barcelona, Spain

Orlando G Elso, Augusto Bivona, Mariana G. Selener, Natacha Cerny, Andres Sanchez Alberti, Emilio Malchiodi, Elisa Lombardo, Flavia Redko, Valeria P. Sulsen, Silvia Cazorla and Cesar Catalan

University of Buenos Aires, Argentina
CONICET, Reference Center for Lactobacillus, Tucuman, Argentina
National University of Tucuman, Argentina

Posters & Accepted Abstracts: Biochem Pharmacol (Los Angel)

Abstract :

Chagas disease is an illness caused by the protozoan Trypanosoma cruzi which affects about 6-7 million people worldwide. Sesquiterpene lactones (STL) are a large group of secondary metabolites mostly found among Asteraceae family plants. Sesquiterpene lactones present a wide range of biological activities such as anti-inflammatory, cytotoxic, antiplasmodial and antitrypanosomal, among others. In a previous work, we have evaluated the effect of a group of STLs against T. cruzi epimastigotes and their cytotoxicity against Vero cells. Eupahakonenin B (EKB), isolated from Stevia gilliesii var. gilliesii Hook. and Arn. (Asteraceae) has shown promising trypanocidal activity and selectivity index (IC50=0.78 �?¼M; CC50=363.72 �?¼M; SI=466). In this work we describe the isolation of EKB by chromatographic methods in order to assess its trypanocidal activity against infective and intracellular forms of T. cruzi. Dried aerial parts of S. gilliesii var. gilliesii were extracted twice with dichloromethane. Dichloromethane extract was partitioned between hexane and a water/ethanol mixture and fractionated by column chromatography using silicagel and dichloromethane/ethyl acetate (1:2) as mobile phase. Eluted fractions were analyzed by thin layer chromatography (sp: silica gel 60 F254, mp: Dichloromethane/ethyl acetate 1:2). EKB containing fractions were joined and taken to dryness to obtain the compound as a greenish gum. EKB purity was analyzed by HPLC. The effect of EKB on bloodstream infective form of T. cruzi was assayed by counting remaining living parasites in a Neubauer chamber and the effect of EKB on intracellular forms of T. cruzi was assayed using �?²-galactosidase transfected parasites as previously described. The sesquiterpene lactone EKB appeared as a blue spot on TLC after spraying the plate with anisaldehyde-sulphuric acid (Figure 2). The STL was purified and isolated by chromatographic techniques (96% purity) and identified by spectroscopic methods (Figure 2). This STL showed activity and selectivity on trypomastigote (IC50=30 �?¼M; SI=11) and amastigote (IC50=29.9 �?¼M; SI=12) forms of T. cruzi. The mechanism of action of EKB and its in vivo activity will be evaluated.