Metabolites identified in an extract of induce cytotoxic effects on human PBMCs Baccharis articulata

CARIDDI L.; SABINI C.; ESCOBAR F.M.; COMINI L.; SABINI L.

Otro; XLVIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Baccharis articulata (Lam.) Pers. is used in the treatment of different disorders. We have demonstrated that cold aqueous extract of B. articulata (Ba-CAE) induced apoptosis in human peripheral blood mononuclear cells (PBMCs). The phytochemical study of the extract showed the presence of luteolin, acacetin and chlorogenic acid. The aim of this study was determine whether these compounds are responsible for the cytotoxic and apoptotic effects exhibited by the extract. The HPLC analysis shows the presence of luteolin (L) (1.96 ± 0.27%), acacetin (A) (1.12 ± 0.14%) and chlorogenic acid (ChA) (0.29 ± 0.05%). Analysis of PBMCs viability of each compound alone determined by staining of Trypan blue dye exclusion method revealed that ChA was the most toxic compound (CC50=18µg/mL), followed by A (CC50=89µg/mL) and L (CC50=144µg/mL). Both, ChA (4µg/mL) and the combination of three compounds (L:25µg/mL+A:14µg/mL+ChA:4µg/mL), in concentrations that these are present in Ba-CAE at 1280µg/mL, showed 50.0±0.88% and 48.50±1.92% of decrease in PBMCs viability, respectively, and induced the cell death by apoptosis determined by Hoechst 33258 staining, TUNEL, and DNA fragmentation analysis. ChA not affect the Bax/Bcl-2 ratio, but neither activated the death receptor DR4. We suggested that toxic effects and death by apoptosis triggered by Ba-CAE on human PBMCs would be mainly produced by ChA