The cold aqueous extract of Baccharis articulata stimulates apoptosis process in human lymphocytes

CARIDDI N.; ESCOBAR F.; SABINI C.; ZAMORA F.; TORRES C.; REINOSO E.; SABINI L.

Puerto Madryn

Encuentro; XLVI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica; 2010

The cytotoxic action of Baccharis articulata (Asteraceae) has not been studied. The aim was to determine the toxic effects of cold aqueous extract of B. articulata (Ba-CAE) on human lymphocytes. Lymphocytes separated from peripheral blood of healthy volunteers by density gradient were exposed to Ba-CAE (10, 20, 40, 80, 160, 320, 640 and 1280 ug/mL) for 18-24 h. Cell viability was determined by staining of trypan blue exclusion and MTT reduction. Apoptosis was determined by Hoechst 33258 staining, TUNEL and DNA fragmentation analysis by agarose gel electrophoresis. A dose-dependent toxicity of Ba-CAE was demonstrated by staining of trypan blue exclusion (CC50=150 ug/mL). By MTT assay could not quantify this effect, since Ba-CAE was able to reduce tetrazolium salt in absence of cells. Hoechst staining, showed apoptotic figures (fragmented nuclei, kidney shaped nuclei and small nuclear blebs) in cells treated with Ba-CAE (80 to 1280 ug/mL). The percentage of TUNEL-positive per 400 cells was: cell with media alone: 7+1%, cells treated with Ba-CAE: 10ug/mL (8+1%), 20ug/mL (9+3%), 40ug/mL (43+11%)*, 80ug/mL (58+18%)*, 160ug/mL (62+13%)* 320ug/mL (68+20%)**, 640ug/mL (73+10%)**, 1280ug/mL (88+13%)**; *p<0.01; **p<0.001. Agarose gel electrophoresis showed typical DNA laddering in cells treated with Ba-CAE (40 to 1280 ug/mL). Ba-CAE stimulated apoptosis in human lymphocytes.