Comparison between the effects of flavonoids on arsenite-treated tumoral and non-tumoral cells.

SORIA, EA; EYNARD, ALDO R; BONGIOVANNI, GUILLERMINA

Rosario, Argentina

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).

Objective: To study the effect of flavonoids on membrane of arsenite treated breast adenocarcinoma cells (MCF-7, ZR-75-1). Methods: Cells were incubated for 2 hours, with and without recovery (2 hours). Treatments: 200 µM NaAsO2 (As), 5 µM silymarin (S), 50 µM quercetin (Q), As+S, As+Q and controls (C). They were assayed for g-glutamyltranspeptidase activity (GGT), conjugated dienes measurement (CD) and sialic acid content (SA). Significant correlation coefficients were <-0.5 (indirect) or >0.5 (direct). Results were analyzed by ANOVA followed by the Tukey test (p<0.05). Results: MCF-7 had significant lower GGT activity than ZR-75-1 and did not response to treatments. After recovery, S, As, As+S and As+Q treatments raised it respect to controls; this behavior was opposite to that in CHO-K1 cells. GGT in ZR-75-1 cells was increased by flavonoids, mainly Q. After recovery, As and As+S inhibited GGT. On the other hand, As, S, Q and As+S decreased SA values in MCF-7 cells respect to C, while As+Q increased membrane SA content independently of the tumor line. SA in CHO-K1 cells did not change. SA presented an inverse relation with CD levels in tumoral cell lines, which were directly associated with GGT activity. Conclusions: The studied breast cancer cells responded dissimilarly to As, and were not protected by flavonoids as occurred in non-tumoral CHO-K1 cells.