Effect of arsenic on nitrosative stress in human breast cancer cells and its modulation by flavonoids.

SORIA, ELIO A; BONGIOVANNI, GUILLERMINA A.; DIAZ, CINTIA; EYNARD, ALDO R

NUTRITION AND CANCER

LAWRENCE ERLBAUM ASSOC INC-TAYLOR & FRANCIS

Lugar: Londres; Año: 2015 vol. 67 p. 659 - 663

0163-5581

Abstract: Arsenic (As) is used in the treatment of leukaemia and breast cancer due to its strong oxidative cytotoxic action. However, it is also cytotoxic to normal cells. One proposed anticancer mechanism induced by As might be nitrosative stress (NS). Hence, it is opined that use of antioxidants such as flavonoids in combination with arsenic might reduce its (As) toxic action on normal cells without interfering with its tumoricidal action. In the present study, we evaluated the antineoplastic potential of As on breast human cancer lines MCF-7 and ZR-75-1 treated with redox-modulating flavonoids, such as quercetin (Q) and silymarin (S). It was noted that, even though both cell lines differed about their oxidative responsiveness, their viability was decreased by NS induction through γ-glutamyltranspeptidase inhibition. As triggered NS in MCF-7 and ZR-75-1 cultures, being the formers more sensitive without recovering capacity. ZR-75-1 cells maintained their antioxidant status, whereas MCF-7 ones treated with S, As and As+Q did not. Silymarin did not interfere with the described As bioactivity. In summary, NS represents an important anticancer mechanism of As depending on the redox cellular response that could be differentially modified by dietary antioxidants. Hence, it is worthwhile to consider the use of dietary antioxidants as adjuvants in cancer chemotherapy especially while using As.