Time-dependent JNK, p38 and p53 pathway inhibition studies induced by CC and polyphenols alone and JNK/p38-dependent apoptosis in sensitized cells.

<p>10⁴ MCF-7 (A)/MDA MB-231 (B) cells were pre-cultured for 48 h in phenol red-free DMEM then exposed to CC (10 µM)/polyphenols <i>per se</i> (RES: 10/100 µM and CUR: 10/30 µM) for MTT analysis. Percentage inhibition was determined per the formula {(Absorbance of Control – Absorbance of drug treated cells without and with inhibitor)/Absorbance of Control cells} ×100. For inhibitor experiments through Flow Cytometry, 0.2×10⁶ MCF-7 (C)/MDA MB-231 (D) cells were pre-cultured for 48 h in phenol red-free DMEM, exposed to CC (10 µM)/polyphenols <i>per se</i> (RES: 10/100 µM and CUR: 10/30 µM) or preconditioned with low/high dose polyphenols for 6 h and continued with CC (10 µM) for next 18 h. JNK (10 µM SP600125), p38 pathway (1 µM SB 203580), Pifithrin (15 µM Pif) and zVAD-fmk (30 µM) inhibitors were added during the last 2 hours prior to CC exposure, followed by the analysis of the Sub-G0/G1 fraction by FACS. Each data point is the Mean ± S.E. of one of three similar experiments each performed in triplicate. * P<0.05, ** P<0.01, *** P<0.001 drugs compared to drug treatment without inhibitor.