Figure 5.

Capsaicin- and capsaicin epoxide-mediated oxidative stress and the effect of N-acetyl cysteine (NAC) in MCF7 cells. The steady-state level of reactive oxygen species (ROS) in the cell culture medium (A) and the intracellular ROS production (B) were measured with 2′,7′-dichlorodihydrofluorescein diacetate (H₂DCF-DA), and superoxide production (C) was measured with dihydroethidium. (D) The NAC-mediated recovery of the proliferative potential was estimated using the MTT assay. The bars indicate the SD (n = 5). ***P < 0.001 compared with the control conditions; ^ ^ ^P < 0.001 compared with 24-hour treatment with capsaicin (CAP) (24-hour treatment with 50 µM capsaicin versus 24-hour treatment with 50 µM capsaicin epoxide); ⁺⁺⁺P < 0.001 compared with 24-hour treatment with capsaicin (24-hour treatment with 50 µM capsaicin versus 2-hour pretreatment with 5 mM NAC and 24-hour treatment with 50 µM capsaicin, NAC/CAP); ^###P < 0.001 compared with 24-hour treatment with capsaicin epoxide (CAPO) (24-hour treatment with 50 µM capsaicin epoxide versus 2-hour pretreatment with 5 mM NAC and 24-hour treatment with 50 µM capsaicin epoxide, NAC/CAPO) (ANOVA and Tukey's a posteriori test).