Table 3: Biomarkers levels of oxidative stress in antioxidant enzymatic system of patients with breast cancer before (C0), during (C2), and after chemotherapy (C4) and control group.

GroupsTBARS levels
(nM/mg de protein)
(µM/mg protein)
GSH concentration
(U/g protein)

Control0.37 ± 0.090.16 ± 0.0536.13 ± 7.65
C01.42 ± 0.45a1.16 ± 0.62a24.94 ± 1.51a
C24.76 ± 0.68a,b1.81 ± 0.02a,b19.30 ± 0.74a,b
C411.98 ± 0.65a.b,c3.49 ± 0.07a,b,c17.75 ± 0.46a,b

TBARS: thiobarbituric acid reactive substances levels, : nitrite content, and GSH: reduced glutathione concentration. Values represent mean ± S.E.M. a when compared with control group (CG) by ANOVA followed by -Student-Newman-Keuls. b when compared with C0 group (before chemotherapy) and c when compared with C2 group (second cycle of chemotherapy).