Influence of smoking on serum and milk malondialdehyde, superoxide dismutase, glutathione peroxidase, and antioxidant potential levels in mothers at the postpartum seventh day

The aim of the study was to investigate simultaneously serum and milk malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and antioxidant potential (AOP) in active-smoking, passive-smoking, and nonsmoking mothers and to search if there is any difference between serum and milk oxidant/ antioxidant status caused by smoking. According to their smoking status, 60 mothers (age range: 20–35 yr) were classified into one of three groups: the active-smoking mothers (n=15), the passive-smoking mothers (n=22), and the nonsmoking mothers (n=23). Serum and milk MDA, SOD, GPx, and AOP values were determined in mothers on the postpartum seventh day by the spectrophotometric method. Serum Zn and Cu concentrations were determined by atomic absorption spectrophotometry (AAS). There was no significant difference in serum samples with respect to MDA (p=0.17), SOD (p=0.51) and AOP (p=0.36) levels, but there was a significant difference in serum GPx (p=0.002) levels among the study groups. The significant differences were also found in milk samples in terms of MDA (p=0.002) and SOD (p=0.011), but not in GPx (p=0.11) and AOP (p=0.29) levels among the study groups. No significant difference was seen in serum zinc concentration (p=0.49), but copper concentration differed significantly among the groups (p=0.005). These observations suggest that human milk is more vulnerable to oxidative stress and lipid peroxidation than serum samples in smoking mothers, even if they are passive smokers.