Introduction: Oxidative stress has been implicated in the etiology of several pathologies.
Objectives: The study was designed to investigate the levels of antioxidants and lipid peroxidation (LPO) in relation to prostate-specific antigen (PSA) levels in blood of Nigerian prostate cancer (PCa) patients.
Patients and methods: One hundred twenty PCa patients were assigned to 3 groups; group 1 (low grade) with a PSA level of 5-10 ng/ml (n = 33), group 2 (medium grade) with PSA of 11-20 ng/ml (n = 45) and group 3 (high grade) with PSA >20 ng/ml (n = 42). The control group comprised 50 healthy subjects with PSA <3.0 ng/ml.
Results: Subjects with a PSA level of 11-20 ng/ml and PSA >20 ng/ml had significantly lower uric acid and reduced glutathione levels (p <0.05). A significant reduction (p <0.05) in plasma vitamin C and E levels was observed in these patients. The levels of vitamins C and E decreased by 27% and 77% in subjects with PSA >20 ng/ml, and by 25% and 47% in subjects with a PSA level of 11-20 ng/ml, respectively. Serum total bilirubin, alkaline phosphatase (ALP) and LPO were significantly (p <0.05) elevated in subjects with PSA >11 ng/ml. More specifically, total bilirubin, ALP and LPO levels were elevated by 75%, 66% and 107% in subjects with PSA at 11-20 ng/ml, and by 167%, 105%, 98% in subjects with PSA > or = 20 ng/ml, respectively. Moreover, superoxide dismutase and catalase activities were lower (p <0.05) in all cancer patients.
Conclusions: The results confirmed the depletion of antioxidants in PCa patients, and an inverse relationship between antioxidants and PSA values in this group.