Cisplatin combination chemotherapy induces a fall in plasma antioxidants of cancer patients

Abstract

Antioxidants protect the body against cellular oxidative damage and thus some of the adverse effects induced by cisplatin and other cytostatic drugs. The effect of cisplatin-combination chemotherapy on concentrations of plasma antioxidants was studied in 36 cancer patients, including osteosarcoma and testicular carcinoma patients. Eight to 15 days after the start of each cytostatic drug infusion concentrations of various plasma antioxidants were measured and compared to pretreatment values: vitamin C and E, uric acid and ceruloplasmin levels fell significantly (P < 0.01-0.005) and returned to baseline levels before the start of the next chemotherapy cycle. Levels of the antioxidants bilirubin albumin and the ratio vitamin E/cholesterol + triglycerides measured three weeks after the start of chemotherapy significantly decreased compared to pretreatment levels and remained low thereafter (P < 0.001-0.002). Dietary intake of antioxidants and anthropometric measurements, evaluated in 14 patients did not change during the whole treatment period. Cisplatin-combination chemotherapy induces a fall in plasma antioxidant levels, that may reflect a failure of the antioxidant defense mechanism against oxidative damage induced by commonly used anticancer drugs. This probably results from consumption of antioxidants caused by chemotherapy induced-oxidative stress as well as renal loss of water-soluble, small molecular weight antioxidants such as uric acid.