Impacto da suplementação de vitamina C sobre níveis de peroxidação lipídica e glutationa reduzida em tecido hepático de camundongos com imunossupressão induzida por ciclofosfamida

Objective: To investigate the effects of vitamin Csupplementation on the levels of lipid peroxidationand reduced glutathionein the liver tissue of mice immunosuppressed with cyclophosphamide. Methods: Thirty-two 45-day-old female Swiss mice were divided into four groups of eight animals each as follows: control (distilled water); vitamin C(50 mg/kg); cyclophosphamide(100 + 150 mg/kg); and treatment ( vitamin C50 mg/kg + cyclophosphamide100 +150 mg/kg). The substances were provided intraperitoneally for six days, and on the seventh day, the mice were euthanized. The biochemical analyses of lipid peroxidation(quantification of thiobarbituric acid-reactive substances) and reduced glutathione(estimate of non-protein thiols) were performed on liver tissue. Results: Cyclophosphamideincreased the levels of lipid peroxidation(p<0.0001). Significant changes were not found in the groups treated with vitamin C. Cyclophosphamidealone did not affect the levels of reduced glutathione. Compared with the control group, vitamin Creduced the levels of reduced glutathionein animals that received or not cyclophosphamide. Vitamin Cinteracted with cyclophosphamide, that is, the chemotherapeutic agent further decreased the lower levels of reduced glutathionesecondary to vitamin Cintake. Conclusion: Cyclophosphamide, in the study dosage and duration, was capable of inducing oxidative damage, verified by increased lipid peroxidation. A vitamin Cdosage of 50mg/kg of body weight did not protect against the oxidative damage caused by the chemotherapeutic agent.