Effect of Zinc Supplementation on Antioxidant Defenses and Oxidative Stress Markers in Patients Undergoing Chemotherapy for Colorectal Cancer: a Placebo-Controlled, Prospective Randomized Trial

Autor(es)

de Figueiredo Ribeiro, Sofia Miranda ^[1] ; Moreno Braga, Camila Bitu ^[1] ; Peria, Fernanda Maris ^[2] ; Domenici, Fernanda Aparecida ^[1] ; Martinez, Edson Zangiacomi ^[3] ; Feres, Omar ^[4] ; Ribeiro da Rocha, Jose Joaquim ^[4] ; de Carvalho da Cunha, Selma Freire ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Internal Med, Div Nutrol, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Internal Med, Div Clin Oncol, Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Social Med, Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Sch Med RibeiraoPreto, Dept Surg, Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOLOGICAL TRACE ELEMENT RESEARCH; v. 169, n. 1, p. 8-16, JAN 2016.
• Citações Web of Science: 5

Resumo

The study aimed to investigate the effect of oral zinc supplementation on antioxidant defenses and oxidative stress markers during chemotherapy for colorectal cancer. Twenty-four patients who had undergone surgical resection of colorectal cancer participated in this placebo-controlled, prospective randomized study. The supplementation was started in the perioperative period, in which 10 patients received 70 mg of zinc (zinc group, n = 10) and 14 patients received placebo (placebo group, n = 14) for 16 weeks. Approximately 45 days after surgical resection of tumor, all patients received a chemotherapeutic regimen (capecitabine, capecitabine combined with oxaliplatin or 5-fluorouracil). Vitamin C, vitamin E, antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and lipid peroxidation markers malondialdehyde (MDA) and 8-isoprostane were determined before the first, second, third, and fourth chemotherapy cycles. Compared with the placebo group, the zinc group presented higher SOD values before the first, second, and fourth chemotherapy cycles and lower GPx values before the third cycle. There were no statistical differences between the study groups in vitamin C, vitamin E, MDA, or 8-isoprostane plasma values. Longitudinal analysis revealed decreased vitamin E concentration in the placebo group before the second and fourth cycles as compared with the initial values. Zinc supplementation during chemotherapy cycles increased SOD activity and maintained vitamin E concentrations. Although no effect of zinc supplementation on oxidative stress markers was observed, the increase in SOD activity indicates a production of stable free radicals, which may have a positive effect in cancer treatment. (AU)

• Processo FAPESP: 11/07867-4 - Marcadores de estresse oxidativo após ciclos de quimioterapia adjuvante para câncer de cólon: efeito da suplementação de zinco
• Beneficiário: Selma Freire de Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular