α-Tocopherol and α-tocopheryl quinone levels in cervical intraepithelial neoplasia and cervical cancer

Objective α-Tocopherol is a potent antioxidant that protects cell membranes against oxidative damage. Red blood cell α-tocopherol levels reflect membrane α-tocopherol concentrations, and altered levels may suggest membrane damage. The objective of this study was to determine the levels of α-tocopherol and α-tocopheryl quinone, the oxidized product of α-tocopherol, in plasma and red blood cells that were obtained from control subjects and patients with cervical intraepithelial neoplasia and cervical cancer. Study design In this cross-sectional study, 72 women, (32 African American and 40 Hispanic) were recruited. Among these subjects, 37 women had cervical intraepithelial neoplasia; 14 women had cervical cancer, and 21 women were considered control subjects, who had normal Papanicolaou test results. α-Tocopherol and α-tocopheryl quinone levels were determined in red blood cell and plasma by high-pressure liquid chromatography. Results Plasma levels of α-tocopherol and α-tocopheryl quinone were decreased significantly (P = .012 and = .005, respectively, by Kruskal-Wallis test) in study groups compared with the control group; red blood cell levels of α-tocopherol and α-tocopheryl quinone were not altered significantly. Conclusion The lower α-tocopherol level that was observed in this study is consistent with our previous reports of decreased antioxidant concentrations and increased oxidative stress in women with cervical intraepithelial neoplasia. Unaltered red blood cell α-tocopherol and α-tocopheryl quinone levels suggest undamaged cell membrane. Further studies are needed to investigate the potential role of oxidative stress in cervical intraepithelial neoplasia.