The influence of hydroxyurea on oxidative stress in sickle cell anemia

• Main Authors: Lidiane de Souza Torres, Danilo Grünig Humberto da Silva, Edis Belini Junior, Eduardo Alves de Almeida, Clarisse Lopes de Castro Lobo, Rodolfo Delfini Cançado, Milton Artur Ruiz, Claudia Regina Bonini-Domingos
• Format: Article
• Language: English
• Published: Elsevier 2012-01-01
• Series: Revista Brasileira de Hematologia e Hemoterapia
• Subjects: Hemoglobinopathies; Oxidative stress; Anemia, sickle cell; Hydroxyurea
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-84842012000600010

OBJECTIVE: The oxidative stress in 20 sickle cell anemia patients taking hydroxyurea and 13 sickle cell anemia patients who did not take hydroxyurea was compared with a control group of 96 individuals without any hemoglobinopathy. METHODS: Oxidative stress was assessed by thiobarbituric acid reactive species production, the Trolox-equivalent antioxidant capacity and plasma glutathione levels. RESULTS: Thiobarbituric acid reactive species values were higher in patients without specific medication, followed by patients taking hydroxyurea and the Control Group (p < 0.0001). The antioxidant capacity was higher in patients taking hydroxyurea and lower in the Control Group (p = 0.0002 for Trolox-equivalent antioxidant capacity and p < 0.0292 for plasma glutathione). Thiobarbituric acid reactive species levels were correlated with higher hemoglobin S levels (r = 0.55; p = 0.0040) and lower hemoglobin F concentrations(r = -0.52; p = 0.0067). On the other hand, plasma glutathione levels were negatively correlated with hemoglobin S levels (r = -0.49; p = 0.0111) and positively associated with hemoglobin F values (r = 0.56; p = 0.0031). CONCLUSION: Sickle cell anemia patients have high oxidative stress and, conversely, increased antioxidant activity. The increase in hemoglobin F levels provided by hydroxyurea and its antioxidant action may explain the reduction in lipid peroxidation and increased antioxidant defenses in these individuals.