The status of antioxidant defences in Glucose-6-phosphate dehydrogenase deficient patients. The role of antioxidants to ameliorate hemolytic crisis

Abstract

In human, G6PD deficiency is the most common enzymopathy affecting over 400 million people throughout the world. It is associated with higher potential for oxidative damage due to chronic redox imbalance in red cells that often results in clinical manifestation of mild to severe hemolysis. The NADPH product of G6PD is required for the reductive biosynthetic reactions as well as for the stability of catalase, and the preservation of the reduced form of glutathione (GSH). The aim of this study was to clarify the role of G6PD in cellular antioxidant defense; the level of glutathione, catalase, NADPH and estimate the level of malondialdehyde which reflect the oxidative stress across the cell membrane. Also to study the effect of antioxidant treatment (vitamins C and E) to ameliorate high sensitivity of red cells to oxidative stress. This study was carried out on fifty G6PD-deficient children during the attack. The children were classified into two groups: Group 1: received blood transfusion only, and considered as an antioxidant-untreated group. Group 2: Received blood transfusion as group I in addition to antioxidant therapy (antioxidant-treated group), and healthy control subjects as control group. Our study proved that hemolytic attack in G6PD deficient patients is due to a concomitant impairment of the two main mechanisms of detoxification of H2O2 in RBCs; GSH system and catalase. The most important finding in this study is the efficiency of treatment with a combination of vitamin E and vitamin C may improve antioxidant status in G6PD deficient patients and in reducing the symptoms of hemolytic crises.

Egyptian Journal of Biochemistry and Molecular Biology Vol. 25 (2) 2007: pp. 114-133