Study of vascular endothelial dysfunction in children with beta-thalassemia major before and after quercetin therapy

Abstract Background Beta-thalassemia stands as an autosomal recessive disorder that occurs as a result of a defect in the beta-globin chain synthesis of hemoglobin. Oxidative stress has a crucial role in the β -thalassemia pathophysiology. It occurs due to erythroid expansion along with ineffective erythropoiesis. The free hemoglobin oxidation generates reactive oxygen species (ROS), free heme, and iron, thus inducing membrane oxidative damage as well as vascular endothelial dysfunction. Quercetin has a crucial impact on enhancing endothelial dysfunction in thalassemia major. This work aimed to investigate endothelial dysfunction among children diagnosed as beta-thalassemia major by assessing serum level of some endothelial markers (thrombomodulin as well as human ROS) and assessing the quercetin’s therapeutic value in improving endothelial dysfunction by measuring the previous markers 12 weeks following therapy. This randomized placebo-controlled study involved 72 children developing transfusion-dependent β-thalassemia major. Their age range fell between 8 and 18 years. They were categorized into two equal groups: group I: received 12 weeks of quercetin therapy and group II: served as control group and received 12 weeks of placebo. Results Serum ferritin, C-reactive protein, and lactate dehydrogenase levels showed significantly lower values among patients after 12 weeks of quercetin therapy compared with controls. Pre-transfusion hemoglobin was significantly higher in patients after 12 weeks of quercetin therapy in comparison to controls. Frequency of transfusion was significantly less in patients after 12 weeks of quercetin therapy in comparison to controls. Serum levels of ROS and thrombomodulin showed significantly lower values among cases after 12 weeks of quercetin therapy in comparison to controls ( p < 0.001). ROS and thrombomodulin respectively carried the sensitivity of 83.33% and 77.78% and specificity of 80.56% and 83.33% in predicting the outcome with cutoff value ≤ 1073 and 232. Conclusions Twelve weeks of 500-mg quercetin therapy had a potent role in decreasing iron overload and improving frequency of transfusion, oxidative stress ,and endothelial dysfunction in children with β-thalassemia major.