Citral Protects Human Endothelial Cells Against Hydrogen Peroxide-induced Oxidative Stress

Oxidative stress plays a major role in endothelial dysfunction. Citral is a monoterpene aldehyde with antioxidant properties. This study aimed to investigate the effect of citral on human umbilical vein endothelial cells (HUVECs) under hydrogen peroxide (H₂O₂)-induced oxidative stress.

The cells were treated with citral (0.625-10 μg/mL) for 24 h before exposure to H₂O₂ (0.5 mM, 2 h). Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The hydroperoxide concentrations and ferric reducing ability of plasma (FRAP) were measured in intra- and extracellular fluids.

Pretreatment of HUVECs with citral at concentrations of 5 and 10 μg/mL significantly enhanced the cell viability in H₂O₂-induced cytotoxicity. It reduced intracellular hydroperoxide levels at the concentrations of 5 and 10 μg/mL and extracellular hydroperoxide levels at the concentrations of 2.5-10 μg/mL. Pretreatment with citral significantly increased the FRAP value in intra- and extracellular fluids at the concentration range of 1.25-10 μg/mL.

Antioxidant and cytoprotective effects were found for citral against oxidative damage induced by H₂O₂ in human endothelial cells. However, more studies in this area are needed to assess its clinical value for prevention and treatment of cardiovascular diseases.