Protective effect of Melissa officinalis extract against H₂O₂-induced oxidative stress in human vascular endothelial...

Melissa officinalis L. is a medicinal plant with a large variety of pharmacological effects and traditional applications. This study aimed to evaluate the protective and antioxidant activities of the extract of M. officinalis aerial parts on human umbilical vein endothelial cells (HUVECs) under oxidative stress induced by H₂O₂. Cells were incubated with H₂O₂ (0.5 mM, 2 h) after pretreatment with M. officinalis extract (25-500 μg/mL). Cell viability was evaluated by 3-(4, 5- Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The concentration of hydroperoxides and ferric reducing antioxidant power (FRAP) were measured in intra- and extra-cellular fluids. Pretreatment of HUVECs with M. officinalis extract at the concentrations of 100-500 μg/mL improved the cell viability after exposure to H₂O₂ significantly. It also decreased hydroperoxides concentration and increased FRAP value in both intra- and extra-cellular fluids. The results revealed antioxidant and cytoprotective effects of M. officinalis against H₂O₂-induced oxidative stress in HUVECs. Due to the valuable antioxidant activity, this plant extract may have potential benefits for the prevention of cardiovascular diseases associated with oxidative stress.