Water extract of mangosteen suppresses H2O2-induced endothelial apoptosis by inhibiting oxidative stress

Abstract

Excessive production of reactive oxygen species (ROS) is a major cause of endothelial apoptosis. Mangosteen extract has been shown to possess antioxidant properties. Mangosteen is commonly extracted either with semi-polar solvent, yielding virtually pure α-mangostin, or with water, yielding a low α-mangostin concentration but including a wide variety of other polyphenols present in the fruit. However, the effect of a water extract of mangosteen (ME) on ROS induced cell death is not yet known. This study evaluated whether ME suppresses H2O2-induced endothelial cell death and ROS production in human endothelial cell lines. The concentrations of ME and H2O2 were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Intracellular ROS levels were determined by 2', 7' dichlorodihydrofluorescein diacetate assay, and cell death rates by MTT and Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling assays. mitogen-activated protein kinase (MAPK) and apoptotic proteins were analyzed by western blot. Results showed that ME concentrations of 1, 5, and 10 μg/ml were non-toxic. ME significantly attenuated ROS formation and cell death, both in a dose-dependent manner. ME also reduced phosphorylation of p38 MAPK as well as cleavage of caspase 3 and poly(ADP-ribose) polymerase-1. In summary, ME demonstrates anti-apoptotic effects against H2O2-induced endothelial cell death by inhibiting ROS formation and suppressing p38 MAPK.