PROTECTIVE EFFECT OF VITAMIN-E ON LINOLEIC-ACID HYDROPEROXIDE-INDUCED INJURY TO HUMAN ENDOTHELIAL-CELLS

The protective effects of vitamin E (alpha-tocopherol) and its model compounds, which act as antioxidants, on linoleic acid hydroperoxide-induced injury to human umbilical vein endothelial cells were examined. When incubated at 50-mu-M with endothelial cells at 37-degrees-C for 24 hr, alpha-tocopherol protected the cells from injury, and 2,2,5,7,8-pentamethylchroman-6-ol showed a similar protective effect. Trolox C, a water-soluble vitamin E model compound, had no protective effect. Tocol, a poor antioxidant, proved toxic. During preincubation, alpha-tocopherol was incorporated into the cells at 16.6 nmol/mg protein, while the pentamethylchromanol was incorporated at 0.5 nmol/mg protein; Trolox C was not incorporated at all. The results suggest that agents having both high antioxidant activity and lipophilicity can protect endothelial cells from linoleic acid hydroperoxide-induced injury.