Catalyzes oxydation of hydroxy-fatty acids. May participate to the lipid metabolism. (5S)-hydroperoxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + 2 glutathione = (5S)-hydroxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + glutathione disulfide + H2O Inhibited by MK-886 and leukotriene C4. Belongs to the MAPEG family.