Displays both glutathione S-transferase and glutathione peroxidase activities toward oxyeicosanoids, as part of cellular detoxification as well as synthesis of bioactive metabolites.Catalyzes conjugate addition of reduced glutathione to the alpha, beta-unsaturated C=C carbonyl group of eisosanoids such as leukotriene A4 and 15-deoxy-Delta12,14-prostaglandin J2 to form GSH adducts relevant to the inflammatory response.