PTGS2 and inflammatory skin disease: Consistent with the upregulation of COX-2 mRNA, SQOOH enhanced ROS generation, nuclear factor kappa B activation, COX-2 protein expression, and prostaglandin E2 production.61,62) On the other hand, tocotrienol (the unsaturated form of vitamin E) ameliorated SQOOH actions.61) The findings indicated that SQOOH plays an important role in inflammatory skin disorders after exposure to excess sunlight.