Fig. 3.

(A) Classification of antioxidant strategies and their antioxidant mechanisms. (B) Melatonin's antioxidant cascade and mechanisms of protection against oxidative damage. We have listed only well-studied melatonin metabolites that have significant antioxidant effects. The direct and indirect antioxidant effects of melatonin and its metabolites are presented with dashed and solid arrows, respectively.

EGCG, epigallocatechin-3-gallate; MSCs, mesenchymal stem cells; ROS, reactive oxygen species; 3-OHM, cyclic 3-hydroxymelatonin; AFMK, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine; AMK, N(1)-acetyl-5-methoxykynuramine; GSH, glutathione.