The Antioxidant Mechanisms Underlying the Aged Garlic Extract- and S-Allylcysteine-Induced Protection

Figure 2

Antioxidant mechanism associated to S-allylcysteine (SAC). SAC can scavenge superoxide anion (O₂^•−), hydrogen peroxide (H₂O₂), hydroxyl radical (OH^•), peroxynitrite radical (ONOO⁻), and peroxyl radical (LOO^•) produced in neuronal cells, as well as hypochlorous acid (HOCl) and singlet oxygen (¹O₂) produced in microglial cells (blue lines). Moreover, SAC also exhibits chelating properties on Fe²⁺ and Cu²⁺ ions (red line), hence avoiding Fenton reaction. SAC also inhibits NF-kB translocation into the nucleus (green line), thus preventing apoptotic signaling. COX-2: cyclooxygenase-2, NOX: NADPH oxidase, nNOS: neuronal nitric oxide synthase, SOD: superoxide dismutase, XO: xanthine oxidase.