Metal chelating agents, flavonoids

The involvement of oxidative stress in AD has opened a new door for potential therapeutic targets. In this regard, several antioxidants are currently in clinical trials such as Idebenone, a-Lipoic acid, acetyl-L-carnitine (ALC), vitamin E, vitamin C, flavonoids, P-carotene, gingko biloba, and metal-chelating agents. Idebenone is a metabolic antioxidant and is normally synthesized as part of the mitochondrial oxidative phosphorylation system. Improvements in clinical status after treatment with idebenone have been shown in a dose-dependent manner compared to placebo and tacrine (Thai et al., 2003). 

Phenolic acids and flavonoids can also act as chelating agents, complexing transition metals that are responsible of the initiation of peroxidative processes (Fenton and Haber-Weiss reactions). This property is much stronger in phenolics having a catechol, pyrogallol, or 3-hydroxy-4-carbonyl group [130]. 

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