Nutraceuticals have been extensively studied worldwide due to its
neuroprotective effects in in vivo and in vitro studies, attributed by the antioxidative properties. Alzheimer (AD) and
Parkinson disease (PD) are the two main
neurodegenerative disorders that are discussed in this review. Both AD and PD share the similar involvement of oxidative stress in their pathophysiology. Nutraceuticals exert their antioxidative effects via direct scavenging of
free radicals, prevent damage to biomolecules, indirectly stimulate the endogenous antioxidative
enzymes and gene expressions, inhibit activation of
pro-oxidant enzymes, and chelate metals. In addition, nutraceuticals can act as modulators of pro-survival, pro-apoptotic, and inflammatory signaling pathways. They have been shown to be effective particularly in preclinical stages, due to their multiple mechanisms of action in attenuating oxidative stress underlying AD and PD. Natural
antioxidants from food sources and natural products such as
resveratrol,
curcumin,
green tea polyphenols, and
vitamin E are promising therapeutic agents in oxidative stress-mediated
neurodegenerative disease as they have fewer adverse effects, more tolerable, cheaper, and sustainable for long term consumption.