Antioxidant Nutraceuticals as Novel Neuroprotective Agents

Antioxidants found in various natural resources have attracted the attention of the medical field. They serve diverse roles in physiological homeostasis through detoxifying reactive oxygen species (ROS). ROS generation creates structural disorganization in neurons due to oxidative stress and leads to the accumulation of reactive oxygen intermediates. Among the other organs of the body, the brain is the most vulnerable one toward the effects of ROS due to the presence of a large number of lipid peroxidation-susceptible cells and its high demand for oxygen. Oxidative stress plays a central role in the pathophysiology of a wide array of neurodegenerative diseases. Nutraceuticals are the potential sources of antioxidants, which are extracted from natural reservoirs. Neutralization of oxidative stress by nutraceuticals is one of the advancing therapies for the betterment of neurological disorders. Nutraceuticals that are useful in the treatment of neurodegenerations may be broadly divided into two categories, viz. phytochemicals and non-phytochemicals. Various phytochemicals such as alkaloids, carotenoids, flavonoid polyphenols, and non-flavonoid polyphenols, and non-phytochemicals such as creatine, polyunsaturated fatty acids (from fish), and melatonin have been studied for their neuroprotective properties. Apart from these, several other compounds have also been observed to possess neuroprotective activities through participating in oxidative stress-mediated pathways that involve mitochondrial damage, autophagy, apoptosis, and neuro-inflammation. The nutraceuticals having persuasive antioxidant property can be useful to limit the progression of neurodegenerative disorders. However, poor bioavailability and inappropriate systemic delivery limit the potential use of many nutraceuticals. In this review, we elucidate various antioxidants having potential neuroprotective proficiency.