Table 32.

Role of different natural antioxidants with their chemical structure and origin.

Chemical Name	Chemical Structure	Plant Extract	Mechanism of Action	Ref.
Baicalein		Roots of Scutellaria baicalensis and Scutellarin lateriflora	Reducesoxidative stress, inhibiting aggregation of amyloid proteins	[112]
Curcumin		Curcuma longa	They have anti-inflammatory, chemotherapeutic, antioxidant, antiproliferative, wound-healing, and antiparasitic properties	[209,210,211]
Resveratrol		Polygonum cuspidatum	Improves motor impairments and reduces oxidative stress	[85]
Ginkgolides		Ginkgo biloba	Is an ntioxidant and decreases oxidative stress	[112]
L-DOPA		Mucuna pruriens	Both the brain and peripheral areas convert it to dopamine	[212]
Nicotine		Nicotiana tabacum	Nicotine reduces SIRT6 levels in brain tissue and neural cells	[75]
St. John’s Wort		Hypericum perforatum	Shows antioxidant and antidepressant effects	[138]
Vitamin C		Citrus limon	Antioxidant	[213]
Vitamin E		Prunus amygdalus	Antioxidant	[214]
Isoflavone		Chamomile	An antioxidant, preventing mitochondrial oxidative stress	[215]
Punicalin		Punica granatum	Shows antioxidative, anti-inflammatory, and antiapoptotic activity	[108]
Oleuropein		Olive oil	Inhibits the buildup of ROS	[161,162]
Theaflavin		Black tea	Removes excess free radical production and metal chelation	[167,216]
Caffeic acid		Coffee	Eliminates excess ROS/RNS production	[217]
Ferulic acid		Peanuts	Inhibitslipid peroxidation and ROS production	[203,218]