Protective Mechanisms of Flavonoids in Parkinson’s Disease

Table 2

Antioxidant enzyme	Function	Chemical reaction
Superoxide dismutase	Catalysing superoxide anion to oxygen and hydrogen peroxide
Catalase	Detoxifying hydrogen peroxide to water and oxygen molecule
Glutathione (GSH)	Electron donor to GPx in reducing hydroperoxides to water molecules
Glutathione peroxidase	Reducing hydroperoxides to water molecules	GS–SG
Glutathione reductase	Catalyzing the reduction of glutathione disulfide (GSSG) to the sulfhydryl form glutathione (GSH)	NADPH   NADP^+

(superoxide anion);   (hydrogen peroxide);   (oxygen);   (water molecule);  GSSG (reduced glutathione); NADPH (nicotinamide adenine dinucleotide phosphate).