ABSTRACT

Abstract-L-Dopa is considered to be one of the best therapies in treating Parkinson's disease (PD), with positive outcome in the beginning of its treatment; however, long treatment periods with this drug have shown both On and Off phenomena and, when it is used in high doses, produces various clinical symptoms. In this chapter, both On and Off PD patients on L-dopa therapy are investigated to determine the role of various neurotransmitters, such as aspartic and glutamic acid, homocysteine, catecholamines, vitamin B12 and free radical nitric oxide, in neurotoxicity and oxidative stress. All these biochemical changes might provide vital information in designing multiple therapy consisting of antioxidants to prolong the avoidance of neurotoxicity and oxidative stress in PD patients.