Inhibition of the formation of the neurotoxin 5-S-cysteinyl-dopamine by polyphenols
Vauzour, D., Vafeiadou, K. and Spencer, J. P. E. (2007) Inhibition of the formation of the neurotoxin 5-S-cysteinyl-dopamine by polyphenols. Biochemical and Biophysical Research Communications, 362 (2). pp. 340-346. ISSN 0006-291X
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To link to this item DOI: 10.1016/j.bbrc.2007.07.153
The death of nigral neurons in Parkinson's disease is thought to involve the formation of the endogenous neurotoxin, 5-S-cysteinyl-dopamine. In the present study, we show that the polyphenols, (+)-catechin and caffeic acid, which contain a catechol moiety, inhibit tyrosinase-induced formation of 5-S-eysteinyl-dopamine via their capacity to undergo tyro sina se-induced oxidation to yield cysteinyl-polyphenol adducts. In contrast, the inhibition afforded by the flavanone, hesperetin, was not accompanied by the formation of cysteinyl-hesperetin adducts, indicating that it may inhibit via direct interaction with tyrosinase. Whilst the stilbene resveratrol also inhibited 5-S-eysteinyl-dopamine formation, this was accompanied by the formation of dihydrobenzothiazine, a strong neurotoxin. Our data indicate that the inhibitory effects of polyphenols against 5-S-cysteinyl-dopamine formation are structure-dependent and shed further light on the mechanisms by which polyphenols exert protection against neuronal injury relevant to neurodegenerative diseases. (C) 2007 Elsevier Inc. All rights reserved.