Tea Polyphenols in Parkinson’s Disease

Abstract

Parkinson's disease (PD) is a common motor neurodegenerative disorder with multifactorial etiology that is an increasing burden on our aging society. PD is characterized by nigrostriatal degeneration which might involve oxidative stress, α-synuclein (αS) aggregation, dysregulation of redox metal homeostasis and neurotoxicity. Although the exact cause remains unknown, both genetic and environmental factors have been implicated. Among the various environmental factors tea consumption has attracted increasing interest, as besides being one of the most consumed beverages in the world, tea contains specific polyphenols which can play an important role in delaying the onset or halting the progression of PD. Green and black teas are rich sources of polyphenols, the most abundant being epigallocatechin-3-gallate (EGCG) and theaflavins. There is now consistent mechanistic data on the neuroprotective and neuroregenerative effects of tea polyphenols, indicating that they do not just possess anti-oxidant or anti-chelating properties but may directly interfere with aggregation of the αS protein and modulate intracellular signalling pathways, both in vitro and in animal models. EGCG in green tea has been by far the most studied compound and therefore future investigations should address more the effects of other polyphenols, especially theaflavins in black tea. Nevertheless, despite significant data on their potential neuroprotective effects, clinical studies are still very limited and to date only EGCG has reached phase II trials. This review collates the current knowledge of tea polyphenols and puts into perspective their potential to be considered as nutraceuticals that target various pathologies in PD.

Supplementation with Herbal Extracts to Promote Behavioral and Neuroprotective Effects in Experimental Models of Parkinson's Disease: A Systematic Review

“…Other herbal plants, such as the leaves of green tea ( Camellia sinensis ), contain high levels of catechins and polyphenols (Peluso and Serafini, ; Stohs and Badmaev, ). Recent data on the neuroprotective and neuroregenerative effects of green tea containing polyphenols indicate that they do not just possess antioxidant and anti‐chelating properties but may directly interfere with aggregation of the α‐sinuclein protein and modulate intracellular signaling pathways, both in vitro and in animal models (Caruana and Vassallo, ).…”

Untitled

“…[37] A study reported that EGCG binds to α-synuclein by hydrophobic interactions in an unstable manner. It was implied that EGCG could potently remodel the aggregates of α-synuclein, thereby acting as a potential disease modifying agent for the treatment of Parkinson's disease and other α-synuclein-related disorders.…”

Medicinal Plants and Natural Products as Potential Sources for Antiparkinson Drugs

“…As mentioned above, Parkinsonʼs disease is characterized by the presence of Lewy bodies and Lewy neurites, which are protein aggregates composed predominantly of the presynaptic protein α-synuclein [36]. Although the role of α-synuclein in the pathogenesis of Parkinsonʼs disease is not completely understood, the stabilization of nontoxic aggregates could represent a potential therapeutic route [37], and the study on the anti-aggregative properties of natural products has been used as a strategy for the screening of potential protective agents against Parkinsonʼs disease [38].…”