Epicatechin Improves Proprioception Without Preventing Neuronal Death in the 6-Hydroxydopamine's Parkinsonism Model

Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases worldwide, and there is evidence to indicate that the consumption of flavonoids, especially from green tea, may be beneficial against PD. This study was designed to investigate the effect of (-) - Epicatechin (EC), one of the green tea catechins, in an animal model of PD. Male Wistar rats (290-350 g, 110 days old) received unilateral infusions of 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle. After 24 hours, they received a unilateral 1.5 μl infusion into the striatum containing .047, .150, .465, or 1.5 μg EC. From the 14th to the 25th day after this infusion, animals were tested for both context- and drug-induced rotational behavior, and were submitted to the sticky tape test (STT). The levels of tyrosine hydroxylase (TH) in the remaining dopamine neurons in the Substantia nigra pars compacta (SNpc) were measured by immunohistochemistry. The paw ipsilateral to the lesion was preferred by all groups but EC at .047 μg in the STT (Signal test, p < .05 and p = .227, respectively). No difference was found in TH content or rotational behavior. This indicates that EC might be beneficial for alleviating proprioceptive symptoms that occur in PD.