Parkinson's disease (PD) is the most common and progressive neurodegenerative and oxidative stress-related disorder, characterized by a dramatic loss of dopamine (DA) neurons in the nigrostriatal tissue. The first-line drug for PD treatment is represented by L-dopa, although clinical and preclinical studies pointed out the potential efficacy of medicinal plant- and food-derived antioxidants as brain protective agents. In this regard, the potential application of Vicia faba, Uncaria rhyncophylla, and Glycyrrhiza glabra extracts is of noteworthy interest, despite a lack of information in the scientific literature as regards their effect on striatal DA level.

The protective effects of V. faba, U. rhyncophylla, and G. glabra water extracts were investigated on HypoE22 cells and isolated rat striatum specimens challenged with 6-hydroxydopamine (6-OH-DA). The extract effects against lactate dehydrogenase (LDH), nitrites, and 8-iso-prostaglandin(PG)F2α were evaluated using either single-extract treatments or a treatment with a pharmacological association. Additionally, the turnover of DA was measured.

The pharmacological association of the extracts was the most effective in contrasting the upregulated LDH and nitrite levels and in reducing striatal DA turnover.

The present findings corroborate the rationale for the traditional use of V. faba, G. glabra, and U. rhyncophylla extracts, supporting their pharmacological association in order to improve their protective effects.