Natural Product Sciences  2016;22(3):187-192

doi:10.20307/nps.2016.22.3.187

Effects of Gypenosides on Dopaminergic Neuronal Cell Death in 6-Hydroxydopamine-lesioned Rat Model of Parkinson's Disease with Long-term L-DOPA Treatment.

Keon Sung SHIN 1 ; Ting Ting ZHAO ; Hyun Jin PARK ; Kyung Sook KIM ; Hyun Sook CHOI ; Myung Koo LEE

Affiliations

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Keywords

Gypenosides; 6-Hydroxydopamine-lesioned rat; Parkinson's disease; Tyrosine hydroxylase immunohistochemistry; L-DOPA

Country

Republic of Korea

Language

English

Abstract

The goal of this study was to determine whether gypenosides (GPS) exert protective effects against dopaminergic neuronal cell death in a 6-hydroxydopamine (OHDA)-lesioned rat model of Parkinson's disease (PD) with or without long-term 3,4-dihydroxyphenylalanine (L-DOPA) treatment. Rats were injected with 6-OHDA in the substantia nigra to induce PD-like symptoms; 14 days after injection, groups of 6-OHDA-lesioned animals were treated for 21 days with GPS (25 or 50 mg/kg) and/or L-DOPA (20 mg/kg). Dopaminergic neuronal cell death was assessed by counting tyrosine hydroxylase (TH)-immunopositive cells in the substantia nigra and measuring levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the striatum. Dopaminergic neuronal cell death induced by 6-OHDA lesions was ameliorated by GPS treatment (50 mg/kg). L-DOPA treatment exacerbated 6-OHDA-induced dopaminergic neuronal cell death; however, these effects were partially reversed by GPS treatment (25 and 50 mg/kg). These results suggest that GPS treatment is protective against dopaminergic neuronal cell death in a 6-OHDA-lesioned rat model of PD with long-term L-DOPA treatment. Therefore, GPS may be useful as a phytotherapeutic agent for the treatment of PD.