The Impact of Paeoniflorin on α-Synuclein Degradation Pathway

Abstract EN

Paeoniflorin (PF) is the major active ingredient in the traditional Chinese medicine Radix.

It plays a neuroprotective role by regulating autophagy and the ubiquitin-proteasome degradation pathway.

In this study, we found PF significantly reduced cell damage caused by MPP+, returning cells to normal state.

Cell viability significantly improved after 24 h exposure to RAPA and PF in the MPP+ group (all P<0.01).

CAT and SOD activities were significantly decreased after PF and RAPA treatment, compared with MPP+ (P<0.001).

In addition, MPP+ activated both LC3-II and E1; RAPA increased LC3-II but inhibited E1.

PF significantly upregulated both LC3-II (autophagy) and E1 (ubiquitin-proteasome pathway) expression (P<0.001), promoted degradation of α-synuclein, and reduced cell damage.

We show MPP+ enhanced immunofluorescence signal of intracellular α-synuclein and LC3.

Fluorescence intensity of α-synuclein decreased after PF treatment.

In conclusion, these data show PF reversed the decline of proteasome activity caused by MPP+ and significantly upregulated both autophagy and ubiquitin-proteasome pathways, promoted the degradation of α-synuclein, and reduced cell damage.

These findings suggest PF is a potential therapeutic medicine for neurodegenerative diseases.