Extensive studies have reported that interaction of α-
synuclein amyloid species with neurons is a crucial mechanistic characteristic of
Parkinson's disease (PD) and small molecules can downregulate the neurotoxic effects induced by
protein aggregation. However, the exact mechanism(s) of these
neuroprotective effects by small molecules remain widely unknown. In the present study, α-
synuclein samples in the amyloidogenic condition were aged for 120 h with or without different concentrations of
mitoquinone (
MitoQ) as a
quinone derivative compound and the
amyloid characteristics and the relevant neurotoxicity were evaluated by
Thioflavin T (ThT)/
Nile red fluorescence,
Congo red absorption, circular dichroism (CD), transmission electron microscopy (TEM), cell viability,
lactate dehydrogenase (LDH),
reactive oxygen species (ROS),
reactive nitrogen species (RNS),
malondialdehyde (MDA),
superoxide dismutase (SOD), and
caspase-9/-3 activity assays. Results clearly showed the capacity of
MitoQ on the inhibition of the formation of α-
synuclein fibrillation products through modulation of the aggregation pathway by an effect on the kinetic parameters. Also, it was shown that α-
synuclein samples aged for 120 h with
MitoQ trigger less neurotoxic effects against SH-SY5Y cells than α-
synuclein amyloid alone. Indeed, co-incubation of α-
synuclein with
MitoQ reduced the membrane leakage, oxidative and nitro-oxidative stress, modifications of macromolecules, and apoptosis.