Considering the central role of oxidative stress in the
onset and
progress of Parkinson’s diseases (PD), search for compounds
with antioxidant properties has attracted a growing body of attention.
Here, we compare the neuroprotective effect of bulk and nano forms
of the polyphenolic fraction of propolis (PFP) against rotenone-induced
cellular and animal models of PD. Mass spectrometric analysis of PFP
confirmed the presence of multiple polyphenols including kaempferol,
naringenin, coumaric acid, vanillic acid, and ferulic acid. In vitro cellular experiments indicate the improved efficiency
of the nano form, compared to the bulk form, of PFP in attenuating
rotenone-induced cytotoxicity characterized by a decrease in cell
viability, release of lactate dehydrogenase, increased ROS generation,
depolarization of the mitochondrial membrane, decreased antioxidant
enzyme activity, and apoptosis induction. In vivo experiments revealed that while no significant neuroprotection was
observed relating to the bulk form, PFP nanosheets were very effective
in protecting animals, as evidenced by the improved behavioral and
neurochemical parameters, including decreased lipid peroxidation,
increased GSH content, and antioxidant enzyme activity enhancement.
We suggest that improved neuroprotective effects of PFP nanosheets
may be attributed to their increased water solubility and enrichment
with oxygen-containing functional groups (such as OH and COOH), leading
to increased antioxidant activity of these compounds.