This study was focused on the possible neuroprotective role of (RS)-
glucoraphanin, bioactivated with
myrosinase enzyme (bioactive RS-GRA), in an experimental mouse model of
Parkinson's disease (PD). RS-GRA is one of the most important
glucosinolates, a thiosaccharidic compound found in Brassicaceae, notably in Tuscan black kale seeds. RS-GRA was extracted by one-step
anion exchange chromatography, further purified by gel-filtration and analyzed by HPLC. Following, pure RS-GRA was characterized by (1)H and (13)C NMR spectrometry and the purity was assayed by HPLC analysis of the desulfo-derivative according to the ISO 9167-1 method. The obtained purity has been of 99%. To evaluate the possible pharmacological efficacy of bioactive RS-GRA (administrated at the dose of 10mg/kg, ip +5μl/mouse
myrosinase enzyme), C57BL/6 mice were used in two different sets of experiment (in order to evaluate the
neuroprotective effects in different phases of the disease), according to an acute (2 injections·40mg/kg
MPTP) and a sub-acute (5 injections·20mg/kg
MPTP) model of PD. Behavioural test,
body weight changes measures and immunohistochemical localization of the main PD markers were performed and post-hoc analysis has shown as bioactive RS-GRA is able to reduce
dopamine transporter degradation,
tyrosine hydroxylase expression, IL-1β release, as well as the triggering of neuronal apoptotic death pathway (data about Bax/Bcl-2 balance and dendrite spines loss) and the generation of radicalic species by oxidative stress (results focused on
nitrotyrosine, Nrf2 and GFAP immunolocalization). These effects have been correlated with the release of
neurotrophic factors, such as
GAP-43,
NGF and
BDNF, that, probably, play a supporting role in the neuroprotective action of bioactive RS-GRA. Moreover, after PD-induction mice treated with bioactive RS-GRA are appeared more in health than animals that did not received the treatment both for phenotypic behaviour and for general condition (movement coordination, presence of
tremors, nutrition). Overall, our results suggest that bioactive RS-GRA can protect neurons against the neurotoxicity involved in PD via an anti-apoptotic/anti-inflammatory action.