Saffron Pre-Treatment Offers Neuroprotection to Nigral and Retinal Dopaminergic Cells of MPTP-Treated mice

Background: There is growing evidence that the spice saffron, which contains powerful anti-oxidants, offers protection against neurodegenerative disorders, including age-related macular degeneration and Alzheimer's disease. Objective: We examined whether saffron pre-treatment protects dopaminergic cells of the substantia nigra pars compacta (SNc) and retina in an acute MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) mouse model of Parkinson's disease. Methods: BALB/c mice received MPTP or saline injections over a 30 hour period, followed by six days survival. For five days prior to injections, the drinking water of the saffron groups was supplemented with saffron (0.01% w/v), while non-saffron groups received normal tap water. After the survival period was complete, brains were processed for tyrosine hydroxylase (TH) immunochemistry and the number of TH+ cells was analysed using the optical fractionator method. Results: In both the SNc and retina, non-conditioned MPTP-injected mice had a reduced number of TH+ cells (30-35%) compared to the saline-injected controls. Saffron pre-conditioning mitigated the reduction, with pre-conditioned MPTP-injected mice having SNc and retinal TH+ cell numbers close to control levels, significantly (25-35%) higher than in non-conditioned MPTP-injected mice. Conclusions: Our results indicated that saffron pre-treatment of mice saved many dopaminergic cells of the SNc and retina from parkinsonian (MPTP) insult.