Neuroprotection in Parkinson's Disease: A Systematic Review of thePreclinical Data

Aim: This study aimed to systematically review the preclinical data of neuroprotective agents for Parkinson's disease (PD) to support the translation of these compounds. Methods: The study consisted of two phases. In phase I, Pubmed and Scopus were systematically searched for neuroprotective agents for PD. In phase II, a systematic search was conducted for each substance identified in phase I. Articles were included if they used MPTP, 6-OHDA, rotenone or paraquat injury models. Results: Phase I led to the identification of 168 putative neuroprotective agents. Eventually ten compounds were included: melatonin, estrogen, nicotine, caffeine, riluzole, curcumin, coenzyme Q10, aspirin, EGCG and resveratrol. Phase II revealed 113 experimental studies and three reviews. Conclusion: This study clearly depicts the preclinical data of ten promising neuroprotective agents. While some of these compounds have already been tested in clinical use, none of them was studied in an appropriately designed trial to determine a neuroprotective effect. In expectation of qualitatively improved neuroprotection trials, the data from this study provide a firm foundation for future research.