Minocycline in neurodegenerative and psychiatric diseases: an update.

BACKGROUND: Minocycline is a broad-spectrum antibiotic, effective as a chronic treatment for recurrent bacterial infections. Beyond its antibiotic action, minocycline has also important anti-inflammatory, antioxidant and antiapoptotic properties. Thus, its efficacy was evaluated in many neurodegenerative and psychiatric diseases with inflammatory basis. Our aim is to review those preclinical and clinical studies performed in neurological and psychiatric diseases whose treatment has involved the use of minocycline and therefore to discern the possible beneficial effect of minocycline in these disorders.
METHODS: Completed and ongoing preclinical studies and clinical trials of minocycline for both neurodegenerative diseases and psychiatric disorders published from January 1995 to January 2020 were identified through searching relevant databases (https://www.ncbi.nlm.nih.gov/pubmed/, https://clinicaltrials.gov/). 74 preclinical studies and 44 clinical trials and open-label studies were selected.
RESULTS: The results of these nearly twenty years of research are diverse. While minocycline mostly proved to be effective in animal models, clinical results showed divergent outcomes, with positive results in some studies counterbalanced with a numbered of cases with no significant improvements. Specific data for each disease will be further individually described in this review.
CONCLUSIONS: Despite minocycline demonstrated antioxidant and anti-inflammatory effects, discrepancies between preclinical and clinical data invite to be cautious in analyzing the outcomes. Improving and standardizing protocols and refining animal models could help us to determine if minocycline is really a useful drug in the treatment of these pathologies. This article is protected by copyright. All rights reserved.