Berberine: Pathways to protect neurons

Berberine, an isoquinoline alkaloid, is demonstrated to have a variety of pharmacologic effects. Widely used as nonprescription drug for diarrhea, berberine has also broadened its applications in therapies of cardiovascular diseases, diabetes mellitus, tumor, and so forth. However, researches about berberine's protective effects on nervous system are still so insufficient that clinical uses cannot popularize and underlying molecules mechanisms are confused and incomplete. Well-known pathways such as Pl3K/Akt/Bcl-2 pathway, Nrf2/HO-1 pathway, and MAPK signaling pathway help berberine to protect neurons through antiapoptotic, antioxidative, and anti-inflammatory activities. New hypotheses have been raised consistently to explore more possible ways of berberine preventing nerves from injuries as attention on its neuroprotective properties is increasing. Therefore, this review is trying to analyze these mechanisms, which actually play roles in neuronal disease models such as brain ischemia, Alzheimer's disease, and experimental autoimmune encephalomyelitis. Much more understanding about how berberine mediates these pathways provides novel insights into the clinical treatment of neurological disorders.