Hordenine inhibits neuroinflammation and exerts neuroprotective effects via inhibiting NF-κB and MAPK signaling pathways in vivo and in vitro

Parkinson's disease (PD) is a usual disease caused by degeneration of the central nervous system, which features the denaturation and death of dopaminergic neurons in the substantia nigra compact (SNc) of the midbrain. Neuroinflammation casts a consequential role in its pathogenesis, and the excessive activation of microglia as a major part of neuroinflammation cannot be ignored. Studies have indicated that Hordenine (HOR) functioned widely as an anti-oxidant and anti-inflammatory substance, but there are no reports on neuroinflammation effects. Therefore, this study is devoted to exploring the effect of HOR on neuroinflammation and its specific mechanism. In vivo, results revealed that HOR depressed the activation of microglia in SNc and protected dopaminergic neurons in the 6-hydroxydopamine (6-OHDA)-induced PD rat model, which terminally reduced movement disorders and weight loss. In vitro, studies have shown that HOR can inhibit inflammatory responses triggered by lipopolysaccharide (LPS) in BV-2 cells. More profound studies have discovered that the specific anti-inflammatory mechanism is intimately associated with the NF-κB and MAPK signaling pathways. All in it together, HOR acts as a significant role in preserving dopaminergic neurons by restraining neuroinflammation mediated by activation of microglia. This may provide a potential drug for Parkinson's treatment.