Baicalein Exerts Anti-Neuroinflammatory Effects by Inhibiting the TLR4-ROS /NF-B-NLRP3 Inflammasome

Emerging evidence indicates that NOD-like receptor protein 3 (NLRP3) inflammasome-induced inflammation plays a critical role in the pathogenesis of Parkinson's disease (PD). Baicalein has been considered as a possible option for PD treatment based on its anti-neuroinflammatory effects. However, no studies have elucidated the precise mechanisms underlying the anti-neuroinflammatory activity of baicalein, particularly inflammasome-mediated effects. In this present study, rotenone-induced PD mice and BV2 microglia were used to investigate the anti-neuroinflammatory effects of baicalein and explore its underlying mechanism in vivo and in vitro. The results demonstrated that baicalein alleviated motor impairments and attenuated several inflammatory responses in rotenone-induced PD mice. Also, baicalein inhibited the expression of NLRP3 and activated caspase-1 in brain tissues. Correspondingly, baicalein prominently suppressed the inflammatory response in BV2 microglia induced by rotenone. Furthermore, in vitro data showed that baicalein suppressed the expression of NLRP3 and activated caspase-1 by abrogating the upregulation of ROS, as well as by inhibiting the TLR4/NF-kappa B signaling cascade. Overall, the results of the present study indicated that baicalein exerted anti-neuroinflammatory effects partly by inhibiting activation of the NLRP3 inflammasome, and targeting NLRP3 inflammasome signaling offers a novel therapeutic strategy for PD treatment.