Tomentosin Reduces Behavior Deficits and Neuroinflammatory Response in MPTP-Induced Parkinson's Disease in Mice

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Tomentosin is an active compound isolated from the I. viscosa plant that has extensive therapeutic value. In this exploration, the neuroprotective actions of tomentosin were investigated against MPTP-stimulated neuroinflammation in mice. PD was stimulated in C57/BL6 mice by injecting 20-mg/kg MPTP at 2-h intervals 4 times a day for 15 days simultaneously with tomentosin treatment. The rota-rod test, grasping test, and pole climbing test were executed to investigate the motor functioning of the test animals. Proinflammatory cytokines, reactive oxygen species, and myeloperoxidase were assayed using commercial ELISA kits. Superoxide dismutase enzyme levels were measured by the standard method. Expression of TLR-4/NF-κB was analyzed by Western blot. Brain tissues of investigational animals were analyzed microscopically. Tomentosin treatment of the MPTP-intoxicated PD mice promoted appreciable regains in body weight and noticeably prevented MPTP-stimulated impairments in motor function. In the PD mice, proinflammatory cytokine, ROS, and MPO levels were lowered by tomentosin, inhibited the TLR-4/NF-κB signaling pathway and prevented inflammation-mediated neuronal cell damage, and reduced glial cell damage and normalized ganglion layers. These findings confirmed the neuroprotective properties of tomentosin against MPTP-induced PD in mice.