Table 2 The neuroprotective role of UDCA/TUDCA in neurological diseases

Inhibits neurotoxic (A1) polarization and activation of astrocytes.

AD, PD, MS

Inhibits microglial activation, decrease pro-inflammatory mediators (TNFa, IL-1β, IL-6, HMGB1, IFN-γ, IFN-β, NO, iNOS, COX-2) production, increase anti-inflammatory factors (IL-10, IL-4, TGF-β, ANXA1) production.

Acute neuroinflammation, AD, PD, HD, MS, SCI, RP

Inhibit apoptosis of neurons via suppressing cytochrome c release, decreasing caspases activation (caspases 2, 3, 6, 12), inhibiting E2F-1/p53/Bax apoptotic pathway, triggering a PI3K dependent survival signaling pathway, or promoting MR nuclear translocation and transactivation.

AD, PD, HD, SCI, ALS

Prevent oxidative stress in neurons via modulating activation of AMPK, JNK and AKT, increasing the expression of antioxidant factors (Nrf2, DJ-1, HO-1, GPx, parkin), preventing ATP levels decrease and ROS production, improving mitochondrial stabilization and function.

PD

Inhibits endoplasmic reticulum stress prevent tau hyperphosphorylation via UPR inhibition, reduce aberrant conformational conversion

AD, Prion diseases