Fig. (2).

The main pleiotropic functions of curcumin in neurodegenerative diseases; Curcumin exerts neuroprotection effects through Nrf2 activation, MAPK inhibition and downregulation of TLR-4 after binding to MD-2, leading to reduced expression of NF-KB and proinflammatory cytokines. Also, curcumin activates the protective systems and removes misfolded proteins by inhibiting ROS production.

Abbreviations: MD-2: myeloid differentiation factor 2, TLR-4: Toll-like receptor 4, MAPK: A mitogen-activated protein kinase, Nf-KB: Nuclear Factor kappa-light-chain-enhancer of activated B cells, ROS: reactive oxygen species, Nrf2: nuclear factor erythroid 2–related factor 2, HO-1: Heme oxygenase-1, ARE: antioxidant response element, COX-2: antioxidant response element, Hsp70: heat shock protein, Sirt-1: sirtuins, Trx: thioredoxin/thioredoxin reductase, γ- γ-GCS: glutamyl cysteine synthetase.