Table 6.

Polysaccharide phytochemicals exerting neuroprotective activities in Alzheimer’s disease models.

Phytochemical tested	Plant	Concentration/Dose tested	Disease model	NRF2-related mechanism	Other observed AD-related effects	Reference
Mini-GAGR	Gellan gum	• 100 nmol/40 μl mini-GAGR (20 μl/nostril)	• 3xTg-AD mice	• Increase of NRF2 levels and activity • Dissociation of NRF2 from Keap1 • Phosphorylation and nuclear translocation of NRF2	• Decrease of ROS, p-tau and Aβ • Mitochondrial protection from oxidative damage • Memory improvement	(129)
Amanita caesarea polysaccharides	Amanita caesarea	• 2.5 or 5 μg/ml	• L-Glu exposed HT22 cells	• Upregulation of NRF2 nuclear levels • Reduction of cytoplasmic NRF2 levels • Keap1 suppression	• Upregulation of HO-1, SOD-1 and CLC • Downregulation of cytochrome C	(130)

AD, Alzheimer’s disease; NRF2, nuclear factor erythroid 2-related factor 2; Keap1, Kelch like ECH associated protein 1; ROS, reactive oxygen species; p-tau, phosphorylated protein tau; Aβ, β-amyloid; L-Glu, L-glutamate; HO-1, heme oxygenase-1; SOD-1, superoxide dismutase 1; CLC, cysteine ligase catalytic subunit.