Stem Cells as Potential Targets of Polyphenols in Multiple Sclerosis and Alzheimer’s Disease

Figure 1

The systematic representation for polyphenols targeting stem cells in AD. Polyphenols rich diets, antioxidants, and vitamins play a quintessential role as a defensive tool for AD. Resveratrol, curcumin, olive polyphenols, blueberry extracts, cocoa polyphenols, and apigenin decrease Aβ-induced cellular changes by counteracting ROS through their anti-oxidant characteristics. Increased accumulation of Aβ in the brain causes synaptic dysfunction and mitochondrial dysfunction, leading to cognitive impairments. Resveratrol stimulates NPCs proliferation, thus accentuating high rates of neuronal survival by mediating SIRT1 activation. Resveratrol in conjunction with tea polyphenols EGCG modulates mitochondrial biogenesis which in turn restores the oxidative phosphorylation. EGCG exerts its neuroprotective action by increasing neuronal plasticity. Curcumin acts through two main pathways: firstly by inducing neuronal differentiation in NSCs through the activation of Wnt signaling and secondly by upregulating the genes required for the cell differentiation, respectively. Other polyphenols, e.g., apigenin, upregulate the levels of neurotrophic factors and expression of neuronal markers in iPSCs and ESCs and result in neuronal differentiation. Cocoa polyphenols, olive polyphenols, and blueberry extracts attenuate the toxic effects of Aβ deposition through increasing the levels of neurotrophic factors. The arrow line represents promoting effects, and the red line represents inhibitory effect.