TNF and Alzheimer disease: In AD and PD models, it has been shown that VIP exerts a neuroprotective effect through the inhibition of tumor necrosis factor-α (TNFα), interleukin 1β (IL-1β), nitric oxide (NO) and different chemokines release (Delgado, 2002; Delgado and Ganea, 2003; Delgado et al., 2008; Song et al., 2012).