NOS2 and Alzheimer disease: Several studies reported that puerarin treatment reversed cognitive deficits in AD models by preventing excessive ROS production and neuronal death via the inhibition of the GSK-3β/Nrf2 and inducible nitric oxide synthase (iNOS)/ nitric oxide (NO) pathways [44,45], as well as activation of the PI3K/Akt/eNOS pathway [46].