Naringenin, a grapefruit flavonoid, that showed neuroprotective effects in Parkinson’s disease and AD models [197,198] increased nuclear Nrf2 and HO-1, GCLC, GCLM, and GSH in SH-SY5Y cells and inside mouse brain and, thus, exerted neuroprotection [199]. The gene discussed is HMOX1; the disease is Alzheimer disease.