HMOX1 and Parkinson disease: Luteolin can also increase the expression of antioxidant enzymes such as heme oxygenase-1 (HO-1) via the nuclear factor erythroid 2–related factor 2/ antioxidant responsive element (Nrf-2/ARE) complex activation, as it was observed in in vitro models of PD [44, 57] and H2O2-induced toxicity in in vitro models [58–60].