Recent research revealed that melatonin reduced kidney damage caused by diabetes and exerted neuroprotective effects by activating the Nrf2/heme oxygenase-1 (HO-1) pathway and increasing levels of the antioxidant enzymes HO-1 and NAD(P)H dehydrogenase [quinone] 1 (NQO1) [30, 31]. This evidence concerns the gene HMOX1 and diabetes mellitus.