ALDHs play a major role in the detoxification of alcohol-derived acetaldehyde. They are involved in the metabolism of corticosteroids, biogenic amines, neurotransmitters, and lipid peroxidation. In the cornea, this enzyme may help in the absorption of the damaging UV-B, as well as in the detoxification of the UV-induced peroxidic aldehydes. an aldehyde + H2O + NAD(+) = a carboxylate + 2 H(+) + NADH Alcohol metabolism; ethanol degradation; acetate from ethanol: step 2/2. Homotetramer. Belongs to the aldehyde dehydrogenase family.