A study on peptide skin extracts from three different amphibian families in the Argentinean Litoral region found that five out of nine evaluated extracts had the potential to act on four critical pathways of AD: inhibition of AChE and butyrylcholinesterase (BChE), which are responsible for low levels of acetylcholine in AD, and monoamine oxidase B (MAO-B), known to improve AD symptoms, as well as exhibiting antioxidant potential due to free radical scavenging activity [97]. The gene discussed is MAOB; the disease is Alzheimer disease.