Notably, serotonin conjugated with isoalantolactone inhibited β-secretase enzyme (BACE-1), prevented Aβ1–42 aggregation, and demonstrated neuroprotective effects in SH-SY5Y neuroblastoma cells, while enhancing learning and memory in the 5xFAD mouse model of AD [66]. This evidence concerns the gene BACE1 and Alzheimer disease.