Our previous study has demonstrated that IRN (20 mg/kg or 40 mg/kg) exerted neuroprotective effects and ameliorated cognitive impairments in several animal models of AD, including Aβ25–35-induced rats, D-galactose-induced mice and transgenic APP mice [20–22], indicating that IRN is a therapeutic candidate in the treatment of AD. This evidence concerns the gene APP and Alzheimer disease.