Effects of solvent fractions of Allomyrina dichotoma larvae through the inhibition of in vitroBACE1 and β-amyloid(25-35)-induced toxicity in rat pheochromocytoma PC12 cells

Amyloid-β peptide (Aβ) generation initiated by β-site amyloid precursor protein cleaving enzyme 1 BACE1 is a critical cause of Alzheimer's disease. In the course of our ongoing investigation of natural anti-dementia resources, the ethyl acetate (EtOAc) fraction exerted strong BACE1-specific inhibition with the half maximal inhibitory concentration (IC₅₀) value of 9.2 × 10^-5μg/mL. Furthermore, Aβ(25-35)-induced cell death was predominantly prevented by the EtOAc fraction of Allomyrinadichotoma larvae through diminishing of cellular oxidative stress and attenuating apoptosis by inhibiting caspase-3 activity. Taken together, the present study demonstrated that A.dichotoma larvae possess novel neuroprotective properties not only via the selective and specific inhibition of BACE1 activity but also through the alleviation of Aβ(25-35)-induced toxicity, which may raise the possibility of therapeutic application of A.dichotoma larvae for preventing and/or treating dementia.