Jung_2015_Arch.Pharm.Res_38_1178

The aim of the present study was to evaluate the comparative anti-Alzheimer's disease (AD) activities of different parts of Nelumbo nucifera (leaves, de-embryo seeds, embryos, rhizomes, and stamens) in order to determine the selectivity and efficient use of its individual components. Anti-AD activities of different parts of N. nucifera were evaluated via inhibitory activities on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) along with scavenging activity on peroxynitrite (ONOO(-)). Among the evaluated parts of N. nucifera, the embryo extract exhibited significant inhibitory potential against BACE1 and BChE as well as scavenging activity against ONOO(-). Thus, the embryo extract was selected for detailed investigation on anti-AD activity using BACE1- and ChEs-inhibitory assays. Among the different solvent-soluble fractions, the dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and n-butanol (n-BuOH) fractions showed promising ChEs and BACE1 inhibitory activities. Repeated column chromatography of the CH2Cl2, EtOAc and n-BuOH fractions yielded compounds 1-5, which were neferine (1), liensinine (2), vitexin (3), quercetin 3-O-glucoside (4) and northalifoline (5). Compound 2 exhibited potent inhibitory activities on BACE1, AChE, and BChE with respective IC50 values of 6.37 +/- 0.13, 0.34 +/- 0.02, and 9.96 +/- 0.47 microM. Likewise, compound 1 showed potent inhibitory activities on BACE1, AChE, and BChE with IC50 values of 28.51 +/- 4.04, 14.19 +/- 1.46, and 37.18 +/- 0.59 microM, respectively; the IC50 values of 3 were 19.25 +/- 3.03, 16.62 +/- 1.43, and 11.53 +/- 2.21 microM, respectively. In conclusion, we identified potent ChEs- and BACE1-inhibitory activities of N. nucifera as well as its isolated constituents, which may be further explored to develop therapeutic and preventive agents for AD and oxidative stress related diseases.