소엽맥문동-에틸아세테이트 분획물의 아밀로이드 베타단백질-유발 세포독성에 대한 억제 효능

Abstract

Amyloid β-protein (Aβ) is the principal component of senile plaques characteristic of Alzheimer’s disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify Aβ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on Aβ25-35-induced cytotoxicity to PC12 cells. We also used a cell- based β-secretase assay system to investigate the inhibitory effect of the OJEA fraction on β-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by Aβ25-35 in PC12 cells. The OJEA fraction had strong protective effects against Aβ25-35-induced cytotoxicity to PC12 cells and was strongly inhibitory to β-secretase activity, which resulted in the attenuation of Aβ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to Aβ25-35. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on Aβ toxicity.