Inhibition of aggregated Aβ-induced PC-12 cells apoptosis by edible plant material extracts and stilbenoids
Date Issued
2008
Date
2008
Author(s)
Luo, Chiau-Wen
Abstract
Alzheimer''s disease (AD), the major cause of dementia, is a neurodegenerative disorder associated with impairment in memory and cognitive function. AD is characterized pathologically by the presence of senile plaques (amyloid plaques), and neurofibrillary tangles (NFT). β-amyloid peptide (Aβ) has been proposed to play an important role in the pathogenesis of AD. Deposits of Aβ are found in the brains of patients with AD and are one of the pathological hallmarks of the disease. Many studies have shown that aggregated Aβ can induce caspase-dependent apoptosis and death by oxidative stress and increase intracellular calcium levels in cultured neurons. The aim of my study is to investigate the antioxidative activities and neuroprotective effects of some edible plant extracts and stilbenoids.he antioxidative potency was evaluated by DPPH radical scavenging activity and trolox equivalent antioxidant capacity (TEAC). The neuroprotective activity was evaluated in vitro in the “Aβ-induced cell death of rat pheochromocytoma (PC-12) cells” model system. Among the different samples (mulberry, roselle and the embryo of Nelumbo nucifera Gaertn. seed extracts), methanol extract of the embryo of Nelumbo nucifera GAERTN. seed (Nn-M) showed better antioxidative activity and also higher inhibitory effect against Aβ25-35 –induced cytotoxicity. Therefore, Nn-M was fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. The n-butanol fraction of Nn-M was found to have the best inhibitory effect against Aβ1-40 –induced cytotoxicity. Among stilbenoids, stilbene glycoside purified from Polygonum multiflorum Thunb. (PM-SG) has better inhibitory effect against Aβ25-35 –induced and Aβ1-40 –induced cytotoxicity than pterostilbene. he mechanism of the possible protective action of PM-SG and n-butanol fraction of Nn-M was further investigated. Results showed that Aβ1-40 signficantly increased ROS level, intracellular [Ca2+] and caspase-3 activity, and also signficantly decreased mitochondrial membrane potential and glutathione content in PC-12 cells. PM-SG and n-butanol fraction of Nn-M showed a significant reduction of the elevated ROS, intracellular [Ca2+] and caspase-3 activity and also replenished the loss of mitochondrial membrane potential and glutathione content induced by Aβ1-40. This study concludes that PM-SG and n-butanol fraction of Nn-M have potential neuroprotective ability against Aβ-mediated cell damage.
Subjects
Alzheimer’s disease
β-Amyloid peptide
Oxidative stress
Embryo of the seed of Nelumbo nucifera GAERTN.
Stilbenoids
Type
thesis
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