• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.227-237
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• 2022

Amyloid beta (Aβ) is produced from an amyloid precursor protein by the activation of the amyloidogenic pathway, and it is widely known to cause Alzheimer's disease (AD). In this study, we investigated the neuroprotective effects of three flavonoids, quercitrin, isoquercitrin, and afzelin, from Acer okamotoanum against Aβ-induced neurotoxicity in SH-SY5Y neuronal cells. Aβ_25-35 treatments resulted in decreased cell viability and increased levels of nuclei condensation and fragmentation. However, an isoquercitrin treatment dose-dependently increased cell viability and decreased nuclei condensation and fragmentation levels. SH-SY5Y cells treated with Aβ_25-35 showed increased reactive oxygen species (ROS) production compared to that from cells not treated with Aβ_25-35. However, treatment with the three flavonoids significantly inhibited ROS production compared to an Aβ_25-35-treated control group, indicating that the three flavonoids blocked neuronal oxidative stress. For a closer examination of the neuroprotective mechanisms, we measured the expressions of the non-amyloidogenic pathway-related proteins of a disintegrin and metalloprotease 10 (ADAM10) and the tumor necrosis factor-α converting enzyme (TACE). An isoquercitrin treatment enhanced the expressions of ADAM10 compared to the control group. In addition, the three flavonoids activated the non-amyloidogenic pathway via the upregulation of TACE. In conclusion, we demonstrated neuroprotective effects of three flavonoids from A. okamotoanum, in particular isoquercitrin, on neurotoxicity by the regulation of the non-amyloidogenic pathway in Aβ_25-35-treated SH-SY5Y cells. Therefore, we suggest that flavonoids from A. okamotoanum may have some potential as therapeutics of AD.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.418-428
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• 2020

The aim of this study was to investigate the effect of resistance exercise(RE) on beta-amyloid(Aβ) metabolism, neuronal cell death, and cognitive function in the transgenic mice model of Alzheimer's disease(AD). Fourteen transgenic(tg) mice and fourteen non-transgenic(non-tg) mice were divided into four groups: (1)non-tg-control(NTC, n=7) (2)non-tg-RE(NTRE, n=7) (3)tg-control(TC, n=7), and (4)tg-RE(TRE, n=7). The groups with RE were performed to progressive RE on ladder equipment for 8 weeks. The groups with RE were performed to progressive RE on ladder equipment for 8 weeks. After then, the cognitive function was measured by using the water maze test, and Aβ metabolism-related proteins, neuronal cell death, and SIRT1/PGC-1α pathway were also measured. Here, we found escape latency and time were significantly increased in the TC compared to the NTC group, but it was significantly reduced in the TRE group, indicating RE may ameliorate cognitive dysfunction. Next, we found an increased in Aβ protein of TC compared to NTC, but it was significantly reduced in the TRE group following RE. In neuronal cell death, Bcl-2 was also significantly decreased and Bax was significantly increased in the TC compared to the NTC group, but RE can increase Bcl-2 and reduce Bax, which may elevate the ratio of Bcl-2/Bax. We further found a decrease in the level of ADAM10 and RARβ protein was significantly increased whereas increased in ROCK1 and BACE1 expression level was significantly reduced following RE in the TRE compared to the TC group. In addition, the level of SIRT1/PGC-1α proteins was decreased in the TC group compared to NTC group, but, these markers were significantly increased in the TRE group following RE. Therefore, our finding indicated that RE may ameliorate cognitive deficits by reducing Aβ protein and neuronal cell death via regulating SIRT1/PGC-1α, amyloidogenic pathway, and non-amyloidogenic pathway, which may play a role in an effective strategy for AD.