Masao Yamasaki

Dr. Masao Yamasaki

Graduate School of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai-Nishi, Miyazaki, Miyazaki 889-2192, Japan
orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2006 in Nutrition
Verified
Journal Article
Closed access
Masao YamasakiMasao Yamasaki
Masao Yamasaki
TKTakae Kitagawa
Takae Kitagawa
NKNami Koyanagi
Nami Koyanagi
HCHitomi Chujo
Hitomi Chujo
HMHidenori Maeda
Hidenori Maeda
KYKoji Yamada
Koji Yamada

15 February 2013 in Plants
Verified
Journal Article
Open access
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HTHirotoshi Tsuda
Hirotoshi Tsuda
Hisato KunitakeHisato Kunitake
Hisato Kunitake
RKRyoko Kawasaki-Takaki
Ryoko Kawasaki-Takaki
KNKazuo Nishiyama
Kazuo Nishiyama
Masao YamasakiMasao Yamasaki
Masao Yamasaki
CYChizuko Yukizaki
Chizuko Yukizaki
Antioxidants are abundant in blueberries, and while there are many studies concerning the bioactive compound of fruit, it is only recently that the wild Vaccinium species has attracted attention for their diverse and abundant chemical components. The aim of this study was to investigate the bioactive compounds of blueberry cultivars and wild species found in Japan. Among the five extracts of the Vaccinium species, Natsuhaze (Vaccinium oldhamii Miq.) was found to be the most effective at inhibiting the growth of HL-60 human leukemia cells in vitro. Although all ethanol extracts showed a growth inhibitory effect on HL-60 cells, the degree of the effects differed among the species. The extract of Natsuhaze induced apoptotic bodies and nucleosomal DNA fragmentation in the HL-60 cells. Of the extracts tested, that of Natsuhaze contained the largest amount of total polyphenols and showed the greatest antioxidant activity, but the anthocyanin content of Natsuhaze was similar to that of rabbiteye blueberry (V. virgatum Ait.). The results showed that total polyphenols contributed to the high antioxidant activity and growth inhibitory effect on HL-60 human leukemia cells of Natsuhaze extract.

7 May 2021 in Molecules
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Journal Article
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Masao YamasakiMasao Yamasaki
Masao Yamasaki
YYYumi Yamasaki
Yumi Yamasaki
RFRina Furusho
Rina Furusho
HKHayaka Kimura
Hayaka Kimura
IKIchiro Kamei
Ichiro Kamei
KNKazuo Nishiyama
Kazuo Nishiyama
The aim of this study was to evaluate the involvement of nanoparticles prepared from Allium cepa L. as anti-inflammatory agents. In the present study, we identified nanoparticles from Allium cepa L. using the ultracentrifugation exosome purification method. The nanoparticles were referred to as 17,000× g and 200,000× g precipitates, and they contained quercetins, proteins, lipids, and small-sized RNA. The nanoparticles inhibited nitric oxide production from lipopolysaccharide (LPS)-stimulated RAW264 cells without cytotoxic properties. Cellular incorporation was confirmed by laser microscopic observation after PKH26 staining. The inhibition of caveolae-dependent endocytosis and macropinocytosis significantly prevented the incorporation of the nanoparticles but had no effect on the inhibition of nitric oxide in RAW264 cells. Collectively, the identified nanoparticles were capable of inhibiting the LPS response via extracellular mechanisms. Taken together, the way of consuming Allium cepa L. without collapsing the nanoparticles is expected to provide an efficient anti-inflammatory effect.

26 October 2020 in Food Science & Nutrition
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Journal Article
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Masao YamasakiMasao Yamasaki
Masao Yamasaki
MMMikako Minesaki
Mikako Minesaki
AIAsuka Iwakiri
Asuka Iwakiri
YMYuko Miyamoto
Yuko Miyamoto
KOKenjiro Ogawa
Kenjiro Ogawa
YAYuo Arima
Yuo Arima
Previous study suggested that dietary intake of Lactobacillus plantarum 06CC2 (LP06CC2) isolated from Mongolian dairy products showed various health beneficial effects. Here, the effect of LP06CC2 on the cholesterol metabolism in mice fed a cholesterol‐loaded diet was evaluated. Cholesterol and LP06CC2 were incorporated into the AIN93G‐based diet to evaluate the effect on cholesterol metabolism in Balb/c mice. Serum and liver cholesterol levels were significantly increased in mice fed a cholesterol‐loaded diet whereas the LP06CC2 ingestion suppressed the increase of liver cholesterol. LP06CC2 suppressed the increase of the hepatic damage indices. The increase of the cecal content and fecal butyrate were observed in mice fed LP06CC2. The analysis of bile acids clearly showed that LP06CC2 increased their deconjugation indicating the decrease of bile acid absorption. The protein expression of hepatic Cyp7A1 was also suppressed by LP06CC2 in mice fed cholesterol. Finally, in vitro studies showed that LP06CC2 had the most potent ability to deconjugate bile acids using glycocholate among the tested probiotic lactic acid bacteria isolated from Mongolian dairy products. Taken together, LP06CC2 is a promising microorganism for the reduction of the cholesterol pool via modulation of bile acid deconjugation.

1 January 2012 in Journal of Oleo Science
Verified
Journal Article
Open access
Masao YamasakiMasao Yamasaki
Masao Yamasaki
TNTaku Nagatomo
Taku Nagatomo
TMTetsuya Matsuyama
Tetsuya Matsuyama
YIYuri Ikeho
Yuri Ikeho
EKEmiko Kato
Emiko Kato
KNKazuo Nishiyama
Kazuo Nishiyama
The anti-cancer effects of various fatty acids are drawing a lot of attention. To determine whether different fatty acids affect the hypoxic response of liver cancer cells, we examined the effects of various fatty acids on the stabilization of the hypoxia-inducible factor (HIF)-1α protein in the HepG2 human hepatocellular carcinoma (HCC) cell line under condition containing 1% O(2). Of the fatty acids examined, only 9cis, 11trans (c9, t11)-conjugated linoleic acid (CLA) and 10trans, 12cis (t10, c12)-CLA inhibited hypoxia-induced HIF-1α stabilization. In addition, HIF-1α prolyl hydroxylase or proteasome inhibition abrogated the effects of c9, t11- and t10, c12-CLA. Moreover, c9, t11- and t10, c12-CLA significantly inhibited cell proliferation and induced apoptotic cell death under hypoxia. This is the first study showing that c9, t11- and t10, c12-CLA inhibit the hypoxic response in HCC cells.

15 August 2005 in Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids
Verified
Journal Article
Closed access
Masao YamasakiMasao Yamasaki
Masao Yamasaki
YMYumi Miyamoto
Yumi Miyamoto
HCHitomi Chujo
Hitomi Chujo
KNKazuo Nishiyama
Kazuo Nishiyama
HTHirofumi Tachibana
Hirofumi Tachibana
KYKoji Yamada
Koji Yamada