Koyomi MIYAZAKI

Dr. Koyomi MIYAZAKI

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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1 July 2017 in Neuroscience Letters
Verified
Journal Article
Closed access
EMEiko N. Minakawa
Eiko N. Minakawa
KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
KMKazushi Maruo
Kazushi Maruo
HYHiroko Yagihara
Hiroko Yagihara
HFHiromi Fujita
Hiromi Fujita
YNYoshitaka Nagai
Yoshitaka Nagai

1 August 2014 in Life Sciences
Verified
Journal Article
Closed access
KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
NINanako Itoh
Nanako Itoh
SYSaori Yamamoto
Saori Yamamoto
SHSayaka Higo-Yamamoto
Sayaka Higo-Yamamoto
YNYasukazu Nakakita
Yasukazu Nakakita
KOKatsutaka Oishi
Katsutaka Oishi

12 October 2017 in Food & Function
Verified
Journal Article
Closed access
PDF file
PSPapawee Saiki
Papawee Saiki
YKYasuhiro Kawano
Yasuhiro Kawano
LGLeo J. L. D. Van Griensven
Leo J. L. D. Van Griensven
KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
For hundreds of years mushrooms have been used as functional food for health. The basidiomycete Agaricus brasiliensis (A. brasiliensis) is famous for the medicinal properties of its beta glucans and of its antioxidants. Most researchers have studied polysaccharides from A. brasiliensis for their anti-inflammatory activity. However, active compounds from this mushroom have not yet been studied for the inactivation of NO inhibitory activity. The present study aimed to find the active compounds from A. brasiliensis for their NO inhibitory activity related inflammatory activity. This study found that linoleic acid isolated from A. brasiliensis inhibited NO production and suppressed the expression of pro-inflammatory cytokines including TNF-α, IL-6, IL-1β, and NOS2 in RAW 264.7 cells. Linoleic acid also suppressed the expression of NF-κB subunit p50 and restored PPARα. This leads to the conclusion that linoleic acid from A. brasiliensis could reduce NO production and inflammatory activity in RAW 264.7 cells by the inhibition of p50 and via the activation of PPARα. This study suggests that linoleic acid present in A. brasiliensis could play a role in the prevention of inflammatory diseases for which this edible mushroom is already known.

30 January 2013 in PLOS ONE
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Journal Article
Open access
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KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
NINanako Itoh
Nanako Itoh
SOSumika Ohyama
Sumika Ohyama
KKKoji Kadota
Koji Kadota
KOKatsutaka Oishi
Katsutaka Oishi
Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

26 April 2022 in Chemical Science
Verified
Journal Article
Open access
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STShunsuke Tomita
Shunsuke Tomita
HKHiroyuki KUSADA
Hiroyuki KUSADA
NKNaoshi Kojima
Naoshi Kojima
SISayaka Ishihara
Sayaka Ishihara
KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
Ryoji KuritaRyoji Kurita
Ryoji Kurita
A biomimetic ‘chemical-nose’ composed of twelve block copolymers with aggregation-induced emission units is presented, which can detect sleep disorder in mice from a small amount of microbiome samples (<10 μg) in a short time (<30 min).

17 September 2020 in Nutrients
Verified
Journal Article
Open access
PDF file
PSPapawee Saiki
Papawee Saiki
YKYasuhiro Kawano
Yasuhiro Kawano
TOTakayuki Ogi
Takayuki Ogi
PKPrapaipat Klungsupya
Prapaipat Klungsupya
TMThanchanok Muangman
Thanchanok Muangman
KMKoyomi MIYAZAKI
Koyomi MIYAZAKI
Gymnema inodorum (GI) is an indigenous medicinal plant and functional food in Thailand that has recently helped to reduce plasma glucose levels in healthy humans. It is renowned for the medicinal properties of gymnemic acid and its ability to suppress glucose absorption. However, the effects of gymnemic acids on adipogenesis that contribute to the accumulation of adipose tissues associated with obesity remain unknown. The present study aimed to determine the effects of gymnemic acids derived from GI tea on adipogenesis. We purified and identified GiA-7 and stephanosides C and B from GI tea that inhibited adipocyte differentiation in 3T3-L1 cells. These compounds also suppressed the expression of peroxisome proliferator-activated receptor gamma (Pparγ)-dependent genes, indicating that they inhibit lipid accumulation and the early stage of 3T3-L1 preadipocyte differentiation. Only GiA-7 induced the expression of uncoupling protein 1 (Ucp1) and pparγ coactivator 1 alpha (Pgc1α), suggesting that GiA-7 induces mitochondrial activity and beige-like adipocytes. This is the first finding of stephanosides C and B in Gymnema inodorum. Our results suggested that GiA-7 and stephanosides C and B from GI tea could help to prevent obesity.