Faculty of Science and Technology

Toyonobu Usuki

  (臼杵 豊展)

Profile Information

Affiliation
Professor, Faculty of Science and Technology, Department of Materials and Life Sciences, Sophia University
Degree
Bachelor of Science(Tohoku University)
Master(Tohoku University)
Doctor of Science(Tohoku University)

Contact information
t-usukisophia.ac.jp
Researcher number
50514535
J-GLOBAL ID
200901076489387829
researchmap Member ID
5000046104

Papers

 116
  • Khin Khin Gyi, Songyot Anuchapreeda, Nutjeera Intasai, Montree Tungjai, Siriporn Okonogi, Arihiro Iwasaki, Toyonobu Usuki, Singkome Tima
    BMC complementary medicine and therapies, 25(1) 172-172, May 13, 2025  
    BACKGROUND: Gynostemma pentaphyllum (Thunb.), a traditional adaptogenic herb, is known for its bioactive components with potential anti-cancer properties. Acute myeloid leukemia (AML) progression is significantly influenced by Feline McDonough Sarcoma (FMS)-like tyrosine kinase 3 (FLT3) signaling, while Wilms' tumor 1 (WT1) serves as a key prognostic marker. This study investigates the anti-leukemia activities of active G. pentaphyllum leaf extracts and their components, focusing on the inhibition of FLT3 and WT1 activity. METHODS: G. pentaphyllum extracts were prepared through maceration, yielding three crude fractional extracts. The cytotoxicity of the extracts was screened against various leukemia cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The most cytotoxic extract was further fractionated and purified via column chromatography. The anti-proliferative and apoptotic induction activities of the active extract and its fraction were evaluated through cell cycle and apoptosis analyses using flow cytometry. Changes in mitochondrial membrane potential (ΔΨm) were assessed by spectrofluorometry. To confirm anti-leukemia activity, the expression levels of FLT3, WT1 and apoptotic-related protein were analyzed using Western blotting. The major active compounds within the active fractions were identified and characterized using Electrospray Ionization Mass Spectrometry (ESI-MS) and Nuclear Magnetic Resonance (NMR) spectroscopy. RESULTS: The ethyl acetate fractional extract (F-EtOAc) demonstrated the highest cytotoxicity, particularly against FLT3-overexpressing EoL-1 (IC50 = 40.82 ± 0.8 µg/mL) and MV4-11 (IC50 = 35.54 ± 4.1 µg/mL) AML cell lines. Fraction F10 was identified as the most active fraction, significantly inhibited FLT3 and WT1 protein expression and induced G0/G1 cell cycle arrest in a dose-dependent manner. Additionally, F10 induced dose-dependent apoptosis through disruption of ΔΨm, p53 up-regulation and caspase-3 activation. Further purification of F10 identified dehydrovomifoliol as its major bioactive compound. CONCLUSION: These findings suggest that the ethyl acetate extract of G. pentaphyllum contains bioactive compounds with anti-leukemia potential, warranting further investigation to evaluate its efficacy against AML. CLINICAL TRIAL NUMBER: Not applicable.
  • Hiroaki Ishii, Ryosuke Shigeta, Kaho Oishi, Toyonobu Usuki
    Tetrahedron Letters, 158 155508-155508, Mar, 2025  Peer-reviewedCorresponding author
  • Futa Koyama, Justin Lamb, Moena Hirao, Noriyuki Suzuki, Masahiro Yoshizawa-Fujita, Toyonobu Usuki, Yumiko Suzuki
    Advanced Synthesis & Catalysis, Oct 4, 2024  
    With a number of biologically active members, 2‐aroylchromones are valuable synthetic targets. A direct route towards 2‐aroylchromones from 2‐(methylsulfonyl)chromones and aldehydes via NHC‐catalyzed C‐C bond formation was developed. Yields of the synthesized 2‐aroylchromones were up to 85%. Chromones with angioprotective or antibacterial properties were easily synthesized using the method developed. Additionally, the synthetic utility of the afforded chromones was demonstrated by using them to synthesize the anticancer compound wrightiadione and analogues of it.
  • Christian Nanga Chick, Francois Eya'ane Meva, Phillippe Belle Ebanda Kedi, Toyonobu Usuki
    Nano Select, Jul 17, 2024  Peer-reviewedCorresponding author
    ABSTRACT This study examined the synthesis of silver nanoparticles (SNPs) with aqueous extracts of Cyclosorus dentatus and Nephrolepis biserrata fronds and the evaluation of their biological activities. Mixing of AgNO3 solution and the aqueous extracts resulted in color change, indicating the formation of SNPs. UV‐Vis spectroscopy analysis gave a surface plasmon resonance (SPR) peak at approximately 420 nm, confirming the presence of the synthesized SNPs. Infrared analysis showed C‐O, N‐O, and C‐C vibrations or stretching and aliphatic vibrations of hydrocarbon chains of the synthesized SNPs. x‐Ray diffraction (XRD) analysis indicated the SNPs were face‐centered, cubic, and crystalline in nature, with crystallite sizes. The scanning electron microscopy (SEM) shows the aggregation of the spherical shape nanoparticles. The SNPs significantly reduced phosphomolybdenum and captured H2O2 with respective IC50 values of 61.55 and 29.03 µg/mL for C. dentatus SNP (SNP‐Cd), and 92.61 and 9.07 µg/mL for N. biserrata SNP (SNP‐Nb), respectively. In terms of albumin‐denaturing activity, the SNPs gave an IC50 value of 21.20 µg/mL for SNP‐Cd and 7.18 µg/mL for SNP‐Nb. Thus, this work confirmed that SNP‐Cd and SNP‐Nb are potential therapeutic agents for treating oxidative stress, inflammatory problems, and related diseases.
  • Eri Tanaka, Yukie Yokota, Masamitsu Urakawa, Toyonobu Usuki
    European Food Research and Technology, Apr 21, 2024  Peer-reviewedCorresponding author

Misc.

 3

Books and Other Publications

 2

Presentations

 283

Research Projects

 25

Other

 7