Noriaki Samukawa

Osaka Metropolitan University

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Kentaro Tokudome

Osaka University of Pharmaceutical Sciences

Shinji Matsunaga

Osaka Metropolitan University

Shuhei Tomita

Nagoya City University

Sohkichi Matsumoto

Niigata University Medical and Dental Hospital

Takehiro Yamaguchi

Osaka Metropolitan University

Yoshikazu Fujita

Osaka University of Pharmaceutical Sciences

Mamiko Asano

Osaka University of Pharmaceutical Sciences

Keiichi Samukawa

Tokyo Metropolitan University

Hitoshi Matsumura

Fukuoka University Hospital

Takujiro Homma

Osaka Metropolitan University

Cooperative Institutions

Gunma University

Sapporo Science Center

Universitat de les Illes Balears

Chiang Mai University

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Osaka University of Pharmaceutical Sciences

The University of Tokyo

Osaka City University

Tokyo Metropolitan University

Analysis Group (United States)

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Pharmacokinetic–pharmacodynamic modelling of the hypoglycaemic effect of pulsatile administration of human insulin in rats

Scientific Reports (2020)

Makoto Miyazaki Mariko Hayata Noriaki Samukawa Kazunori Iwanaga Junya Nagai

Abstract The relationship between the plasma insulin (INS) concentration–time course and plasma glucose concentration–time course during and after pulsatile INS administration to rats was characterized using a pharmacokinetic–pharmacodynamic (PK–PD) model. A total INS dose of 0.5 IU/kg was intravenously injected in 2 to 20 pulses over a 2-h period. Compared with the single bolus administration, the area under the effect-time curve (AUE) increased depending on the number of pulses, and the AUEs for more than four pulses plateaued at a significantly larger value, which was similar to that after the infusion of a total of 0.5 IU/kg of INS over 2 h. No increase in plasma INS concentration occurred after pulsatile administration. Two indirect response models primarily reflecting the receptor-binding process (IR model) or glucose transporter 4 (GLUT4) translocation (GT model) were applied to describe the PK–PD relationship after single intravenous bolus administration of INS. These models could not explain the observed data after pulsatile administration. However, the IR-GT model, which was a combination of the IR and GT models, successfully explained the effects of pulsatile administration and intravenous infusion. These results indicate that the receptor-binding process and GLUT4 translocation are responsible for the change in AUE after pulsatile administration.

Pulsatile flow

Pharmacodynamics

Bolus (digestion)

GLUT4

10.1038/s41598-020-76007-3

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Red ginseng extract modulates cellular energy homeostasis and protects against cell death during nutrient deprivation.

Proceedings for Annual Meeting of The Japanese Pharmacological Society (2023)

Takujiro Homma Shinji Matsunaga Kentaro Tokudome Noriaki Samukawa Keiichi Samukawa

Red Ginseng Extract (RGE) is known to have various health benefits such as fatigue relief and tonicity. However, the effects of RGE on intracellular energy metabolism are not well understood. In this study, we treated HK-2 cells, a human proximal tubular cell line, with RGE and examined the effects on cell proliferation and changes in intracellular metabolites. First, RGE was found to promote cell proliferation in HK-2 cells in a concentration-dependent manner; LC-MS/MS analysis revealed that RGE significantly increased intracellular pantothenate, proline, and glutathione levels. In contrast, extracellular (culture medium) pantothenate levels decreased in a RGE concentration-dependent manner, suggesting that RGE enhances intracellular uptake of pantothenate. Pantothenate is synthesized intracellularly to coenzyme A (CoA), which is then converted to acetyl CoA and involved in various intracellular events, including energy metabolism. We found that inhibition of the synthesis of coenzyme A from pantothenate inhibited the effect of RGE on HK-2 cell proliferation. These results suggest that RGE activates cell proliferation via an increase in intracellular pantothenate levels and is involved in the activation of antioxidant effects and energy metabolism. Next, we investigated the protective effect of RGE during nutrient starvation in HK-2 cells. The results showed that RGE abrogated intracellular stress signals and inhibited cell death in HK-2 cells during acute nutrient starvation. Collectively, our results suggest that RGE acts as a regulator of intracellular energy metabolism under both nutrient and starvation conditions.

10.1254/jpssuppl.97.0_1-b-p-066

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CRISPR Interference-based Screening for Prediction of Synergistic/Additive Effects of Novel Combinations of Anti-Tuberculosis Drugs

Proceedings for Annual Meeting of The Japanese Pharmacological Society (2022)

Noriaki Samukawa Takehiro Yamaguchi Yuriko Ozeki Sohkichi Matsumoto Kentaro Tokudome

Tuberculosis (TB) patients must receive treatment for a long period, spanning at least 6 months. In some cases, this long period of treatment leads to inappropriate administration of anti-TB drugs and cessation of TB therapy, a hotbed of antimicrobial resistance. From this perspective, novel drugs that act synergistically or additively in combination with major anti-TB drugs are required to shorten the duration of TB therapy. Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is a powerful genetic tool which is expected to accelerate the development of TB drugs. In this study, we investigated whether CRISPRi could be used for predictive screening of the combined effect of anti-TB drugs. Knockdown of inhA, a target molecule of isoniazid (INH), increased susceptibility to rifampicin (RFP) and ethambutol, which act synergistically or additively with INH. This phenomenon was also true in the case of knockdown of rpoB, a target molecule of RFP. Moreover, CRISPRi could successfully predict the synergistic action of cyclomarin A with INH or RFP. These results demonstrate that CRISPRi is a helpful tool not only for exploring drug targets, but also for screening the combinatorial effects of known anti-TB drugs. This study provides evidence of CRISPRi platform-based anti-TB drug development.

INHA

10.1254/jpssuppl.95.0_2-o-092

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An efficient CRISPR interference-based prediction method for synergistic/additive effects of novel combinations of anti-tuberculosis drugs

Microbiology (2022)

Noriaki Samukawa Takehiro Yamaguchi Yuriko Ozeki Sohkichi Matsumoto Masayuki Igarashi

Tuberculosis (TB) is treated by chemotherapy with multiple anti-TB drugs for a long period, spanning 6 months even in a standard course. In perspective, to prevent the emergence of antimicrobial resistance, novel drugs that act synergistically or additively in combination with major anti-TB drugs and, if possible, shorten the duration of TB therapy are needed. However, their combinatorial effect cannot be predicted until the lead identification phase of the drug development. Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is a powerful genetic tool that enables high-throughput screening of novel drug targets. The development of anti-TB drugs promises to be accelerated by CRISPRi. This study determined whether CRISPRi could be applicable for predictive screening of the combinatorial effect between major anti-TB drugs and an inhibitor of a novel target. In the checkerboard assay, isoniazid killed Mycobacterium smegmatis synergistically or additively in combinations with rifampicin or ethambutol, respectively. The susceptibility to rifampicin and ethambutol was increased by knockdown of inhA, which encodes a target molecule of isoniazid. Additionally, knockdown of rpoB, which encodes a target molecule of rifampicin, increased the susceptibility to isoniazid and ethambutol, which act synergistically with rifampicin in the checkerboard assay. Moreover, CRISPRi could successfully predict the synergistic action of cyclomarin A, a novel TB drug candidate, with isoniazid or rifampicin. These results demonstrate that CRISPRi is a useful tool not only for drug target exploration but also for screening the combinatorial effects of novel combinations of anti-TB drugs. This study provides a rationale for anti-TB drug development using CRISPRi.

INHA

10.1099/mic.0.001285

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Spectrophotometric Determination of Germanium(IV) and Organogermanes with <i>o</i>-Sulfophenylfluorone

BUNSEKI KAGAKU (2016)

H. Tomita Noriaki Samukawa Mamiko Asano Takako Yamaguchi Hitoshi Matsumura

A novel spectrophotometric method was established for the determination of germanium(IV) and organogermanes. The method is based on ternary complex formation among germanium(IV), o-sulfophenylfluorone (SPF) and cetyltrimethylammonium chloride (CTAC). In the determination of germanium(IV), the absorbance at 530 nm obeyed Beer’s law in the range of 7.0−400 ng mL−1. The effective molar absorptivity at 530 nm and the relative standard deviation were 1.7 × 105 L mol−1 cm−1 and 0.96 % (n = 6), respectively. In the determination of propagermaniumu as organogermanes, the absorbance at 536 nm obeyed Beer’s law in the range of 30−1000 ng mL−1. The effective molar absorptivity at 536 nm and the relative standard deviation were 1.5 × 105 L mol−1 cm−1 and 1.13 % (n = 6), respectively. The recovery of germanium(IV) added to human urine was satisfactory being about 98 %. The proposed method requiring no solvent extraction should be useful for a simple and sensitive determinations of germanium(IV) and organogermanes.

Molar absorptivity

Absorbance

Relative standard deviation

Spectrophotometry

10.2116/bunsekikagaku.65.465

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Announcements

Analytical Sciences (2016)

Mai Furukawa Hideyuki Katsumata T. Suzuki Satoshi Kaneco Masato Sasaki

10.2116/analsci.32.917

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Antimicrobial activities of ginseng saponins isolated from Red Ginseng to non-tuberculous mycobacteria

Proceedings for Annual Meeting of The Japanese Pharmacological Society (2022)

Noriaki Samukawa Takehiro Yamaguchi Keiichi Samukawa Kentaro Tokudome Takujiro Homma

Non-tuberculous mycobacterial lung disease (NTM lung disease) is the infection which is caused by mycobacteria, such as Mycobacterium avium (M. avium), M. intracellulare, M. kansasii. The prognosis of NTM lung disease is relative benign than that of TB, but in some cases NTM lung disease is highly resistant to chemotherapy. The incident rate of NTM lung disease is increased and it is estimated that the number of NTM patients exceeds the number of tuberculosis (TB) patients. Here, we investigated the antimicrobial activity of ginseng saponins from red ginseng (Red Ginseng Extract; RGE) against NTM.

Mycobacterium kansasii

Lung infection

10.1254/jpssuppl.96.0_2-b-p-177

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