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Iwata, Japan

Hong J.-Y.,BioLead Inc. | Hara K.,Iwata Chemical CO. | Kim J.-W.,Kangwon National University | Sato E.F.,Suzuka University of Medical Science | And 2 more authors.
Korean Journal of Physiology and Pharmacology | Year: 2016

Recently, it was reported that the role of mitochondria-reactive oxygen species (ROS) generating pathway in cisplatin-induced apoptosis is remarkable. Since a variety of molecules are involved in the pathway, a comprehensive approach to delineate the biological interactions of the molecules is required. However, quantitative modeling of the mitochondria-ROS generating pathway based on experiment and systemic analysis using the model have not been attempted so far. Thus, we conducted experiments to measure the concentration changes of critical molecules associated with mitochondrial apoptosis in both human mesothelioma H2052 and their ρ0 cells lacking mitochondrial DNA (mtDNA). Based on the experiments, a novel mathematical model that can represent the essential dynamics of the mitochondrial apoptotic pathway induced by cisplatin was developed. The kinetic parameter values of the mathematical model were estimated from the experimental data. Then, we have investigated the dynamical properties of this model and predicted the apoptosis levels for various concentrations of cisplatin beyond the range of experiments. From parametric perturbation analysis, we further found that apoptosis will reach its saturation level beyond a certain critical cisplatin concentration. © Copyright Korean J Physiol Pharmacol,. Source

Ogita S.,Toyama Prefectural University | Shichiken M.,Toyama Prefectural University | Ito C.,Iwata Chemical CO. | Yamashita T.,Botanic Gardens of Toyama | And 2 more authors.
Natural Product Communications | Year: 2015

In order to demonstrate the potential of plant cell culture systems to produce a target natural bioactive compound, we proposed a stepwise protocol for β-thujaplicin production as follows. 1. Induction phase: Characteristics of callus cultures originating from newly flushed shoots of 10 conifer species were evaluated on different basal media such as Murashige and Skoog (MS), Schenk and Hildebrandt (SH), and Lloyd and McCown's Woody Plant medium (WP) containing 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D) either alone or in combination with 1 μM of N6-benzyladenine (BA). The conifer species used were as follows: Chamaecyparis (C. obtusa Sieb. et Zucc. and C. pisifera Sieb. et Zucc.), Juniperus (J. chinensis L. Kaizuka', J. chinensis L. var. sargentii, and J. conferta Parlatore), Thuja (T. occidentalis L. and T. standishii (Gord.) Carr.), Thujopsis (T. dolabrata Sieb. et Zucc. and T. dolabrata Sieb. et Zucc. var. hondae), and Cryptomeria (C. japonica D. Don). We observed the phenotypes of each callus to determine the optimal conditions for callus induction and to infer biosynthetic activity of the calli over 4-8 weeks. 2. Habituation phase: Each of the cell cultures obtained was transferred to a modified MS medium containing 680 mg L-1 KH2PO4 and 10 μM Picloram to select the habituated cells with synchronous growth pattern. The growth of each cell culture was highly improved in the habituation medium, except that of J. chinensis ¡1Kaizuka'. 3. Metabolite-production phase: The concentration of β-thujaplicin (known as hinokitiol in Japan) in the shoots of donor trees and the habituated cell cultures was analyzed via high-performance liquid chromatography (HPLC). Histochemical characteristics of the cells were also observed using laser scanning microscopy (LSM) imaging. After the third step, we tested the biosynthetic activity of two habituated calli (C. obtusa and J. conferta) on a 0.3%, w/v, yeast extract (YE)-containing medium. We found significant improvement in β-thujaplicin production in J. conferta callus (4600 £gg g DW-1), which was up to 20-fold higher than in the habituation phase. Source

Hara K.,Osaka City University | Hara K.,Iwata Chemical CO. | Kasahara E.,Osaka City University | Kasahara E.,Hyogo College of Medicine | And 8 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2011

Although chemotherapy is an important method for the treatment of patients with cancer, its efficacy is limited because of different sensitivities of tumor cells to anticancer agents and/or side effects on normal tissues. The present work demonstrates that mitochondria play a crucial role in the apoptosis of cancer cells induced by anticancer agents that interact with DNA but not with the cytoskeleton. Agents that interact with DNA selectively enhanced generation of reactive oxygen species (ROS) in mitochondria, released cytochrome c, and activated caspase-9 and caspase-3 to induce apoptosis of mesothelioma H2052 cells but not their ρo cells, which lack mitochondrial DNA (mtDNA). The sensitivity of a variety of cells to the agents showed positive correlation with the amounts of their mitochondria. In contrast, agents that selectively affect the cytoskeleton activated caspase-8 and caspase-3 and equally induced apoptosis of both H2052 and their ρo cells by a mitochondria-independent mechanism. The results suggest that mtDNA is a potential target for the anticancer agents that interact with DNA to induce ROS-dependent apoptosis of cancer cells, whereas agents that affect the cytoskeleton induce cell death by a mitochondria- and ROS-independent mechanism. The present observation is important for the selection of medicine for chemotherapy of patients with cancer. Copyright © 2011 by The American Society for Pharmacology and Experimental Therapeutics. Source

Miwa S.,Ishikawa Agricultural Research Center | Nakamura M.,Ishikawa Agricultural Research Center | Okuno M.,Iwata Chemical CO. | Miyazaki H.,Iwata Chemical CO. | And 6 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2011

A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment. Source

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