Springer Science and Business Media LLC Acta Medica Okayama 0971-5894 2026 Suppression of salt-enhanced apoplastic flow by salicylic acid in rice EN Md. Asadulla Al Galib Graduate School of Environmental and Life Science, Okayama University Maoxiang Zhao Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshihiko Hirai Graduate School of Environmental and Life Science, Okayama University Yoshitaka Nakashima Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Izumi C. Mori Institute of Plant Science and Resources, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Salinity enhances apoplastic flow, resulting in an increment of Na+ uptake and a lower K+/Na+ ratio. Salicylic acid (SA) plays an important role in improving salinity tolerance in plants. The effect of exogenous SA on apoplastic flow in salt-treated rice seedlings was studied using an apoplastic tracer, 8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS) in light. Application of NaCl at 25 mM to the hydroponic solution significantly increased PTS uptake, while 25 mM NaCl did not affect seedling growth. Application of 25 mM NaNO3 increased PTS uptake to the same degree. Salinity significantly increased sodium (Na+) content but had no significant effect on potassium (K+) content, resulting in a lower K+/Na+ ratio. The application of SA at 0.05 mM and 0.1 mM to the hydroponic solution reduced Na-enhanced PTS uptake. Salicylic acid at 0.05 mM and 0.1 mM significantly reduced Na+ content and slightly increased K+ content in the shoots of rice seedlings, resulting in a higher K+/Na+ ratio. However, SA at up to 0.1 mM did not increase SA contents in shoots under salt stress. These results suggest that exogenous SA reduces Na+ uptake by suppressing Na+-enhanced apoplastic flow in rice seedlings. These findings provide insight into modulation of Na+ transport pathways from roots to shoots by SA and may allow us to utilize brackish water for rice cultivation and to improve salt-tolerant rice through suppression of salt-enhanced apoplastic flow by chemicals such as salicylic acid. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0003-9861 779 2026 Comparison of bioavailability of quercetin and its structural analogs in mice 110775 EN Nozomi Maeda Graduate School of Environmental and Life Science, Okayama University Atsushi Hashimoto Graduate School of Environmental and Life Science, Okayama University Ryosei Morita Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Flavonoids are thought to provide beneficial effects on health. However, there are still uncertainties regarding their bioavailability. In this study, we investigated the bioavailability of 6 flavonoids, galangin, kaempferol, quercetin, myricetin, fisetin, and luteolin, by oral administration to mice. Analysis of plasma concentrations of free flavonoids after deconjugation by LC-MS/MS revealed that all flavonoids were rapidly absorbed after administration. Among 6 flavonoids, kaempferol and fisetin showed high absorbed amounts in blood plasma. With the LogP value of the two flavonoids as the maximum value, the amount absorbed decreased for both lower and higher LogP values. The results of the tissue distribution of galangin, kaempferol, and quercetin suggested that the order of fastest movement from the stomach to the small intestine was kaempferol > quercetin > galangin. In addition, the amount of kaempferol and quercetin distributed in the liver was greater than that of galangin. These results suggest that the bioavailability of flavonoids varies with the slight structural differences, possibly due to differences in their rapid accessibility to the small intestine that is the primary site of absorption and metabolism within the body. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0031-9317 178 1 2026 Reactive Carbonyl Species Mediate Isothiocyanate Signaling Pathway in Arabidopsis thaliana Guard Cells e70775 EN Sumaiya Farzana Graduate School of Environmental and Life Science, Okayama University Md. Moshiul Islam Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Jun'ichi Mano Science Research Center, Yamaguchi University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Our previous results demonstrated that depletion of glutathione (GSH) rather than elevation of levels of reactive oxygen species (ROS) is highly correlated with the decrease in stomatal aperture induced by isothiocyanates (ITCs), although ROS is considered a key second messenger in stomatal closure, suggesting that another signal component regulates stomatal apertures along with GSH depletion. This study, using Arabidopsis, clarified that reactive carbonyl species (RCS), especially acrolein and 4-hydroxy-(E)-2-nonenal, are determinants of stomatal aperture responses to ITCs. All tested ITCs, allyl isothiocyanate (AITC), sulforaphane (SFN), benzyl isothiocyanate (BITC), and phenethyl isothiocyanate (PEITC), significantly induced stomatal closure, which was inhibited by the RCS scavengers, carnosine and pyridoxamine. The RCS scavengers suppressed ITC-induced depletion of GSH but not elevation of ROS levels. All tested ITCs (AITC, SFN, BITC, and PEITC) increased levels of RCS and non-RCS aldehydes in the epidermal tissues. However, acrolein, 4-hydroxy-(E)-2-nonenal, crotonaldehyde, and (E)-2-pentenal induced stomatal closure at 10 and 100 μM, whereas propionaldehyde, butyraldehyde, and n-pentanal did not at concentrations up to 100 μM. Acrolein and 4-hydroxy-(E)-2-nonenal more effectively induced stomatal closure and GSH depletion than crotonaldehyde and (E)-2-pentenal did. The contents of RCS were more strongly correlated with GSH levels and stomatal closure than with ROS levels. These results suggest that RCS, especially acrolein and 4-hydroxy-(E)-2-nonenal, acts as key regulators of stomatal closure in guard cells in response to ITCs. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0718-9508 2025 Suppression of Na+ Uptake Via Apoplastic Flow by Chitosan in Rice EN Maoxiang Zhao Graduate School of Environmental and Life Science, Okayama University Md. Asadulla Al Galib Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshihiko Hirai Graduate School of Environmental and Life Science, Okayama University Yoshitaka Nakashima Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Izumi C. Mori Institute of Plant Science and Resources, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Purpose: Chitosan enhances tolerance to salinity in rice. Apoplastic flow plays a crucial role in the accumulation of sodium (Na+) in rice under salinity. This study investigated the effects of exogenous chitosan on apoplastic flow and Na+ uptake in NaCl-treated rice seedlings. Methods: We employed an apoplastic tracer, trisodium salt of 8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), in order to evaluate apoplastic flow in rice (Oryza sativa L., cv. Nipponbare) seedlings that were hydroponically grown in the solution containing NaCl (0 and 25 mM), and chitosan (0 mg L− 1, 10 mg L− 1, and 50 mg L− 1). Results: Application of 25 mM NaCl significantly increased PTS uptake and Na+ content in shoots but did not affect K+ content, resulting in a lower K+/Na+ ratio although 25 mM NaCl did not affect the seedling growth. The application of chitosan suppressed Na+-enhanced PTS uptake and Na+ accumulation in shoots without affecting the K+ content, which led to a higher K+/Na+ ratio. Moreover, chitosan did not affect the reducing sugar content or electrical conductivity in the solution containing NaCl. Conclusions: These results suggest that application of chitosan suppressed Na+-enhanced apoplastic flow to reduce Na+ uptake in rice seedlings. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 1422-0067 26 17 2025 Augmentation of the Benzyl Isothiocyanate-Induced Antiproliferation by NBDHEX in the HCT-116 Human Colorectal Cancer Cell Line 8145 EN Ruitong Sun Graduate School of Environmental and Life Science, Okayama University Aina Yano Graduate School of Environmental and Life Science, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Increased drug metabolism and elimination are prominent mechanisms mediating multidrug resistance (MDR) to not only chemotherapy drugs but also anti-cancer natural products, such as benzyl isothiocyanate (BITC). To evaluate the possibility of combined utilization of a certain compound to overcome this resistance, we focused on glutathione S-transferase (GST)-dependent metabolism of BITC. The pharmacological treatment of a pi-class GST-selective inhibitor, 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX), significantly increased BITC-induced toxicity in human colorectal cancer HCT-116 cells. However, NBDHEX unexpectedly increased the level of the BITC–glutathione (GSH) conjugate as well as BITC-modified proteins, suggesting that NBDHEX might increase BITC-modified protein accumulation by inhibiting BITC–GSH excretion instead of inhibiting GST. Furthermore, NBDHEX significantly potentiated BITC-induced apoptosis with the enhanced activation of apoptosis-related pathways, such as c-Jun N-terminal kinase and caspase-3 pathways. These results suggested that combination treatment with NBDHEX may be an effective way to overcome MDR with drug efflux and thus induce the biological activity of BITC at lower doses. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0031-9317 177 4 2025 CNGC2 Negatively Regulates Stomatal Closure and Is Not Required for flg22- and H2O2-Induced Guard Cell [Ca2+]cyt Elevation in Arabidopsis thaliana e70396 EN Rojina Akter Graduate School of Environmental and Life Science, Okayama University Yasuhiro Inoue Graduate School of Environmental and Life Science, Okayama University Saori Masumoto Faculty of Agriculture, Okayama University Yoshiharu Mimata Graduate School of Environmental and Life Science, Okayama University Takakazu Matsuura Institute of Plant Science and Resources, Okayama University Izumi C. Mori Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University In guard cells, cytosolic Ca2+ acts as a second messenger that mediates abscisic acid (ABA)- and pathogen-associated molecular pattern (PAMP)-induced stomatal closure. It was reported that Arabidopsis cyclic nucleotide-gated ion channel 2 (CNGC2) functions as hydrogen peroxide (H2O2)- and PAMP-activated Ca2+-permeable channels at the plasma membrane of mesophyll cells and mediates Ca2+-dependent PAMP-triggered immunity. In this study, we examined the role of CNGC2 in the regulation of stomatal movement because CNGC2 is also expressed in guard cells. We found that stomata of the CNGC2 disruption mutant cngc2-3 are constitutively closed even in the absence of ABA or the flagellar-derived PAMP, flg22. Consistently, leaf temperatures of the cngc2-3 mutant were higher than those of wild-type (WT) plants. The stomatal phenotype of the cngc2-3 mutant was restored by complementation with wild-type CNGC2 under the control of the guard cell preferential promoter, pGC1. Elevation of cytosolic free Ca2+ concentration in guard cells induced by flg22 and H2O2 remained intact in the cngc2-3 mutant. The introduction of the ost1-3 mutation into the cngc2-3 background did not alter the stomatal phenotype. However, the stomatal phenotype of the cngc2-3 mutant was successfully rescued in the double disruption mutant cngc2-3aba2-2. Taken together, these results suggest that CNGC2 negatively regulates stomatal closure response and does not function as flg22– and H2O2-activated Ca2+ channels in guard cells. Though CNGC2 is responsive for H2O2- and flg22-induced [Ca2+]cyt elevation in mesophyll cells, the involvement of CNGC2 in the response to H2O2 and flg22 in guard cells is questionable. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0278-6915 197 2025 Fraglide-1 from traditional Chinese aromatic vinegar: A natural AhR antagonist for atopic dermatitis 115301 EN Kosuke Kato Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Miki Akamatsu Graduate School of Environmental and Life Science, Okayama University Saya Kakimaru Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Masahiro Takagi School of Materials Science, Japan Advanced Institute of Science and Technology Masahiro Miyashita Graduate School of Agriculture, Kyoto University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshio Tsujino Graduate School of Science, Technology and Innovation, Kobe University Traditional Chinese Zhenjiang aromatic vinegar (Kozu) contains Fraglide-1 (FG1), a bioactive lactone with demonstrated peroxisome proliferator-activated receptor gamma (PPARγ) agonist and antioxidant activities. This study explored FG1's novel ability to antagonize the aryl hydrocarbon receptor (AhR) signaling pathway, which regulates artemin expression and contributes to itching and inflammation in atopic dermatitis. Through molecular docking simulations and cell-based assays in human keratinocytes, we demonstrated FG1's potent antagonistic activity against AhR signaling. FG1 effectively suppressed FICZ-induced inflammatory responses, including artemin expression, with potency (half maximal inhibitory concentration, IC50 = 5.1 μM) comparable to the synthetic antagonist StemRegenin 1 (SR1) while demonstrating a superior safety profile (median lethal concentration, LC50 > 100 μM vs. 27.5 μM for SR1). These findings expand our understanding of bioactive compounds from traditional fermented foods and their regulatory effects on AhR signaling, providing a foundation for future studies on FG1's role in modulating skin inflammation. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1756-4646 125 2025 Resveratrol, a food-derived polyphenol, promotes Melanosomal degradation in skin fibroblasts through coordinated activation of autophagy, lysosomal, and antioxidant pathways 106672 EN Saki Okamoto Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Saya Kakimaru Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mika Sakamoto National Institute of Genetics, ROIS Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Hideya Ando Department of Applied Chemistry and Biotechnology, Okayama University of Science Yoshio Tsujino Graduate School of Science, Technology, and Innovation, Kobe University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Resveratrol, a polyphenol found in grapes and peanuts, is known for diverse biological activities, yet its effects on dermal hyperpigmentation (so-called dark spots) remain unexplored. We investigated resveratrol's ability to enhance melanosomal degradation in human dermal fibroblasts. At concentrations of 25-50 mu M, resveratrol increased autophagy as measured by microtubule-associated protein 1A/1B-light chain 3 (LC3)-II/LC3-I ratio and enhanced lysosomal activity as assessed by a lysosomal activity reporter system. RNA sequencing revealed upregulation of lysosomal and autophagy-related genes, including cathepsins. Furthermore, reporter assays showed resveratrol's activation of antioxidant response via nuclear factor erythroid 2-related factor 2 (NRF2)mediated, leading to upregulation of transcription factor EB/transcription factor E3 (TFEB/TFE3), master regulators of lysosomal function. In fibroblasts pre-loaded with melanosomes, resveratrol reduced melanosome content compared to control by day 3. The findings reveal the activation of interconnected autophagy, lysosomal, and antioxidant pathways by resveratrol, suggesting potential applications in functional foods targeting dermal hyperpigmentation. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1661-6596 25 16 2024 Quercetin Attenuates Acetaldehyde-Induced Cytotoxicity via the Heme Oxygenase-1-Dependent Antioxidant Mechanism in Hepatocytes 9038 EN Kexin Li Graduate School of Environmental and Life Science, Okayama University Minori Kidawara Graduate School of Environmental and Life Science, Okayama University Qiguang Chen Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University It is still unclear whether or how quercetin influences the toxic events induced by acetaldehyde in hepatocytes, though quercetin has been reported to mitigate alcohol-induced mouse liver injury. In this study, we evaluated the modulating effect of quercetin on the cytotoxicity induced by acetaldehyde in mouse hepatoma Hepa1c1c7 cells, the frequently used cellular hepatocyte model. The pretreatment with quercetin significantly inhibited the cytotoxicity induced by acetaldehyde. The treatment with quercetin itself had an ability to enhance the total ALDH activity, as well as the ALDH1A1 and ALDH3A1 gene expressions. The acetaldehyde treatment significantly enhanced the intracellular reactive oxygen species (ROS) level, whereas the quercetin pretreatment dose-dependently inhibited it. Accordingly, the treatment with quercetin itself significantly up-regulated the representative intracellular antioxidant-related gene expressions, including heme oxygenase-1 (HO-1), glutamate-cysteine ligase, catalytic subunit (GCLC), and cystine/glutamate exchanger (xCT), that coincided with the enhancement of the total intracellular glutathione (GSH) level. Tin protoporphyrin IX (SNPP), a typical HO-1 inhibitor, restored the quercetin-induced reduction in the intracellular ROS level, whereas buthionine sulphoximine, a representative GSH biosynthesis inhibitor, did not. SNPP also cancelled the quercetin-induced cytoprotection against acetaldehyde. These results suggest that the low-molecular-weight antioxidants produced by the HO-1 enzymatic reaction are mainly attributable to quercetin-induced cytoprotection. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 1347-6947 87 11 2023 The effect of exogenous dihydroxyacetone and methylglyoxal on growth, anthocyanin accumulation, and the glyoxalase system in Arabidopsis 1323 1331 EN Maoxiang Zhao Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Izumi C Mori Institute of Plant Science and Resources, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Dihydroxyacetone (DHA) occurs in wide-ranging organisms, including plants, and can undergo spontaneous conversion to methylglyoxal (MG). While the toxicity of MG to plants is well-known, the toxicity of DHA to plants remains to be elucidated. We investigated the effects of DHA and MG on Arabidopsis. Exogenous DHA at up to 10 mM did not affect the radicle emergence, the expansion of green cotyledons, the seedling growth, or the activity of glyoxalase II, while DHA at 10 mM inhibited the root elongation and increased the activity of glyoxalase I. Exogenous MG at 1.0 mM inhibited these physiological responses and increased both activities. Dihydroxyacetone at 10 mM increased the MG content in the roots. These results indicate that DHA is not so toxic as MG in Arabidopsis seeds and seedlings and suggest that the toxic effect of DHA at high concentrations is attributed to MG accumulation by the conversion to MG. No potential conflict of interest relevant to this article was reported.

Public Library of Science Acta Medica Okayama 1932-6203 19 1 2024 Aromatic oil from lavender as an atopic dermatitis suppressant e0296408 EN Haruna Sato Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kosuke Kato Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshio Tsujino Graduate School of Science, Technology, and Innovation, Kobe University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University In atopic dermatitis (AD), nerves are abnormally stretched near the surface of the skin, making it sensitive to itching. Expression of neurotrophic factor Artemin (ARTN) involved in such nerve stretching is induced by the xenobiotic response (XRE) to air pollutants and UV radiation products. Therefore, AD can be monitored by the XRE response. Previously, we established a human keratinocyte cell line stably expressing a NanoLuc reporter gene downstream of XRE. We found that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan metabolite and known inducer of the XRE, increased reporter and Artemin mRNA expression, indicating that FICZ-treated cells could be a model for AD. Lavender essential oil has been used in folk medicine to treat AD, but the scientific basis for its use is unclear. In the present study, we investigated the efficacy of lavender essential oil and its major components, linalyl acetate and linalool, to suppress AD and sensitize skin using the established AD model cell line, and keratinocyte and dendritic cell activation assays. Our results indicated that lavender essential oil from L. angustifolia and linalyl acetate exerted a strong AD inhibitory effect and almost no skin sensitization. Our model is useful in that it can circumvent the practice of using animal studies to evaluate AD medicines. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 24 1 2023 Cycloartenyl Ferulate Is the Predominant Compound in Brown Rice Conferring Cytoprotective Potential against Oxidative Stress-Induced Cytotoxicity 822 EN Hongyan Wu School of Food Science and Technology, Dalian Polytechnic University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yingnan Guo School of Food Science and Technology, Dalian Polytechnic University Riho Matsumoto Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Since brown rice extract is a rich source of biologically active compounds, the present study is aimed to quantify the major compounds in brown rice and to compare their cytoprotective potential against oxidative stress. The content of the main hydrophobic compounds in brown rice followed the order of cycloartenyl ferulate (CAF) (89.00 +/- 8.07 nmol/g) >> alpha-tocopherol (alpha T) (19.73 +/- 2.28 nmol/g) > gamma-tocotrienol (gamma T3) (18.24 +/- 1.41 nmol/g) > alpha-tocotrienol (alpha T3) (16.02 +/- 1.29 nmol/g) > gamma-tocopherol (gamma T) (3.81 +/- 0.40 nmol/g). However, the percent contribution of CAF to the radical scavenging activity of one gram of whole brown rice was similar to those of alpha T, alpha T3, and gamma T3 because of its weaker antioxidant activity. The CAF pretreatment displayed a significant cytoprotective effect on the hydrogen peroxide-induced cytotoxicity from 10 mu M, which is lower than the minimal concentrations of alpha T and gamma T required for a significant protection. CAF also enhanced the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation coincided with the enhancement of the heme oxygenase-1 (HO-1) mRNA level. An HO-1 inhibitor, tin protoporphyrin IX (SnPP), significantly impaired the cytoprotection of CAF. The cytoprotective potential of CAF is attributable to its cycloartenyl moiety besides the ferulyl moiety. These results suggested that CAF is the predominant cytoprotector in brown rice against hydrogen peroxide-induced cytotoxicity. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 23 19 2022 Immune State Conversion of the Mesenteric Lymph Node in a Mouse Breast Cancer Model 11035 EN Tsukasa Shigehiro Research Institute for Biomedical Sciences, Tokyo University of Science Maho Ueno Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University Mayumi Kijihira Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University Ryotaro Takahashi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Chiho Umemura Division of Medical Bioengineering, Graduate School of Natural Science and Technology, Okayama University Eman A. Taha Division of Medical Bioengineering, Graduate School of Natural Science and Technology, Okayama University Chisaki Kurosaka Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University Megumi Asayama Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University Hiroshi Murakami Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Junichiro Futami Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Junko Masuda Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Secondary lymphoid tissues, such as the spleen and lymph nodes (LNs), contribute to breast cancer development and metastasis in both anti- and pro-tumoral directions. Although secondary lymphoid tissues have been extensively studied, very little is known about the immune conversion in mesenteric LNs (mLNs) during breast cancer development. Here, we demonstrate inflammatory immune conversion of mLNs in a metastatic 4T1 breast cancer model. Splenic T cells were significantly decreased and continuously suppressed IFN-gamma production during tumor development, while myeloid-derived suppressor cells (MDSCs) were dramatically enriched. However, T cell numbers in the mLN did not decrease, and the MDSCs only moderately increased. T cells in the mLN exhibited conversion from a pro-inflammatory state with high IFN-gamma expression to an anti-inflammatory state with high expression of IL-4 and IL-10 in early- to late-stages of breast cancer development. Interestingly, increased migration of CD103(+)CD11b(+) dendritic cells (DCs) into the mLN, along with increased (1 -> 3)-beta-D-glucan levels in serum, was observed even in late-stage breast cancer. This suggests that CD103(+)CD11b(+) DCs could prime cancer-reactive T cells. Together, the data indicate that the mLN is an important lymphoid tissue contributing to breast cancer development. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 23 3 2022 A Major Intestinal Catabolite of Quercetin Glycosides, 3-Hydroxyphenylacetic Acid, Protects the Hepatocytes from the Acetaldehyde-Induced Cytotoxicity through the Enhancement of the Total Aldehyde Dehydrogenase Activity 1762 EN Yujia Liu School of Biological Engineering, Dalian Polytechnic University Takumi Myojin Graduate School of Environmental and Life Science, Okayama University Kexin Li Graduate School of Environmental and Life Science, Okayama University Ayuki Kurita Graduate School of Environmental and Life Science, Okayama University Masayuki Seto Graduate School of Environmental and Life Science, Okayama University Ayano Motoyama Graduate School of Environmental and Life Science, Okayama University Xiaoyang Liu Graduate School of Environmental and Life Science, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Aldehyde dehydrogenases (ALDHs) are the major enzyme superfamily for the aldehyde metabolism. Since the ALDH polymorphism leads to the accumulation of acetaldehyde, we considered that the enhancement of the liver ALDH activity by certain food ingredients could help prevent alcohol-induced chronic diseases. Here, we evaluated the modulating effects of 3-hydroxyphenylacetic acid (OPAC), the major metabolite of quercetin glycosides, on the ALDH activity and acetaldehyde-induced cytotoxicity in the cultured cell models. OPAC significantly enhanced the total ALDH activity not only in mouse hepatoma Hepa1c1c7 cells, but also in human hepatoma HepG2 cells. OPAC significantly increased not only the nuclear level of aryl hydrocarbon receptor (AhR), but also the AhR-dependent reporter gene expression, though not the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent one. The pretreatment of OPAC at the concentration required for the ALDH upregulation completely inhibited the acetaldehyde-induced cytotoxicity. Silencing AhR impaired the resistant effect of OPAC against acetaldehyde. These results strongly suggested that OPAC protects the cells from the acetaldehyde-induced cytotoxicity, mainly through the AhR-dependent and Nrf2-independent enhancement of the total ALDH activity. Our findings suggest that OPAC has a protective potential in hepatocyte models and could offer a new preventive possibility of quercetin glycosides for targeting alcohol-induced chronic diseases. No potential conflict of interest relevant to this article was reported.

Springer Nature Acta Medica Okayama 1226-4601 24 1 2021 Synthesis and characterization of conductive flexible cellulose carbon nanohorn sheets for human tissue applications 18 EN Karthik Paneer Selvam Graduate School of Natural Science and Technology, Okayama University Taichi Nagahata Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kosuke Kato Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Background<br> Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications.<br> Method<br> To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100mg) in 200mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials.<br> Results<br> The obtained sheets possess a conductivity of 1.83x10(-10)S/m and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100mg to retain the consistent geometry of free-standing sheets of <100<mu>m thickness. Since CNHs have a unique arrangement of aggregates (dahlia structure), the composite is homogeneous, as verified by transmission electron microscopy (TEM) and, scanning electron microscopy (SEM), and other functional properties investigated by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), conductivity measurement, tensile strength measurement, and skin sensitization.<br> Conclusion<br> It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications. No potential conflict of interest relevant to this article was reported.

Oxford University Press Acta Medica Okayama 0022-0957 71 10 2020 Inhibition of light-induced stomatal opening by allyl isothiocyanate does not require guard cell cytosolic Ca2+ signaling 2922 2932 EN Wenxiu Ye Graduate School of Environmental and Life Science, Okayama University Eigo Ando Graduate School of Science, Nagoya University Mohammad Saidur Rhaman Graduate School of Environmental and Life Science, Okayama University Md Tahjib-Ul-Arif Graduate School of Environmental and Life Science, Okayama University Eiji Okuma Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Toshinori Kinoshita Institute of Transformative Bio-Molecule, Nagoya University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University The glucosinolate-myrosinase system is a well-known defense system that has been shown to induce stomatal closure in Brassicales. Isothiocyanates are highly reactive hydrolysates of glucosinolates, and an isothiocyanate, allyl isothiocyanate (AITC), induces stomatal closure accompanied by elevation of free cytosolic Ca2+ concentration ([Ca2+](cyt)) in Arabidopsis. It remains unknown whether AITC inhibits light-induced stomatal opening. This study investigated the role of Ca2+ in AITC-induced stomatal closure and inhibition of light-induced stomatal opening. AITC induced stomatal closure and inhibited light-induced stomatal opening in a dose-dependent manner. A Ca2+ channel inhibitor, La3+, a Ca(2+)chelator, EGTA, and an inhibitor of Ca2+ release from internal stores, nicotinamide, inhibited AITC-induced [Ca2+](cyt) elevation and stomatal closure, but did not affect inhibition of light-induced stomatal opening. AITC activated non-selective Ca2+-permeable cation channels and inhibited inward-rectifying K+ (K-in(+)) channels in a Ca2+-independent manner. AITC also inhibited stomatal opening induced by fusicoccin, a plasma membrane H+-ATPase activator, but had no significant effect on fusicoccin-induced phosphorylation of the penultimate threonine of H+-ATPase. Taken together, these results suggest that AITC induces Ca2+ influx and Ca2+ release to elevate [Ca2+](cyt), which is essential for AITC-induced stomatal closure but not for inhibition of K-in(+) channels and light-induced stomatal opening. No potential conflict of interest relevant to this article was reported.

Nature Publishing Group Acta Medica Okayama 2045-2322 9 2019 Yeast screening system reveals the inhibitory mechanism of cancer cell proliferation by benzyl isothiocyanate through down-regulation of Mis12 8866 EN Naomi Abe-Kanoh Graduate School of Environmental and Life Science, Okayama University Narumi Kunisue Graduate School of Environmental and Life Science, Okayama University Takumi Myojin Graduate School of Environmental and Life Science, Okayama University Ayako Chino Research Core for Interdisciplinary Sciences, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Ayano Satoh Graduate School of Natural Science and Technology, Okayama University Hisao Moriya Research Core for Interdisciplinary Sciences, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University, Okayama Benzyl isothiocyanate (BITC) is a naturally-occurring isothiocyanate derived from cruciferous vegetables. BITC has been reported to inhibit the proliferation of various cancer cells, which is believed to be important for the inhibition of tumorigenesis. However, the detailed mechanisms of action remain unclear. In this study, we employed a budding yeast Saccharomyces cerevisiae as a model organism for screening. Twelve genes including MTW1 were identified as the overexpression suppressors for the antiproliferative effect of BITC using the genome-wide multi-copy plasmid collection for S. cerevisiae. Overexpression of the kinetochore protein Mtw1 counteracts the antiproliferative effect of BITC in yeast. The inhibitory effect of BITC on the proliferation of human colon cancer HCT-116 cells was consistently suppressed by the overexpression of Mis12, a human orthologue of Mtw1, and enhanced by the knockdown of Mis12. We also found that BITC increased the phosphorylated and ubiquitinated Mis12 level with consequent reduction of Mis12, suggesting that BITC degrades Mis12 through an ubiquitin-proteasome system. Furthermore, cell cycle analysis showed that the change in the Mis12 level affected the cell cycle distribution and the sensitivity to the BITC-induced apoptosis. These results provide evidence that BITC suppresses cell proliferation through the post-transcriptional regulation of the kinetochore protein Mis12. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2296634X 7 2019 The Golgin Protein Giantin Regulates Interconnections Between Golgi Stacks 160 EN Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mitsuko Hayashi-Nishino Institute of Scientific and Industrial Research, Osaka University Takuto Shakuno Graduate School of Natural Science and Technology, Okayama University Junko Masuda Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Runa Murakami Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yoshimasa Nakamura raduate School of Environmental and Life Science, Okayama University Toshiyuki Nakamura raduate School of Environmental and Life Science, Okayama University Naomi Abe-Kanoh raduate School of Environmental and Life Science, Okayama University Yasuko Honjo esearch Institute for Radiation Biology and Medicine, Hiroshima University Joerg Malsam Center for Biochemistry (BZH), Heidelberg University Sidney Yu School of Biomedical Sciences, The Chinese University of Hong Kong Kunihiko ishino Institute of Scientific and Industrial Research, Osaka University Golgins are a family of Golgi-localized long coiled-coil proteins. The major golgin function is thought to be the tethering of vesicles, membranes, and cytoskeletal elements to the Golgi. We previously showed that knockdown of one of the longest golgins, Giantin, altered the glycosylation patterns of cell surfaces and the kinetics of cargo transport, suggesting that Giantin maintains correct glycosylation through slowing down transport within the Golgi. Giantin knockdown also altered the sizes and numbers of mini Golgi stacks generated by microtubule de-polymerization, suggesting that it maintains the independence of individual Golgi stacks. Therefore, it is presumed that Golgi stacks lose their independence following Giantin knockdown, allowing easier and possibly increased transport among stacks and abnormal glycosylation. To gain structural insights into the independence of Golgi stacks, we herein performed electron tomography and 3D modeling of Golgi stacks in Giantin knockdown cells. Compared with control cells, Giantin-knockdown cells had fewer and smaller fenestrae within each cisterna. This was supported by data showing that the diffusion rate of Golgi membrane proteins is faster in Giantin-knockdown Golgi, indicating that Giantin knockdown structurally and functionally increases connectivity among Golgi cisternae and stacks. This increased connectivity suggests that contrary to the cis-golgin tether model, Giantin instead inhibits the tether and fusion of nearby Golgi cisternae and stacks, resulting in transport difficulties between stacks that may enable the correct glycosylation of proteins and lipids passing through the Golgi. No potential conflict of interest relevant to this article was reported.

Japanese Society of Plant Physiologists Acta Medica Okayama 0032-0781 57 8 2016 Involvement of OST1 Protein Kinase and PYR/PYL/RCAR Receptors in Methyl Jasmonate-Induced Stomatal Closure in Arabidopsis Guard Cells 1779 1990 EN Ye Yin Graduate School of Environmental and Life Science, Okayama University Yuji Adachi Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Izumi C. Mori Institute of Plant Science and Resources, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Methyl jasmonate (MeJA) induces stomatal closure. It has been shown that stomata of many ABA-insensitive mutants are also insensitive to MeJA, and a low amount of ABA is a prerequisite for the MeJA response. However, the molecular mechanisms of the interaction between ABA and MeJA signaling remain to be elucidated. Here we studied the interplay of signaling of the two hormones in guard cells using the quadruple ABA receptor mutant pyr1 pyl1 pyl2 pyl4 and ABA-activated protein kinase mutants ost1-2 and srk2e. In the quadruple mutant, MeJA-induced stomatal closure, H2O2 production, nitric oxide (NO) production, cytosolic alkalization and plasma membrane Ca(2+)-permeable current (ICa) activation were not impaired. At the same time, the inactivation of the inward-rectifying K(+) current was impaired. In contrast to the quadruple mutant, MeJA-induced stomatal closure, H2O2 production, NO production and cytosolic alkalization were impaired in ost1-2 and srk2e as well as in aba2-2, the ABA-deficient mutant. The activation of ICa was also impaired in srk2e. Collectively, these results indicated that OST1 was essential for MeJA-induced stomatal closure, while PYR1, PYL1, PYL2 and PYL4 ABA receptors were not sufficient factors. MeJA did not appear to activate OST1 kinase activity. This implies that OST1 mediates MeJA signaling through an undetectable level of activity or a non-enzymatic action. MeJA induced the expression of an ABA synthesis gene, NCED3, and increased ABA contents only modestly. Taken together with previous reports, this study suggests that MeJA signaling in guard cells is primed by ABA and is not brought about through the pathway mediated by PYR1, PYL1 PYL2 and PYL4. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2041-4889 5 2014 Nuclear factor-kappaB sensitizes to benzyl isothiocyanate-induced antiproliferation in p53-deficient colorectal cancer cells EN N Abe D-X Hou S Munemasa Y Murata Y Nakamura Benzyl isothiocyanate (BITC), a dietary isothiocyanate derived from cruciferous vegetables, inhibits the proliferation of colorectal cancer cells, most of which overexpress β-catenin as a result of mutations in the genes for adenomatous polyposis coli or mutations in β-catenin itself. Because nuclear factor-κB (NF-κB) is a plausible target of BITC signaling in inflammatory cell models, we hypothesized that it is also involved in BITC-inhibited proliferation of colorectal cancer cells. siRNA-mediated knockdown of the NF-κB p65 subunit significantly decreased the BITC sensitivity of human colorectal cancer HT-29 cells with mutated p53 tumor suppressor protein. Treating HT-29 cells with BITC induced the phosphorylation of IκB kinase, IκB-α and p65, the degradation of IκB-α, the translocation of p65 to the nucleus and the upregulation of NF-κB transcriptional activity. BITC also decreased β-catenin binding to a positive cis element of the cyclin D1 promoter and thus inhibited β-catenin-dependent cyclin D1 transcription, possibly through a direct interaction between p65 and β-catenin. siRNA-mediated knockdown of p65 confirmed that p65 negatively affects cyclin D1 expression. On the other hand, when human colorectal cancer HCT-116 cells with wild-type p53 were treated with BITC, translocation of p65 to the nucleus was inhibited rather than enhanced. p53 knockout increased the BITC sensitivity of HCT-116 cells in a p65-dependent manner, suggesting that p53 negatively regulates p65-dependent effects. Together, these results identify BITC as a novel type of antiproliferative agent that regulates the NF-κB pathway in p53-deficient colorectal cancer cells. No potential conflict of interest relevant to this article was reported.

岡山大学農学部 Acta Medica Okayama 0474-0254　 95 1 2006 イソチオシアネートによるがんの化学予防の可能性 87 91 EN Yoshimasa Nakamura A promising group of compounds that have a chemopreventive property are isothiocyanates (ITCs). ITCs have been shown to induce apoptosi in various cancer cell lines and experimental rodents. Multiple signaltransduction pathways as well as apoptosis intermediates have been also posturalted. We recently clarified the moleculae mechanism underlying the relationship between cell cycle arrest ad apoptosis induced by benzyl isothiocyanate(BITC), a major ITC compound isolated from papaya. The exposure of cells to BITC resulted in the inhibition of the G₂/M progression that coincided with not only hte up-regulated expression of the G₂/M cell cycle arrest-regulating genes but also the apoptosis induction. Conversely, treatment with an excessive concentration of BITC resulted in an abortive apoptotic pathway without DNA ladder formation. This commentary will review the biological impact of cell death induction by BITC as well as other ITCs and the involved signal transduction pathways. No potential conflict of interest relevant to this article was reported.