BPB Reports

2023 - Vol. 6 No. 3

2023 - Vol. 6

Regular Article
Insulin Treatment Combined with Exercise Training Does Not Prevent the Exacerbation of 12-O-Tetradecanoylphorbol-13-Acetate-Induced Inflammation in Type 2 Diabetic db/db Mice Vol.6, No.3, p.115-121
Yoshinori Iba , Ryousuke Sugimoto , Kosuke Itoh , Mizuki Yamasaki , Shota En , Kiyokazu Ozaki , Tetsuro Matsuura
Received: March 23, 2023
Accepted: June 08, 2023
Released: June 21, 2023
Abstract Full Text PDF[1M]

We investigated whether 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear inflammation is exacerbated in type 2 diabetic db/db mice, and if it is prevented by the control of blood glucose levels. Ear inflammation was assessed by ear thickness and the mRNA expression of the pro-inflammatory cytokines IL-1beta, IL-6, and TNF-alpha. Six-week-old db/db mice received an insulin treatment combined with exercise training daily for three weeks to lower blood glucose to normal levels. The other db/db group and their control (db/m) mice received saline without exercise training. TPA-induced ear swelling peaked after 8 h in db/m mice and after 32 h in db/db mice. The gene expression levels of cytokines 24 and 32 h after the TPA treatment were higher in db/db mice than in db/m mice. The insulin treatment combined with exercise training significantly suppressed blood glucose and HbA1c levels in 9-week-old db/db mice, but did not prevent the TPA-induced inflammatory response. These results revealed that TPA-induced ear inflammation was exacerbated in db/db mice and was not prevented by the insulin treatment combined with exercise training.

Regular Article
Chloroform Fraction of Panax Ginseng Extract Enhances Zip4-Mediated Zinc Influx into the Cytosol Vol.6, No.3, p.108-114
Yoshito Ikeda , Mizuki Kawakami , Yasuyuki Yamada , Masayuki Munekane , Kohei Sano , Takahiro Mukai , Taiho Kambe , Nobukazu Shitan
Received: April 26, 2023
Accepted: June 05, 2023
Released: June 15, 2023
Abstract Full Text PDF[2M]

Zinc is an essential nutrient with important biological functions, and its deficiency can lead to several diseases. The zinc transporter families, ZIP and ZNT, play essential roles in regulating zinc homeostasis and dynamics in the body and cells. Specifically, ZIP4 is the primary zinc transporter responsible for zinc absorption in the small intestine. Previous studies have shown that Panax ginseng (P. ginseng) extract can promote mouse Zip4 expression, and ginsenosides, including Rc and Re, enhance zinc uptake. However, the effects of other metabolites present in P. ginseng extract remain unclear. Therefore, we fractionated P. ginseng extract using chloroform, ethyl acetate, and n-butyl alcohol, and evaluated the effect of each fraction on zinc uptake using mouse Hepa and Hepa/MRE-Luc cells that stably expressed luciferase under the promoter of metal-responsive elements. Luciferase activity assays demonstrated that the chloroform (F1), ethyl acetate (F2), and n-butyl alcohol (F3) fractions increased cellular zinc uptake. In particular, F1 fraction was found to induce Zip4 mRNA and protein expressions, which significantly enhanced zinc uptake. Ginsenosides were mainly present in the F2 and F3 fractions, indicating that metabolites other than ginsenosides in the F1 fraction would enhance zinc uptake by inducing Zip4 mRNA and protein expressions. Our study offers novel insights into the molecular mechanisms underlying zinc uptake by P. ginseng.

Cell Morphology-Based Screening Identified Vitetrifolin D from Vitex Rotundifolia as an Inhibitor of Phorbol Ester–Induced Downregulation of E-Cadherin in HHUA Endometrial Cells Vol.6, No.3, p.103-107
Yusuke Hanaki , Nichika Iwase , Yasunori Sugiyama , Sena Miyoshi , Ryo C. Yanagita
Received: April 28, 2023
Accepted: June 02, 2023
Released: June 13, 2023
Abstract Full Text PDF[1M]

The epithelial–mesenchymal transition (EMT) of endometrial cells contributes to the development of endometrial cancer, endometriosis, and adenomyosis. We have recently reported that 12-O-Tetradecanoylphorbol 13-acetate (TPA), a protein kinase C activator, induces EMT in HHUA endometrial cells cultured on collagen type I gels. HHUA cells showed an obvious morphological change from spheroids to scattered spindle cells during the TPA-induced EMT. In this study, we searched for inhibitors of the TPA-induced morphological change, and isolated vitetrifolin D from Vitex rotundifolia leaves. Vitetrifolin D suppressed the TPA-induced downregulation of E-cadherin, a major component of the epithelial adherens junction. Since vitetrifolin D showed a modest cytotoxicity at the concentration required to inhibit E-cadherin downregulation, it would not be suitable as a drug to treat endometrial disorders. However, our cell morphology-based screening could contribute to the discovery of new compounds that inhibit the loss of epithelial cell junctions.

Report (Case Report)
Warfarin Drug-Drug Interactions with Amiodarone and Tramadol in a Patient with Paroxysmal Atrial Fibrillation: A Case Report Vol.6, No.3, p.98-102
Marina Higa , Eisuke Katsuren , Jose Carlos S. Tayag , Masashi Iwabuchi , Yusuke Ohya , Hideo Shiohira , Katsunori Nakamura
Received: March 14, 2023
Accepted: May 08, 2023
Released: May 26, 2023
Abstract Full Text PDF[868K]

Amiodarone and tramadol are known to have drug-drug interactions that potentiate the effects of the anticoagulant warfarin. Herein we report a case which suggests increasing prothrombin time-international normalized ratio (PT-INR) and PT-INR/dose ratio due to the concomitant administration of warfarin, amiodarone (a cytochrome P450 2C9 inhibitor) and tramadol (an enhancer of anticoagulant effects of warfarin). A 72-year-old woman underwent emergency surgery following a suspected non-obstructive mesenteric ischemia, and diagnosis was confirmed. After surgery, the patient was given 2 mg/day of WF, and tramadol/acetaminophen, followed by amiodarone. After the concomitant dose of the triple combination, the PT-INR increased to over 7.02 (above the upper limit of the laboratory). The physician consulted the pharmacist for dose adjustment, and the pharmacist recommended a reduction in the dose to 0.5 mg. After restarting warfarin, PT-INR was controlled to 1.66–2.02. However, the PT-INR/dose ratio increased from 1.22 to 3.32–4.04 compared to the initial dose. The results suggest that these enhanced anticoagulant effects may be due to the inhibition of WF metabolism. Although the patient underwent resection of the small intestine, the effects of oral vitamin K1 were observed one day after administration. In conclusion, frequent PT-INR monitoring, and pharmacist intervention such as the assessment and dose adjustment in this report should be beneficial during anticoagulation therapy when multiple concomitant medications with suspected drug-drug interactions are present.

Regular Article
Blueberry Stem Extract Suppresses Blue Light-Emitting Diode Light-Induced Endoplasmic Reticulum Stress on Retinal Photoreceptor Cells Vol.6, No.3, p.87-97
Kenjirou Ogawa , Takara Karitani , Wataru Otsu , Kazuo Nishiyama , Hisato Kunitake , Yo Goto , Shota Nomiyama , Hideaki Hara , Masao Yamasaki
Received: March 16, 2023
Accepted: April 20, 2023
Released: May 26, 2023
Abstract Full Text PDF[4M]

Background: Blue light causes retinal photoreceptor damage via oxidative and endoplasmic reticulum (ER) stress. A previous study showed that blueberry stem extract (BStEx) and its active components have cytoprotective effects against blue-light-induced photoreceptor cell damage by suppressing oxidative stress. This study demonstrated the inhibitory effect of BStEx against blue light-induced ER stress in photoreceptor cells. Methods: The photoreceptor cells treated with BStEx or the antioxidant N-Acetyl-L-cysteine (NAC) as a positive control were used and then exposed to blue light. The cytoprotective effects of BStEx and NAC were evaluated using CCK-8. The ER stress-related protein expression changes over time, and its levels were measured after each exposure time to blue light in photoreceptor cells treated with BStEx or NAC. Results: BStEx and NAC showed protective effects against blue-light-induced photoreceptor morphological abnormalities and cell damage. Although blue light triggered ER stress factors such as BiP, PERK, ATF6, eIF2α, ATF4, and CHOP, which in turn stimulated cell cycle arrest factors p53 and p21 and upregulation of apoptosis-inducing factors caspase-3. However, BStEx suppressed the increase in expression of BiP, ATF4, ATF6, CHOP, p53, p21, and caspase-3, but not mitochondrial apoptotic factors Bax and cytochrome c. Furthermore, the antioxidant NAC showed similar suppressive effects on BStEx. Conclusion: Our findings suggest that blue light-induced ER stress is primarily caused by oxidative stress, and BStEx might suppress ER stress via an antioxidant effect. The antioxidant NAC contributes to the cell proliferative capacity and suppression of apoptosis in photoreceptor cells.

Regular Article
Bactericidal Effect of 405-nm LED Light against Aggregatibacter Actinomycetemcomitans Is Due Primarily to Disruption of Respiratory Chain Terminal Members Cytochrome bd Oxidase and Quinol Peroxidase Vol.6, No.3, p.81-86
Tomoyuki Nakada , Kiyoshi Konishi
Received: March 19, 2023
Accepted: April 27, 2023
Released: May 12, 2023
Abstract Full Text PDF[1M]

Irradiation with 405-nm visible violet LED light without additional photosensitizers decreased the viability of the aggressive periodontopathic bacterium Aggregatibacter actinomycetemcomitans. The number of CFU/mL decreased linearly on a logarithm chart versus irradiation time, with a 1-log reduction time of 1.32 min. The antimicrobial photodynamic effect of 405-nm LED light involved inhibition of the activity of membrane-bound cytochrome bd, a terminal quinone: oxygen oxidoreductase, and quinol peroxidase, a terminal quinone:H2O2 oxidoreductase. The 405-nm LED irradiation reduced minus oxidized difference spectrum showed that the 640-nm peak (α-peak of heme d) completely disappeared, and the height of the 556-nm (α-peak of hemes b and c) and Soret band (425 nm; γ-peak of hemes b, c, and d) was reduced to approximately half of the peak heights of non-irradiated controls. Survival of bacteria-injected silkworm larvae was also examined. Fifth-instar silkworm larvae were almost completely killed by approximately 40 h after bacterial injection, but almost all silkworm larvae irradiated with 405-nm LED light (20 mW/cm2 for 5 min, energy density: 6 J/cm2) survived, similar to controls not injected with bacteria, indicating that 405-nm LED light killed the injected bacteria. The bactericidal effect of 405-nm blue-light on A. actinomycetemcomitans is primarily due to disruption of cytochrome bd oxidase and quinol peroxidase of the respiratory chain.

Regular Article
Development of a Standard Test Method for Insecticides in Indoor Air by GC-MS with Solid-Phase Adsorption/Solvent Extraction
[Notice] An Corrigendum to this article was published on 31 October 2023
Vol.6, No.3, p.76-80
Taichi Yoshitomi , Iwaki Nishi , Aya Onuki , Tokuko Tsunoda , Masahiro Chiba , Shiori Oizumi , Reiko Tanaka , Saori Muraki , Naohiro Oshima , Hitoshi Uemura , Maiko Tahara , Shinobu Sakai
Received: November 16, 2022
Accepted: April 22, 2023
Released: May 12, 2023
Abstract Full Text PDF[1M]

Semi-volatile organic compounds (SVOCs), which can cause indoor air pollution, include plasticizers, insecticides, and flame retardants. In Japan, the Ministry of Health, Labour and Welfare has set guidelines for indoor air concentrations of di-n-butyl phthalate and di-2-ethylhexyl phthalate in plasticizers and fenobucarb, diazinon, and chlorpyrifos in insecticides. However, this analytical method has only been tentatively proposed for more than 20 years. In this study, we attempted to construct an analytical method for insecticides for which guideline values have been established based on recently standardized sampling and extraction methods for phthalates in indoor air. The results of the recovery tests for the insecticides were excellent, with recovery rates and relative standard deviations in the ranges 88%–104% and 1.4%–7.5%, respectively. Furthermore, the limits of detection and quantification were less than 1/50 of the current guideline values. Additionally, inter-laboratory validation was conducted at five research institutions. By excluding outliers with the Grubbs test, the accuracies were in the ranges of 81.9%–126.3%, 76.8%–121.7%, and 76.7%–112.8% for chlorpyrifos, diazinon, and fenobucarb, respectively. The target ranges for repeatability (RSDr) and reproducibility (RSDR) were 30% and 35%, respectively, and the validation results met these criteria. Based on these results, we propose the developed method as the standard test method for insecticide-originated pollutants in indoor air in Japan.