Drug Discoveries & Therapeutics
Online ISSN : 1881-784X
Print ISSN : 1881-7831
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Review
  • Chan Hum Park, Jae Sue Choi, Takako Yokozawa
    2018 Volume 12 Issue 3 Pages 114-121
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    Panax ginseng C.A. Meyer (Araliaceae), mainly cultivated in Korea and Northeast China, is processed before use based on its long history of ethnopharmacological evidence. Ginsenosides have been regarded as the main active components responsible for the pharmacological activities of ginseng. Although the Maillard reaction is known as a major source of compounds related to enhanced antioxidant activity by heat treatment in various crude drugs or foods, the chemical and free radical-scavenging activity changes of ginsenosides brought about by the Maillard reaction have not yet been elucidated. This paper gives a review of our recent findings, with emphasis on the hydroxyl radical (•OH)-scavenging activity changes of ginsengs and ginsenosides by heat-processing using an electron spin resonance spectrometer. 20(S)- Rg3 showed the strongest activity, and the next was in the decreasing order of Rb1, Rg1, Rc, Rb2, and Rd. The •OH-scavenging activities of ginsenosides were related to the ferrous metal ion-chelating activities of their aglycone, 20(S)-protopanaxadiol. In addition, the ferrous metal ion-chelating activities of ginsenosides were thought to be influenced by their types of hydrophilic sugar moieties. Moreover, Rb1 was changed into 20(S)-Rg3, 20(R)-Rg3, Rk1, and Rg5 by heat-processing, and the sugar moieties at carbon-20 were separated. The generated amount of 20(S)-Rg3 was higher than when Rb1 was heat-processed without amino acids, and a significant increase in Maillard reaction products was noted. Based upon chemical and •OH-scavenging activity tests using Maillard reaction model experiments, the scientific evidence underlying the increase in free radical-scavenging activity of ginseng induced by heat-processing was elucidated.

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Original Articles
  • Masaki Ishii, Yasuhiko Matsumoto, Kazuhisa Sekimizu
    2018 Volume 12 Issue 3 Pages 122-125
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    Cyclodextrins (CyDs) are cyclic oligosaccharides consisting of six to eight glucose residues. Administration of α-CyD (six glucose residues) inhibits sucrose-induced hyperglycemia in humans. Here we show that oral administration of α-CyD and dimethyl α-CyD suppresses sucrose-induced hyperglycemia in an in vivo evaluation system using silkworms. On the other hand, β-CyD (seven glucose residues), γ-CyD (eight glucose residues), and their derivatives did not show the suppressive effect. These findings suggest that dimethyl α-CyD is a new inhibitor against sucrose-induced hyperglycemia and the silkworm system is useful for evaluation of suppressive activities of α-CyD derivatives against postprandial hyperglycemia.

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  • Adchareeya Kaewpinta, Sakornrat Khongkhunthian, Pisaisit Chaijareenont ...
    2018 Volume 12 Issue 3 Pages 126-132
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    Carbamide peroxide (CP) is commonly used as a tooth whitening agent. However, efficacy of CP can be enhanced if it is in the suitable delivery system. In the present study, CP loaded in pigmented rice gels were developed and investigated for their physicochemical properties and tooth whitening efficacy. The modified pigmented rice of two varieties, Homnil (HN) and Doisket (DS) were prepared and used as a gelling agent. The outer appearance of the obtained rice gels containing 10% CP (CP-HN and CP-DS, respectively) were transparent and homogeneous texture. The pH of both rice gel bases was neutral but became slightly acidic after incorporating with CP. The adhesive property of HN gel was significantly higher than DS gels. In vitro drug release profile exhibited that the release of CP from CP-DS was significantly higher than CP-HN and the commercial gel (CP-CG), respectively. In vitro tooth whitening efficacy in 45 normal teeth revealed that the tooth whitening efficacy of the gels was time dependent. At the end of the treatment, CP-HN showed significantly higher tooth whitening efficacy than CP-DS and CP-CG, respectively. It is concluded that the physicochemical properties, particularly the adhesive and dissolution properties, play an important role in the tooth whitening efficacy of the CP gels.

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  • Pimpak Phumat, Sakornrat Khongkhunthian, Phenphichar Wanachantararak, ...
    2018 Volume 12 Issue 3 Pages 133-141
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    The overgrowth of certain strains of normal flora in oral cavity can cause many kinds of oral infections or diseases such as carries, periodontitis, and gingivitis. Prevention and treatment of these diseases are usually achieved by chemical antiseptics. However, these chemicals are found as negative impacts of human health hazards and accession of microbial resistance. The present study explores the potential of Piper betle extracts on inhibition of two oral pathogenic bacteria; Streptococcus mutans DMST 41283 and Streptococcus intermedius DMST 42700. P. betle demonstrated significantly higher inhibitory activity against both pathogenic strains than Acacia catechu, Camellia sinensis, Coccinia grandis, Solanum indicum, and Streblus asper. Among fractionated extracts of P. betle from several solvents, the extract from ethyl acetate (Pb-EtOAc) possessed the widest inhibition zone of 11.0 ± 0.1 and 11.3 ± 0.4 mm against both bacterial strains, respectively. Pb-EtOAc showed the same minimum inhibitory concentration of 0.5 mg/mL against both strains, whereas its minimum bactericidal concentrations were 2.0 and 0.5 mg/mL against S. mutans and S. intermedius, respectively. HPLC analysis demonstrated that the major active compound of Pb-EtOAc was 4-allylpyrocatechol. It was found that the killing kinetics of Pb-EtOAc against both test strains were time and dose dependent. Scanning electron microscopy micrographs showed the morphological changes and depletion of the tested pathogens indicating cell destruction after exposure to Pb-EtOAc. It is confirmed that Pb-EtOAc is potentially effective against both oral pathogens and might be used as natural alternative agents in prevention and treatment of oral infections caused by oral pathogenic bacteria.

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  • Yeonoh Shin, Rutika Kokate, Vilas Desai, Alok Bhushan, Gagan Kaushal
    2018 Volume 12 Issue 3 Pages 142-153
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    D-cycloserine (DCS), a partial agonist at N-methyl-D-aspartate (NMDA) receptors, is used as an enhancer of exposure therapy for anxiety disorders. The purpose of the present study was to investigate the feasibility of using polymeric gels to increase the viscosity of the formulation and thereby increase the nasal residence time and sustained release of DCS in vitro. Hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose (HPC), and methyl cellulose (MC) were prepared at concentrations of 0.5 to 5% w/v. Pluronic F-127 (PF-127) was prepared at concentrations of 15 to 35% w/v. pH, viscosity and in vitro DCS release behavior of the formulated gels were analyzed. All four gels that were tested, demonstrated sustained DCS release behavior over a 24-hour period, but with different rates. Based on the results of this study, HPMC, HPC, MC, and PF-127 are capable of increasing the viscosity of nasal gel formulations and of releasing DCS in sustained manner. Therefore, these polymeric gels can be suitable carriers for DCS nasal gel formulation.

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  • Yohei Ono, Hiroto Takamatsu, Masahiro Inoue, Yukio Mabuchi, Tetsuya Ue ...
    2018 Volume 12 Issue 3 Pages 154-160
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    The effectiveness of long-term administration of tolvaptan in heart failure (HF) patients with chronic kidney disease (CKD) has not been fully studied. Hence, in this study, we investigated the effects of chronic administration of tolvaptan on patients with HF and CKD. We consecutively enrolled 31 patients with acute HF syndrome (AHFS) who were administrated tolvaptan as a long-term medication (TLV group). All patients had a history of prior HF admission and CKD. We also consecutively enrolled 27 patients with AHFS, a prior history of HF and CKD (conventional group). We compared renal function and outcomes between the two groups at discharge for AHFS and after 6 months of follow-up. The estimate glomerular filtration rate (eGFR) was maintained at approximately the same level in the TLV group exhibited approximately the same eGFR (–1.1 ± 8.3 mL/min/1.73 m2) but decreased in the conventional group (–7.4 ± 10.4 mL/min/1.73 m2). There was a significant difference in the changes observed in eGFR between the conventional and TLV groups (p = 0.01). There were no significant differences in the frequencies of rehospitalization and death. Long-term administration of tolvaptan may prevent increased renal dysfunction in HF patients with CKD. This conclusion should be confirmed in a large-scale prospective study.

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  • Yongcheng Ni, Chunlong Mu, Xiangyu He, Kaiming Zheng, Hongmin Guo, Wei ...
    2018 Volume 12 Issue 3 Pages 161-169
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    Alterations in gut microbiota have been known to play a critical role in metabolic syndrome. However, the microbial features in elderly patients with metabolic syndrome remain unclear. A traditional Chinese Herbal Formula, Yangyin Tiluo Decoction (YTD), can alleviate metabolic syndrome and cardiovascular disease. To characterize gut microbiota in elder patients and effects of YTD on gut microbiota during treatment of metabolic syndrome, 11 healthy elderly persons and 12 elderly persons (aged 60-90 years) with metabolic syndrome were enrolled. The patients were randomly assigned to receive YTD for 4 weeks (200 mL of the decoction two times daily). The microbial composition in healthy control, pre- and post- YTD treatment group were analyzed by 16S rRNA sequencing of fecal DNAs. Biochemical measurements were conducted for elderly patients. The results showed a high inter-individual variation of gut microbiota in elderly persons. The gut microbiota was dominated by phylum Firmicutes and Actinobacteria, which was distinct from the previously defined microbiota in Irish elderly persons. The elderly patients with metabolic syndrome had higher proportions of Lactobacillus and Bifidobacterium, and lower proportions of Anaerostipes, Coprococcus, Ruminococcus than healthy controls. YTD treatment reduced the abundance of genus Bacteroidales Incertae Sedis and species Enterobacteriaceae Incertae Sedis. The concentration of plasma lipoprotein (a) was also reduced, which was negatively correlated with the abundance of an Acinetobacter species. These results reveal a remarkable dominance of Firmicutes and Actinobacteria, and highlight the distinct gut microbiota in elderly patients with metabolic syndrome, which may be involved in pathogenesis. Furthermore, the benefits of YTD treatment were observed, providing an approach to improve metabolic syndrome in elderly patients.

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  • Ryoko Murayama, Toshiaki Takahashi, Hidenori Tanabe, Koichi Yabunaka, ...
    2018 Volume 12 Issue 3 Pages 170-177
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    The risk of peripheral intravenous catheter failure varies according to the insertion site. This study examined catheter shape just after removal to evaluate the causes of catheter failure according to site. This study was a secondary analysis of previous study data. Our observational study was conducted during a 6-month period at The University of Tokyo Hospital. Participants were hospitalized adults who received infusion therapy via a short peripheral catheter. We acquired ultrasound images of blood vessels and surrounding tissues at the catheter insertion site before catheter removal and clinical images of the removed catheters. We analyzed 184 catheters from 142 participants. There were no significant differences in the catheter failure rate (29.9%) among insertion sites. Curvature in the middle of the catheter was present in 9.2% of cases; the median bend angle at the catheter base was 9.1° (range: 0.0°-68.3°). The bend angle of catheters inserted in the upper arm was significantly greater than of catheters in the forearm (p = 0.013). Catheter curvature was related to catheter failure (14.8% of failed catheters had curvature; p = 0.035) and occlusion (35.3% of occluded catheters had curvature; p = 0.008) in upper arm and forearm placements. The median distance from the elbow to the insertion site was shorter for failed catheters than for surviving catheters. To prevent catheter failure, especially occlusion resulting from catheter curvature, a catheter should be inserted at an appropriate insertion site far from the antecubital fossa.

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Brief Reports
  • Kohei Mitsunami, Miwa Nakai
    2018 Volume 12 Issue 3 Pages 178-181
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    This paper proposes a new product development of yogurt project based on industry academia collaboration between Teikyo University and Tohoku Kyodo Milk Industry and discusses the possible economic impact of this project on the Tohoku region as well as the Tama area in Tokyo. We also introduce a preliminary survey to partially clarify the consumption patterns for yogurt among students at Teikyo University. The survey reveals that most of our respondents consume yogurt regularly. The stated reason for yogurt consumption is to enjoy yogurt as a dessert rather than as a health food. We also find that the most significant determinant factors for purchasing yogurt are taste, price, and quantity. Based on the data, respondents are willing to pay between 100 JPY and 145 JPY for yogurt. In response to these findings, we discuss some additional surveys that need to be conducted in the future.

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  • Yasushi Ohkusa, Tamie Sugawara, Hirokazu Kawanohara, Miwako Kamei
    2018 Volume 12 Issue 3 Pages 182-184
    Published: June 30, 2018
    Released: July 10, 2018
    JOURNALS FREE ACCESS

    Antimicrobial resistance (AMR) has garnered the most attention among public health concerns worldwide. Japan formulated a national action plan for AMR in April 2016. The plan seeks to reduce the amount of antimicrobials used in 2020 to two-thirds of the use recorded in 2013. Prescription surveillance (PS) is being used to monitor trends in the amount of antimicrobials used. PS estimates the number of patients prescribed an antimicrobial each day. The number of patients who were prescribed an antimicrobial under the action plan was analyzed by including dummy variables with other control variables. Data from April 1, 2011 to 30 September 30, 2017 were analyzed. When the number of patients with an infectious disease (1 of 13 specified diseases) served as a dummy variable, estimates indicated that the coefficient of that dummy variable was not significant. If the number of patients with an infectious disease (1 of 13 specified diseases) was excluded as an explanatory variable, then the estimated coefficient was significant. The global action plan in Japan might not reduce the amount of antimicrobials used. The current results indicated that the number of patients who were prescribed an antimicrobial did not decrease significantly after initiation of the action plan. This finding does not exclude the possibility that the average amount of antimicrobials used per patient has decreased.

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