- 著者
- Keiko Unno Hiroshi Yamada Kazuaki Iguchi Hitoshi Ishida Yasunori Iwao Akio Morita Yoriyuki Nakamura
- 出版者
- 公益社団法人日本薬学会
- 雑誌
- Biological and Pharmaceutical Bulletin (ISSN:09186158)
- 巻号頁・発行日
- vol.40, no.6, pp.902-909, 2017-06-01 (Released:2017-06-01)
- 参考文献数
- 38
- 被引用文献数
- 19
Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period. The participants ingested theanine (ca. 15 mg/d) in low-caffeine green tea. To assess the anxiety of participants, the state-trait anxiety inventory test was used before pharmacy practice. The subjective stress of students was significantly lower in the low-caffeine-group than in the placebo-group during pharmacy practice. The level of salivary α-amylase activity, a stress marker, increased significantly after daily pharmacy practice in the placebo-group but not in the low-caffeine-group. These results suggested that the ingestion of low-caffeine green tea suppressed the excessive stress response of students. This study was registered at the University Hospital Medical Information Network (ID No. UMIN14942).
- 著者
- Keiko Unno Shigenori Noda Yohei Kawasaki Hiroshi Yamada Akio Morita Kazuaki Iguchi Yoriyuki Nakamura
- 出版者
- SOCIETY FOR FREE RADICAL RESEARCH JAPAN
- 雑誌
- Journal of Clinical Biochemistry and Nutrition (ISSN:09120009)
- 巻号頁・発行日
- vol.61, no.3, pp.210-216, 2017 (Released:2017-11-01)
- 参考文献数
- 51
- 被引用文献数
- 26
Epidemiological and animal studies have demonstrated that ingestion of green tea enhances healthy life. However, caffeine in green tea can interfere with sleep. In this report, we examined the effect of green tea with lowered caffeine, low-caffeine green tea, on stress and sleep of the elderly. The participants (n = 10, mean age 89.3 ± 4.2 years) drank five cups/day of standard green tea for 1 week. Subsequently, they drank five cups/day of low-caffeine green tea for 2 weeks. Salivary α-amylase activity (sAA) was measured as a stress marker. Sleep stages were measured using a portable electroencephalography (n = 7, 6 female and 1 male). The level of sAA in the morning (sAAm) was significantly lower when the participants drank low-caffeine green tea than standard green tea. While the levels of sAAm were different among individuals, lower sAAm correlated with a higher quality of sleep. In those participants whose sAAm was lowered by the ingestion of low-caffeine green tea, some sleep parameters improved. Daily ingestion of low-caffeine green tea may be a beneficial tool for improving the quality of sleep of the elderly via the suppression of stress, although further research is required to fortify this hypothesis.
- 著者
- Keiichic Ohshima Sachiyo Takeda Mariko Hirose Yasuto Akiyama Kazuaki Iguchi Minoru Hoshino Ken Yamaguchi Tohru Mochizuki
- 出版者
- バイオメディカルリサーチプレス
- 雑誌
- Biomedical Research (ISSN:03886107)
- 巻号頁・発行日
- vol.33, no.3, pp.191-199, 2012 (Released:2012-07-05)
- 参考文献数
- 29
- 被引用文献数
- 1 6
Parathyroid hormone-related protein (PTHrP) contains a nuclear localization signal (NLS) sequence within 87-107. NLS sequences are generally capable of penetrating cellular membranes due to a richness of basic amino acid residues, and thus have been used as cell-penetrating peptides (CPPs) to translocate biologically active peptides/proteins into cells. The NLS sequence of PTHrP is not exception to this finding; however, PTHrP(87-107) contains 2 acidic glutamate residues at 99 and 101 within the basic amino acid stretch, which is not commonly observed in other CPPs such as HIV-1 Tat(48-60). In this study, we indicated structure-function relationship of the PTHrP NLS to understand the effect of acidic glutamate residues on cell permeability and intracellular localization. We chemically synthesized PTHrP(87-107) and its N-terminally truncated analogues. Their intracellular localization pattern was analyzed by microscopy, radioimmunoassay, and fluorescence-activated cell sorting. Although all analogues were translocated into cells, internalization by the cytoplasm and/or nucleus was length-dependent; specifically, PTHrP(97-107), PTHrP(95-107), and PTHrP(93-107) were more frequently localized in the cytoplasm. We assume that reduction in the net positive charge within PTHrP NLS analogues resulted in increased cytoplasm- translocation activity. We propose that PTHrP(97-107) is a useful carrier peptide for delivery and expression of cargo molecules in the cytoplasm.