Publications by authors named "Shimoi K"

Purple yam (Dioscorea alata L.) is a tuber widely distributed in the tropics and subtropics. We previously isolated several acylated anthocyanins from purple yam.

View Article and Find Full Text PDF
Article Synopsis
  • Social stress in adult mice increased blood corticosterone levels after 2 days, disrupted liver metabolism pathways at 30 days, and raised the risk of becoming overweight at 90 days.
  • A study on male BALB/c mice revealed that younger mice (2 months old) had elevated corticosterone after 2 days of stress, but levels returned to normal afterward, while older mice (14 and 26 months) showed a decrease in liver gene expression related to stress response.
  • The findings suggest that as mice age, their liver's response to stress becomes less effective, highlighting the impact of aging on health and stress reactions.
View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to create a new method for assessing sperm quality by measuring mitochondrial oxygen metabolism in human sperm.
  • Using normozoospermic samples, researchers optimized parameters for an extracellular flux analyzer to track oxygen consumption rates at different storage temperatures.
  • Findings showed that while sperm motility decreased at lower temperatures (4°C) compared to 37°C, overall sperm vitality and oxygen consumption remained similar, indicating that OCR could be a reliable metric for sperm quality evaluation.
View Article and Find Full Text PDF

Epidemiological studies have indicated that a disturbed circadian rhythm resulting from night-shift work is a potential risk factor for breast cancer. However, the mechanism of increased risk of breast cancer by night-shift work remains unclear, and there have been few in vivo studies conducted to definitively associate the two factors. In this study, BJMC3879Luc2 mouse breast cancer cells were transplanted into BALB/c mice.

View Article and Find Full Text PDF

Omega (ω) 3 fatty acid (FA) is a polyunsaturated FA (PUFA) that can modulate some mental statuses. However, most studies have not considered the functional differences between eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We investigated associations among happiness, a sense of fulfillment and serum ω3 PUFA levels.

View Article and Find Full Text PDF

Polyphenols, a category of plant compounds that contain multiple phenol structural units, are widely distributed throughout the plant kingdom and have multiple benefits for human health including anti-obesity, anti-hyperglycemic, and anti-hyperlipidemic effects. Additionally, polyphenols have recently gained attention for their anti-stress effects. In this review article, we summarize physiological responses against exposure to stressors and discuss biomarkers for exposure to stressors that are widely used in animal studies and human trials.

View Article and Find Full Text PDF

In order to estimate the potential risk of chemicals including drug in patients with type 2 diabetes mellitus (T2DM), we investigated allyl alcohol induced liver injury using SD rats and Spontaneously Diabetic Torii-Lepr (SDT fatty) rats as a model for human T2DM. The diabetic state is one of the risk factors for chemically induced liver injury because of lower levels of glutathione for detoxification by conjugation with chemicals and environmental pollutants and their reactive metabolites. Allyl alcohol is metabolized to a highly reactive unsaturated aldehyde, acrolein, which is detoxified by conjugation with glutathione.

View Article and Find Full Text PDF

Previously, we reported that the frequency of micronucleated reticulocytes (MNRETs) in the peripheral blood of male C3H/He mice intraperitoneally administered ethylnitrosourea (ENU) (25 mg/kg body weight) in the dark period (zeitgeber time, ZT15) was higher than in the light period (ZT3). In this study, to clarify the mechanism underlying this phenomenon, we investigated the differences in micronucleus (MN) induction observed between ZT3 and ZT15 using five chemicals, methylnitrosourea (MNU), ethylmethane sulfonate (EMS), mitomycin C, cyclophosphamide and vincristin. MNU and EMS, monofunctional alkylating agents, showed higher frequencies of MNRETs in the ZT15 than the ZT3 treatment similar to ENU.

View Article and Find Full Text PDF

Background: Chronic low-grade inflammation and oxidative stress are commonly observed in persons with depression or depressive symptoms. We explored the degree of depressive symptoms under psychological stress in relation to serum LDL oxidation, inflammatory markers, and fatty acid (FA) distribution among female population. The purpose of this study was to identify peripheral factors that are related to depressive symptoms, and to assess how each factor is related to depressive symptoms.

View Article and Find Full Text PDF

Group-housed male mice exhibit aggressive behaviour towards their cage mates and form a social hierarchy. Here, we describe how social hierarchy in standard group-housed conditions affects behaviour and gene expression in male mice. Four male C57BL/6 mice were kept in each cage used in the study, and the social hierarchy was determined from observation of video recordings of aggressive behaviour.

View Article and Find Full Text PDF

Breast cancer is one of the most commonly diagnosed female cancers and a leading cause of cancer-related death in women. Multiple factors are responsible for breast cancer and heritable factors have received much attention. DNA damage in breast cancer is induced by prolonged exposure to estrogens, such as 17β-estradiol, daily social/psychological stressors, and environmental chemicals such as polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs).

View Article and Find Full Text PDF

In March, 2011, large amounts of radioactive materials were released from the Fukushima Daiichi nuclear power plant after the nuclear accident. Especially, for humans, internal exposure to ¹³⁷Cs and ⁹⁰Sr radionuclides presents very high risks because of their very long physical half-lives (¹³⁷Cs: 30.2 years, ⁹⁰Sr: 28.

View Article and Find Full Text PDF

Recent evidence points to a possible role for hypoxia-inducible factor (HIF)-1 in the pathogenesis and development of endometriosis. The objectives of this study were to investigate the critical role of HIF-1 in endometriosis and the effect of the HIF-1 inhibitor echinomycin on human ectopic endometriotic stromal cells (eESCs). Ectopic endometriotic tissues were obtained from 20 patients, who received an operation for ovarian endometriomas.

View Article and Find Full Text PDF

To elucidate the bioavailability of luteolin and its glycosides in Chrysanthemum morifolium flowers, the absorption and metabolism of luteolin from them was investigated in rats and Caco-2 cells using HPLC and LC-MS. After oral administration of C. morifolium extract (1.

View Article and Find Full Text PDF

Practical application of flavonoid-poor menus was evaluated on the bioavailability of anthocyanins as model flavonoids. Detectable amounts of flavonoids were not found in plasma and urine collected from 13 participants, who took the menus. After ingesting bilberry anthocyanins (919 μmol), average plasma AUC0-6h, Cmax, Tmax values and urinary recovery were 386.

View Article and Find Full Text PDF

Background: The activity of creatine kinase (CK) in serum has recently been reported to be potentially associated with several types of depression. The aim of this study is to evaluate whether serum enzymes, including CK, vary even in a healthy population with depressive symptoms caused by work-related stress. We gave questionnaires and blood examinations to 93 healthy female nursing home workers and did an enzyme-linked immunosorbent assay for the quantitative detection of CK isozyme muscle-type M chain (CK-MM) in serum.

View Article and Find Full Text PDF

Recent studies have suggested the possibility that nocturnal light exposure affects many biological processes in rodents, especially the circadian rhythm, an endogenous oscillation of approximately 24 h. However, there is still insufficient information about the physiological effects of nocturnal light exposure. In this study, we examined the changes in gene expression and serum levels of plasminogen activator inhibitor-1 (PAI-1), a major component of the fibrinolytic system that shows typical circadian rhythmicity, in C3H/He mice.

View Article and Find Full Text PDF

The in vitro potential of sensitizers and related compounds (SRCs) originating from impurities in waste paper in activating the human aryl hydrocarbon receptor (AhR) α was assessed using yeast reporter gene as well as cytochrome P450 (CYP)1A1 and ethoxyresorufin O-deethylase (EROD) assays. In the yeast assay, eight compounds exhibited agonist activity, and their activity relative to β-naphthoflavone (BNF) ranged from 1.4 × 10(-4) to 8.

View Article and Find Full Text PDF

Endogenous catecholamines such as adrenaline (A) and noradrenaline (NA) are released from the adrenal gland and sympathetic nervous system during exposure to stress. The adrenergic system plays a central role in stress signaling, and excessive stress was found to be associated with increased production of reactive oxygen species (ROS). Overproduction of ROS induces oxidative damage in tissues and causes the development of diseases such as cancer.

View Article and Find Full Text PDF

Risk factors for breast cancer include estrogens such as 17β-estradiol (E2) and high stress levels. 4-Hydroxyestradiol (4-OHE2), a metabolite of E2 formed preferentially by cytochrome P450 1B1, is oxidized to E2-3,4-quinone, which reacts with DNA to form depurinating adducts that exert genotoxicity and carcinogenicity. Endogenous catecholamines such as adrenaline (A) and noradrenaline (NA) are released from the adrenal gland and sympathetic nervous system during exposure to stress.

View Article and Find Full Text PDF

In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects.

View Article and Find Full Text PDF

Endogenous estrogens, such as 17β-estradiol (E2), are implicated in the development of breast cancer. The putative mechanisms by which estrogens exert the carcinogenic effects have been recognized to involve the redox cycling of estrogen metabolites and subsequent estrogen-DNA adduct formation as well as the estrogen receptor-dependent pathway of estrogen-induced cell growth. The former pathway is regulated by phase I enzymes, mainly cytochrome P450 (CYP) 1A1, 1A2, and 1B1.

View Article and Find Full Text PDF

We previously reported that 14-day exposure to 7-chlorinated benz[a]anthracene (7-Cl-BaA), a new environmental pollutant, selectively induced hepatic cytochrome P450 (CYP)1A2 in rats, although treatment with its parent, benz[a]anthracene (BaA), induced CYP1A1, CYP1A2, and CYP1B1. In this study, to better understand the relative contribution of chlorination to the toxicity of polycyclic aromatic hydrocarbons (PAHs), we investigated the organ-specific distributions of 7-Cl-BaA and BaA in F334 rats. After 14 days of oral administration of 7-Cl-BaA or BaA at a concentration of 1 or 10 mg/kg body weight/day, both chemicals were detected in their plasma, which was collected 24 hr after the last administration, even at the lower dosage.

View Article and Find Full Text PDF

Objective: To investigate whether hypoxia or the female sex steroids exert direct effects on angiopoietin-1 (ANGPT1), ANGPT2, and vascular endothelial growth factor (VEGF) in human endometrial stromal cells (ESCs) to clarify the regulatory function of these local angiogenic factors in the endometrium.

Study Design: Human endometrial tissues were obtained from 18 patients aged 34-47 years undergoing hysterectomy for benign reasons. ESCs were cultured under hypoxic condition or treated with 17β-estradiol (E) and/or medroxyprogesterone acetate (MPA).

View Article and Find Full Text PDF