Expression of precipitating factors of pruritus found in humans in an imiquimod-induced psoriasis mouse model.

AIMS: To use a mouse model of imiquimod-induced psoriasis to investigate the relationship between pruritus and mast cells, nerve growth factor (NGF) and endogenous pruritogenic peptides, which are highly expressed in the skin of psoriasis patients. MAIN METHODS: We developed a mouse model of imiquimod-induced psoriasis and measured the frequency and duration of the model animals' self-scratching behavior using the SCLABA®-Real real-time scratch counting system. We then harvested the ears and subjected them to toluidine blue staining and real-time PCR. KEY FINDINGS: Topical application of imiquimod increased the Psoriasis Area and Severity Index score as well as the frequency and duration of self-scratching. Regarding internal factors, increases in mast cells number and mRNA expression of NGF and endogenous pruritogenic peptide precursor were confirmed. SIGNIFICANCE: Self-scratching behavior is accompanied by increased number of mast cells and expression of NGF and endogenous pruritogenic peptides in our imiquimod-induced psoriasis model. The expression of these factors was consistent with the features in patients with pruritic psoriasis, suggesting that our model reflects at least some of the precipitating factors of pruritus found in humans.

A survey on awareness of the "finger-tip unit" and medication guidance for the use of topical steroids among community pharmacists.

Atopic dermatitis (AD) is a common chronic, pruritic inflammatory skin condition. AD is most commonly treated with topical corticosteroids, and the finger-tip unit (FTU) should be used as a guideline for the amount to be used per application. In this study, we investigated the adequacy of pharmacists' instructions on the amount of topical steroids to be applied and the way in which they enhance the effect of pharmaceutical interventions. A self- administered anonymous questionnaire was distributed using QLifePro to 300 pharmacists working in insurance pharmacies that filled at least one dermatologist's prescription per month on average in Japan. Out of 300 pharmacists, 196 (65.3%) recognized the Japanese Dermatological Association's 2016 guidelines for the treatment AD, 107 (35.6%) gave instructions using the FTU as an index of external dose of topical steroids, 157 (52.3%) explained the amount of steroid application using an index other than FTU, and 61 (38.9% of 157) had inadequately instructed AD patients to apply steroids as a thin layer. Pharmacists who had read the guidelines for AD tended to give an appropriate instruction using FTU as an index of external dose of topical steroids (p < 0.001). We found that many pharmacists in pharmacies gave inadequate instructions on the amount of topical steroid application and deviated from the guidelines for AD, mainly because of inadequate knowledge of the guidelines.

Protective effect of young green barley leaf (Hordeum vulgare L.) on restraint stress-induced decrease in hippocampal brain-derived neurotrophic factor in mice.

BACKGROUND: Many health experts support the hypothesis that stressful lifestyles are the leading cause of illness, like depression. Therefore, from the standpoint of preventive medicine, it is important to reduce stress. Young green barley leaves are a good natural source of vitamins and minerals, and their juice is widely consumed as a functional food for health reasons in Japan. This study investigated the protective effect of young green barley leaves for stress control. MATERIALS AND METHODS: ICR outbred mice were exposed to 3-h sessions of restraint stress. Young green barley leaves (400 and 1,000 mg/kg) were administered orally 1 h before the sessions for 5 days. To analyze voluntary behavior, wheel-running activity was monitored during the dark period. Brain-derived neurotrophic factor (BDNF) messenger RNA (mRNA) expression in the whole hippocampus was measured by real-time quantitative polymerase chain reaction. RESULTS: Restraint stress resulted in a significant decrease in voluntary wheel-running behavior, but this decrease was ameliorated by the administration of young green barley leaves. The leaves also enhanced the decreased levels of BDNF mRNA induced by restraint stress; in particular, a significant protective effect was shown in the exon IV variant as compared to vehicle control mice. CONCLUSION: The findings suggest that young green barley leaves have potent anti-stress properties, as evidenced by preventing decreases in the levels of voluntary wheel-running activity and hippocampal BDNF mRNA in response to restraint stress. Our findings support the possibility that supplementation with young green barley leaves might be beneficial for preventing stress-related psychiatric disorders like depression.

Sex differences in stress reactivity of hippocampal BDNF in mice are associated with the female preponderance of decreased locomotor activity in response to restraint stress.

The incidence and prevalence of depression is higher in women than in men, but the cause of this sex discrepancy remains unknown. Brain-derived neurotrophic factor (BDNF) is a key protein for maintaining neuronal integrity. The purpose of this study was to investigate the female preponderance in behavioral responsivity to restraint stress focusing on the stress reactivity of BDNF in the hippocampus. Male and female ICR mice were exposed to a 3-h session of restraint stress. Plasma corticosterone was measured by high-performance liquid chromatography. BDNF mRNA expression in the whole hippocampus was measured by quantitative real-time reverse transcription-polymerase chain reaction. Wheel-running activity was monitored during the dark period. In response to restraint stress, the increase in levels of serum corticosterone was higher in female than in male mice. Restraint stress resulted in decreased voluntary wheel-running behavior that was greater in female than male animals. In addition to these sex differences in stress reactivity, we found a significant sex difference in BDNF levels in the hippocampus of restraint-stressed mice; total BDNF levels significantly decreased in female mice, but not in male mice in response to the stress. Furthermore, BDNF exon I and IV mRNA expression also showed the same tendency. These data indicate that the reduction in levels of voluntary wheel-running activity in response to stress can be significantly influenced by sex. Moreover, our findings suggest a link between the sex differences in this behavioral response to stress and differential stress reactivity in the production of BDNF in the hippocampus.