ABSTRACT: Yokukansan (YKS) has been used in Japan as a remedy for neurosis, insomnia, and children with night crying. In a previous study, we reported that YKS controls scratching behavior and inhibits the development of atopic dermatitis (AD)-like lesions in NC/Nga mice. In this study, we investigated the effects of YKS on the development of AD-like lesions in socially isolated NC/Nga mice compared with the effects of fexofenadine and elucidated the mechanism of the ameliorating effect of YKS on the skin lesions. Ten-week-old male NC/Nga mice were divided into three groups (n = 5/group): the conventional control, the YKS-treated, and the fexofenadine-treated groups, and were kept isolated under conventional conditions for 6 weeks. Measurements were made of dermatitis scores and transepidermal water loss (TEWL), scratching and grooming behaviors. Immunohistochemistry and mRNA levels were also evaluated. We performed similar experiments under specific pathogen free (SPF) conditions that served as a SPF control. YKS and fexofenadine inhibited the aggravation of skin lesions and decreased TEWL, but only YKS decreased the numbers of scratching and pathologic grooming behaviors. Immunohistochemistry and RT-PCR revealed that N-methyl-D: -aspartate (NMDA) receptor expression was increased in the skin of conventional control mice and was decreased in YKS-treated mice. Glutamate transporter-1 (GLT-1) mRNA levels were decreased in the skin of conventional control mice and were increased in YKS-treated mice. The results indicate that YKS ameliorates AD-like skin lesions in NC/Nga mice through a mechanism distinct from that of fexofenadine. Furthermore, the effects of YKS are suggested to be mediated via glutamate signaling in the skin lesions.
Archives for Dermatological Research 03/2011; 303(9):659-67. · 2.28 Impact Factor
ABSTRACT: Increasing evidence suggests that stress can trigger and exacerbate atopic dermatitis (AD). Psychotherapy is becoming more important in the treatment of AD patients. Yokukansan (YKS, Yi-Gan San in Chinese), a traditional Japanese medicine, has been widely utilized in the treatment of neurosis, insomnia and anxiety especially in Asian countries. Furthermore, it was reported that YKS inhibited skin lesions in socially isolated mice but not in group-housed mice. Therefore, in the present study it was investigated whether or not YKS was effective in the treatment of AD using socially isolated NC/Nga mice.
The present study was designed to assess the effect of YKS on the development of AD-like lesions in socially isolated NC/Nga mice to obtain information about its usefulness in the treatment of AD.
Ten-week-old male NC/Nga mice were socially isolated under conventional conditions. YKS was administered orally to mice at the dose of 0.5% or 1.0% together with diet. The efficacy of YKS was evaluated by assessing skin lesion severity, scratching behaviors, skin hydration, and infiltration of inflammatory cells in the skin. Grooming behaviors evoked by social isolation stress and serum corticosterone levels were also measured.
Oral administration of YKS to socially isolated NC/Nga mice resulted in the inhibition of exacerbation of AD-like skin lesions. It seemed that the inhibition of exacerbation of AD-like skin lesions observed in NC/Nga mice might be due to suppression of the scratching and grooming behaviors, inhibition of the infiltration of mast cells and eosinophils, and retention of humidity in the skin. Serum corticosterone levels were also significantly inhibited in the 1%-YKS-treated mice as compared with those of the control mice. There were no significant differences in the levels of serum total IgE and nerve growth factor (NGF) between the YKS-treated mice and the non-treated control mice.
YKS inhibited the development of AD-like skin lesions in socially isolated NC/Nga mice by suppressing scratching and infiltration of inflammatory cells in the skin. These results indicate that YKS possesses an anti-itching property, and its anti-itching may be partly through attenuation on social isolation stress. It is expected that YKS might provide an effective alternative therapy for AD in human patients.
Journal of dermatological science 08/2009; 56(1):37-42. · 3.71 Impact Factor
Archives of dermatology 06/2009; 145(5):609-10. · 4.76 Impact Factor