Oral administration of persimmon leaf extract ameliorates skin symptoms and transepidermal water loss in atopic dermatitis model mice, NC/Nga.

Summary Background We have previously shown that persimmon leaf extract and its major flavonoid constituent, astragalin, inhibited histamine release by basophils and that oral administration of these substances prior to the onset into an atopic dermatitis (AD) model mouse, NC/Nga, prevented development of dermatitis. Objectives This study was designed to assess the clinical therapeutic effect of persimmon leaf extract and astragalin in NC/Nga mice suffering from dermatitis and the dose–response preventive effects of persimmon leaf extract on dermatitis and transepidermal water loss (TEWL). Methods The efficacy of persimmon leaf extract or astragalin in NC/Nga mice was judged by measurement of skin severity, scratching behaviour, serum IgE levels or TEWL. Results Oral administration of persimmon leaf extract (250 mg kg-1 ) or astragalin (1·5 mg kg-1 ) for 4 weeks into NC/Nga mice with overt dermatitis resulted in a decrease in the severity of the condition. The preventive effect of persimmon leaf extract on the dermatitis was dose-dependent and continuous intake of persimmon leaf extract significantly decreased its onset and development. In addition, TEWL was also suppressed at a persimmon leaf extract dose of 250 mg kg-1 . No significant adverse reaction by these substances could be observed. Conclusions These observations suggest that persimmon leaf extract or the flavonoid astragalin may be alternative substances for the management of AD. [ABSTRACT FROM AUTHOR]