Abstract
The consumption of Citrus unshiu ( C. unshiu ) is decreasing in recent years and the C. unshiu farmers’ income is going down. The aim of this study is to boost the use of immature C. unshiu , which is currently discarded. This research focused on the effect of immature C. unshiu powder (ICP) on the photoaged skin. ICP was orally administered at dose of 200 mg/ kg body weight / day to six-week old male hairless mice for seven weeks. Through the whole experiment, UVB was irradiated at their dorsal skin three times a week. As UVB irradiation reduces skin moisture content and increases transepidermal water loss, these skin barrier disruptions are triggering wrinkle formation. Oral administration of ICP improved these symptoms. The histological analysis of hairless mice dorsal skin revealed that oral administration of ICP improved overgrowth of epidermal cell and decreased the number of dead cells. Hyaluronan content in the skin was analyzed with ELISA was increased in the ICP-treated mice. These findings suggest that ICP may have the anti- photoaging activity by restoring skin barrier function. These results showed that ICP has a potential to be used as a functional food.
