薬理と治療

Abstract

Objective Kale has been used as a health food and beverage. Cruciferous vegetables such as kale are known to decrese risk of cancer and glucosinolates were focused on effective components. The present study investigated the effects of kale containing glucoraphanin on subjects with skin dryness. Furthermore, it was evaluated whether glucoraphanin and metabolite （sulforaphane） enhance to produce collagen and hyaluronic acid in vitro. Methods In clinical study, randomized, double-blind, placebo-control, parallel-group study was conducted. 44 healthy Japanese female subjects aged 30-59 years were randomly assigned to kale group（kale containing 20 mg glucoraphanin）or placebo group. Skin moisture content, transepidermal water loss（TEWL）, color difference, visual judgment by medical specialist and visual analogue scale（VAS）were performed for evaluation of skin condition. In vitro study, collagen and hyaluronic acid were determined using ELISA in normal human dermal fibroblasts treated with glucoraphanin or sulforaphane. Results In clinical study, skin moisture content was significantly increased after 12 weeks only in kale group. Regarding with the visual judgment by medical specialist, dryness was significantly improved in kale group compared to that in placebo group. Also, VAS score showed greater improvement in kale group than placebo group. In addition, there were no adverse clinical events throughout the study period. In vitro study, glucoraphanin and sulforaphane significantly enhanced to produce collagen and hyaluronic acid. Conclusion These results suggest that daily intake of kale containing glucoraphanine could improve skin moisture content and awareness of skin condition. Furthermore, glucoraphanin and sulforaphane may be effective to recover dermal function.