Oral administration of cysteine peptides attenuates UV-B-induced skin erythema and pigmentation in humans

The oral administration of antioxidants may suppress UV-B-induced skin damage. HITHION YH-15, the extract of Torula yeast ( Cyberlindnera jadinii ), is rich in cysteine-containing peptides such as reduced and oxidized glutathione (GSH and GSSG), γ-glutamylcysteine (γ-Glu-Cys), and cysteinylglycine (Cys-Gly). These four constituents are termed cysteine peptides. In this study, we investigated the protective effects of cysteine peptides against UV-B in a randomized, placebo-controlled, double-blind, parallel-group study. A total of 90 healthy males and females aged 30–59 years were enrolled and randomized into two groups of 45 individuals each (cysteine peptides (48 mg/day) and placebo). Changes in UV-B-induced erythema and pigmentation were compared between groups after 5 weeks of test food intake. The minimal erythema dose (MED) significantly increased (* p = 0.019) in the cysteine peptides group compared to that in the placebo group, indicating suppression of UV-B-induced erythema. ΔL* value significantly increased (*** p