Mice drinking goji berry juice (Lycium barbarum) are protected from UV radiation-induced skin damage via antioxidant pathways

The goji berry, Lycium barbarum, has long been recognised in traditional Chinese medicine for various therapeutic properties based on its antioxidant and immune-modulating effects. This study describes the potential for orally consumed goji berry juice to alter the photodamage induced in the skin of mice by acute solar simulated UV (SSUV) irradiation. In Skh:hr-1 hairless mice, 5% goji berry juice significantly reduced the inflammatory oedema of the sunburn reaction. Dilutions of goji berry juice between 1% and 10% dose-dependently protected against SSUV-induced immunosuppression, and against suppression induced by the mediator, cis-urocanic acid, measured by the contact hypersensitivity reaction. The immune protection could not be ascribed to either the minor excipients in the goji juice, pear and apple juice, nor the vitamin C content, nor the preservative, and appeared to be a property of the goji berry itself. Antioxidant activity in the skin was demonstrated by the significant protection by 5% goji juice against lipid peroxidation induced by UVA radiation. Furthermore, two known inducible endogenous skin antioxidants, haem oxygenase-1 and metallothionein, were found to be involved in the photoimmune protection. The results suggest that consumption of this juice could provide additional photoprotection for susceptible humans.