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.

Topical isoflavonoids reduce experimental cutaneous inflammation in mice.

The antioxidant and anti-proliferative biological effects of isoflavonoids are relevant properties to counteract the characteristics of many cutaneous diseases. This study uses ultraviolet (UV)B irradiation to induce inflammation in the mouse skin, as a model for some symptoms of cutaneous inflammatory and hyperproliferative diseases such as psoriasis in humans, with the objective of testing two topically applied isoflavonoid compounds for therapeutic properties. UVB exposure resulted in the overexpression of the cytokines, tumour necrosis factor (TNF)-α, interleukin (IL)-6 and the adhesion molecule P-cadherin. Infiltration into the dermal compartment of mast cell populations was also induced. These factors are also overexpressed in psoriatic skin. The effect of topical applications of two isoflavonoids, equol and a synthetic analogue NV-38, was tested. Both isoflavonoids dose dependently inhibited the UVB induction of cutaneous TNF-α mRNA and protein, a cytokine critical for the initiation of psoriatic inflammation. Expression of IL-6 mRNA and protein was also decreased, and the number of infiltrating mast cells into the dermis was reduced by both isoflavonoids. Furthermore, the upregulated mRNA and protein levels of P-cadherin, a marker characteristic of cutaneous hyperproliferation, were also normalized by both isoflavonoids. These results suggest that this class of compounds has the potential for useful, innocuous anti-inflammatory therapy from topical application in human cutaneous diseases.