Extract of Deschampsia antarctica (EDA) Prevents Dermal Cell Damage Induced by UV Radiation and 2,3,7,8-Tetrachlorodibenzo-p-dioxin.

Exposure to natural and artificial light and environmental pollutants are the main factors that challenge skin homeostasis, promoting aging or even different forms of skin cancer through a variety of mechanisms that include accumulation of reactive oxygen species (ROS), engagement of DNA damage responses, and extracellular matrix (ECM) remodeling upon release of metalloproteases (MMPs). Ultraviolet A radiation is the predominant component of sunlight causative of photoaging, while ultraviolet B light is considered a potentiator of photoaging. In addition, different chemicals contribute to skin aging upon penetration through skin barrier disruption or hair follicles, aryl hydrocarbon receptors (AhR) being a major effector mechanism through which toxicity is exerted. Deschampsia antarctica is a polyextremophile Gramineae capable of thriving under extreme environmental conditions. Its aqueous extract (EDA) exhibits anti- photoaging in human skin cells, such as inhibition of MMPs, directly associated with extrinsic aging. EDA prevents cellular damage, attenuating stress responses such as autophagy and reducing cellular death induced by UV. We demonstrate that EDA also protects from dioxin-induced nuclear translocation of AhR and increases the production of loricrin, a marker of homeostasis in differentiated keratinocytes. Thus, our observations suggest a potential use exploiting EDA's protective properties in skin health supplements.

Fernblock Prevents Dermal Cell Damage Induced by Visible and Infrared A Radiation.

Sun overexposure leads to higher risk of photoaging and skin cancer. The contribution of infrared (IR) and visible light (VIS) radiation is currently being taken into account in their pathogenesis. Erythema, hyperpigmentation, genotoxicity or the increase of matrix metalloproteinases (MMPs) expression are some of the effects induced by these types of radiation. Extracts of various botanicals endowed with antioxidant activity are emerging as new photoprotective compounds. A natural extract from Polypodium leucotomos (Fernblock®, FB) has antioxidant and photoprotective properties and exhibits a strong anti-aging effect. In this study, we evaluated the protective capacity of FB against the detrimental effects of infrared A (IRA) and VIS radiation in human dermal fibroblasts. We analyzed the effects of FB on the morphology, viability, cell cycle and expression of extracellular matrix components of fibroblasts subjected to VIS and IRA. Our results indicate that FB prevents cell damage caused by VIS and IRA. Moreover, it reduces the increase in MMP-1 and cathepsin K expression induced by both VIS and IRA radiation, and curbs alterations in fibrillin 1, fibrillin 2 and elastin expression. All these findings support FB as a feasible approach to prevent or treat skin damage caused by IRA or VIS exposure.

Photoactivation of ROS Production In Situ Transiently Activates Cell Proliferation in Mouse Skin and in the Hair Follicle Stem Cell Niche Promoting Hair Growth and Wound Healing.

The role of reactive oxygen species (ROS) in the regulation of hair follicle (HF) cycle and skin homeostasis is poorly characterized. ROS have been traditionally linked to human disease and aging, but recent findings suggest that they can also have beneficial physiological functions in vivo in mammals. To test this hypothesis, we transiently switched on in situ ROS production in mouse skin. This process activated cell proliferation in the tissue and, interestingly, in the bulge region of the HF, a major reservoir of epidermal stem cells, promoting hair growth, as well as stimulating tissue repair after severe burn injury. We further show that these effects were associated with a transient Src kinase phosphorylation at Tyr416 and with a strong transcriptional activation of the prolactin family 2 subfamily c of growth factors. Our results point to potentially relevant modes of skin homeostasis regulation and demonstrate that a local and transient ROS production can regulate stem cell and tissue function in the whole organism.