New Sun Protection Strategies Needed
The damaging effects of UV light are well documented. But UV light only makes up approximately 8.3 % of solar light. Visible light (VIS) and infrared (IR) make up for the remaining 91.7 %. The blue light fraction makes up 30 % and occupies the highest energy portion of the visible spectrum. It penetrates deep into the skin where it can induce the following damages:
- Skin hyperpigmentation
- Premature skin-ageing (increased level of free radicals)
- Less collagen production (fibroblasts are damaged)
- Impaired skin barrier (keratinocytes are damaged)
Fibroblasts are the primary cell type of the dermis that maintain the extracellular matrix (ECM), produce collagen & elastin and provide skin structure. Keratinocytes are the major cell type of the epidermis which play an essential role in the protection of the skin. They form a tight barrier that minimizes the loss of moisture, heat and other constituents.
Study on the damage caused by UV-only and complete solar light
Hudson et al, measured the individual and combined effects of UV, VIS and IR on damage biomarkers in human skin cells in their study published in 2020. The three biomarkers of cellular damage were:
- Reactive oxygen species (ROS) generation
- Mitochondrial DNA (mtDNA) damage
- Nuclear DNA (nDNA) damage.
In the first experiment, the researchers irradiated keratinocytes and fibroblasts from donors with two hours of Mediterranean sun with UV-only light and complete solar light (UV + VIS + IR).
The keratinocytes had a similar significant ROS generation, mtDNA damage and nDNA damage for UV-only and UV + VIS + IR. However, the ROS generation, mtDNA damage and nDNA damage in fibroblasts were significantly greater for UV + VIS + IR than UV-only.
These findings show that the impact of visible and infrared light on the skin is far greater than previously assumed. When combined with UV the damage VIS and IR cause in fibroblasts is nearly double what is caused by UV alone. This calls for new sun protection strategies that go beyond actual UV protection. New formulations shall be developed to protect skin against UV light and against blue light.
Micro-alga against damage from blue light
Our partner DSM has been researching the adverse effects of visible, especially blue light on the skin. Their researchers identified the strategy of a micro-alga living in freshwater lakes against blue light-induced damage. Scenedesmus Rubescens produces carotenoids, a compound known to absorb blue light. DSM farms these carotenoids and produces PEPHA?-AGE CB – an aqueous extract of Scenedesmus Rubescens. PEPHA?-AGE CB is aimed at protecting the skin from the damage caused by blue light. DSM conducted different tests with Scendemus dry extract and Scendemus extract.
In-vivo results showed that Scendemus Rubescens:
- Reduces blue light-induced skin pigment darkening, dark spots and redness
- Restores an even skin tone
Ex-vivo results showed that Scendemus Rubescens:
- Stimulates collagen-3 synthesis which is known to decrease with ageing
- Prevents the formation of sunburn cells
- Protects against blue light-induced ROS and carbonylated proteins
In-vitro results showed that Scendemus Rubescens:
- Boosts and protects cell viability of fibroblasts
- Boosts total collagen content in fibroblasts
- Helps the cellular regeneration of fibroblasts
Hudson, L., Rashdan, E., Bonn, C.A., Chavan, B., Rawlings, D., Birch‐Machin, M.A. (2020). Individual and combined effects of the infrared, visible, and ultraviolet light components of solar radiation on damage biomarkers in human skin cells. The FASEB Journal, 34(3), 3874-3883. https://doi.org/10.1096/fj.201902351RR
Learn more about PEPHA?-AGE CB and its functionality here.
For the efficacy data on Scendemus Rubescens conducted by DSM please contact us: [email protected]