Last year, the Clinics of Dermatology journal acknowledged the growing trend in CBD skincare products, underlining there is still insufficient data on its efficiency and safety. This was followed by an interesting study published by the MDPI last August.
A group of scientists from the University of Bialystock and the University of Aveiro published a study on the differences in the proteome profile of cannabidiol-treated skin fibroblasts following UVA or UVB irradiation in 2D and 3D cell cultures.
The dangers of UV radiation are already well known to the general public. It penetrates the skin and affects fibroblast metabolism through induction of oxidative stress. Oxidative stress-induced cell damage is involved in the pathogenesis of skin diseases, skin disorder, and skin aging. The UV radiation is one of the most common factors leading to this damaging of human skin cells, which is why we are witnessing a constant effort in developing novel cytoprotective solutions.
The scientists who conducted this study have found it extremely important to establish an experimental model as close as possible to physiological conditions. Since it has been previously found that cells in 3D culture differ in proteomic profile from 2D cultured cells, this study examined changes in the proteomic profile of 2D cultured skin fibroblasts and compared these changes to what was observed in the 3D system.
The results showed significant differences in the level of protein-lipid peroxidation products adduct formation in cells treated with CBD, compared with non-treated cells. In all cases, the level of adducts following UV radiation was higher in 2D than in 3D cultured fibroblasts. The CBD treatment resulted in a decrease in the level of 4-HNE and MDA–protein adducts in UVB irradiated cells by approximately 40%, regardless of the used culture model. In the case of UVA irradiation, the CBD treatment decreased the level of 4-HNE and MDA—protein adducts by 15–65%. The strongest CBD effect was observed in the level of acrolein-protein adducts in 2D cultured fibroblasts following UVA and UVB radiation. In this portion of the study, CBD treatment led to a decrease of around 80% compared to irradiated cells. (Acrolein decreases the water-holding capacity of the outer layer of the skin.)
Furthermore, the study confirmed that CBD prevents collagen degradation. Collagen remodeling in skin fibroblasts plays a crucial role in organizing tissue structures that are essential to motility during wound repair, development, and regulation of cell growth. Therefore, the CBD-induced stimulation of the enzymes involved in collagen cross-linking, including lysyl hydroxylase, prevents collagen degradation following UV radiation.
CDB also protects structural proteins against UV-induced decreases in their expression and affects other signaling pathways connected with kinase activity. The most visible changes in the protein level are observed in the case of FAK (focal adhesion kinase), AKT (serine/threonine-specific protein kinase), and PI3K (phosphoinositide 3-kinase), where CBD strongly increases expression. This further protects cells against harmful UV effects. The PI3K/AKT pathway plays a predominant role in cell proliferation, survival, and progression. It is known that both AKT and PI3K have several active binding sites specific for CBD.
The data from this research showed enhanced levels of these kinases, suggesting that CBD may stimulate protein synthesis or prevent degradation. Recent publications have shown that CBD-kinase adducts formation significantly stimulates the activity of AKT and PI3K in mice spinal cord cells or human ligament stem cells, but inhibits these molecules in breast cancer cells. In the case of kinase FAK, this study observed an increased expression by CBD. Other researchers have shown that in CBD treated cancer cells, such as glioma cells, the activity of this kinase is significantly decreased, providing evidence that this compound might be useful in anti-cancer therapy.
This study has shown the capacity of CBD to function as a cytoprotective agent against UV-induced changes in both 2D and 3D cultured fibroblasts. Overall, 2D cultured cells showed a greater number of differentially expressed proteins, but there were significant differences in the molecular functions of the altered proteins. CBD-treated 2D cultured cells exposed to UV-radiation exhibited a more marked effect on the levels of proteins involved with antioxidant response and inflammation. On the other hand, 3D-cultured fibroblasts showed a higher response to CBD action against UV induced changes, which were based on the activation of signaling pathways.
This improved understanding of CBD action in a multilayer skin cell model subjected to UV irradiation has provided new insight into the nature of fibroblast cell-cell interaction, as well as on the alteration of skin cell metabolism. Knowledge about the lower protective effect of CBD in 3D cultured fibroblasts should be taken into account during the design of UV light protection.
These findings are likely to give an additional boost to CBD sunscreen product developments. The interest in CBD skincare products is already growing at a significant rate. According to a report by Grand View Research Inc., the global CBD skincare market is expected to grow at a CAGR of 32,9% from 2019 to 2025, reaching a value of 1.7 billion USD by 2025.
In this light, we look forward to the new research at the scientific level, and more data on the exact effect of CBD and other cannabinoids on human cells.