Evaluation of the biological effect in dna damage repair of a high broad spectrum sunscreen containing nicotinamide and panthenol using 3d line-field optical coherence tomography

Nicotinamide is the precursor of NAD (nicotinamide adenine dinucleotide), an essential coenzyme in the production of ATP (adenosine triphosphate), the main source of cellular energy. Previous studies in mice showed that oral consumption or topical application of Nicotinamide prevents immunosuppression and reduces the number of tumors induced by UV radiation. In humans, topical application of 5% Nicotinamide prevents immunosuppression caused by solar UV radiation, but not from burns. Furthermore, oral Nicotinamide reduces the diagnosis rate of new non-melanoma skin cancers and actinic keratosis (AK) in high-risk patients. It has been suggested that one of the mechanisms by which Nicotinamide may protect against photodamage is by increasing ATP production which enhances DNA repair. Additionally, Nicotinamide acts as a PARP1 inhibitor. Extensive DNA damage leads to over-activation of PARP1 which can lead to NAD depletion. Thus, cells are unable to enter apoptosis, since the process requires a large amount of energy. Using a sunscreen with a high broad spectrum UVB-UVA and containing Nicotinamide and Panthenol, may allow to reverse chronic sun damage of the DNA of skin cells and therefore improve the morphological structure of the skin and keratinocyte nuclei.