The harmful effects of UVB radiation on the skin are about 1000 times higher than of UVA radiation. Sunscreen-based cosmetics use UVB absorbers to improve their safety and function; with the most common being Ethylhexyl methoxycinnamate but it has low photo stability and it also impedes cell proliferation and DNA synthesis, which can fasten mutagenic activity. 

Thus UV absorbers that mimic the UV-absorption effect of ethylhexyl methoxycinnamate but without cell membrane-damaging and -inflammatory effects were explored in the present study.  

UV absorbers were applied prior to exposure to UV irradiation followed by determining IL-1α levels in the culture supernatant and IL-1α mRNA expression levels in a 3D human epidermis model.

Ethylhexyl methoxycinnamate increased IL-1α levels but not IL-1α mRNA expression in the culture medium after UV irradiation, suggesting its potential to damage the cell membrane.  

2-carboxyphenyl salicylate and tranexamic acid salicylate treatments decreased both IL-1α levels in the cell culture medium and IL-1α mRNA expression, regardless of UV irradiation. 

These results suggest that 2-carboxyphenyl salicylate and tranexamic acid salicylate inhibit IL-1α at the transcriptional level and both these compounds have anti-inflammatory effects in addition to UV absorption. 

SOURCE- Jiahao H, Kazuhisa M. Experimental Study of the Effect of UVB Absorbers and Salicylic Acid Derivatives on the Release and Production of Interleukin-1α After UV Irradiation. JOJ Dermatol & Cosmet. 2021; 4(3): 555636. DOI: 10.19080/JOJDC.2021.04.555636