Are FDA-Approved Sunscreen Components Effective in Preventing Solar UV-Induced Skin Cancer?

Abstract

Solar ultraviolet (SUV) exposure is a major risk factor in the etiology of cutaneous squamous cell carcinoma (cSCC). People commonly use sunscreens to prevent SUV-induced skin damage and cancer. Nonetheless, the prevalence of cSCC continues to increase every year, suggesting that commercially available sunscreens might not be used appropriately or are not completely effective. In the current study, a solar simulated light (SSL)-induced cSCC mouse model was used to investigate the efficacy of eight commonly used FDA-approved sunscreen components against skin carcinogenesis. First, we tested FDA-approved sunscreen components for their ability to block UVA or UVB irradiation by using VITRO-SKIN (a model that mimics human skin properties), and then the efficacy of FDA-approved sunscreen components was investigated in an SSL-induced cSCC mouse model. Our results identified which FDA-approved sunscreen components or combinations are effective in preventing cSCC development. Not surprisingly, the results indicated that sunscreen combinations that block both UVA and UVB significantly suppressed the formation of cutaneous papillomas and cSCC development and decreased the activation of oncoproteins and the expression of COX-2, keratin 17, and EGFR in SSL-exposed SKH-1 (Crl:SKH1-Hrhr) hairless mouse skin. Notably, several sunscreen components that were individually purported to block both UVA and UVB were ineffective alone. At least one component had toxic effects that led to a high mortality rate in mice exposed to SSL. Our findings provide new insights into the development of the best sunscreen to prevent chronic SUV-induced cSCC development.

Optical coherence tomography‐based non‐invasive evaluation of premalignant lesions in SKH‐1 mice

“…It is known that individuals who are often exposed to the sun, such as construction workers, farmers, sailors, and truck drivers, frequently suffer from severe effects of UVR over a lifetime 34, 35 . For these individuals, apart from taking other preventive measures, 36 regular monitoring of sun‐exposed skin by OCT could be meaningful and prevent the development of skin cancer, such as cSCC 37, 38 . Once the typical shape of the DEJ and a continuous increase in epidermal thickness are found, this may indicate that the skin is undergoing AK.…”

Ultraviolet Filters for Cosmetic Applications

“…The value of ε is 4300 mol −1 cm −1 [35]. It is approved by the FDA for a maximum concentration of 15% and is one of the most frequently used UVB filters in sunscreen products in the US [35,41]. In…”

“…The value of ε is 4300 mol −1 cm −1 [35]. It is approved by the FDA for a maximum concentration of 15% and is one of the most frequently used UVB filters in sunscreen products in the US [35,41]. In the EU, it is approved at a concentration up to 7.34% for face products, with the exception of propellant spray products [38].…”

“…The discussion of mineral filters is beyond the scope of this review, but it is important to highlight the main difference between these two main categories in order to better understand the advantages and the drawbacks of organic filters. Both zinc oxide and titanium dioxide are approved and widely used as active ingredients in sunscreen products [37,41]. Titanium dioxide is the most frequently used inorganic UV filter due to its photo-and chemical stability.…”

Peptide Cysteine Thiols Act as Photostabilizer of Avobenzone through Stabilizing the Transition State of Keto‐Enol Tautomerization

“…Upon photoexcitation, the enol form of avobenzone undergoes photoketonization followed by Norrish Type-I cleavage leading to the formation of carbon-centered radicals (4,(10)(11)(12)(13)(14)(15)(16). The feature of photoinstability of avobenzone is causing it to lose its significance as a protectant against skin cancer over the period of exposure to sunlight necessitating the addition of an external photostabilizer in the formulation (3,6,8,(17)(18)(19)(20). Various photostabilizers have been identified for avobenzone such as L-ascorbic acid (21), quercetin (22,23), ethylhexyl methoxycrylene (EHMCR) (24,25), bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinsorb S) (26)(27)(28), encapsulation b-cyclodextrin and micelles (29,30) including the glutathione peptide (31).…”