Safer Sunscreens: Investigation of Naturally Derived UV Absorbers for Potential Use in Consumer Products

Abstract

Topical sunscreens are widely used to prevent sunburns and long-term skin damage including cancer. Recently, conventional chemical UV absorbers have been criticized and in some cases banned for adverse human and environmental health impacts. In this investigation, we evaluated naturally derived UV absorbers including vitamins, polyphenols, carotenoids, and amino acids to determine safety and efficacy profiles. Human and ecological hazards were evaluated, as well as the in vitro sun protection factor and critical wavelength. These attributes were compared to commercial UV absorbers such as octinoxate and oxybenzone to determine viability in personal care products. We found that resveratrol, ferulic acid, and ethyl ferulate demonstrate significant UV-absorbing capacity and lower hazard levels compared to current-use sunscreen active ingredients.

Polyphenolic sunscreens for photoprotection

“…2e). 28,96,106 All the above examples clearly describe the role and performance of small molecular polyphenols in sunscreens. However, small molecules usually possess inherent disadvantages including narrow wavelength absorption, long-term instability, and easy skin penetration, which may cause several side effects, such as low efficiency, allergies and toxicity of the corresponding sunscreen materials.…”

“…In detail, polyphenols have strong and broad spectral absorption across the UV regions due to the presence of phenol and ketone groups. 19,28,33 Moreover, their polyphenolic structures including catechol and pyrogallol units could introduce strong reactive oxygen species (ROS) scavenging abilities that possess considerable interest for sunscreen materials. This promising feature allows polyphenolic materials to effectively remove the excess free radicals from the skin, thus promoting the metabolism of the skin and providing all-around protection against UV irradiation.…”

“…Organic molecules such as octinoxate, avobenzone and oxybenzone are all commercial UV absorption agents in current sunscreens. 28 Due to their distinct absorbance ranges in the spectrum, the commercial sunscreens usually consist of two or more kinds of small organic molecules as the hybrid ingredients in order to completely cover the entire UVA and UVB regions. Therefore, it would be an effective and reasonable way to combine specific organic molecules and polyphenolic materials to construct the hybrid ingredients with excellent UV absorbance abilities across the full UV region via various covalent and noncovalent interactions for better sunscreen application (Fig.…”

“…Very recently, the effects of conventional sunscreen filters on the environment and human health have become a central topic in this area. 16,28,29 To address these issues, various strategies have been proposed to design new ingredients in sunscreen applications. For example, the usage of plant extracts inspired by nature as the alternative ingredients for sunscreens has become a promising solution to the quest, where polyphenolic materials are the most common components.…”

“…[60][61][62][63][64][65][66] Although those polyphenol-based sunscreens have been well documented, their narrow UV absorbance spectrum usually could not cover the entire range across the UVA and UVB region, thus resulting in limited sun protection factor (SPF) values. Meanwhile, these small molecules may suffer from the risks, such as instability and epidermis penetration, which would cause harmful effects, 28,67,68 such as allergies and irritation. 69 To address these critical issues, the macromolecular engineering strategies have been proposed to assemble those small molecular polyphenols into high molecular weight polyphenolic ingredients, such as polymers, coatings, capsules as well as nanoparticles.…”