Comparison of the photoprotective effect between hydrolyzed and aglycones flavonoids as sunscreen: A systematic review

ABSTRACT

Currently, there is growing evidence of the role of polyphenols as protection agents against ultraviolet radiation(UVR), both in plant and animal cells, especially flavonoids, which are considered beneficial compounds that increasephotoprotection of sunscreen formulations. The objective of this systematic review is to analyze if there is an increase inphotoprotection of the hydrolyzed forms of polyphenols, specifically of flavonoids, such as quercetin and kaempferol,with respect to their corresponding glycosides, which are present in polar extracts of aerial parts of plants. Followingthe PRISMA guidelines, the systematic review was carried out in three electronic databases (Science Direct, Pubmed,and Embase) to identify the main articles that evaluated the effect of polyphenols against UVR protection. From atotal of 1,230 research articles found, 21 met the inclusion parameters, of which 13 studies evaluated extracts isolatedfrom different plants, and one study evaluated an agroindustrial residue. In all the cases, the main constituents werecharacterized as flavonoid compounds, including some of the compounds of interest of this revision. The effect ofthe pure compounds rutin and quercetin, as photoprotection enhancers, was evaluated in seven articles. Although aconclusive answer to the objective question of this systematic review could not be obtained, all the studies confirmedthe biological activity of the polyphenols as photoprotector.