Thin-layer chromatographic identification of flavonoids and phenolic acids contained in cosmetic raw materials

Abstract

ABSTRACTPolyphenols, widespread in the kingdom of plants, are targeted in numerous chemical, biochemical, and clinical studies. Flavonoids make a particularly interesting group of polyphenols due to their diverse biological activities. In both in vivo and in vitro studies, they strongly demonstrate antioxidant, anti-inflammatory, anticancer, and anti-aggregation activities, and they are also known for tightening the capillary blood vessels. Due to their remarkable biological activities, flavonoids find a wide spectrum of practical applications and the botanical materials rich in flavonoids are omnipresent in traditional medicines, phytotherapy, pharmacotherapy, and cosmetics. Particularly attractive biological properties and, hence, considerable valor of the cosmetics are attributed to such flavonoids, as rutin, quercetin, naringenin, catechin, catechin hydrate, and apigenin. In our study, we selected a simple and cost-friendly thin-layer chromatographic technique to identify the aforementioned flavonoids, and also caffeic, ferulic, gallic, and coumaric acids, in the commercially available cosmetic raw materials (such as extracts derived from red wine, grape skins, pomegranate peels and juice, green tea, etc.) Quercetin and rutin proved to be the two flavonoids most frequently encountered in the examined cosmetic raw materials. The results of such investigations provide the phenolics-oriented evaluation of the quality of the cosmetic raw materials and, hence, better judgment on the applicability thereof, e.g., as components of specific cosmetics prepared to treat various skin problems.