Evaluation of the Anti-Aging Properties of Ethanolic Extracts from Selected Plant Species and Propolis by Enzyme Inhibition Assays and 2D/3D Cell Culture Methods.

Background: Skin aging is a complex biological process affected by internal and external factors that disrupt the skin structure, especially in sun-exposed areas. Elastin and collagen in the dermis layer, responsible for the skin's resistance and elasticity, have been the main subject of research. Since tyrosinase (TYR) is an enzyme found in different organisms and plays an essential role in melanogenesis, inhibitors of this enzyme have been the target mechanism for skin-bleaching product research. Methods: We selected the plant species Cotinus coggygria Scop., Garcinia mangostana L., Pistacia vera L., Vitis vinifera L., and propolis, which exhibited activity against a minimum of three target enzymes-elastase, collagenase, and TYR-in our previous screening study to find the suitable raw material for a cosmetic product. In the current research, the extracts from these samples were tested through a cell-free enzyme assay using validated elastase, collagenase, and TYR inhibition kits. We also performed the safety and efficacy tests of the selected extracts with 2D/3D cell culture methods. Results: Our data revealed the propolis extract among the tested ones displayed remarkable anti-inflammatory activity in the 2D (NF-κB induction: 10.81%) and 3D assays. Cotinus coggygria leaf and Garcinia mangostana shell extracts exhibited anti-inflammatory activity in the 2D luciferase reporter assay via TNFα addition. C. coggygria leaf, V. vinifera (grape) seed, and propolis extracts were selected for testing in 3D cell culture methods based on the 2D cytotoxicity results with cell viability values of 54.75%, 93.19%, and 98.64% at 34.25 µg/mL, respectively. The general phytochemical profiles of these three extracts were examined in terms of 53 phenolic compounds with LC-MS/MS, revealing that quinic acid, epicatechin, and acacetin were the dominant phenolics among the tested ones. Conclusions: It is the first study conducted to evaluate the use of the extracts indicated above in cosmetics by employing procedures involving 3D cell culture.