LAUSR

Abstract Plants have been a very rich resource for the development of potentially new drug candidates and also the development of cosmetic products for skincare. The skin produces free radicals or reactive oxygen species through repeated exposure to the sun and these molecules cause oxidative stress and inflammatory reactions in the dermal and epidermal layers of the skin. Matrix metalloproteinases are triggered by aging and in inflamed skin, such as photo-aged skin, skin damage, and wrinkles occurred by collapsing dermal proteins such as collagen and elastin. In the development of plant-based skin whitening products, the first target is to investigate the inhibitors of the tyrosinase enzyme, which provides melanin production. The ethanol extracts of 92 herbal extracts and propolis were tested for their elastase, collagenase, and tyrosinase inhibitory effects using ELISA microtiter assays. Their antioxidant effect was determined using DPPH, DMPD, and NO radical scavenging activity, metal-chelation capacity, FRAP, PRAP, and CUPRAC assays. Total phenolic and flavonoid contents of the extracts were also determined spectrophotometrically. Our results from the screening studies showed that the ethanol extracts prepared from the aerial parts of Lamium purpureum subsp. purpureum, the pericarpium of Garcinia mangostana and Pistacia vera, the flowers of Punica granatum, and the seeds of Vitis vinifera were effective against at least two of these enzymes and therefore, the plant species were selected for further studies.