The present work was performed to investigate the phenolic composition of P. lentiscus L. distilled leaves (PDL) and examine its potential against certain key enzymes related to skin aging. High-pressure liquid chromatography coupled to mass spectrometry (HPLC-MS) and various separation procedures combined with nuclear magnetic resonance (NMR) and MS analysis were performed to isolate and identify compounds present in the ethyl acetate extract (EAE) of PDL. A high amount of flavonol glycoside was detected in EAE. Indeed, quercetin-3-O-rhamnoside (FC), myricetin-3-O-rhamnoside (FM2), and kaempferol-3-O-rhamnoside (FB2) were isolated from EAE, and are present in high quantities of 10.47 ± 0.26, 12.17 ± 0.74, and 4.53 ± 0.59 mg/g dry weight, respectively. A transdermal diffusion study was carried out to determine the EAE-molecules that may transmit the cutaneous barrier and showed that FM2 transmits the membrane barrier with a high amount followed by FC. EAE, FM2, and FC were tested against tyrosinase and elastase enzymes. Moreover, intracellular tyrosinase inhibition and cytotoxicity on skin melanoma cells (B16) were evaluated. The results indicated that EAE, FC, and FM2 have important inhibitory activities compared to the well-known standards, at non-cytotoxic concentrations. Therefore, they could be excellent agents for treating skin pigmentation and elasticity problems.
Keywords: LC-MS; Pistacia lentiscus L. leaves; cytotoxicity; elastase inhibition; myricetin-3-O-rhamnoside; nuclear magnetic resonance; quercetin-3-O-rhamnoside; transdermal diffusion; tyrosinase inhibition.