Abstract
Tyrosinase plays a crucial role in the melanin biosynthesis. Abnormalities in pigment synthesis and accumulation are associated with numerous skin diseases. Moreover, since tyrosinase is the main factor for browning of fruits and vegetables, its uncontrolled activity also resulted in serious problems in the food and agriculture industries. Given the importance of tyrosinase inhibition in various fields, identifying safe natural inhibitors is of growing interest in different industries, including agriculture, food, pesticides, pharmaceuticals, and cosmetics. This study investigated tyrosinase inhibitory, antibrowning, antibacterial, and some other biologically important properties of the essential oil isolated from the leaf materials of Juniperus excelsa subsp. polycarpos, known as Persian juniper, was used for the first time. The maximum tyrosinase inhibitory effect was ∼55%, and kinetic measurements showed a mixed type of inhibition. While fluorescence quenching data revealed decreased intrinsic fluorescence intensity of the enzyme in the presence of increasing amounts of essential oil, molecular docking studies also predicted that the most abundant active compounds bind to the critical binding sites of the enzyme. The J. excelsa essential oil also exhibited an efficient antibrowning effect on the tested vegetables and fruits, and it seems that it can decrease tyrosinase-induced hyperpigmentation-related problems in the food and agriculture industries. It exhibited good antioxidant and antibacterial activities and did not show hemolytic activity against human red blood cells in the tested range. These findings suggested that J. excelsa essential oil can be considered as a suitable candidate for further investigations on tyrosinase inhibition and antibrowning studies.