In vitro tyrosinase inhibitory and antioxidant potential of Consolida orientalis, Onosma isauricum and Spartium junceum from Turkey

Traditionally used botanical remedies have attracted much interest as pharmacological targets in the management and/or treatment of several diseases. Recently, they have been probed as tyrosinase inhibitors for the management of epidermal hyperpigmentation. This study aims to investigate into the antioxidant and tyrosinase inhibitory potential of methanol, ethyl acetate, and water extracts of three medicinal plants (Consolida orientalis (J. Gay) Schrödinger, Onosma isauricum Boiss. & Heldr. and Spartium junceum L.), from Turkey. Methanolic extract of O. isauricum and S. junceum showed the highest phenolic (63.08 mgGAE/g extract) and flavonoid contents (45.55 mgRE/g extract). Additionally, O. isauricum methanolic extract exhibited the most powerful antioxidant capacity followed by methanolic extract of S. junceum (86.02 and 62.81 mgAAE/g extract, respectively). S. junceum extracts yielded the higher kojic acid equivalent values (21.42–23.04 mgKAE/g extract), confirming that these extracts were the most potent inhibitors of tyrosinase. S. junceum showed promising activity that warrant further studies and could be considered as a potent candidate for the development of phytoremedies for the management of epidermal hyperpigmentation. To the best of our knowledge, this study can be considered as the first report of on the antioxidant and tyrosinase inhibitory action of C. orientalis, O. isauricum, and S. junceum from Turkey.