Chemical Composition, Anti-Tyrosinase and Antioxidant Potential of Essential Oils from Acorus calamus (L.) and Juniperus communis (L.)

The essential oils (EOs) represent a natural source of diverse phytoconstituents that may exert a wide range of health-promoting effects, including antioxidative, anti-inflammatory, antimicrobial, and immunomodulatory activities. Compounds with antioxidative and anti-tyrosinase properties present in EOs may suppress excessive melanin production and protect skin cells from oxidative stress factors that often aggravate the pigmentation process. Acorus calamus L. and Juniperus communis L. plants have been traditionally used in phytotherapy, either individually or in combination. However, the biological and pharmacological effects of the essential oils derived from A. calamus rhizomes (EOA) and J. communis cone-berries (EOJ) remain underexplored. This study aimed to evaluate (1) the chemical composition of both EOA and EOJ using the gas chromatography–mass spectrometry (GC-MS) technique; (2) the anti-tyrosinase activity of the two examined EOs; and (3) their antioxidant potential against DPPH and ABTS free radicals. In addition, the anti-tyrosinase and antioxidant activities of mixtures of EOA and EOJ were also investigated. GC-MS analyses identified 48 and 81 chemical compounds in the EOA and EOJ, respectively. The main constituents of the EOA were sesquiterpenoids, including acorenone (18.1%), preisocalamendiol (12.0%), shyobunone (7.5%), and isoshyobunone (5.7%). In contrast, EOJ was primarily composed of α-pinene (22%), a monoterpene. In vitro analyses demonstrated that both individual and combined EOs exhibited notable antioxidant and anti-tyrosinase activities. The health-promoting potential of these EOs is discussed.