Chemical Composition, Antimicrobial, Antioxidant activity, Tyrosinase Inhibition and Chelating Ability of the Leaf Essential Oil of Artemisia diffusa

The present study evaluates the chemical composition, antimicrobial and antioxidant activities of the leaf oil of Artemisia diffusa growing wild in Iran. As well as total phenolic content, ferrous-ion chelating, tyrosinase inhibition and radical scavenging activities of the leaf essential oil of A. diffusa were measured. Camphor (28.30 %), 1,8-cineole (21.03 %) and beta-thujone (14.20 %) were the major components in this oil. The largest part of the leaf oil of A. diffusa was formed by oxygenated monoterpenes (75.58 %). Kinetics of bacterial death indicated that Candida albicans is the most vulnerable with MIC of 5 mg/mL. The total phenol content of the oil of A. diffusa was estimated to be 194.87 +/- 7.64 mu g GAE/mg of the oil. The oil of A. diffusa exhibited a dose-dependent scavenging of DPPH, nitric oxide and superoxide anion radicals with IC50 values of 13.01 mg/mL, 14.35 mu g and 41.97 mu g, respectively. There was no correlation between ferrous ion chelating activity (IC50 = 833.13 mu g) and total phenolics implying that the oil contains no chelating ligands. Anti-tyrosinase activity of A. diffusa oil at 50 % concentration (IC50) was 6.08 mg. The essential oil of A. diffusa may be exploited as a natural source of bioactive phytochemicals bearing antimicrobial and antioxidant potentials.