Comparative study of the chemical composition and bioactivities of essential oils of fresh and dry seeds from Myoporum insulare R. Br.

Essential oils of fresh and dry fruits from Myoporum insulare R. Br. were analyzed by GC and GC-MS. A total of twenty eight components were identified in essential oil of fresh fruits with γ-irone (14.4%), bicyclogermacrene (13.9%) and α-cadinol (13.2%) as main constituents. Twenty seven compounds were characterized in the oil of dry seeds with elemicin (20.1%), spathulenol (16.8%), α-cadinol (16.8%) and T-cadinol (14.2%) as main compounds. The present study was undertaken to evaluate the antioxidant, antibacterial, anti-tyrosinase and cytotoxic activities of essential oils of fresh and dry fruits from M. insulare. Dry seeds oil exhibited the highest activity of DPPH (IC50 = 54.0 ± 1.3 μg/mL), ABTS (IC50 = 68.0 ± 2.0 μg/mL), catalase (504.0.28 ± 0.655 u/mg protein) and paraoxonase (77.51 ± 0.47 μM/min/L). It's also exerted the best cytotoxic effect against A549 cell line and an interesting anti-tyrosinase activity with 81% of inhibition at 100 μg/mL. Essential oil of fresh fruits exhibited the highest antibacterial and antifungal activities against all tested organisms and fungi with IZ values 15.5-25.0 mm and 16-24.5 mm, respectively.