Essential Oil Composition, Cytotoxicity against Hepatocellular Carcinoma, and Macro and Micro-Morphological Fingerprint of Laurus nobilis Cultivated in Egypt

GC/MS analysis of hydro-distillated essential oil (1.9 % v/w) from fresh leaves of Laurus nobilis cultivated in Egypt revealed the presence of 81 components from which 59 compounds were identified, the identified compounds represent 96.3 % of the oil composition. The major constituents were 1,8-cineole (27.41%), linalool (19.37%), α-terpinyl acetate (14.65%), methyl eugenol (7.73%), α-terpineol, (2.84), terpinen-4-ol (2.09), elemicin (2.08) and sabinene (1.80%). Qualitative and quantitative identification of the essential oil constituents was based on comparison of retention indices (RIs) of standard n-alkanes (C8-C24) and mass spectra of the oil components with those reported in the literature. The essential oil exhibited potent cytotoxic activity against Hep-G2 (IC50= 1.83 µg/ml). The cytotoxic activity study was enriched using molecular docking analysis of the oil components against caspase3 (apoptotic enzyme). The docking reflected the ability of 32 compounds to interact with caspase3 at different sites and initiating its activity. Moreover, macro- and micromorphological studies of the plant’s leaves, petioles and stem in both entire and isolated elements forms were carried out. They reflected the presence of characteristic oil cells and fibers in the leaves, petioles and stems in addition to mucilage cells in the leaves and petioles, sclereids in the leaves and old stems and small trichomes on the young stem surface.