Thymus vulgaris, (Lamiaceae), essential oils composition and yield, were found to be greatly influenced by water stress and growth enhancers. Therefore, three controlled cultivation conditions were applied to achieve the highest essential oil productivity of T. vulgaris. The essential oils obtained by hydro-distillation of the aerial parts were analyzed using (GC-MS). The tested plant subjected to drought showed a 66% increase in the essential oil yield, while those subjected to drought stress and foliar spray showed 57.1% increase and the regularly irrigated group with foliar spraying showed 23.8% increase relative to the control group. The cytotoxic activity of T. vulgaris essential oils was evaluated against lung (A-549), colon (HCT-116), intestinal (CACO) and breast (MCF-7) carcinoma using the cell viability assay. The lowest IC values 0.44 and 0.33 μg/mL were seen against (HCT-116) and (CACO) cells respectively. These IC values were lower than that of doxorubicin used as reference drug.

Objectives: Essential oils (EOs) are valuable natural products whose composition pattern, concentration of individual components and yield depend on many intrinsic and extrinsic factors. This study aimed to evaluate the impact of foliar spray of ethephon, water stress, organic and inorganic fertilizers on the EOs composition of Foeniculum vulgare, Miller, var. Dulce roots. Methods: Automated rapid headspace solid phase micro extraction (SPME) was applied for the extraction of volatile components combined with gas chromatography coupled to mass spectrometry GC/MS for identification of the volatile compounds. Results: forty two volatile components were identified in Foeniculum vulgare, Miller, var. Dulce roots which were dominated by hydrocarbons (55.36%-87.2%) with monoterpenes being the major class of components (53.15%-87.08%) in the six various applied conditions. Dehydro-p-cymene represented the major constituent (55.8%) in the oil of the non-treated control plant while limonene was the major component in both condition 4 and 6 upon applying drought stress, while alpha terpinolene is the major component in conditions 1, 2, 3 and 5 (30.59%, 39.93%, 50.37% and 35.41% respectively) using different organic and inorganic fertilizers. Conclusion: It is concluded that manipulation of agricultural conditions strongly affects biosynthesis and accumulation of essential oils obtained from Foeniculum vulgare Miller var. dulce roots.