Essential Oils and Extracts of Juniperus macrocarpa Sm. and Juniperus oxycedrus L.: Comparative Phytochemical Composition and Anti-Proliferative and Antioxidant Activities.

In this work, we conducted a comparative phytochemical, chemotaxonomic, and biological study of essential oils (EOs) and extracts (ethyl acetate and methanol) obtained from the leaves of Juniperus macrocarpa and J. oxycedrus . The dominant compounds of J. macrocarpa EO, analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), are α-pinene, sabinene, manoyl oxide, and germacrene D, whereas α-pinene, limonene, ( Z , E )-farnesol, β-pinene, and γ-cadinene are the most representative volatiles of J. oxycedrus EOs. A multivariate analysis of EOs, included a selection of literature data comparing our samples to samples of J. oxycedrus / macrocarpa / deltoides from the Mediterranean area, was performed. As evident by high-performance liquid chromatography (HPLC) analyses, apigenin, (-)-epicatechin, and luteolin were abundant in J. oxycedrus extracts, while gallic acid, kaempferol-3- O -glucoside, and protocatechuic acid were the dominant constituents of J. macrocarpa extracts. EOs and extracts have been investigated for their potential antioxidant properties and anti-proliferative activity against lung adenocarcinoma (A549), breast cancer (MCF-7 and MDA-MB-231), and lung large cell carcinoma (COR-L23) human cell lines. The methanol and ethyl acetate extracts of J. oxycedrus exerted the most valuable antioxidant activity and exhibited the most promising activity against the COR-L23 cell line with an IC 50 of 26.0 and 39.1 μg/mL, respectively, lower than that obtained with the positive control (IC 50 of 45.5 μg/mL). To the best of our knowledge, this is the first report highlighting the anti-proliferative activity of J. oxycedrus and J. macrocarpa extracts against this lung cancer cell line. Our results indicate that J. oxycedrus may be considered a source of natural compounds with antioxidant and anti-proliferative effects that could be suitable for future applications.