Context: Origanum (Lamiaceae) has been used in food and pharmaceutical industries. Objective: Isolation and identification of bioactive compounds from Origanum rotundifolium Boiss. and investigation of their antiproliferative and antioxidant activities. Materials and methods: The aerial part of O. rotundifolium was dried and powdered (1.0 kg ±2.0 g) then extracted with hexane, ethyl acetate, methanol and water. Solvent (3 × 1 L) was used for each extraction for a week at room temperature. The aqueous extract was partitioned with ethyl acetate (3 × 1 L) to yield the water/EtOAc extract subjected to chromatography to isolate the active compounds. The structures of isolated compounds were elucidated by 1 D, 2 D NMR and LC-TOF/MS. Results: Apigenin (1), ferulic acid (2), vitexin (3), caprolactam (4), rosmarinic acid (5), and globoidnan A (6) were isolated and identified. Globoidnan A (6), vitexin (3), and rosmarinic acid (5) revealed the excellent DPPH^• scavenging effect with IC₅₀ values of 22.4, 31.4, 47.2 μM, respectively. Vitexin (3) (IC₅₀ 3.6), globoidnan A (6) (IC₅₀ 4.6), apigenin (1) (IC₅₀ 8.9) and ferulic acid (2) exhibited more ABTS^•+ activity than standard Trolox (IC₅₀ 13.8 μg/mL). Vitexin (3) revealed the most antiproliferative activity against HeLa, HT29, C6 and Vero cells lines with IC₅₀ values of 35.6, 32.5, 41.6, 46.7 (μM), respectively. Discussion and conclusion: Globoidnan A (6) has the most antioxidant effects on all assays. This has to do with the chemical structure of the compound bearing the acidic protons. Vitexin (3) could be a promising anticancer agent.

Inula species are medicinal and aromatic plants used for folk medicine extensively. In this work, hydrodistilled essential oil of Inula graveolens (Linnaeus) Desf. analyzed by GC-MS which revealed that bornyl acetate was the major product (69.15%). Camphene was the second major compound (11.11%). Antiproliferative activity of the essential oil and bornyl acetate was investigated on HeLa (human cervix carcinoma), HT29 (human colon carcinoma) , A549 (human lung carcinoma), MCF7 ( human breast adenocarcinoma) cancer cells and FL (human amnion cells) normal cells. The cytotoxicity was executed by a Lactate Dehydrogenase (LDH) Cytotoxicity Detection Kit. Essential oil and bornyl acetate displayed the outstanding activities on HeLa (IC 50, 64.1, 72.0 µg/mL), HT29 (IC 50, 24.6, 60.5 µg/mL), A549 (IC 50, 28.3, 44.1 µg/mL), MCF-7 (IC 50, 66.5, 85.6 µg/mL), and FL (IC 50, 42.1, 50.6 µg/mL) cell lines respectively.

Keywords Candida albicans; Surface properties; Denture cleansers; Denture bases