C: Food Chemistry Oregano: Chemical Analysis and Evaluation of Its Antimalarial, Antioxidant, and Cytotoxic Activities Fatiha El Babili, Jalloul Bouajila, Jean Pierre Souchard, C´ edric Bertrand, Florian Bellvert, Isabelle Fouraste, Claude Moulis, and Alexis Valentin Abstract: GC-FID and GC-MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p-cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC 50 = 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC 50 = 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC 50 of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic. Keywords: antimalarial activity, antioxidant activity, cytotoxicity MCF7, essential oil, GC-MS, oregano Introduction “Oregano” is the common name for the aroma and taste that comes primarily from more than 60 species of plants used world- wide as a spice. The genus origanum (lamiaceae) includes 39 species widely distributed in the Mediterranean region (Vokou and others 1993). These plants are perennial herbs spontaneously growing in calcareous substrates. One of the morphological characteristics of oregano is the presence of glandular and nonglandular trichomes covering the aerial organs. The glandular trichoma secrete essen- tial oils with a unique flavor, which is mainly due to its major compounds such as carvacrol, thymol, and so on. Throughout Morocco, oregano, known locally as “zaatar” and corresponding to the species Origanum compactum, is traditionally considered as a panacea for health. In aqueous infusion, zaatar is traditionally used to treat dysentery, colitis, bronco-pulmonary, gastric acidity, and gastro-intestinal diseases (Bellakhdar 1997). Oregano powder can also be smoked when mixed with tobacco. MS 20101365 Submitted 12/2/2010, Accepted 1/24/2011. Author El Babili is with Facult´ e des Sciences Pharmaceutiques de Toulouse, Laboratoire de Botanique- Mycologie, Facult´ e de Pharmacie, 35 ch. des Maraˆ ıchers, F- 31062 Toulouse, France. Authors El Babili, Fouraste, Moulis, and Valentin are with Laboratoire de Phar- macochimie des Substances Naturelles et Pharmacophores Redox, UMR 152, UPS and authors Bouajila, Souchard are with Laboratoire des Interactions Mol´ eculaires et R´ eactivit´ e Chimique et Photochimique UMR CNRS 5623, Univ. de Toulouse, 118 Route de Narbonne, F-31062 Toulouse Cedex 9, France. Authors Bertrand and Bellvert are with Univ. de Lyon, Lyon F-69003, France, Univ. Lyon 1, Villeur- banne F-69622, France, Centre d’Etude des Substances Naturelles, CNRS, UMR 5557, Ecologie Microbienne, Villeurbanne F-69622, France. Direct inquiries to author Bouajila (E-mail: bouajila@cict.fr, elbabili@cict.fr). To treat mouth diseases (blisters, ulcers, gingivitis), it is used as a gargle. Additionally, oregano has been used as a tonic, aphrodisiac, and as an appetite stimulant. Its culinary use is also highly devel- oped because oregano is used as a flavoring and food preservative. It is the aromatic ingredient of choice in the preparation of melted butter or “smen” (Bellakhdar 1997), widely used to go with salads, fish, “berkˆ ukes,” “rfissa,” and couscous. Many scientific studies have been conducted to examine and justify the practices associated with zaatar. Van den Brouke and Lemli (van den Broucke and Lemli 1982) have demonstrated an- tispasmodic activity. Total inhibition (100%) was achieved with Origanum compactum oil to 4 ppm for molds, yeasts, and bacteria. In addition, a preparation with the whole plant has also prevented the development of various species of yeasts, molds, and bacte- ria (Charai and others 1996). The ethyl acetate extract showed molluscicidal activity (Hmamouchi and others 2000). Origanum compactum was been shown as a potential cercaricide (against Schis- tosoma haematobium) in Morocco (Lahlou 2002). Origanum com- pactum inhibited Botrytis cinerea 100% at 100 ppm, while its IC 50 was 35.1 ppm (Bouchra and others 2003). Carvacrol, the major component of oregano essential oil showed antimutagenic activity (Mezzoug and others 2007), which seems to be mainly linked to the induction of mitochondrial dysfunction (Bakkali and others 2006). More recently, this essential oil showed strong insecticidal activity against larvae of Spodoptera littoralis with an LD 50 ≤ 0.05 mL/larva (Roman 2005) and was lethal when administered at 13 mg/fly (Musca domestica L.) (Roman 2008). As these previous researches show, O. compactum has great po- tential in the culinary and health fields. The aim of our research on “zaatar” was to study the chemical composition of its essential oil C  2011 Institute of Food Technologists R  C512 Journal of Food Science  Vol. 76, Nr. 3, 2011 doi: 10.1111/j.1750-3841.2011.02109.x Further reproduction without permission is prohibited