This study describes the chemical composition and the antibacterial, antifungal and antioxidant activities of the essential oil extracted from aerial parts of the Algerian Eryngium tricuspidatum L., obtained by hydrodistillation and analysed by using the combination of gas chromatography (GC) and GC/mass spectrometry. A total of 63 compounds were identified accounting for 93.1% of the total oil. Chemical composition of oil was characterised by a high proportion of oxygenated sesquiterpenes (49.6%) among which α-bisabolol (32.6%) was the predominant compound. The sesquiterpene hydrocarbons represent the second major fraction (31.9%) with α-curcumene (6.5%) being the predominant one. Antibacterial and antifungal activities of the oil were tested using the micro-well determination of minimum inhibitory concentration (MIC) assay against eleven bacteria and two Candida species. It was found that the aerial parts of E. tricuspidatum exhibited interesting antibacterial and anticandidal activities (MIC = 9 μg/mL against several strains of bacteria and MIC = 4.6 μg/mL against Candida albicans). The antioxidant effect of this oil was evaluated using the 2,2-diphenyl-l-1-picrylhydrazil (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results revealed significant activities (DPPH method: IC₅₀ = 510 μg/mL; FRAP assay: reducing power of oil increases from 0.0188 at 5 μg/mL to 0.5016 at 1000 μg/mL).

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The aim of the present study is to investigate the chemical composition, antibacterial and antioxidant activities of three essential oils extracted by hydrodistillation from the aerial parts of Artemisia arborescens L., which was collected from three different regions near Tlemcen city in the West Northern of Algeria: Beni Snous, Bidar and Chetouane. The chemical composition was investigated using both capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) techniques. Fifty-two compounds were detected, a total of fifty compounds, representing 81.8 to 90.2% of the total oils were identified in the three samples of essential oils. The essential oils of A. arborescens were rich in camphor (Beni Snous: 72.2%, Bidar: 50.3% and Chetouane: 32.8%). The present composition of the essential oils, with camphor as the only most abundant component, was considered as a new chemotype of A. arborescens growing in West Northern of Algeria. Antibacterial activity of the essential oils against gram-positive and gram-negative bacteria, was tested using the diffusion method and by determining the inhibition zone. The results showed that the oils had a great potential antibacterial activity against some bacteria. The maximum zone of inhibition was obtained against Enterococcus faecalis (22 mm). In contrast, the oils were ineffective on the inactivation of Lysteria monocytogenes and Escherichia coli. Antioxidant capacity was assessed by in vitro tests using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and significant activity was found for these A. arborescens oils.

Objective: To find a new natural source of antioxidant, the phenolic contents and antioxidant activities of some secondary metabolites extracted from roots of Ziziphus lotus were evaluated. Methods: The total polyphenol contents were determined spectrophotometrically. Pyrrocatechol, catechin and cyanidin equivalents were used for these parameters. The antioxidant activities of the extracts were determined by several in vitro systems of assays, namely DPPH radical scavenging activity method, b-Carotene Bleaching assay (BCB), Ferric Reducing Antioxidant Power assay (FRAP) and Total Antioxidant capacity test (TAC). Results: The quantitative estimation showed that the roots of Z. lotus were rich in polyphenols (20.09 mg PE/g DW) and proanthocyannidins (1.56%) and they contained a small amount of flavonoids (0.02 mg CE/g DW). The most fractions exhibited high antioxidant activities, and some even showed higher potency than the standard synthetic antioxidants in some instances. In DPPH assay, all extracts had shown significant inhibition (58.535 -94.730% at 1 mg/mL). In addition, the IC 50 values ranged from 0.211 to 0.816 mg/mL, compared to 0.110, 0.214, 0.214 and 0.413 mg/mL for gallic acid, tannic acid, butylated-hydroxyanisol and ascorbic acid respectively. In (BCB) assay, the extracts showed strong inhibition (55.55 -100.00% at 1 mg/mL) and the IC 50 values ranging from 0.123 to 0.850 mg/mL compared to 0.433 mg/mL for gallic acid. A dose dependant curve was obtained for all extracts in the FRAP assay. However, the antioxidant potencies of ascorbic acid and extracts were comparable at low concentrations. The majority of extracts showed the highest value of antioxidant activity, based on TAC test (0.073 -0.398 mg ascorbic acid / mg extract). Conclusion: The results indicate that Z. lotus roots could be an important sources of natural antioxidants.

RésuméRuta chalepensis L. (Rutacée), est une plante aromatique médicinale encore utilisée dans la médecine traditionnelle de nombreux pays comme laxatif, antiinflammatoire, analgésique, antipasmodique, abortif, antiépileptique, emménagogue et pour le traitement de pathologies cutanées. Des screening phytochimiques ont mis en évidence la présence de coumarines en sus d'alcaloïdes et ont donné la composition chimique de l'huile essentielle de la partie aérienne de la plante provenant de différents pays. Ce travail a porté sur la composition chimique de l'huile essentielle de la plante provenant de l'Algérie, qui n'a jamais fait l'objet de publication. Les analyses ont été réalisées par chromatographie en phase gazeuse (CG) et CGspectrométrie de masse (SM). 20 composés représentant 64.66 -93.99% de l'huile essentielle ont été identifiés et, comme composé majoritaire le 2-undécanone (20.40 -82.74%). L'étude des variations du rendement, des propriétés physicochimiques et de la composition chimique de l'huile essentielle a été réalisée en fonction de la partie de la plante étudiée, la période et le lieu de cueillette de la plante. Les résultats ainsi obtenus ont montré l'extrême variabilité du rendement, des propriétés physicochimiques et de la composition. Mots-clés :Ruta chalepensis, huile essentielle, composition chimique, chromatographie en phase gazeuse, spectrométrie de masse, chemotype, 2-undécanone. Afrique SCIENCE 05(1) (2009) 67 -81Salima MERGHACHE et al. 68 AbstractPhysicochemical study of the essential oil of Ruta chalepensis L. from Tlemcen, AlgeriaRuta chalepensis L. (Rutaceae), is an ancient aromatic medicinal plant still used in the traditional medicine of many countries as a laxative, anti-inflammatory, analgesic, antispasmodic, abortifacient, antiepileptic, emmenagogue and for dermatopathy treatment.Phytochemical screening showed that Ruta chalepensis yielded coumarins as well as alkaloids and gave the chemical composition of essential oil of plant from different countries. This work was done on the composition of the essential oil of Ruta chalepensis from Algeria witch have never been a matter of publication. The analyses were done on gas chromatography (GC) and GC -mass spectrometry (MS). 20 compounds representing 64.66 -93.99% of the essential oil were identified and as major compound the 2-undecanone (20.40 -82.74%). Variation in yield, physicochemical properties and chemical composition of essential oil were studied according to the part of plant, harvesting period and place. The results showed the extreme variability of the yield, physicochemical properties and chemical composition.

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In the last years, the development of the drug for the treatment of inflammation is very fast. The inflammation is a first-rate example of a disease that symbolizes turmoil in normal host defense systems. COX-2 is an oxido-reductase having a role in prostaglandin biosynthesis, inflammatory responses and in cardiovascular events. COX-2 has gained special focus on research since past few decades. The compounds isolated from plants have good inhibitory effects against cyclooxygenase.In this study, Molecular modeling and docking analysis were used to predict and understand interactions between COX-2 and some compounds isolated from Artemisia arborescensL. The approach is applicable in engineering 3D structures of enzymatic models, and studying interactions of active site residues with ligands show that the three compounds: L 9, L 8 and L 4 give the best results, so they may be effective as the potential inhibitor compound against COX-2 protein and can be evaluated as anti-inflammatory drug molecule using clinical trials.