Comparative study of the antioxidant activity of the essential oils of five plants against the H2O2 induced stress in Saccharomyces cerevisiae.

The purpose of this work was to investigate the protective effect of five essential oils (EOs); Rosmarinus officinalis, Thymus vulgaris, Origanum compactum Benth., Eucalyptus globulus Labill. and Ocimum basilicum L.; against oxidative stress induced by hydrogen peroxide in Saccharomyces cerevisiae. The chemical composition of the EOs was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). The in vitro antioxidant activity was evaluated and the protective effect of EOs was investigated. Yeast cells were pretreated with different concentrations of EOs (6.25-25 µg/ml) for an hour then incubated with H2O2 (2 mM) for an additional hour. Cell viability, antioxidants (Catalase, Superoxide dismutase and Glutathione reductase) and metabolic (Succinate dehydrogenase) enzymes, as well as the level of lipid peroxidation (LPO) and protein carbonyl content (PCO) were evaluated. The chemical composition of EOs has shown the difference qualitatively and quantitatively. Indeed, O. compactum mainly contained Carvacrol, O. basilicum was mainly composed of Linalool, T. vulgaris was rich in thymol, R. officinalis had high α-Pinene amount and for E. globulus, eucalyptol was the major compound. The EOs of basil, oregano and thyme were found to possess the highest amount of total phenolic compounds. Moreover, they have shown the best protective effect on yeast cells against oxidative stress induced by H2O2. In addition, in a dose dependent manner of EOs in yeast medium, treated cells had lower levels of LPO, lower antioxidant and metabolic enzymes activity than cells exposed to H2O2 only. The cell viability was also improved. It seems that the studied EOs are efficient natural antioxidants, which can be exploited to protect against damages and serious diseases related to oxidative stress.

Nutrigenomics of essential oils and their potential domestic use for improving health.

The use of essential oils as industrial food additives is notorious, like their medicinal properties. However, their use in household food spicing is for now limited. In this work, we have made a review to reveal the nutrigenomic actions exerted by their bioactive components, to promote awareness of their modulating gene expression ability and the potential that this implies. Also considered is how essential oils can be used as flavoring and seasoning after cooking and before consumption, such as diet components which can improve human health. Genetic mechanisms involved in the medicinal properties of essential oils for food use are identified from literature. These genetic mechanisms reveal nutrigenomic actions. Reviews on the medicinal properties of essential oils have been particularly considered. A wide diversity of nutrigenomic effects from essential oils useful potentially for food spicing is reviewed. General ideas are discussed about essential oils and their properties, such as anti-inflammatory, analgesic, immunomodulatory, anticancer, hepatoprotective, hypolipidemic, anti-diabetic, antioxidant, bone-reparation, anti-depressant and mitigatory for Alzheimer's disease. The essential oils for food use are potentially promoting health agents, and, therefore, worth using as flavoring and condiments. Becoming aware of the modulating gene expression actions from essential oils is important for understanding their potential for use in household dishes as spices to improve health.

Two new alkaloids from Narcissus serotinus L.

The Amaryllidaceae family is well known for the presence of an exclusive group of alkaloids with a wide range of biological activities. Narcissus serotinus L. is a plant belonging to this family and its geographical distribution is mainly located along the Mediterranean coast. In the present work, specimens collected near Casablanca (Morocco) were used to study the alkaloid content of this species. Starting with 350 g of the whole plant we used standard extraction and purification procedures to obtain fractions and compounds for GC-MS and NMR analysis. As well as five known alkaloids, we isolated two new compounds: 1-O-(3´-acetoxybutanoyl)lycorine and narseronine. The latter has been previously published, but with an erroneous structure.