The chemical composition of the Tamarix boveana volatile oils obtained from the whole aerial part, flowers, leaves and stems by steam distillation was analysed using gas chromatograph (GC)-flame ionization detectors (FID) and GC-MS. Sixty-two components were identified. Hexadecanoic acid (18.14%), docosane (13.34%), germacrene D (7.68%), fenchyl acetate (7.34%), Benzyl benzoate (4.11%) were found to be the major components in the whole aerial parts. This composition differed according to the tested part: 2.4 Nonadienal was the main compound in the flowers (12.13%) while germacrene D was the major component in leaves (31.43%) and hexadecanoic acid in the stems (13.94%). To evaluate in vitro antimicrobial activity, all volatile oils were tested against six Gram-positive and Gram-negative bacteria and four fungi. The T. boveana volatile oils exhibited an interesting antibacterial activity against all strains tested except Pseudomonas aeruginosa but no antifungal activity was detected.

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The chemical composition of the essential oils obtained by hydrodistillation from the flowers of Retama raetam (Forssk.) Webb cultivated in Tunisia was determined by GC and GC/MS analysis. A total of 50 components representing 98.58% of the oil were identified: nonanal (35.75%), alpha-humulene (29.29%), acetaldehyde (7.84%), linalool (5,62%), myrcene (3.38%), tridecanal (2.21%), beta-caryophyllene (1.79%), alpha-terpinyl acetate (1.46%), terpinolene (1.26%) and methyl anthranilate (1.06%) were found to be the major components. The oil was evaluated for antibacterial and antifungal activities using a microdilution assay against some bacteria and yeasts. The minimal inhibitory concentrations (MIC) of the essential oil varied between 0.625 and 5 mg mL(-1) and the minimum bactericidal concentrations (MBC) were superior to 5 mg mL(-1) of oil for most strains. The antioxidant potential of the essential oil was evaluated using the 2,2'-diphenyl-1-picrylhydrazyl free radical scavenging method. The essential oil possesses good antioxidant properties (IC(50) = 0.800 mg mL(-1)). The results may suggest that the flower oil of R. raetam possesses compounds with antibacterial, antifungal and antioxidant capacities, and thus the oil can be explored as a natural preservative ingredient in food and/or pharmaceutical preparations.

Oxidative stress is an important pathomechanism of neurological disorders such as Alzheimer disease and Parkinson disease, cardiovascular disorders and many others. This study sought to verify whether extra-virgin olive oil (EVOO), lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) exerted a brain protective effect against the oxidative stress caused by 2,4-dichlorophenoxyacetic acid (2,4-D) pesticide at a dose of 5 mg/kg body weight. 2,4-D, EVOO and its fractions were administered to rats by gavages for four consecutive weeks. Oxidative stress was assessed by measuring brain lipid peroxide level, acetylcholinesterase (AChE), antioxidant enzyme activities and fatty acid composition. 2,4-D induced a decrease in both plasma and brain acetylcholinesterase activity and a rise in Brain TBARS (Thiobarbituric acid reactive substances) level and antioxidant enzyme activities compared with the control group. These changes were partly reversed by either EVOO or its fractions oral administration to 2,4-D treated rats. EVOO enhanced a neuroprotective effect evaluated by the restoration of brain fatty acid composition especially the level of docosahexaenoic acid (DHA). Our results indicate that EVOO exerts a neuroprotective activity against oxidative damage in brain induced by 2,4-D, which could be attributed to its antioxidative property.

The antimicrobial properties of essential oil from various species have not been investigated enough in the previous studies dealing with the biological activities of medicinal plants. In Tunisia, L. (Asteraceae) is the only species recorded and is used as vermifuge and emmenagogue. The chemical composition, antibacterial and antifungal properties of essential oils from the flowerheads and roots of spontaneous growing in Tunisia and the chemical composition which leads to the Tunisian chemotype are investigated here for the first time. Essential oils isolated by hydro distillation from flowerheads and roots of were analyzed by GC and GC/MS. Two methods served for antimicrobial assays of the essential oils: diffusion in a solid medium and micro-well dilution assay. Antifungal tests were carried out by the agar incorporation method. Sixty-seven constituents were identified from the essential oil of the flowerhead. The major constituents were: 1,8-cineole and-eudesmol. Two non identified compounds were present at the highest concentration in root oil. Flowerhead oil was characterized by high contents in monoterpenes and sesquiterpenes oxygenated compounds. The flowerhead essential oil demonstrated potent of antibacterial properties against ATCC and ATCC, with MIC of 0.625 μg/ml. These findings demonstrate that the flowerhead essential oils of have excellent antibacterial properties and for this reason they could contribute to decrease the problem of microbial resistance to antibiotics.

Numerous studies have focused on trans fatty acids (TFA) technologically produced by partial hydrogenation of oils. However, TFA can also be present in fresh oils. For this reason, cis fatty acid (CFA), TFA and conjugated linoleic acid (CLA) of fresh and heated Aleppo pine seed oil (APSO) at frying temperature (180°C) were evaluated and correlated with the antioxidant characteristics. Results showed that fresh APSO had a low oleic/linoleic ratio O/L (0.4). Total TFA in fresh APSO reached 1%. The predominant TFA was 18:2 n-6 (t9, t12) in both fresh and heated APSO. Individual TFA increased with significant differences (p<0.05) with heating time. CLA occurred after 4 h and significantly increased (p<0.05) accounting 10% of total TFA after 10 h. Total TFA are negatively correlated with α-tocopherol, γ-tocopherol (p<0.05) and carotenoïds (p< 0.01) and positively correlated with remaining DPPH. Oil stability index (OSI) showed significant negative correlation with TFA (r0−0.925; p00.008). A principal component analysis (PCA) showed a clear discrimination between fresh and heated oils. Temperature, heating time, unsaturation degree and antioxidants are combined factors which significantly affect the isomerization rate and nutritional quality of APSO.

The essential oils isolated from three organs, i.e., fruits, stems and leaves, and flowers, of the endemic North African plant Scabiosa arenaria Forssk. were screened for their chemical composition, as well as their possible antibacterial, anticandidal, and antifungal properties. According to the GC‐FID and GC/MS analyses, 61 (99.26% of the total oil composition), 79 (98.43%), and 51 compounds (99.9%) were identified in the three oils, respectively. While α‐thujone (34.39%), camphor (17.48%), and β‐thujone (15.29%) constituted the major compounds of the fruit oil, chrysanthenone (23.43%), together with camphor (12.98%) and α‐thujone (10.7%), were the main constituents of the stem and leaf oil. In the case of the flower oil, also chrysanthenone (38.52%), camphor (11.75%), and α‐thujone (9.5%) were identified as the major compounds. Furthermore, the isolated oils were tested against 16 Gram‐positive and Gram‐negative bacteria, four Candida species, and nine phytopathogenic fungal strains. It was found that the oils exhibited interesting antibacterial and anticandidal activities, comparable to those of thymol, which was used as positive control, but no activity against the phytopathogenic fungal strains was observed.