Chemical Variability of the Essential Oil of Pituranthos scoparius from Algeria

The chemical composition of 93 oil samples from the aerial parts of Pituranthos scoparius, harvested in three regions of Algeria, was investigated by GC‐FID, GC/MS and ¹³C‐NMR. Monoterpene hydrocarbons dominated in association with phenylpropanoids and a chemical variability was found highlighting three clusters. The composition of group I (36 samples) exhibited an atypical composition characterized by a very high contents of 6‐methoxyelemicine (13.0 – 59.6%), followed by sabinene (1.1 – 43.0%) and limonene (6.6 – 39.0%), while the samples of group II (12 samples) contained a high content of limonene (9.2 – 44.0%), followed by myristicine (0.0 – 29.4%) and a lower amount of sabinene (0.8 – 2.3%). Group III (45 samples) could be divided in two subgroups. Subgroup SGIIIA was characterized by a very high content of sabinene (28.0 – 55.6%), followed by elemicine (0.0 – 29.1%), while the samples belonging to SGIIIB were characterized by the lower content of sabinene (6.2 – 35.5%) and a significant content of myristicine (1.5 – 32.4%), α‐pinene (4.2 – 31.0%) and dill apiole (0.1 – 31.4%). Each harvested region was characterized by a different chemical composition.     

Diversity of Sterol Composition in Tunisian Pistacia lentiscus Seed Oil

Pistacia lentiscus L. seed oil is used in some Mediterranean forest area for culinary and medicinal purposes. In this study, we aim to examine, for the first time, the effect of growing area on sterol content of Pistacia lentiscus seed oil. Fruits were harvested from 13 different sites located in northern and central Tunisia. Gas chromatography‐flame‐ionization detection (GC‐FID) was used to quantify sterols and gas chromatography/mass spectrometry (GC/MS) was used to identify them. The major sterol identified was β‐sitosterol with a value ranging from 854.12 to 1224.09 mg/kg of oil, thus making up more than 54% of the total sterols. The other two main sterols were cycloartenol (11%) and 24‐methylene‐cycloartenol (5%). Statistical results revealed that growing location significantly (P < 0.001) affected phytosterol levels in these oils.     

Analysis of lipid transfer activity between model nascent HDL particles and plasma lipoproteins: implications for current concepts of nascent HDL maturation and genesis

The specifics of nascent HDL remodeling within the plasma compartment remain poorly understood. We developed an in vitro assay to monitor the lipid transfer between model nascent HDL (LpA-I) and plasma lipoproteins. Incubation of α-¹²⁵I-LpA-I with plasma resulted in association of LpA-I with existing plasma HDL, whereas incubation with TD plasma or LDL resulted in conversion of α-¹²⁵I-LpA-I to preβ-HDL. To further investigate the dynamics of lipid transfer, nascent LpA-I were labeled with cell-derived [³H]cholesterol (UC) or [³H]phosphatidylcholine (PC) and incubated with plasma at 37°C. The majority of UC and PC were rapidly transferred to apolipoprotein B (apoB). Subsequently, UC was redistributed to HDL for esterification before being returned to apoB. The presence of a phospholipid transfer protein (PLTP) stimulator or purified PLTP promoted PC transfer to apoB. Conversely, PC transfer was abolished in plasma from PLTP^−/− mice. Injection of ¹²⁵I-LpA-I into rabbits resulted in a rapid size redistribution of ¹²⁵I-LpA-I. The majority of [³H]UC from labeled r(HDL) was esterified in vivo within HDL, whereas a minority was found in LDL. These data suggest that apoB plays a major role in nascent HDL remodeling by accepting their lipids and donating UC to the LCAT reaction. The finding that nascent particles were depleted of their lipids and remodeled in the presence of plasma lipoproteins raises questions about their stability and subsequent interaction with LCAT.     

Variation in Volatile Leaf Oils of 13 Eucalyptus Species Harvested from Souinet Arboreta (Tunisia)

Hydrodistillation of the dried leaves of 13 species of the genus Eucalyptus L' Hér ., viz., E. bicostata Maiden, Blakely & Simmonds , E. cinerea F. Muell . ex Benth ., E. exerta F. Muell ., E. gigantea Hook . f ., E. gunnii Hook . f ., E. macarthurii Deane & Maiden ., E. macrorrhyncha F. Muell ., E. maidenii F. Muell ., E. odorata Behr ., E. pauciflora Sieber ex Sprengel , E. sideroxylon A. Cunn . ex Woolls , E. tereticornis Sm ., and E. viminalis Labill ., harvested from Souinet arboreta (region of Ain Draaham, north of Tunisia) in June 2006, afforded essential oils in yields varying from 0.5±0.2 to 3.9±0.4%, dependent on the species. E. cinerea and E. exerta provided the highest and the lowest percentage of essential oil amongst all the species examined, respectively. Analysis by GC (RI) and GC/MS allowed the identification of 142 components, representing 81.5 to 98.9% of the total oil. The contents of the different samples varied according to the species. The main components were 1,8‐cineole ( 1 ), followed by cryptone, spathulenol ( 4 ), p‐cymene ( 2 ), viridiflorol ( 6 ), globulol ( 7 ), β‐eudesmol, α‐terpineol ( 5 ), limonene ( 8 ), D ‐piperitone, α‐pinene ( 3 ), cuminal, and γ‐eudesmol. The principal component and the hierarchical cluster analyses separated the 13 Eucalyptus leaf essential oils into three groups, each constituting a chemotype.     

Chemical Characterization of Five Tunisian Eucalyptus Essential Oils Species

Hydrodistillation of the dried leaves of five Eucalyptus species, E. alba Reinw. ex Blume , E. citriodora Hook ., E. paniculata Sm. , harvested from Choucha arboreta (region of Sejnane, northwest of Tunisia), E. pimpiniana Maiden from Mjez Elbab arboreta (north east of Tunisia) and E. bicolor A.Cunn ex Hook from Sidi Smail arboreta (center of Tunisia), in March 2017, afforded essential oils in yields varying from 1.3±0.2 to 6.0±0.9 % according to the species. E. citriodora provided the highest mean percentage of essential oil amongst all the species. Analysis by GC (RI) and GC/MS allowed the identification of 138 components representing 84.6–98.7 % of the total oil. The content of the different samples varied according to the species. The main components were citronellol, followed by 1,8‐cineole, α‐pinene, τ‐cadinol, 7‐epi‐α‐eudesmol, trans‐pinocarveol, spathulenol, aromadendrene, γ‐cadinene and δ‐cadinene. The principal components and the hierarchical cluster analyses separated the five leaf essential oils into three groups, each group constituted a chemotype.     

Matrix metalloproteinase-9 deficiency results in enhanced allergen-induced airway inflammation

Matrix metalloproteinases (MMPs) are a large family of endopeptidases that proteolytically degrade extracellular matrix. Many different cells produce MMP-9, and levels have been shown to be up-regulated in patients with allergic asthma. The aim of this study was to investigate the in vivo role of MMP-9 during allergen-induced airway inflammation. Acute allergic pulmonary eosinophilia was established in MMP-9 knockout (KO) and wild-type (WT) control mice by sensitization and challenge with OVA. Cell recruitment was significantly increased in both bronchoalveolar lavage (BAL) and lung tissue compartments in MMP-9 KO mice compared with WT mice. This heightened cell recruitment was primarily due to increased eosinophils and Th2 cells in the BAL and lung tissue of MMP-9 KO mice in comparison with WT controls. Moreover, levels of the Th2 cytokines, IL-4 and IL-13, and the chemokines eotaxin/CCL11 and macrophage-derived chemokine/CCL22 were substantially increased in MMP-9 KO mice compared with WT after OVA challenge. Resolution of eosinophilia was similar between MMP-9 KO and WT mice, but Th2 cells persisted in BAL and lungs of MMP-9 KO mice for longer than in WT mice. Our results indicate that MMP-9 is critically involved in the recruitment of eosinophils and Th2 cells to the lung following allergen challenge, and suggest that MMP-9 plays a role in the development of Th2 responses to allergen.     

Biogenesis and speciation of nascent apoA-I-containing particles in various cell lines

It is generally thought that the large heterogeneity of human HDL confers antiatherogenic properties; however, the mechanisms governing HDL biogenesis and speciation are complex and poorly understood. Here, we show that incubation of exogenous apolipoprotein A-I (apoA-I) with fibroblasts, CaCo-2, or CHO-overexpressing ABCA1 cells generates only alpha-nascent apolipoprotein A-I-containing particles (alpha-LpA-I) with diameters of 8-20 nm, whereas human umbilical vein endothelial cells and ABCA1 mutant (Q597R) cells were unable to form such particles. Interestingly, incubation of exogenous apoA-I with either HepG2 or macrophages generates both alpha-LpA-I and prebeta1-LpA-I. Furthermore, glyburide inhibits almost completely the formation of alpha-LpA-I but not prebeta1-LpA-I. Similarly, endogenously secreted HepG2 apoA-I was found to be associated with both prebeta1-LpA-I and alpha-LpA-I; by contrast, CaCo-2 cells secreted only alpha-LpA-I. To determine whether alpha-LpA-I generated by fibroblasts is a good substrate for LCAT, isolated alpha-LpA-I as well as reconstituted HDL [r(HDL)] was reacted with LCAT. Although both particles had similar V(max) (8.4 vs. 8.2 nmol cholesteryl ester/h/microg LCAT, respectively), the K(m) value was increased 2-fold for alpha-LpA-I compared with r(HDL) (1.2 vs. 0.7 microM apoA-I). These results demonstrate that 1) ABCA1 is required for the formation of alpha-LpA-I but not prebeta1-LpA-I; and 2) alpha-LpA-I interacts efficiently with LCAT. Thus, our study provides direct evidence for a new link between specific cell lines and the speciation of nascent HDL that occurs by both ABCA1-dependent and -independent pathways.     

Iron deficiency-induced changes in carbon fixation and leaf elemental composition of sugar beet (Beta vulgaris) plants

In this experiment we (i) tested the hypothesis that, besides decreasing leaf C fixation, lime induced iron (Fe) deficiency increases root C fixation via PEP carboxylase and (ii) assessed the Fe-induced modifications in the elemental composition of plant tissues. Sugar beet plants were grown in nutrient solutions with Fe (45 M Fe-EDTA; +Fe control) or in a similar nutrient solution without Fe (–Fe) and in presence of CaCO₃ (1.0 gL^–1), either labelled with ¹³C (20 at. %) or unlabelled. After 7 and 17 days from treatment imposition, plants were harvested and single organs analysed for total O, C, H, macro and micronutrients. ¹³C abundance was also assessed in control, unlabelled and labelled –Fe plants. Iron deficiency caused significant growth reductions; chlorophyll and net photosynthesis decreased markedly in Fe-deficient plants when compared to the controls, whereas leaf transpiration rates and stomatal conductance were not affected by Fe deficiency. Iron deficient plants had leaf biomass with lower C (2 to 4%) and higher O (3 to 5%) concentrations than +Fe plants. The ¹³C was higher (less negative) in +Fe than in –Fe unlabelled plants. Iron deficient plants grown in the nutrient solution enriched with labelled CaCO₃ absorbed a relatively small amount of labelled C, which was mainly recovered in the fine roots and accounted for less than 2% of total C gain in the 10 d treatment period. Evidences suggest that iron deficient sugar beets grown in the presence of CaCO₃ do not markedly shift their C fixation from leaf RuBP to root PEPC.