Activités anti-radicalaires de l'huile essentielle et des extraits bruts de Thymus numidicus Poiret., Algérie

Thymus numidicus Poiret. (Lamiaceae) est une plante largement utilisée en médecine traditionnelle algérienne pour ses propriétés thérapeutiques. Le but de ce travail est d'évaluer l'activité antioxydante de l'huile essentielle ainsi que plusieurs extraits bruts (dichlorométhane, méthanol, méthanol-eau 5:1 v/v, et l'infusé) du Thymus numidicus Poiret. récolté à Annaba (Algérie). L'activité antioxydante a été estimée par deux méthodes photométriques, la méthode de DPPH et celle de réduction du peroxyde d'hydrogène. Les résultats ont révélé que les deux extraits méthanol et méthanol-eau 5:1 ont exercé une forte activité de piégeage des radicaux libres DPPH en comparaison avec le BHT ainsi qu'une haute capacité de blocage du peroxyde d'hydrogène en comparaison avec les contrôles positifs de l'acide gallique et l'acide caféique.Mots-clés : Thymus numidicus, extraits bruts, activité antioxydante. Anti-radical activities of essential oil and crude extracts of Thymus numidicus Poiret., AlgeriaThymus numidicus Poiret. (Lamiaceae) is a plant widely used in Algerian traditional medicine. The aim of this work was to assess the antioxidant activity of the volatile compounds as well as different crude extracts (dichloromethane, methanol, methanol-water 5:1 v/v, infusion) of the endemic Thymus numidicus Poiret. collected from Annaba city (Algeria). The antioxidant activity was estimated by two fluorimetric methods, the DPPH method and the hydrogen peroxide scavenging method. The results revealed that methanol and methanol water 5:1 v/v extracts exerted very high free radical scavenging activity compared to the well-known butylated hydroxytoluene (BHT) and high hydrogen peroxide blocking activity than positive controls gallic acid and caffeic acid.Keywords : Thymus numidicus, crude extracts, anioxidant activity

Dynamique Des Eléments Nutritifs Et Du Phytoplancton Dans Le Barrage Béni Haroun Dans l’Est Algérien

In order to monitor the water quality of the Beni Haroun dam, used for the drinking water production, our research work aims to provide new scientific data on the phytoplankton population of the dam. This contribution is a qualitative and quantitative investigation of this important link in the ecosystem equilibrium. To our knowledge, this study has never been the subject of a previous one, despite many works already done on this dam. Water samples were collected monthly from January to December 2015 at five stations, spread over Beni Haroun dam. The exploitation of a database, relating to fourteen physicochemical and biotic variables, made it possible to determine: the spatiotemporal evolution of each variable, the correlations between variables, the annual variability of the algal biomass, the diversity and phytoplankton dominance

Pathogenic Variants in the Myosin Chaperone UNC-45B Cause Progressive Myopathy with Eccentric Cores

The myosin-directed chaperone UNC-45B is essential for sarcomeric organization and muscle function from Caenorhabditis elegans to humans. The pathological impact of UNC-45B in muscle disease remained elusive. We report ten individuals with bi-allelic variants in UNC45B who exhibit childhood-onset progressive muscle weakness. We identified a common UNC45B variant that acts as a complex hypomorph splice variant. Purified UNC-45B mutants showed changes in folding and solubility. In situ localization studies further demonstrated reduced expression of mutant UNC-45B in muscle combined with abnormal localization away from the A-band towards the Z-disk of the sarcomere. The physiological relevance of these observations was investigated in C. elegans by transgenic expression of conserved UNC-45 missense variants, which showed impaired myosin binding for one and defective muscle function for three. Together, our results demonstrate that UNC-45B impairment manifests as a chaperonopathy with progressive muscle pathology, which discovers the previously unknown conserved role of UNC-45B in myofibrillar organization

Pathogenic Variants in the Myosin Chaperone UNC-45B Cause Progressive Myopathy with Eccentric Cores.

The myosin-directed chaperone UNC-45B is essential for sarcomeric organization and muscle function from Caenorhabditis elegans to humans. The pathological impact of UNC-45B in muscle disease remained elusive. We report ten individuals with bi-allelic variants in UNC45B who exhibit childhood-onset progressive muscle weakness. We identified a common UNC45B variant that acts as a complex hypomorph splice variant. Purified UNC-45B mutants showed changes in folding and solubility. In situ localization studies further demonstrated reduced expression of mutant UNC-45B in muscle combined with abnormal localization away from the A-band towards the Z-disk of the sarcomere. The physiological relevance of these observations was investigated in C. elegans by transgenic expression of conserved UNC-45 missense variants, which showed impaired myosin binding for one and defective muscle function for three. Together, our results demonstrate that UNC-45B impairment manifests as a chaperonopathy with progressive muscle pathology, which discovers the previously unknown conserved role of UNC-45B in myofibrillar organization

Secondary metabolites from Centaurea grisebachii ssp. grisebachii

The aerial parts of Centaurea grisebachii ssp. grisebachii, a Greek endemic species belonging to section Acrolophus (Cass.) DC., were investigated for the occurrence of sesquiterpene lactones. The eudesmanolide, 4-epi-malacitenolide was the major compound. In addition to the sesquiterpene lactones, five flavonoid aglycons, two lignans, one nor-isoprenoid and one sterol were found. © 2007 Elsevier Ltd. All rights reserved

Analysis of the essential oils of some centaurea species (asteraceae) growing wild in algeria and greece and investigation of their antimicrobial activities

The volatile composition of Centaurea pullata L., C. grisebachii (Nyman) Heldr. subsp. grisebachii and C. affinis Friv. have been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the components was made by comparison of mass spectra and retention indices with literature records and by co-chromatography with authentic compounds. Their main constituents were caryophyllene oxide for C. pullata, 6,10,14-trimethyl pentadecan-2-one and spathulenol for C. grisebachi subsp. grisebachii, thymol and dodecanol for C. affinis. The essential oils were evaluated for their antimicrobial potential and showed a moderate activity against all microorganisms tested. © 2011 Taylor & Francis Group, LLC