Antimicrobial and Antioxidant Activities of Flavonoids Extracted from Pistacia lentiscus L., Leaves

Increasingly, the flavonoids becoming the subject of biomedical researches, and many groups have isolated and identified the structures of flavonoids possessing important biological activities. This assess investigates the antimicrobial fight and the antioxidant strengths of flavonoids extracted from Pistacia lentiscus L. leaves.  The extract was first analyzed for its phenolic content, then the flavonoids were tested for their antimicrobial capacities by the method of diffusion against fourteen bacteria, two fungi and one yeast. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of flavonoids were determined using the dilution method on solid medium, however, the antioxidant activity was evaluated through the ability of the extract to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals and the reducing power essay. The results indicate that flavonoids extract contain other phenolics groups. On the other side, the Antibacterial tests exhibited different activities depending on the strains. Unlike, the MIC and the MBC showed that the flavonoids extract showed a best activity against Candida albicans and Vibrio cholerae. Concerning antioxidant activity, the results indicate a moderate capacity of the flavonoid extract. These preliminary results may justify the use of this plant in the treatment of some diseases and may be exploited for therapeutic purposes. Keywords: Antimicrobial, Antioxidant, Pistacia lentiscus, flavonoids, MIC, MBC

Antifungal Activity of Mentha Rotundifolia Essential Oil Against Fusarium Oxysporum

The antifungal activity of Mentha rotundifolia essential oil, harvested in Setif (Algeria) was evaluated in vitro against a phytopathogenic fungi Fusarium oxysporum, causing damage on tomato. The molecular identification of the strain was based on a comparison (BLAST) of the sequences obtained against a database and was often supplemented by microscopic observations. After quot%253BSANGERquot%253B sequencing of the PCR products, the sequences were received in FASTA format. Analysis of M. rotundifolia essential oil by Gas Chromatography%252FMass Spectrometry method (GC-MS) identified 14 compounds. The 3-Cyclopenten-1-one, 2-hydroxy-3- (3-methyl-2-butenyl) - was the major constituent of this oil with a rate of about 89.09%25. For this activity, we adopted the technique of direct contact on agar. F. oxysporum continued to grow on oil-free media at 1%25 and 0.1%25 (fungistatic effect)%253B also on media with an oil concentration of 0.01%25. While the explants taken from petri dish with essential oil concentration of 2%253B 4 and 10%25 did not grow (fungicidal effect). The very interesting antifungal effect of M. rotundifolia essential oil indicates the potential of this plant species as a source of natural fungicidal material. The present study revealed that this mint exhibited antifungal effect against F. oxysporum which provided a scientific basis for the use of this species as a good source of antifungal compounds. This preliminary work could provide a basis for the determination of sufficient and effective concentrations for in planta studies for the biological control of natural active substances of M. rotundifolia against fungal diseases

Pulmonary complications of sickle cell disease: a narrative clinical review

Sickle cell disease (SCD) is associated with vaso-occlusive episodes that affect different organs. Pulmonary involvement is a major cause of morbidity and mortality in this patient population. We performed a literature search in the PubMed database for articles addressing SCD and pulmonary diseases. Acute chest syndrome is defined as a new radiodensity on chest radiograph imaging with a history consistent of the disease. Management includes broad spectrum antibiotics, pain control, and blood transfusions. Microvasculature infarcts lead to functional asplenia, which in turn increases the risk of being infected with encapsulated organisms. Universal vaccinations and antibiotic prophylaxis play a significant role in decreasing mortality from pulmonary infections. Venous thromboembolism in patients with SCD should be treated in the same manner as in the general population. Pulmonary hypertension in patients with SCD also increases mortality. The American Thoracic Society treatment modalities are based on the underlying etiology which is either directed at treating SCD itself, using vasodilator medications if the patient is in group 1, or using long-term anticoagulation if the patient is group 4 (in terms of etiology). Patients with SCD are more likely to suffer from asthma in comparison to controls. Sleep disorders of breathing should be considered in patients with unexplained nocturnal and daytime hypoxemia, or recurrent vaso-occlusive events. Lastly, the utility of pulmonary function tests still needs to be established

Bellis prostrata Pomel (Asteraceae), a new species for Morocco

Investigations conducted in temporary wetlands of the coastal Meseta of W Morocco (Benslimane region) lead to the discovery of Bellis prostrata in a small endoreic temporary pool (ca. 1 ha) of the quartzitic-limestone plateau of Benslimane

Joumine Marsh; National Park of Ichkeul, Tunisia: floristic diversity, vegetation mapping and dynamics (1925-2011)

The vegetation of Joumine Marsh (National Park of Ichkeul, Tunisia) has been studied from 2005 to 2011 with the aims: (1) to characterize the present-day status of the marsh vegetation based on plant inventories and phytosociological surveys, (2) to identify the influence of interannual hydrological changes on the plant distribution, and (3) to reconstruct, on the basis of previous works, the vegetation dynamics over the past 86 years (1925-2011). Results reveal the regression and sometimes the local extinction of the plants of temporary freshwater habitats, and their replacement by halophilous, cultivation-tolerant, footpath and grazing-tolerant species. Such changes express the artificialisation of the marsh. The mid-term dynamics of Joumine Marsh (1925-2011) is characterized by four periods: (1) before the first hydrological developments realized on the Joumine Wady in 1948, the marsh was dominated by the helophytic formation of Bolboschoenus glaucus and Schoenoplectus litoralis; (2) between 1948 and the putting into service of the Joumine Dam in 1982/83, the helophytic vegetation remained dominant; (3) between 1982-1983 and the summer 2002, because of an inappropriate management of the reservoir (without freshwater release), the salinity of the marsh has considerably increased, triggering the decline of the hydrophilous vegetation and the expansion of salt scrubs of Sarcocornia fruticosa; (4) finally, since autumn 2002, occasional releases of freshwater from the Joumine reservoir and the realization of new hydrological developments on the Joumine ditch lead to the inundation and washing of the marsh. These changes have induced the partial replacement of the salt scrubs by renewed helophytic herbaceous formations. This study reveals the significance of the ratio “hydro-hygrophilous plants/halophilous plants” as an indicator of the health of coastal wetlands. This ratio, as a simple tool for helping the management, may be used at the scale of the entire system lake-marsh of IchkeulLa végétation du marais de Joumine (Parc National de l'Ichkeul, Tunisie) a été étudiée entre 2005 et 2011 dans les buts: (1) de caractériser l'état actuel de la végétation du marais sur la base d'inventaires floristiques et de relevés phytosociologiques, (2) d'identifier l'influence des changements hydrologiques interannuels sur la répartition de la végétation, et (3) de reconstruire, sur la base de travaux antérieurs, la dynamique de la végétation sur 86 ans (1925-2011). Les résultats révèlent la réduction, voire la disparition, des espèces inféodées aux milieux temporaires d'eau douce, et leur remplacement par des espèces halophiles, adventices, rudérales et indicatrices de surpâturage. Ces changements dénotent l'artificialisation du marais. La dynamique à moyen terme de la végétation du marais de Joumine (1925-2011) est caractérisée par quatre périodes: (1) avant les premiers aménagements hydrauliques réalisés sur l'oued Joumine en 1948, le marais était dominé par la scirpaie à Bolboschoenus glaucus et Schoenoplectus litoralis ; (2) entre 1948 et la mise en service du barrage de Joumine en 1982/83, la scirpaie est restée dominante ; (3) entre 1982-83 et l'été 2002, sous l'effet d'une gestion inappropriée du barrage (sans lâcher d'eau douce), la salinité du marais a considérablement augmenté, provoquant le déclin de la végétation hydro-hygrophile et l'extension de la sansouïre à Sarcocornia fruticosa ; (4) enfin, depuis l'automne 2002, des lâchers occasionnels d'eau douce à partir du barrage de Joumine et la réalisation de nouveaux aménagements sur le canal de Joumine ont conduit à l'inondation et au lessivage du marais. Ces changements ont entraîné le déclin de la végétation halophile au profit de la régénération de la scirpaie. Cette étude met en évidence l'importance du rapport « végétation hydro-hygrophile/végétation halophile » en tant qu'indicateur de l'état de santé de marais littoraux. Ce rapport, qui apparaît comme un outil simple d'aide à la gestion, peut être exploité à l'échelle de l'ensemble du système lac-marais de l'Ichkeul

Rare, endemic and threatened vascular flora of Tunisian wetlands

Tunisian wetlands harbour a large floristic richness, estimated at 407 species representing 228 genera and 75 families. This flora comprises species strictly limited to wetlands, and species originating from surrounding lands. It is characterized by a big proportion of rare and/or threatened taxa (~ 29 %). Kroumirie is the richest region, with 290 taxa among which 54 are considered as very rare, rare or infrequent, because of their limited distribution area, generally located in frail or degraded ecosystems. The preservation of this exceptional biodiversity, threatened on short term, implies the urgent development of scientific investigations and adapted protection measuresLes zones humides de Tunisie présentent une grande richesse floristique, évaluée à 407 espèces représentant 228 genres et 75 familles. Ces espèces sont, soit strictement inféodées aux zones humides, soit transgressives des milieux terrestres. Cette flore est caractérisée par une forte proportion des taxons rares et/ou menacés (∼ 29 %). La Kroumirie est la région la plus riche, avec 290 taxons dont 54 sont considérés comme très rares, rares ou peu répandus, en raison de leur répartition réduite et généralement située au niveau d'écosystèmes très fragiles ou dégradés. La préservation de cette biodiversité exceptionnelle et menacée à court terme nécessite la mise en place urgente d'études scientifiques et de mesures de protection appropriées

Enjeux de conservation d’une zone humide d’eau douce méditerranéenne exceptionnelle : la Garâa Sejenane (Tunisie septentrionale)

Cet article a pour but d’évaluer les enjeux de conservation concernant la végétation hydrophytique de la plus grande zone humide naturelle d’eau douce de Tunisie, la Garâa Sejenane. Les 55 relevés phytosociologiques réalisés révèlent une richesse floristique exceptionnelle, avec 74 hydrophytes dont 26 sont à forte valeur patrimoniale. Des analyses multivariées (AFC, CHA) effectuées sur ces données distinguent trois types d’habitats : des cultures inondables, des marais temporaires, et des pelouses humides/mares temporaires. Leur cartographie montre une structure en 3 zones concentriques : une ceinture externe constituée de pelouses humides, de mares temporaires et de prairies fourragères sèches, une zone intermédiaire occupée par des marais temporaires et des prairies fourragères humides, et une zone centrale formée de cultures inondables. Un Indice de Rareté des Espèces très élevé, et des espèces à fort enjeu conservatoire (1 endémique stricte à la Garâa Sejenane, 5 espèces dont elle constitue l’unique localité tunisienne, et 2 espèces dont elle abrite les plus grandes populations nord-africaines) révèlent l’intérêt écologique et conservatoire majeur du site, et ceci malgré de fortes pressions anthropiques subies depuis les années 60. Dans le contexte actuel d’augmentation de la pression de perturbation, la conservation à long terme de cette biodiversité exceptionnelle nécessite la mise en place de mesures de gestion appropriées intégrant les populations locales.This study addresses the conservation issues of the hydrophytic vegetation of Garâa Sejenane, the largest natural freshwater wetland in Tunisia. Fifty-five phytosociological relevés reveal the exceptional floristic wealth, including 74 hydrophytes of which 26 are patrimonial species. Multivariate analyses (CA, AHC) differentiate three types of habitats: flooded crops, temporary marshes, and wet lawns/temporary pools. Their mapping shows concentric zones, including an external belt of wet lawns, temporary pools and dry fodder meadows, an intermediate belt of temporary marshes and wet fodder meadows, and a central area of flood crops. A high Species Rarity Index and the occurrence of several species with high conservation values (1 strictly endemic species to the Garâa Sejenane, 5 others that exist in Tunisia only in this site, and 2 species whose local populations are the largest in North Africa) confirm the major ecological and conservatory interest of the site, despite anthropogenic pressures on the Garâa Sejenane since the sixties. In the present-day context of increasing human pressure, the long-term conservation of this exceptional biodiversity needs the implementation of targeted management measures integrating local populations

Influence of grazing on structure, composition and dynamics of vegetation in Mediterranean temporary pools (northern Tunisia)

Three temporary pools of Sejenane region (northern Tunisia) have been studied with the aims of characterizing their vegetation, and of specifying the impact of grazing on their structure, composition and dynamics. Permanent transects of quadrats have been surveyed in spring and summer during two (not-grazed pool) to three years (grazed pools). The vegetation of the three pools is organized in three concentric belts related to the topographic gradient. The between-years dynamics is strongly characterized by the alternation of distinct spring and summer vegetations. Grazing appears as the main control of the composition and structure of hydrophytic plant communities. It prevents the colonization by competitive, perturbation-sensitive species, and favours the persistence of annual, light-demanding dwarf plants. In order to protect the biodiversity of these rare habitats in Tunisia, it is necessary to maintain, through an adapted management of grazing, a landscape mosaic of grazed and not-grazed zonesTrois mares temporaires de la région de Sejenane (Tunisie septentrionale) ont été étudiées afin de caractériser leur végétation et de préciser l’influence du pâturage sur sa structure, sa composition et sa dynamique intra- et interannuelle. Des transects de quadrats permanents ont été suivis au printemps et en été durant deux (mare non pâturée) à trois ans (mares pâturées). Le cortège floristique des mares étudiées est organisé en trois ceintures concentriques liées au gradient topographique. La dynamique intra-annuelle de la végétation est nettement marquée par l’alternance de cortèges printaniers et estivaux distincts. Le pâturage apparaît comme le principal facteur contrôlant la composition et la structure des communautés végétales hydrophytiques. Il limite le développement des espèces compétitives sensibles aux perturbations et favorise le maintien d’une flore de petite taille, thérophytique et héliophile. Afin de préserver la biodiversité de ces habitats rares en Tunisie, il apparaît nécessaire de maintenir, par une gestion adaptée du pâturage, une mosaïque paysagère de zones non pâturées et pâturée

Inferring causal molecular networks: empirical assessment through a community-based effort

Inferring molecular networks is a central challenge in computational biology. However, it has remained unclear whether causal, rather than merely correlational, relationships can be effectively inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge that focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results constitute the most comprehensive assessment of causal network inference in a mammalian setting carried out to date and suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess the causal validity of inferred molecular networks