Research Unit of Biology

Tunis, Tunisia

Research Unit of Biology

Tunis, Tunisia
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Yacoubi L.,Research Unit 03 UR 08 05 | Rabaoui L.,Research Unit of Biology | Hamdaoui M.H.,Unite de recherche sur les composes antioxidants stress oxidants elements traces et maladies met. | Fattouch S.,Tunisian National Institute of Applied Sciences and Technology | And 3 more authors.
Journal of Medicinal Plants Research | Year: 2011

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia. A large part of research focusing on the pathogenesis of IPF suggested that oxidative stress has been implicated in the pathogenesis of bleomycin induced lung fibrosis. We therefore examined whether fenugreek Trigonella foenum-graecum Linnaeus, 1753 and its phenolylic extract inhibits bleomycin induced lung fibrosis in rats. Forty male Wistar rats were given a single dose of bleomycin (4 mg/kg, intratracheally). After 2 weeks of treatment, both fenugreek seed polyphenol extract (FSPE) and fenugreek powder supplementation (FPS) significantly reduced MDA (0.280±0.053 and 0.205±0.031 nmol/mg protein respectively) and increased TAS (0.888±0.086 and 0.695±0.086 mmol/l) in comparison to control groups (0.434±0.043 and 0.417±0.034 nmol/mg protein for MDA; 0.345±0.043 and 0.561±0.050 mmol/l for TAS). The restoration of oxidant/antioxidant balance was seen concretely through the diminution of inflammation in treated groups (3.29±0.49 and 4.29±0.76) in contrast to untreated groups (4.70±0.48 and 5.00±0.00). TGFβ was increased only in inflammatory infiltrate of parenchyma lung. In spite of these results, no correlation was found with increasing fibrosis, suggesting that a direct role for inflammation in pulmonary fibrosis is unlikely. The data suggest, in the first hand, that fenugreek's polyphenol has a potent antioxidant activity and therefore has a potent anti-inflammatory activity against bleomycin induced lung fibrosis model in rats, and in the second hand, they confirm that besides inflammation, other factors probably interfere in the pathogenesis of pulmonary fibrosis. © 2011 Academic Journals.

Tlig-Zouari S.,Research Unit of Biology | Rabaoui L.,Research Unit of Biology | Cosentino A.,Messina University | Irathni I.,Research Unit of Biology | And 2 more authors.
Journal of Sea Research | Year: 2011

The macrozoobenthos associated with the introduced pearl oyster Pinctada radiata has been sampled at two different spatial scales of three sectors (order of hundreds of kilometres) and of eight localities (order of tens of kilometres). Moreover, the NW sector was selected to compare three localities with the presence of P. radiata (low density) and one locality where it was totally absent. The first design was hierarchical, with random localities nested within sectors; the second one was an asymmetrical factorial design, in which the presence/absence of Pinctada and hydrodynamism were considered. Similarity relationships were investigated by means of multivariate clustering, similarity percentage analysis and nm-MDS ordination; the two experimental designs have been tested by permutational MANOVA and analysis of dispersion (PERMDISP). Most of the variability of the associated zoobenthic community appeared to be mainly captured by local environmental factors; the meso-scale variability was more discriminating than differences at larger spatial scale. Large scale NW-SE biogeographic gradient may also have some effects in the assemblage composition. Although the whole arrangement of samples in the MDS plane showed a clear Bray-Curtis distance between the locality without Pinctada and all the remaining sites, pair-wise contrasts were not all significant. The factor "presence/absence" was not significant in this design, whereas the exposure was more indicative of differences in the local assemblage composition. These results may not confirm that the community structure variability is due to the impact of Pincata invasion because the potential and subtle community shift may be masked by the overwhelming influence of just the local environmental gradients. In spite of this, the introduced oyster may play the role of an engineer species at high densities, contributing to the complexity of the benthic habitat and influencing the trophic pattern of its fauna. © 2010 Elsevier B.V.

Ben Ismail D.,Research Unit of Biology | Rabaoui L.,Research Unit of Biology | Diawara M.,Research Unit of Biology | Ben Hassine O.K.,Research Unit of Biology
Cahiers de Biologie Marine | Year: 2012

In this study, bryozoan communities were investigated along the Tunisian coastline, using both univariate and multivariate analyses. Seven populations situated at different localities belonging to different geographic sectors, were sampled, and the communities were analysed and compared taking into account different environmental factors. The analysis of similarity (ANOSIM) showed that the population structure of Bryozoans seems to be influenced by "geographic location", "habitat type" and "substratum type" factors. The latter two factors seemed to be linked since each habitat type was characterized by a special type of substratum. The similarity percentage (SIMPER) analysis showed that each analysed community was dominated by some particular species. In fact, some bryozoan species were exclusive to marine sites, while others were exclusive to lagoons. In addition, bryozoan community was qualitatively richer in marine sites than that in lagoons. The species Electra posidoniae, Collarina balzaci and Microporella ciliata were found to be the most contributing to the dissimilarity between the two habitat types. The marine/lagoon discrimination obtained with univariate analyses was also confirmed by multivariate ones i.e. non metrical MDS and Bray-Curtis similarity. In terms of constancy index, the majority of assemblages was dominated by "not very common" species.

Tlig-Zouari S.,Research Unit of Biology | Rabaoui L.,Research Unit of Biology | Fguiri H.,Research Unit of Biology | Ben Hassine O.K.,Research Unit of Biology
Cahiers de Biologie Marine | Year: 2010

The present study is a first contribution to the knowledge of the status and distribution of the endangered Mediterranean species Patella ferruginea Gmelin, 1791 and the density of individuals along the northern and eastern Tunisian coastline. Field work carried out from December 2005 to August 2006 revealed that the distribution of this mollusc is limited to the Gulf of Tunis (6 stations) and Cape Bon Peninsula (1 station). The densest populations were encountered in the less polluted localities (Korbous, El Haouaria, the Island of Zembra, and Kelibia). Patella ferruginea was primarily encountered in midintertidal rocky shores (medium horizon) in biotopes characterized by clear waters and alga-covered (Ralfsia verrucosa) rocky substratum which are generally hardly accessible and thus not subject to human predation. The Island of Zembra (National protected area) seems to host the most equilibrated and preserved population of Patella ferruginea. It is dominated by large specimens showing the importance of marine protected areas in the conservation of this endangered species. Our results argue in favor of human predation impact on the structure of Patella ferruginea populations.

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