Lamjed Mansour

Evaluation of cytotoxic, oxidative stress, proinflammatory and genotoxic effect of silver nanoparticles in human lung epithelial cells.

Silver nanoparticles are increasingly used in various products, due to their antibacterial properties. Despite its wide spread use, only little information on possible adverse health effects exists. Therefore, the aim of this study was to assess the toxic potential of silver nanoparticles (<100 nm) in human lung epithelial (A549) cells and the underlying mechanism of its cellular toxicity. Silver nanoparticles induced dose and time‐dependent cytotoxicity in A549 cells demonstrated by MTT and LDH assays. Silver nanoparticles were also found to induce oxidative stress in dose and time‐dependent manner indicated by depletion of GSH and induction of ROS, LPO, SOD, and catalase. Further, the activities of caspases and the level of proinflammatory cytokines, namely interleukin‐1β (IL‐1β) and interleukin‐6 (IL‐6) were significantly higher in treated cells. DNA damage, as measured by single cell gel electrophoresis, was also dose and time‐dependent signicants in A549 cells. This study investigating the effects of silver nanoparticles in human lung epithelial cells has provided valuable insights into the mechanism of potential toxicity induced by silver nanoparticles and warrants more careful assessment of silver nanoparticles before their industrial applications.

Molecular and Morphometric Characteristics of Ceratomyxa hamour n. sp. (Myxosporea: Bivalvulida) Infecting the Gallbladder of the Orange-spotted Grouper Epinephelus coioides from the Arabian Gulf, Saudi Arabia

Ceratomyxa hamour n. sp. was found to infect the gallbladder of the orange‐spotted grouper, Epinephelus coioides located off the Saudi Arabian coast of the Arabian Gulf. The infection was reported as a free‐floating spore in the bile, and pseudoplasmodia were not observed. Mature spores were crescent‐shaped and measured on average 7 μm in length and 16 μm in thickness. The polar capsule, meanwhile, had length to width measurements of 4 μm and 3 μm on average. A periodical survey was conducted throughout a sampling period between December 2012 and December 2013, with the results showing that the parasite was present throughout the year with a mean prevalence of 32.6%. The objective of this study was to characterize this new species based on its morphological and molecular differences from previously described species. Molecular analysis based on the partial sequence of the SSU rDNA gene, showed the highest similarity (97.8%) to Ceratomyxa buri, reported in the cultured yellow tail Seriola quinqueradiata in Japan. Indeed, C. buri and the new species described here formed an individual cluster with a high degree of bootstrap support. This is the first reported species of genus Ceratomyxa from the Arabian Gulf fishes off Saudi Arabia.

Ceratomyxa tunisiensis n. sp. (Myxosporea: Bivalvulida) from the Gallbladders of Two Carangid Fish Caught Off the Coast of Tunisia

A new coelozoic Myxozoan species, Ceratomyxa tunisiensis n. sp., was found infecting the gallbladders of two carangid fish, Caranx rhonchus and Trachurus trachurus (Perciforme, Carangidae), from the Gulf of Gabès, on the southern coast of Tunisia. The parasite develops in spherical mono‐, diplo‐, or polysporic tropozoites in the gallbladder of the hosts. Mature spores are typical of the genus Ceratomyxa. They are transversely elongated and narrowly crescent‐shaped with a slightly convex anterior and concave posterior, and measure 23 ± 0. 27 (20–25) μm width × 6 ± 0.26 (5–8) μm in length. Spore shell valves are symmetrical with rounded ends. Two spherical polar capsules situated on either side of the sutural line measure 2.2 μm (2.0–3.0) in diam. Periodical sampling of C. rhonchus and T. trachurus from Marsh 2012 to February 2013 showed that infection due to C. tunisiensis occurs in 59% and 69% of the examined fish, respectively. Molecular analysis based on the small subunit (SSU) rRNA sequence shows high genetic divergence with all other ceratomyxid species. A Maximum Likelihood phylogenetic tree shows association with the species C. leatharjecketi Fiala, kova, Kodadkova, Freeman, Bartošova‐Sojkova, and Atkinson, 2015 reported from the gallbladder of Aluterusmonoceros (L.) caught in the Andaman Sea, off Malaysia. Nonetheless, the SSU rRNA sequences of C. tunisiensis and C. leatharjecketi have only a 90% similarity.

Spraguea lophii (Microsporidia) parasite of the teleost fish, Lophius piscatorius from Tunisian coasts: evidence for an extensive chromosome length polymorphism.

A microsporidian of the genus Spraguea was found parasitizing the nervous tissues of Lophius piscatorius collected from various localities in the Mediterranean coastal areas of Tunisia. The tissue localization, the infection focus aspect and sporal dimorphism are characteristics of Spraguea lophii species. Molecular data based on partial sequence of SSUrRNA encoding gene shows few nucleotide polymorphisms, compared to all described Spraguea isolates. Molecular karyotype obtained on pulsed field gel electrophoresis (1D-PFGE) shows a profile with 14 stained bands in the range of 230-880 kbp and a genome size estimated to 6.700 kbp. The rare cutter endonuclease MluI KARD 2-D-PFGE fingerprint shows an extensive chromosome length polymorphism, but the number of chromosome is unchanged and consists of 15 different molecules. The extensive chromosome length polymorphism is associated to a reduced number of genetic events.

Metal bioaccumulation in two edible cephalopods in the Gulf of Gabes, South-Eastern Tunisia: environmental and human health risk assessment

Samples of Octopus vulgaris and Sepia officinalis were collected from four areas in the Gulf of Gabes, south-eastern Tunisia, and their edible tissues (mantle and arms) were analyzed for cadmium, copper, mercury, and zinc. While the concentrations of metals showed significant differences between the sampling sites, no differences were revealed between the tissues of the two species. The spatial distribution of metals analyzed showed similar pattern for both tissues of the two species, with the highest concentrations found in the central area of Gabes Gulf, and the lowest in the northern and/or southern areas. From a human health risk point of view, the highest values of estimated daily intake, target hazard quotient, and hazard index were found in the central area of Gabes Gulf. Although the results of these indices were, in general, not alarming, the health risks posed by the consumption of cephalopods on local consumers cannot be excluded.

In Vitro Scolicidal Effects of Salvadora persica Root Extract against Protoscolices of Echinococcus granulosus

It has been known that Arak, Salvadora persica, has a number of medicinal properties. We tried to investigate in vitro scolicidal effect of root extracts of this plant against protoscolices from hydatid cysts of Echinococcus granulosus. Protoscolices were aseptically collected from sheep livers containing hydatid cysts. S. persica root extract was used in 10, 30, and 50 mg/ml concentration for 10, 20, and 30 min. The viability of protoscolices was ascertained by 0.1% eosin staining. Scolicidal activity of S. persica extract at a concentration of 10 mg/ml was 36.3%, 50.3%, and 70.8% after 10, 20, and 30 min of exposure, respectively. The scolicidal effect of this extract at a concentration of 30 mg/ml was 52.9%, 86.7%, and 100% after 10, 20, and 30 min of exposure, respectively. S. persica extract at a concentration of 50 mg/ml, meanwhile, killed 81.4%, 100%, and 100% of protoscolices after 10, 20, and 30 min, respectively. Also, the cytotoxic potential of S. persica was assessed on human liver cells (HepG2) using trypan blue exclusion test. No cytotoxic effect was observed on HepG2 cell line. The present study confirmed for the first time that the ethanolic extract of S. persica has high scolicidal power in vitro. However, in vivo effect of this material remains to be studied for treatment of echinococcosis in humans and herbivorous animals.

Expression and Polymorphism of Toll-Like Receptor 4 and Effect on NF-κB Mediated Inflammation in Colon Cancer Patients.

Our aim was to evaluate the association between the expression and the polymorphism of TLR4/NF-κB pathways and colon cancer. TLR4 (rs4986790, rs10759932, rs10759931 and rs2770150) were genotyped in blood samples from Colorectal patients and healthy controls. TLR4 and cytokines inflammatory expression were evaluated by real time PCR on 40 matching normal and colon tissues and the protein level by Immunohistochemistry. The high level of TLR4 expression in colon cancer tissues is mainly due to infections by bacteria in the human colon and leads to induction of an acute secretion of inflammatory cytokines mediated by NF-κB. Also, we report here a clear evidence for an association between TLR4 rs10759931 polymorphism (OR = 0.086, CI: 0.04–0.18, P = <0.00001). This polymorphism affects the entire population without being specific to either gender or to any age group. In contrast, the rs2770150 is associated with colon cancer in women aged over 50 years and is closely linked with the decreased levels of female sex hormones during the post-menopausal period (OR = 0.188, CI: 0.074–0.48, P = <0.00084). rs10759932 and rs4986790 appear to have any association with colon cancer. Our data suggest that TLR4 SNPs could possibly serve as biomarkers for decision making in colon cancer treatment.

Genotypic diversity of the Killer Cell Immunoglobulin-like Receptors (KIR) and their HLA class I Ligands in a Saudi population

Abstract Killer Cell Immunoglobulin-like Receptors (KIR) have been used as good markers for the study of genetic predisposition in many diseases and in human genetic population dynamics. In this context, we have investigated the genetic diversity of KIR genes and their main HLA class I ligands in Saudi population and compared the data with other studies of neighboring populations. One hundred and fourteen randomly selected healthy Saudi subjects were genotyped for the presence or absence of 16 KIR genes and their HLA-C1, -C2, -Bw4Thr80 and Bw4Ile80 groups, using a PCR-SSP technique. The results show the occurrence of the framework genes (3DL2, 3DL3 and 2DL4) and the pseudogenes (2DP1 and 3DP1) at highest frequencies. All inhibitory KIR (iKIR) genes appeared at higher frequencies than activating genes (aKIR), except for 2DS4 with a frequency of 90.35%. A total of 55 different genotypes were observed appearing at different frequencies, where 12 are considered novel. Two haplotypes were characterized, AA and Bx (BB and AB), which were observed in 24.5% and 75.5% respectively of the studied group. The frequencies of iKIR + HLA associations were found to be much higher than aKIR + HLA. KIR genes frequencies in the Saudi population are comparable with other Middle Eastern and North African populations.

Morphological and molecular aspects of Ceratomyxa mehlhorni n. sp., a parasite of the golden trevally Gnathanodon speciosus in the Arabian Gulf off the Saudi Arabian coast, with data on its seasonal prevalence

During a survey of the myxosporean fauna of the golden trevally Gnathanodon speciosus from the Arabian Gulf off Saudi Arabia, a species of Ceratomyxa that did not conform to any known species was recorded. The infection was detected as a large number of mature spores free-floating in the bile. Mature spores were hat- or helm-like in the frontal view with two short and unequal valves. The spores measured 8 (7–9) × 12 (10–14). The two polar capsules were spherical, equal in size and measured 3 (2–4) in diameter with three filament turns. Sporoplasm was binucleated and filled the whole extracapsular space. The small subunit ribosomal DNA sequence of this species did not match any available sequences in GenBank. The lowest genetic distance was 0.017, observed with Ceratomyxa moseri infecting Pomacentrus wardi from Australia’s Great Barrier Reef. A maximum likelihood phylogenetic tree showed a close association between the new species and a variety of ceratomyxid species, including Ceratomyxa arabica reported from the Arabian Gulf. Given the morphological and molecular differences between this species and other Ceratomyxa spp., we proposed the present form was a new species and the name Ceratomyxa mehlhorni sp. n. for this parasite from the gallbladder of G. speciosus.

Infertility in the hyperplasic ovary of freshwater planarians: the role of programmed cell death.

Ex-fissiparous planarians produce infertile cocoons or, in very rare cases, cocoons with very low fertility. Here, we describe the features of programmed cell death (PCD) occurring in the hyperplasic ovary of the ex-fissiparous freshwater planarian Dugesia arabica that may explain this infertility. Based on TEM results, we demonstrate a novel extensive co-clustering of cytoplasmic organelles, such as lysosomes and microtubules, and their fusion with autophagosomes during the early stage of oocyte cell death occurring through an autophagic pattern. During a later stage of cell death, the generation of apoptotic vesicles in the cytoplasm can be observed. The immunohistochemical labeling supports the ultrastructural results because it has been shown that the proapoptotic protein bax was more highly expressed in the hyperplasic ovary than in the normal one, whereas the anti-apoptotic protein bcl2 was slightly more highly expressed in the normal ovary compared to the hyperplasic one. TUNEL analysis of the hyperplasic ovary confirmed that the nuclei of the majority of differentiating oocytes were TUNEL-positive, whereas the nuclei of oogonia and young oocytes were TUNEL-negative; in the normal ovary, oocytes are TUNEL-negative. Considering all of these data, we suggest that the cell death mechanism of differentiating oocytes in the hyperplasic ovary of freshwater planarians is one of the most important factors that cause ex-fissiparous planarian infertility. We propose that autophagy precedes apoptosis during oogenesis, whereas apoptotic features can be observed later.