Fagonia cretica: Identification of compounds in bioactive gradient high performance liquid chromatography fractions against multidrug resistant human gut pathogens.

Plants are alternative source of natural medicines due to secondary active metabolites. Fagonia cretica extracts and Gradient High-Pressure Liquid Chromatography fractionations were checked against multidrug-resistant gastrointestinal pathogens including, Salmonella typhi, Escherichia coli and Shigella flexneri. ESI-MS/MS analysis of bioactive HPLC fractions was performed to elucidate antibacterial compounds. F. cretica extracts exhibited potential antibacterial activity. Twenty-four (24) HPLC fractions were obtained from methanol, ethanol and aqueous extracts of F. cretica. Eighteen (18) fractions showed antibacterial activity, while no activity was observed by the remaining six (6) fractions. HPLC fractions, F1 (25g ± 0.20 mm) and F2 (15f ± 0.12 mm) of aqueous extract exhibited activity against multidrug resistant GI pathogens. Gallic acid, quinic acid, cyclo-l-leu-l-pro, vidalenolone, liquirtigenin, rosmarinic acid and cerebronic acid were identified in F1 fraction of aqueous extract, while succinic acid, cyclo (l-Leul-Pro) and liquirtigenin were identified in F2 fraction of aqueous extract through ESI-MS/MS analysis. F. cretica extracts and HPLC fractions showed potential activity against MDR GI pathogens. Vidalenolone, Cyclo-1-leu-1-pro and Cerebronic acid are first time reported in F. cretica. Further characterization of bioactive compounds from F. cretica may be helpful to elucidate antibacterial therapeutic molecules.

Isolation, Characterization, and Efficacy of Three Lytic Phages Infecting Multidrug-Resistant Salmonella Serovars from Poultry Farms in Egypt.

Multidrug-resistant (MDR) Salmonella serovars are considered a significant threat to veterinary and public health. Developing new antimicrobial compounds that can treat the infection caused by these notorious pathogens is a big challenge. Bacteriophages can be adsorbed on and inhibit the growth of bacteria, providing optimal and promising alternatives to chemical antimicrobial compounds against foodborne pathogens due to their abundance in nature and high host specificity. The objective of the current study was to isolate and characterize new phages from poultry farms and sewage and to evaluate their efficacy against S. Enteritidis isolates. The study reports three lytic phages designated as ϕSET1, ϕSET2, and ϕSET3 isolated from poultry carcasses and sewage samples in Qalubiya governorate Egypt. The effectiveness of phages was evaluated against multidrug-resistant S. Enteritidis strains. Electron microscopy showed that these phages belong to the Siphoviridae family. Phages were tested against 13 bacterial strains to determine their host range. They could infect four S. Enteritidis and one S. Typhimurium; however, they did not infect other tested bacterial species, indicating their narrow infectivity. The bacteriophage's single-step growth curves revealed a latent period of 20 min for ϕSET1 and 30 min for ϕSET2 and ϕSET3. The isolated Salmonella phages prevented the growth of S. Enteritidis for up to 18 hrs. The findings revealed that Salmonella phages could be used as alternative natural antibacterial compounds to combat infection with MDR S. Enteritidis in the poultry industry and represent a step forward to using large panels of phages for eliminating Salmonella from the food chain.

Effect of replacement of antibiotics with thyme and celery seed mixture on the feed intake and digestion, ruminal fermentation, blood chemistry, and milk lactation of lactating Barki ewes.

The study investigated the effect of in-feed administration of dried thyme leaf and celery seed mixture (at 1 : 1 DM basis) compared with salinomycin ionophore on milk production and milk nutritive value of Barki ewes. Thirty ewes (37.5 ± 1.8 kg), divided into 3 treatment groups, were fed: (1) a complete control diet comprising concentrates and fodder maize (Zea mays L.) at 60 : 40 dry matter basis, (2) the control diet plus 20 g of thyme and celery mixture supplementation and (3) the control diet supplemented with 1 g of salinomycin per ewe daily for 90 days. Inclusion of thyme-celery treatment increased (P < 0.05) weight gain, average daily gain, milk yield, milk component yields, and feed efficiency, without affecting milk composition. In addition, the thyme-celery treatment enhanced (P < 0.05) nutrient intake and digestibility, total ruminal volatile fatty acids, branched chain fatty acids, and acetate proportions and decreased ammonia-N concentration. Thyme-celery treatment increased (P < 0.05) serum glucose, thyroxine, and glutamate-pyruvate transaminase concentrations. It is concluded that the thyme and celery mixture (1 : 1 DM basis) at 20 g per lactating ewe daily can replace the salinomycin ionophore. Enhanced feed utilization and lactational performance as well as milk nutritive value for human consumption were observed with the natural additive mixture supplementation.

TLR4 signaling modulation of PGC1-α mediated mitochondrial biogenesis in the LPS-Chronic mild stress model: Effect of fluoxetine and pentoxiyfylline.

AIM: The addition of repeated lipopolysaccharide (LPS) to chronic mild stress was recently proposed in our lab as an alternative model of depression, highlighting the possible interaction between stress and immune-inflammatory pathways in predisposing depression. Given that CMS-induced depressive behavior was previously related to impaired hippocampal energy metabolism and mitochondrial dysfunction, our current study aimed to investigate the interplay between toll-like receptor 4 (TLR4) signaling and peroxisome proliferator-activated receptor gamma coactivators-1-alpha (PGC1-α) as a physiological regulator of energy metabolism and mitochondrial biogenesis in the combined LPS/CMS model. MAIN METHODS: Male Wistar rats were exposed to either LPS (50 µg/kg i.p.) over 2 weeks, CMS protocol for 4 weeks or LPS over 2 weeks followed by 4 weeks of CMS (LPS/CMS). Three additional groups of rats were exposed to LPS/CMS protocol and treated with either pentoxifylline (PTX), fluoxetine (FLX) or a combination of both. Rats were examined for behavioral, neurochemical, gene expression and mitochondrial ultra-structural changes. KEY FINDINGS: LPS/CMS increased the expression of TLR4 and its downstream players; MyD88, NFκB and TNF-α along with an escalation in hippocampal-energy metabolism and p-AMPK. Simultaneously LPS/CMS attenuated the expression of PGC1-α/NRF1/Tfam and mt-DNA. The antidepressant (AD) 'FLX', the TNF-α inhibitor 'PTX' and their combination ameliorated the LPS/CMS-induced changes. Interestingly, all the aforementioned changes induced by the LPS/CMS combined model were significantly less than those induced by CMS alone. SIGNIFICANCE: Blocking the TLR4/NFκB signaling enhanced the activation of the PGC1-α/NRF1/Tfam and mt-DNA content independent on the activation of the energy-sensing kinase AMPK.

Dose- dependent ameliorative effects of quercetin and l-Carnitine against atrazine- induced reproductive toxicity in adult male Albino rats.

This study aimed to determine the protective effects of co-administration of Quercetin (QT) or l-Carnitine (LC) against the oxidative stress induced by Atrazine (ATZ) in the reproductive system of intact male Albino rats. 36 rats were divided equally into 6 groups. Rats in the control negative "CNT" group received 1.5 ml distilled water for 21 days. All rats in the other groups received ATZ (120 mg/kg bw) through gavage. Groups 3 and 4 were co-administered with either low or high dose of QT (10 "ATZLQT" and 50 "ATZHQT" mg/kg bw, respectively). Groups 5 and 6 were co-administered with either low or high dose of LC (200 "ATZLLC" and 400 "ATZHLC" mg/kg bw, respectively). At the end of the experiment, animals were sacrificed and all samples were collected. ATZ significantly increased serum level of malondialdehyde (MDA) and decreased total antioxidant capacity (TAC). Also, ATZ increased significantly the sperm cell abnormalities and reduced both testicular IgA and serum testosterone levels. Testicular DNA laddering % and CYP17A1 mRNA expression were significantly reduced in ATZ group. Interestingly, co-administration with low dose QT or different doses of LC succeeded to counteract the negative toxic effects of ATZ on serum oxidative stress indicators, serum testosterone levels, testicular IgA level and improved testicular CYP17A1 mRNA expression. In conclusion, QT in low dose and LC in both low and high doses exerted a significant protective action against the reproductive toxicity of ATZ, while higher dose of QT failed induce immune-stimulant effect against ATZ in adult male Albino rats.

The angiotensin II AT2 receptor is an AT1 receptor antagonist.

The vasopressor angiotensin II activates AT(1) and AT(2) receptors. Most of the known in vivo effects of angiotensin II are mediated by AT(1) receptors while the biological functions of AT(2) receptors are less clear. We report here that the AT(2) receptor binds directly to the AT(1) receptor and thereby antagonizes the function of the AT(1) receptor. The AT(1)-specific antagonism of the AT(2) receptor was independent of AT(2) receptor activation and signaling, and it was effective on different cells and on human myometrial biopsies with AT(1)/AT(2) receptor expression. Thus, the AT(2) receptor is the first identified example of a G-protein-coupled receptor which acts as a receptor-specific antagonist.

Increased expression of a novel early activation surface membrane receptor in cutaneous T cell lymphoma cells.

Using a newly generated monoclonal antibody we identified the 96 kDa transmembrane receptor SC5 expressed simultaneously on a human Sezary cell line and a minor T cell subset in normal individuals. SC5 antigen was detected mostly on CD45RO+ lymphocytes from both CD4+ and CD8+ subsets as well as on natural killer and B lineage cells. SC5 surface expression increased very early after polyclonal stimulation of CD3+ cells due to the transfer of intracellular SC5 molecules to the cell membrane. Engagement of SC5 receptor by its monoclonal antibody inhibited the anti-CD3-induced proliferation and cytokine secretion of peripheral blood T cells and cell clones, whereas SC5 monoclonal antibody did not affect the cytotoxic activity of CD8+ T cell clones. Extensive phenotypic analysis revealed that the percentage of SC5+ CD4+ circulating lymphocytes in Sezary syndrome patients was significantly increased in comparison with controls (p < 0.01) and correlated with the morphologically detected percentage of Sezary syndrome cells in peripheral blood (p < 0.001). In one patient we clearly demonstrated that the circulating malignant T cells coexpress SC5 molecules. Importantly, ligation of SC5 receptor in a cutaneous T cell lymphoma cell line profoundly inhibited the anti-CD3-induced proliferation. Consequently, the expression of SC5 receptor in the peripheral blood of Sezary syndrome patients may serve not only to detect the presence of circulating malignant CD4+ cells but also as a target for immunotherapy.

G10.3 monoclonal antibody identifies novel functional cell surface structures expressed by normal B lymphocytes and various malignant cell lines.

G10.3, a unique monoclonal antibody (mAb), was produced to better characterize lymphocyte subsets. In the present study, we show that this mAb identifies 118, 83 and 51 kDa cell surface sialylated glycoproteins on the immunizing cell line YTindi. The reactivity of G10.3 mAb is restricted in normal cells to B lymphocytes, whereas within tumoral cell lines various lymphoid and non-lymphoid cells were found positive. Interestingly, functional studies revealed that triggering G10.3 mAb reactive molecules with soluble antibody led to an inhibition of growth and to an induction of programmed cell death in tumor cell lines expressing high levels of reactive molecules.

Cutting edge: MHC class I triggering by a novel cell surface ligand costimulates proliferation of activated human T cells.

BY55 is a human cell surface molecule whose expression is restricted to NK cells, a subset of circulating CD8+ T lymphocytes, and all intestinal intraepithelial T lymphocytes. Here, we report that BY55 is a novel NK receptor showing broad specificity for both classical and nonclassical MHC class I molecules, and that optimal binding requires a prior aggregation of MHC class I complexes. Using BY55 transfectants, we have identified functional consequences of MHC class I/ligand interactions for the class I-bearing cell. The triggering of MHC class I molecules on human T cell clones by BY55 delivered a potent proliferative signal in the presence of soluble CD3 mAb. The costimulatory signal provided by MHC class I ligation was only seen in activated, and not resting, peripheral blood T cells. This observation represents an additional and/or alternative pathway to CD28 costimulation and may be of particular relevance in memory T cells lacking CD28, such as intestinal intraepithelial T lymphocytes, which are CD28- but BY55+.

Parasitological effects of simultaneous infections induced by Schistosoma mansoni and aflatoxin B1 in Syrian golden hamsters.

To determine the effect of S. mansoni and aflatoxin B1, 120 hamsters were divided into six groups of 20 each as follows: group I, S. mansoni only, group II, aflatoxin B1 only, group III, S. mansoni then aflatoxin B1 eight week, group IV, aflatoxin B1 then infected with S. mansoni six weeks, later, group V, aflatoxin B1 and S. mansoni simultaneously, group VI control. Loss of body, liver, and spleen weight was more prominent in groups IV and V than in other four groups. The higher mortality rate was in group III. Animals treated with aflatoxin followed by S. mansoni infection appeared to have a less deteriorating effect on the liver (group IV) than group III treated with by S. mansoni first followed by aflatoxin treatment. No morphological abnormalities were detected in the worms including testicular changes in males but a significant number of females was immature even in copula (P < 0.01) in groups III, IV, and V. The average number of S. mansoni eggs was less in groups III, IV, and V in comparison to group I. No abnormalities were detected in the eggs for groups infected with S. mansoni. The diameters of granulomas around eggs, were large on an average in groups III, IV and V as compared with groups I and II.