Ashraf Awad

Efficacy of Spirulina platensis diet supplements on disease resistance and immune-related gene expression in Cyprinus carpio L. exposed to herbicide atrazine

Abstract The present study evaluated the immunotoxicological effects of the herbicide atrazine (ATZ) at sub‐lethal concentrations and the potential ameliorative influence of Spirulina platensis (SP) over a sub‐chronic exposure period on Cyprinus carpio L., also known as common carp. Common carp was sampled after a 40‐days exposure to ATZ (428 &mgr;g/L) and SP (1%), individually or in combination to assess the non‐specific immune response, changes in mRNA expression of immune‐related genes [lysozyme (LYZ), immunoglobulin M (IgM), and complement component 3 (C3)] in the spleen, and inflammatory cytokines (interleukins IL–1ß and IL–10) in the head kidney using real‐time PCR. Additionally, disease resistance to Aeromonas sobria was evaluated. The results revealed that ATZ exposure caused a significant decline in most of the hematological variables, lymphocyte viability, and lysozyme and bactericidal activity. Moreover, ATZ increased the susceptibility to disease, reflected by a significantly lower post‐challenge survival rate of the carp. ATZ may induce dysregulated expression of immune‐related genes leading to downregulation of mRNA levels of IgM and LYZ in the spleen. However, expression of C3 remained unaffected. Of the cytokine‐related genes examined, IL–1B was up‐regulated in the head kidney. In contrast, the expression of IL–10 gene was down‐regulated in the ATZ‐exposed group. The SP supplementation resulted in a significant improvement in most indices; however, these values did not match with that of the controls. These results may conclude that ATZ affects both innate and adaptive immune responses through the negative transcriptional effect on genes involved in immunity and also due to the inflammation of the immune organs. In addition, dietary supplements with SP could be useful for modulation of the immunity in response to ATZ exposure, thereby presenting a promising feed additive for carps in aquaculture. HighlightedsExposure to atrazine (ATZ) for 40 days exhibited immunotoxic effects in common carp (Cyprinus carpio).ATZ altered hematological variables and increased disease susceptibility.ATZ had a more pronounced immunosuppressive effect at the genomic level.Dietary Spirulina platensis (SP) (1%) could be useful for maintaining the altered immunity in response to ATZ exposure.

Effects of florfenicol on the immune responses and the interferon-inducible genes in broiler chickens under the impact of E. coli infection.

Florfenicol (FFC) as a chloramphenicol’s derivative is a special broad-spectrum antibiotic that was used in veterinary clinics. In the present study, we investigated the effect of different doses of FFC on the humoral immune response of broiler chickens to Newcastle disease virus (NDV) vaccine under the impact of E. coli infection. In addition, the expression of the interferon-inducible genes (IRF7, 2′-5′OAS and Mx1) were analyzed in the spleen tissue of these chickens using quantitative real-time PCR (qRT-PCR). The non-treated group with FFC and non-infected with E. coli had the highest immune responses against NDV compared with the FFC treated groups. In the case of E. coli infection, the group treated with FFC (30 mg/Kg BWt) showed lower NDV HI and IgG ELISA Ab levels compared to the group treated with FFC (60 mg/Kg BWt). A dose dependent up-regulation was observed in the level of the interferon-alpha pathway related genes (IRF7 and 2′-5′OAS) in the FFC treated groups compared to the non-treated group. At the slaughter time, the numbers of adipocyte in the bone marrow were significantly higher with moderate atrophy of the hematopoietic lineages in the FFC treated birds compared to the non-treated birds. These results indicated that this FFC dosage dependent increase in the humoral immune responses against NDV vaccine could be attributed to its efficient therapeutic effect on the E. coli infection. However, the increase in the FFC dosage can negatively but temporarily affect the chicken body weights. Additionally, it can exert up regulation effect on the chicken innate immune response with moderate hypoplasia of the bone marrow cells.

Antidotal impact of extra virgin olive oil against genotoxicity, cytotoxicity and immunotoxicity induced by hexavalent chromium in rat

Abstract An in vivo study was carried out to verify whether extra-virgin olive oil (EVOO) has the potential to modulate alterations resulted from exposure to hexavalent chromium (CrVI) as potassium dichromate in rats. For this purpose, CrVI was injected intraperitoneally (i.p.) at a dose of 0.4 mg/kg bw/day, EVOO was given orally at a dose of 300 μl daily either a lone or co-treated with CrVI at the same doses, routes and duration (26 days). At the end of the experiment, blood and spleen samples were collected. Genotoxicity, cytotoxicity and immunotoxicity biomarkers induced by CrVI were evaluated. Also, histopathological and immunohistochemical investigations of spleen tissue were conducted. A significant increase in genotoxicity and cytotoxicity biomarkers (micronucleus frequency, 8-hydroxy-2-deoxyguanosine level and lactate dehydrogenase activity) were recorded in CrVI treated rats. In addition, the immunotoxicity biomarkers showed a significant decrease in phagocytic%, stimulated nitric oxide production and decrease in the serum lysozyme activity. Histopathological and immunohistochemical studies support the cytotoxicity study. Oral administration of EVOO can ameliorate those effects but not restored to control level. Thus, authors recommend that regular consumption of this oil in the diet provides a constant supply of potential antioxidants that could reduce these alterations.

Combined Cytogenotoxic Effects of Bee Venom and Bleomycin on Rat Lymphocytes: An In Vitro Study

This study was carried out to determine the cytotoxic and genotoxic effects of bee venom (BV) and/or the chemotherapeutic agent bleomycin (BLM) on healthy isolated rat lymphocytes utilizing morphometric and molecular techniques. Using the Ficoll-Histopaque density gradient centrifugation technique, lymphocytes were isolated, divided into groups, and subjected to BV and/or BLM at incubation medium concentrations of 10 or 20 μg/mL respectively for 24 and 72 hrs. An MTT assay and fluorescent microscopy examinations were used to assess the cytotoxic effects. To determine the predominant type of BV and/or BLM-induced cell death, LDH release assay was employed beside quantitative expression analyses of the apoptosis-related genes (Caspase-3 and Bcl-2). The genotoxic effects of the tested compounds were evaluated via DNA fragmentation assay. The results of these assays demonstrated that BV potentiates BLM-induced cytotoxicity through increased LDH release and diminished cell viability. Nevertheless, BV significantly inhibited the BLM-induced DNA damage. The results verify that BV significantly attenuates the genotoxic effects of BLM on noncancerous isolated rat lymphocytes but does not diminish BLM cytotoxicity.

Melamine and/or formaldehyde exposures affect steroidogenesis via alteration of StAR protein and testosterone synthetic enzyme expression in male mice

The reproductive effects of melamine and formaldehyde, either alone or in combination, on mature male Swiss mice were investigated. The animals were orally administered melamine (50mg/kg/day), formaldehyde (25mg/kg/day), a mixture of melamine and formaldehyde, or a vehicle control for 65 consecutive days. As a result, the deterioration of sperm characteristics and inhibition of testicular enzyme activity were observed in the melamine- and formaldehyde-exposed groups. In addition, testosterone and luteinizing hormone levels were significantly reduced in the melamine but not in the formaldehyde-exposed group, which correlated with down-regulation of transcription levels of steroidogenic-related genes. Histopathologically, both compounds caused lesions in the testes. However, the co-exposure reduced the induced alterations in spermatogenesis, steroidogenesis, and testicular architecture that were obviously observed in the melamine-exposed group. Consequently, we demonstrated that melamine exhibited more pronounced reproductive impact in comparison with formaldehyde. In addition, formaldehyde was able to substantially temper the melamine -induced reproductive toxic effect.

Effect of dietary supplementation with Spirulina platensis on Atrazine-induced oxidative stress- mediated hepatic damage and inflammation in the common carp (Cyprinus carpio L.)

The present study evaluated the potential modulatory effect(s) of dietary supplementation with Spirulina platensis (SP) on Atrazine (ATZ)-induced oxidative stress and inflammation in common carp (Cyprinus carpio L.). Common carp was exposed to ATZ (428μg/L) and SP (1%), either alone or in combination, for 40 days. Subsequently, the treatment groups were evaluated for ATZ-induced oxidative stress-mediated hepatic damage and the potential antioxidant effect(s) of SP supplementation. The results indicated that ATZ exposure led to a significant increase in the oxidative stress as suggested by the increased levels of lipid and DNA oxidative damage markers and the significant decline of antioxidant status biomarkers. Further, a real-time PCR analysis of the liver tissues revealed that the ATZ exposure resulted in the significant modulation of the mRNA expression of cytokines involved in the inflammatory response pathway in the liver, such as Interleukin (IL)-1ß and IL-10. The expression of IL-1ß mRNA was up-regulated while that of IL-10 mRNA was down-regulated. The group subjected to supplementation with SP exhibited a significant decrease in ATZ-induced oxidative stress-mediated hepatotoxic and inflammatory responses; however, these did not attain the levels of the control group. Owing to its ability for protecting against ATZ-induced oxidative stress-mediated hepatic damage in carps, SP could be a potentially effective and promising candidate as a feed additive for carps in aquaculture.

Behavioral response and gene expression changes in fipronil-administered male Japanese quail (Coturnix japonica) ☆

Fipronil is an important member of the phenylpyrazole group of insecticides and is widely used for various crops and vegetables to control insects, thereby exposing birds, animals, and humans to fipronil. Currently, there is limited information on the effects of fipronil exposure in Japanese quail. Therefore, our aim was to assess the reproductive toxicological effects of fipronil in the Japanese quail in a 15-day gavage study and then its recovery over a period of 60 days. Fipronil-administration led to significant losses in both feed intake and body weight. Whereas, the gonadosomatic index was not affected, and histological changes observed in the testes were reversible, particularly by day 45 and day 60 of recovery. Cloacal gland atrophy, reduced foam quantity and a reduction in fertility, sexual and aggressive behaviors, and serum testosterone with elevated estradiol (E2) hormone levels were also observed. All these changes gradually reversed during various recovery periods. Further, alterations in hepatic vitellogenin (Vtg) and estrogen receptor α (ERα) gene expression, assessed by quantitative polymerase chain reaction, were also observed. Specifically, ERα1 was induced after fipronil administration, while the Vtg transcript was elevated during both exposure and recovery periods. Our results showed that fipronil exposure has a profound negative influence on reproductive traits in the male Japanese quail and exhibits an estrogenic activity that can raise the incidence of infertility in males. Nevertheless, most of the changes could be reversed after a recovery period of 30-45 days.

Regulation of chick early B-cell factor-1 gene expression in feather development

The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.

Quercetin Reverses Altered Energy Metabolism in the Heart of Rats Receiving Adriamycin Chemotherapy

The primary aim of this study was to find the potential modulatory roles of quercetin (QUE) against Adriamycin (ADR)-induced cardiotoxicity. A total of 50 rats were assigned to five groups: a control group, an ADR-treated group, a QUE-treated group, a prophylaxis-cotreated group, and a therapeutic-cotreated group, respectively. QUE exhibited a significant cardioprotective effect, particularly, when it was administered prior to and concurrently with ADR treatment (prophylaxis-cotreated group). This effect was biochemically evident by the significant decreases in the serum levels of myocardial injury biomarkers such as troponin, creatine kinase–myocardium bound, and creatine phosphokinase. In addition, significant elevations in myocardial antioxidant indices coupled with significant reductions in myocardial malondialdehyde contents and DNA damage, elicited by ADR injection, were observed. All these biochemical improvements were accompanied by a significant histopathological recovery and obvious modulation of the AMP-activated protein kinase (AMPK) signaling pathway by promoting the expression of the AMPKα2, PPARα, and PCG-1α genes. Taken together, these findings conclusively showed that QUE administration through its antioxidant capacity and myocardial energy metabolism restoration provides a prophylactic effect in response to ADR-induced deleterious effects, in the rat heart.

Imidacloprid insecticide exposure induces stress and disrupts glucose homeostasis in male rats

In the present study, we evaluated the stress response in adult rats who were administered imidacloprid (IMI) orally in two doses (0.5 and 1.0mg/kg bw for 60days). It led to an alteration in the levels of cortisone and catecholamines and induced behavioral deficits, particularly in the animals exposed to the dose of 1.0mg/kg. IMI was further analyzed for the effect on glucose homeostasis in developing and adult rats at a dose of 1.0mg/kg bw where it elicited a hyperglycemic effect. Moreover, we observed an alteration in the mRNA levels of glucose transporters. Histopathological and immunohistochemical data displayed structural perturbations in pancreatic tissue with a decline in the expression of insulin and GLUT4, particularly in the developing rats. Collectively, IMI treatment resulted in stress represented by behavioral and biochemical changes, particularly at a dose of 1.0mg/kg bw. Moreover, IMI perturbed the glucose regulation through hyperglycemic activity in both developing and adult rats, an observation clearly evident in the developing rats.