Constitutive Effects of Lead on Aryl Hydrocarbon Receptor Gene Battery and Protection by beta-carotene and Ascorbic Acid in Human HepG2 Cells

Lead (Pb) is an environmental pollutant that can get entry into human body through contaminated foods, drinks, and inhaled air leading to severe biological consequences, and has been responsible for many deaths worldwide. The objectives of this study were 1st to investigate the modulatory effects of environmentally relevant concentrations of Pb on AhR gene battery, which is controlling xenobiotics metabolism. 2nd, trials to reduce Pb-induced adverse effects were done using some phytochemicals like beta-carotene or ascorbic acid. Human hepatoma (HepG2) cell lines were exposed to a wide range of Pb concentrations varying from physiological to toxic levels (0 to 10 mg/L) for 24 h. High Pb concentrations (1 to 10 mg/L) significantly reduced phase I (CYP1A1 and 1A2) and phase II (UGT1A6 and NQO1) xenobiotic metabolizing enzyme mRNA expression in a mechanistic manner through the AhR regulation pathway. Additionally, these Pb concentrations induced oxidative stress in HepG2 cells in terms of production of reactive oxygen species (ROS) and induced heme oxygenase-1 mRNA expression in a concentration-dependent phenomenon. Coexposure of HepG2 cells to physiological concentrations of some micronutrients, like beta-carotene (10 mu M) or ascorbic acid (0.1 mM), along with Pb (1 mg/L) for 24 h significantly reduced the levels of ROS production and recovered AhR mRNA expression into the normal levels. Thus, consumption of foods rich in these micronutrients may help to reduce the adverse effects of lead in areas with high levels of pollution

Prevalence, antibiogram, molecular characterization and reduction trial of Salmonella typhimurium isolated from different fish species

Salmonella is a major cause of food-borne outbreaks and infections in many countries worldwide. The present work aimed to investigate the prevalence, antibiotic sensitivity and detection of virulence-associated genes in Salmonella typhimurium isolated from fish samples (tilapia, mullet and catfish) collected from Zagazig city markets, Egypt. Salmonella typhimurium was isolated only from tilapia with a percentage of 13.3%. Antibiotic susceptibility testing of Salmonella typhimurium revealed marked susceptibility to ofloxacin. Two different virulence genes (ssaP and pipB) were expressed in the isolated Salmonella typhimurium. Dipping of tilapia in liquid smoke 5% for 30 min reduced Salmonella typhimurium count by 40%. In conclusion, our results confirm contamination of tilapia by Salmonella typhimurium. Dipping of fish in liquid smoke is an efficient strategy in reducing Salmonella typhimurium load in fish

Mould contamination and aflatoxin residues in frozen chicken meat-cuts and giblets

Mould contamination of frozen chicken meat and giblets has a particular public health significance in the field of food safety due to its related food spoilage and production of mycotoxins. The objectives of this study were firstly, to investigate the incidence of mould contamination in frozenchicken meat-cuts and giblets. Secondly, to estimate aflatoxin residues in these products. The public health importance of the prevalent mould genera and aflatoxin residues was discussed. Frozen gizzards had the highest total mould count followed by frozen liver, breast and thigh respectively. The prevalent mould genera were Aspergillus, Penicillium, Cladosporium and alternaria. Aspergillus niger, flavus, parasiticus and versicolor were the identified Aspergilli. Examined frozen chicken samples had variable residual concentrations of total aflatoxins. Thus, strict hygienic precautions during processing of frozen chicken products should be adopted to reduce mould contamination and mycotoxin production

Could fungi be detected in the fluid of persistent otitis media with effusion?

Background: Otitis media with effusion (OME) often is considered a direct extension of the inflammatory process that occurs during long-lasting or recurrent episodes of acute otitis media. Most bacterial and viral cultures of middle ear fluid that had been performed were often negative suggesting that other infectious agents may be involved such as fungi.Materials and methods: Thirty patients suffering from chronic secretory otitis media (OME) were enrolled. Three samples were collected and investigated using PCR assay with universal fungal primers and Sabouraud agar. The first sample was obtained from the fluid of the middle ear before insertion of the ventilation tube; the second sample was obtained from nasal secretions; and the third sample was obtained from the ipsilateral peritubal area of the nasopharynx. Samples were tested using PCR assay with universal fungal primers and Sabouraud agar.Results: PCR examination of the middle ear aspirate in group cases was positive in 7 cases (23.3%), in nasal secretions samples 2 cases only (13.3%) were positive and no positive cases were detected in nasopharyngeal swab samples. Sabouraud agar culture was positive for fungal culture of middle ear aspirates in 5 cases (16.6%) but in no cases for nasal secretion samples. Results also showed negative(N0) growth in 30 (100%) patients for nasopharyngeal swab on Sabouraud agar.Conclusion: Fungal DNA could be detected in the middle ear fluid in seven (23.3%) of 30 patients with persistent OME using PCR assay and fungi could be detected in five (16.6%) patients on Sabouraud agar. A significant relationship was found between detection of fungi in the middle ear fluid and the duration of the disease, associated adenoid, and history of asthma.Supported by: Otolaryngology Department Fayoum University, Clinical Pathology Department Fayoum University, Clinical Pathology Department National Institute OF OncologyDer Erstautor gibt keinen Interessenkonflikt an

Could fungi be detected in the fluid of persistent otitis media with effusion?

Background: Otitis media with effusion (OME) often is considered a direct extension of the inflammatory process that occurs during long-lasting or recurrent episodes of acute otitis media. Most bacterial and viral cultures of middle ear fluid that had been performed were often negative suggesting that other infectious agents may be involved such as fungi.Materials and methods: Thirty patients suffering from chronic secretory otitis media (OME) were enrolled. Three samples were collected and investigated using PCR assay with universal fungal primers and Sabouraud agar. The first sample was obtained from the fluid of the middle ear before insertion of the ventilation tube; the second sample was obtained from nasal secretions; and the third sample was obtained from the ipsilateral peritubal area of the nasopharynx. Samples were tested using PCR assay with universal fungal primers and Sabouraud agar.Results: PCR examination of the middle ear aspirate in group cases was positive in 7 cases (23.3%), in nasal secretions samples 2 cases only (13.3%) were positive and no positive cases were detected in nasopharyngeal swab samples. Sabouraud agar culture was positive for fungal culture of middle ear aspirates in 5 cases (16.6%) but in no cases for nasal secretion samples. Results also showed negative(N0) growth in 30 (100%) patients for nasopharyngeal swab on Sabouraud agar.Conclusion: Fungal DNA could be detected in the middle ear fluid in seven (23.3%) of 30 patients with persistent OME using PCR assay and fungi could be detected in five (16.6%) patients on Sabouraud agar. A significant relationship was found between detection of fungi in the middle ear fluid and the duration of the disease, associated adenoid, and history of asthma.Supported by: Otolaryngology Department Fayoum University, Clinical Pathology Department Fayoum University, Clinical Pathology Department National Institute OF OncologyDer Erstautor gibt keinen Interessenkonflikt an

Metabolic Activation of Heterocyclic Amines and Expression of Xenobiotic-Metabolizing Enzymes in the Gastrointestinal Tract of Rats

Heterocyclic amines get entry into human body mainly through ingestion of pan-fried meats cooked at high temperatures. Exposure of the gastrointestinal tract (GIT) to ingested xenobiotics prior to delivery to the liver may lead to metabolic activation, which may explain the high incidence of GIT carcinogenesis. Therefore, this study investigated the mutagenic activation of 2 heterocyclic amines, 2-aminoanthracene (2-AA) and 3-amino-1-methyl-5H-prydo[4,3-b]indole (Trp-P-2), in the GIT of rats. In addition, the constitutive mRNA expression profiles of xenobiotic-metabolizing enzymes (XMEs) in the GIT of rats were examined. Metabolic activation of 2-AA was detected in all GIT tissues except the duodenum and rectum, and it was detected at high levels in the ileum and cecum. Furthermore, we revealed high metabolic activation of 2-AA and Trp-P-2 in the jejunum. The mRNA expression of phase I and II enzymes in rat GIT corresponded with their mutagenic activation ability. In conclusion, our results suggest that different expression levels of XME among GIT tissues may contribute to the tissue-specific differences in metabolic activation of xenobiotics such as heterocyclic amines in rats. Practical Application This study declares mutagenic activation of 2 heterocyclic amines namely 2-aminoanthracene (2-AA) and 3-amino-1-methyl-5H-prydo[4,3-b]indole (Trp-P-2), in the gastrointestinal tract (GIT) of rats. In addition, results obtained in this study suggest that GIT tissue-specific expression of xenobiotic metabolizing enzymes may contribute to the tissue-specific mutagenesis/carcinogenesis

Effects of the organochlorine p,p '-DDT on MCF-7 cells: Investigating metabolic and immune modulatory transcriptomic changes

The organochlorine pesticide dichloro-diphenyl-trichloroethane (DDT) is persistent in the environment and leads to adverse human health effects. High levels in breast milk pose a threat to both breast tissue and nursing infants. The objectives of this study were to investigate DDT-induced transcriptomic alterations in enzymes and transporters involved in xenobiotic metabolism, immune responses, oxidative stress markers, and cell growth in a human breast cancer cell line. MCF-7 cells were exposed to both environmentally-relevant and previously-tested concentrations of p,p'-DDT in a short-term experiment. Significant up-regulation of metabolizing enzymes and transporters (ACHE, GSTO1, NQO1 and ABCC2) and oxidative stress markers (CXCL8, HMOX-1, NFE2L2 and TNF) was clearly observed. Conversely, UGT1A6, AHR and cell growth genes (FGF2 and VEGFA) were severely down-regulated. Identification of these genes helps to identify mechanisms of p,p'-DDT action within cells and may be considered as useful biomarkers for exposure to DDT contamination