Polychlorinated biphenyl congeners in water canals and their relationships with water quality parameters: Insights into their risk assessment.

Water pollution with pesticides is one of the most important environmental problems. Polychlorinated biphenyls (PCBs) reach water bodies via agricultural discharge. The aim of this study was to determine the contamination of different water bodies with PCB congeners, and detect the correlation between water quality parameters and seasonal distribution of these PCBs. The results indicated that water canals of AlGharbiah showed the highest ranges of temperature, total dissolved solids (TDS) in spring, and dissolved oxygen (DO) in autumn, while AlQaliobiah water bodies witnessed the highest pH and electrical conductivity (EC) ranges in summer. The highest range of a PCB congener was that of PCB44 (7.96-118.29 µg/g) in sediment samples of Giza, followed by its range (18.01-85.44 µgL-1) in surface water of AlQaliobiah. We found a potential cancer risk from dermal contact with all the investigated PCBs. Principal component analysis (PCA) showed positive correlations between most PCBs and each of EC and TDS, and a negative correlation with DO. While the correlation between PCBs and each of temperature and pH varied according to the geographic location of the governorate. In conclusion, the investigated water canals were contaminated with PCBs, which posed a potential cancer risk and deteriorated water quality.

Residues of pyrethroids and triazoles pesticides in water and sediment of certain Egyptian watercourses: assessing their influence on fungal diversity.

Contamination of water and sediment with pyrethroids and triazoles residues can affect fungal diversity, and hence the aquatic system functioning. The aim of the present study is to investigate the effect of water and sediment contamination with pyrethroids and triazoles on fungal diversity. Water and sediment samples were seasonally collected along 2019 from water bodies representing Gharbeya and Qualubeya governorates. Concentrations of pyrethroids and triazoles were determined, and fungal species in water and sediment samples were molecularly identified. The results indicated that temperature and pH varied according to the season. Permethrin, deltamethrin, lambda-cyhalothrin and esfenvalerate showed the highest pyrethroids concentrations, whereas tetraconazole, tebuconazole and difenconazole were of the highest triazoles concentrations. Aspergillus niger was one of the most frequent species, in addition to Trichoderma capillare, Fusarium oxysporum, Penicillium commune and Penicillium polonicum. Principal component analysis indicated a positive correlation between temperature and different Aspergillus spp., and between pH and each of pyrethroids and triazoles. Moreover, a negative correlation was observed between triazoles and Trichoderma asperellum, Penicillium griseofulvum and Aspergillus fumigatus. In conclusion, contamination of water with pesticides affected fungal diversity. This disturbance in fungal assemblages might result in a reduction of some key organisms, or an increase and emergence of new pathogens.

Cornu aspersum mucin attenuates indomethacins-induced gastric ulcers in mice via alleviating oxidative stress and inflammation.

In the past three decades, a significant progress has been made in the prevention and treatment of gastric ulcers. The incidence of the disease has decreased, but gastric ulcer is still a medical problem. Currently, the available drugs for gastric ulcer treatment have many side effects; therefore, searching for new and safe therapeutic agents is mandatory. The present study aims to investigate the gastroprotective potential of Cornu aspersum (C. aspersum) mucin against gastric ulcers, and the mechanisms related to oxidative stress and inflammation. C. aspersum mucin was collected from 50 snails. The characteristics of C. aspersum mucin (chemical and microbiological) were evaluated. Mice were pretreated with famotidine and C. aspersum mucin (7.5 and 15 ml/kg b.w.) for 5 days, and then gastric ulcers were induced by indomethacin. Macroscopic examination, biochemical estimations, and Quantitative real-time PCR were carried out. Also, histopathological and immunohistopathological examinations were evaluated. We found that the high dose of the mucin significantly decreased the gastric mucosal malondialdehyde (MDA) and nitric oxide (NO) contents as well as interleukin 1ß (IL-1ß) and nuclear factor kappa ß (NF-Ò¡B) expression, and inducible nitric oxide synthase (iNOS) immunostaining. It also increased the gastric mucosal GSH and catalase contents as well as hemoxygenase-1 (HO-1) and nuclear factor-erythroid 2-related factor 2 (Nrf2) expressions with regressions in gastric mucosal lesions. In conclusion, C. aspersum mucin could be a potential therapeutic candidate to protect against gastric ulceration.

Metallothionein expression in Aspergillus exposed to environmentally relevant concentrations of heavy metals at different pH levels.

Heavy metal pollution represents a health threat. Many fungal species are capable of tolerating various heavy metals, especially if they are isolated from a contaminated watercourse. One of the mechanisms by which fungi can sequester certain heavy metals is synthesizing stress proteins. The aim of this study is to investigate the production of metallothioneins in Aspergillus oryzae and Aspergillus clavatus exposed to environmentally relevant concentrations of Cd, Cu, Fe, and Zn at neutral, alkaline, and acidic pH conditions within 10 days. We determined the concentrations of these heavy metals in certain watercourses representing Behira and Giza governorates; also, we identified the most prevalent fungal species. We carried out a statistical correlation between different heavy metals and the isolated fungi. Then, in the laboratory, we exposed two of the most prevalent fungal species to the environmentally detected concentrations of the heavy metals and their doubles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that in A. oryzae, the metallothionein bands appeared in neutral medium containing Cd and Cu and in alkaline medium containing Cd and Zn, while in A. clavatus, no metallothionein bands appeared at all. In conclusion, metallothionein is a good indicator of pollution with Cd, Cu, and Zn in Aspergillus oryzae, and pH plays a central role in metallothionein production.