Genotoxicity and Trace Elements Contents Analysis in Nile Tilapia (Oreochromis niloticus) Indicated the Levels of Aquatic Contamination at Three Egyptian Areas

Abstract

The toxic waste and pollutants of heavy metals continuously pollute freshwater aquatic reservoirs, which have severe implications on aquatic life and human health. The present work aims to evaluate trace elements (Zn, Mn, Cu, Cd, and Pb) along with three sites, Mariout Lake, Abbassa, and River Nile Aswan in Egypt, using Nile tilapia (Oreochromis niloticus) as bioindicator. The quality assurance, health-risk assessment, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), quantitative polymerase chain reaction (qPCR), and micronucleus test were performed to investigate the effect of different trace elements on Hsp70 gene level and micronuclei formation. We observed the highest expression of Hsp70 protein band of 70 KD and stress-responsive Hsp70 gene in the liver followed by gills of Nile tilapia caught from Mariout and Abbassa, but the lowest expression was in Nile tilapia caught from Aswan. Obvious micronuclei were observed under the microscope in erythrocytes, and their number was gradually decreased in the following manner: Mariout > Abbassa > Aswan. Noticeably, Cu, Zn, and Mn contents were low. Still, Pb and Cd contents were higher than the toxicity level recommended by the Food and Agriculture Organization (FAO), The World Health Organization (WHO), and the European Commission (EC). These results showed that Hsp70's appearance at the two levels of mRNA and protein is an effective indicator for aquatic pollution besides the aberration at the chromosome level represented in the micronucleus test. Furthermore, these results showed that Nile tilapia of the Aswan region had comparatively low trace elements contamination and were suitable for consumption.

Saccharomyces cerevisiae additions normalized hemocyte differential genes expression and regulated crayfish (Procambarus clarkii) oxidative damage under cadmium stress

“…Over the past few years, heavy metal-caused pollution in aquatic systems has drawn increasing attention 1 . Cadmium (Cd) is a non-decomposable pollutant that has brought concerns about environmental issues and its impact on human health worldwide 2 , 3 .…”

Agri-Nanotechnology and Tree Nanobionics: Augmentation in Crop Yield, Biosafety, and Biomass Accumulation

“…The poisoning potential of NPs can be measured through a variety of assays such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) ( Raja et al, 2019 ), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay ( Jin et al, 2021 ), Alamar blue assay ( Usman et al, 2020 ), sulforhodamine B (SRB) ( Massard et al, 2018 ), and cell counting kit-8 (CCK-8; Dojindo Molecular Technologies) ( Jin et al, 2021 ) can be used to determine the cellular toxicity (mortality or viability percentage). In vivo application of NPs in agriculture can cause genotoxicity to both terrestrial and aquatic animals which can be measured using sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) assay ( El-Sappah et al, 2022 ). Immunotoxicity caused by NPs can be determined by pro-inflammatory and anti-inflammatory cytokines ( Engin and Hayes, 2018 ).…”

Oleic acid from Marine seaweed Caulerpa scalpelliformis induced toxicity in Oreochromis niloticus

“…The main species among all aquatic creatures living in the Nile River is the Nile tilapia, Oreochromis niloticus. This species is used as a study tool in scientific research (3) . Due to its high protein content and low cost of production, tilapia can provide for the daily nutritional needs of a vast population, including the underprivileged and malnourished.…”