Toxic effects of copper on liver and cholinesterase of Clarias gariepinus

Abstract

The release of pollutants, especially heavy metals, into the aquatic environment is known to have detrimental effects on such an environment and on living organisms including humans when those pollutants are allowed to enter the food chain. The aim of this study is to analyse the damage to Clarias gariepinus' liver caused by exposure to different concentrations of copper. In the present study, samples of C. gariepinus were exposed to sub-lethal copper sulphate (CuSO) concentrations (from 0.2 to 20.0 mg/L) for 96 h. Physiological and behavioural alterations were observed with respect to their swimming pattern, mucus secretion and skin colour. Mortality was also observed at high concentrations of copper. Histopathological alterations of the liver were analysed under light, transmission and scanning electron microscopies. The liver of the untreated group showed normal tissue structures, while histopathological abnormalities were observed in the treated fish under light and electron microscopes with increased copper concentrations. Histopathological abnormalities include necrosis, melanomacrophage, hepatic fibrosis and congested blood vessels. In addition, the enzyme activity of liver cholinesterase (ChE) was also found to be affected by copper sulphate, as 100% of cholinesterase activity was inhibited at 20.0 mg/L. Thus, liver enzyme activity and histopathological changes are proven to be alternative sources for biomarkers of metal toxicity.

Elevated intracellular copper contributes a unique role to kidney fibrosis by lysyl oxidase mediated matrix crosslinking

“…Copper is one of the most important trace elements in the human body, as it is a cofactor or structural component for many enzymes that are required for cellular physiology 1,2 . Recently, some studies have shown that copper accumulation is associated with fibrosis in various tissues such as in human liver 3 , oral submucous tissue in humans 4 and lung fibrosis in rats 5 . However, there have been no reports of association of copper with fibrosis in the kidney, and the underlying mechanism involving the role of copper in organ fibrosis is unknown.…”

Fabrication of super-hydrophobic nickel film on copper substrate with improved corrosion inhibition by electrodeposition process

“…If copper material is used for water pipelines, these corrosion products can go into human stomach and then react with gastric acid to generate copper ion (Cu 2+ ). The continuous accumulation of heavy metal ion (Cu 2+ ) in body would cause the disruption of biochemical functions and cellular morphology by its toxicity [28]. Researchers proposed that the corrosion resistance will be remarkably enhanced through decreasing the contact area between the copper substrate and the corrosive liquids [29].…”

Histopathological and cholinesterase changes in the gills of Clarias gariepinus as a result of cadmium exposure

“…Journal of Environmental Biology, July 2019 biosensor for heavy metals was evaluated. Previous studies have reported that there can be more than one ChE present in the tissues of fish and these different forms may vary in their sensitivity to anticholinesterase agents (Monteiro et al, 2005;Padrilah et al, 2017). In the present study, attempts were made to elucidate the effect of cadmium on the histopathology and cholinesterase enzyme activity in gills of Clarias gariepinus.…”

“…Pollutants significantly affect the aquatic life and all trophic levels from primary producers to predators, ultimately humans. It may disturb the organisation of many freshwater fish species and other aquatic communities and hampering the normal balance of the ecosystem (Padrilah et al, 2017;Todd et al, 2010;Agtas et al, 2007).…”