RESUMEN
The environment has been implicated to be a strong determinant of brain health with higher risk of neurodegeneration. The drastic rise in the prevalence of neurodegenerative diseases (NDDs) including Alzheimer's disease (AD), Parkinson's disease (PD), autism spectrum disorder (ASD), multiple sclerosis (MS) etc., supports the idea that environmental factors may play a major role in NDDs aetiology. Nickel is one of the listed environmental metals reported to pose a serious threat to human health. This paper reported available studies on nickel level in NDDs covering both animal and human studies. Different databases were searched for articles reporting the main neurotoxicity mechanisms and the concentration of nickel in fluids and tissues of NDDs patients compared to controls. Data were extracted and synthesized by ensuring the articles were related to nickel and NDDs. Various mechanisms were reported as oxidative stress, disturbances in mitochondrial membrane potential, trace elements homeostasis destabilization, etc. Nickel was found elevated in biological fluids as blood, serum/plasma and CSF and in the brain of NDDs, as a consequence of unintentional exposure thorough nickel-contaminated air, food, water, and skin contact. In addition, after exposure to nickel, the concentration of markers of lipid peroxidation were increased, while some antioxidant defence systems decreased. Thus, the reduction in the exposure to nickel contaminant may hold a promise in reducing the incidence of NDDs.
RESUMEN
There exists a visible evidence of linkage between pollutant exposure and nutritional deficiency in many organisms. The aim of the present study was to analyze the proximate composition of juvenile African catfish (Clarias gariepinus) exposed to polydimethylsiloxane (antifoam) for 56 days using a renewal bioassay. The moisture, crude protein, ash, and fat content of the fish samples were analyzed using standard methods. Antifoam concentrations at 0.0mg/L, 63.96mg/L, 127.9mg/L, 255.82mg/L, and 511.64mg/L were used for the sublethal exposure after which the proximate composition was analyzed. The water quality variables including dissolved oxygen, conductivity, and total dissolved solids varied as the concentration increased. The moisture and lipid contents were highest at 511.64mg/L concentration while the control(0.0mg/L) had the highest percentage composition of ash, protein, carbohydrate, and fiber contents which were normal values. The differences in proximate values were slightly significant at P>0.05 among the different concentrations. The findings in this study may be an indication that antifoam can significantly affect some water quality variables and proximate composition, while also portraying the risk associated with the consumption of such exposed fish.
