Biochemical Markers of Oxidative Stress in Brain of Zebrafish Danio rerio Exposed to Different Heavy Metals Lead and Cobalt

Abstract

ABSTRACT-Aquatic organisms have been considered to concentrate metals several times greater than environmental levels. Fishes have been used for many decades to evaluate the pollution status of water and thus considered as excellent biological indicator of heavy metals in aquatic environments. Heavy metals are natural tress components of the aquatic environment, but their levels have increased due to domestic, industrial, mining and agricultural activities. These heavy metals when accumulated in the fish tissues, they damage and weaken the mechanisms concerned leading to physiological, pathological and biochemical changes. The lead is non essential element while cobalt is an essential element for living organisms but its presence in fresh water in higher concentration are toxic to organism's brain, liver, ovary, kidney and gills of the fish. The present study was aimed to investigate the changes due to two heavy metals (lead & cobalt) on the activity of the antioxidant enzyme, Catalase (CAT), Reduced glutathione (GSH), and Lipid peroxidation (LPO) in the brain of Danio rerio during 5, 10, 15 and 20 days of exposure period. For this study adult fishes were exposed to four different concentrations viz., 20, 30, 40 and 50 mg/l of cobalt and 5, 9, 13, and 17 mg/l of lead.

Chronic Exposure to Low Concentration Lead Chloride-Induced Anxiety and Loss of Aggression and Memory in Zebrafish

“…We observed the significant increase of the superoxide dismutase (SOD) levels in the brain of PbCl 2 -treated fish. In zebrafish, SOD is required as an antioxidant defense system to reduce accumulated superoxide anions as the consequence of heavy metal overload [36]. The level of malondialdehyde (MDA), a lipid peroxidation product, was also increased significantly.…”

Efficacy of Aquatic Plants for Removal of Heavy Metals from Wastewater

“…Toxic heavy metals such as cadmium, copper, lead, chromium, zinc, and nickel are important environmental pollutants, particularly in areas with high anthropogenic pressure. They can't be biodegraded so released into the environment and contribute to lots of toxic effects even in relatively lower concentrations on living organisms in food chain [2][3][4][5][6] by bioaccumulation and bio-magnification [7] . Several methods already used to clean up the environment from these heavy metals including chemical precipitation, oxidation or reduction, filtration, ion exchange, reverse osmosis, membrane technology, evaporation and electrochemical treatment (but most of them are expensive, time consuming and environmentally destructive [8] .…”