Effects of burnt tire-ash on Na+/K+, Ca2+-ATPase, serum immunoglobulin and brain acetylcholinesterase activities in clarias gariepinus (Burchell, 1822).

Aquatic pollution may continue to deepen following the emergence of new class of toxicants. The present study investigated the effect of water-soluble fraction of burnt tire-ash on Clarias gariepinus. The fish were exposed to sublethal doses; 0.00 g/L, 2.24 g/L, 1.12 g/L and 0.56 g/L of tire-ash solution, representing 1/5, 1/10 and 1/20 of 11.2 g/L median lethal concentration (96 LC50), for 28 days, followed by 14 days recovery trial. Biological sampling was done on exposure day 1, 14 and 28, and on day14 recovery period for biochemical analysis such as the liver and gill Na+/K+ and Ca2+-ATPase, serum immunoglobulin (IgM) and brain acetylcholinesterase (AChE) of the experimental fish. Also, body biomass and behavior were evaluated. The behavioral responses exhibited by the fish to BTA exposure include reduced feeding, hypoactivity, air gulping and skin discoloration, which was observed to be concentration dependent. The body weight of 2.24 g/L and 1.12 g/L BTA-exposed fish decreased significantly than 0.56 g/L exposed fish and the control. Furthermore, findings revealed evident induction of Na+/K+ and Ca2 +-ATPase activities in both tissues, elevation of serum immunoglobulin content and inhibition of AChE activity in the brain of the exposed fish relative to the control. However, it was also observed that the biochemical parameters normalized after the recovery period. In conclusion, water-soluble fraction of burnt tire-ash produced toxicological effects in the experimental model, hence the present study provides the ecotoxicological insight of tire ash.

Genotoxicity, oxidative stress and lysozyme induction in Clarias gariepinus chronically exposed to water-soluble fraction of burnt tire ash.

The safety of aquatic ecosystems has been compromised by numerous anthropogenic activities, especially leachates from non-point source toxicants, leaching into aquatic systems. This study evaluated the toxicity of the water-soluble fractions (WSFs) of burnt tire ash (BTA) on Clarias gariepinus via a battery of integrated biomarkers. Juvenile C. gariepinus were exposed to sublethal (0.56, 1.12, and 2.24 g/L) concentrations of BTA, derived from 11.2 g/L median lethal concentration (96 LC50), at duration intervals of 1, 14, and 28 days, followed by a recovery trial that lasted for 14 days. Serum biochemical parameters, antioxidant enzyme activities of the gill and liver, lysozymes activity and erythron profile were assessed. The findings of the present study revealed that BTA-WSF induced prominent alterations on biochemical parameters, lysozymes activity and antioxidant enzymes activities in the exposed fish. Furthermore, toxicant exposure promoted oxidative stress, cellular damage and genotoxicity (erythrocytic nuclear and cellular abnormalities) in the exposed fish. In general, a post-exposure trial showed partial recovery from the exposure effects of the toxicant, following the evident modifications of serum enzymes and erythron pathopathology in the experimental model. Biomonitoring of BTA, using sentinel aquatic species such as C. gariepinus, provides insights into the ecotoxicological potency of this toxicant.

Biomarkers of neurotoxicity, oxidative stress, hepatotoxicity and lipid peroxidation in Clarias gariepinus exposed to melamine and polyvinyl chloride.

PURPOSE: Plastic particulates and chemicals are emerging environmental pollutants with significant impact on aquatic ecosystems. In this study, the effects of oral uptake of melamine, melamine formaldehyde, and polyvinyl chloride on serum biochemical profiles, antioxidant enzymes activities, lipid peroxidation levels and brain acetyl cholinesterase activities in Clarias gariepinus juveniles were investigated. METHODS: Fish specimens were fed diets spiked with melamine, melamine formaldehyde and poly vinyl chloride at 0.3% (3.0 g Kg-1) dietary inclusion for 45 days. Toxicity effect of these plastic chemicals was estimated by assaying relevant biomarkers. RESULTS: After 45 days exposure, Serum glucose was significantly elevated, whereas plasma protein levels were substantially reduced in the exposed fish groups. Serum transaminases were significantly elevated in the exposed groups. Brain acetylcholinesterase and antioxidant enzyme activities declined significantly, while malondialdehyde levels were elevated in the exposed groups. CONCLUSION: C. gariepinus is an important bioindicator to monitor the ecotoxicological impact of plastic chemicals such as melamine, and polyvinyl chloride.