Toxicity studies of nonylphenol and octylphenol: hormonal, hematological and biochemical effects inClarias gariepinus

Abstract

Among the numerous chemicals discharged into aquatic ecosystems, nonylphenol (NP) and octylphenol (OP) have been shown to have a potent effect on the endocrine system of fish; this issue has been clearly dealt with in several studies. The objective of this study was to assess and compare the general toxicity of these estrogenic chemicals individually on Clarias gariepinus. Fish were exposed to different concentrations of both NP and OP (250, 500, 750 and 1000 μg l(-1) ) under semi-static conditions for a period of 7 days. The adverse effect was evaluated with use of blood cell counting, hemoglobin (Hb), hematocrit (HCT), hematimetric indices, bilirubin, protein, glucose, serum transaminases, serum phosphatases, lactate dehydrogenase and cortisol. The results showed a clear indication of anemia, increases in leukocyte count and bilirubin content and a reduction in plasma protein levels with higher concentrations of both the toxicants compared with controls. Furthermore, with all the concentrations the inevitable increase in serum cortisol and plasma glucose showed primary and secondary stress responses. Moreover, probable tissue damage gave rise to a series of fluctuations of enzyme levels at lower concentrations, but a decrease with higher concentrations showed the severity of the effect. Depending on the parameters examined, OP had a relatively greater effect than NP. Overall, these two chemicals seemingly affected hematology and the activity of some enzymes, leading to serious impairment of the metabolism and physiology of C. gariepinus.

The response of thyroid hormones, biochemical and enzymological biomarkers to pyrene exposure in common carp (Cyprinus carpio)

“…Therefore, these chemicals through cortisol induction could modulate intermediary metabolism and modify energy metabolism in fish (Mommsen et al, 1999). Senthil Kumaran et al (2011) stated that glucose elevation after exposure to nonylphenol and octylphenol in African catfish (Clarias gariepinus) may be the result of increased synthesis of adrenocorticotropic hormone and glucagon and reduced synthesis of insulin. As a result, glycogen stored in the liver is converted to glucose leading to an increase in blood glucose level.…”

“…The plasma biochemical constituents, thyroid hormones, liver function enzymes and ionoregulatory endpoints could also be used as biomarkers to reflect the toxicity of chemicals as they have been frequently used for the toxicity assessment of other PAHs in fish and other animals (Alonso-Alvarez et al, 2007;Kim et al, 2008;Latif et al, 2014;Maria et al, 2002;Okwu et al, 2014;Osman et al, 2009;Salman, 2011;Tintos et al, 2008;Wegwu and Omeodu, 2010). Plasma biochemical indicators and transaminases have been proved to be suitable stress biomarkers in fish because they are inexpensive, less variable, more highly conserved between species and are easy to measure (Naderi et al, 2015;Senthil Kumaran et al, 2011).…”

Acute and sublethal effects in an Indian major carp Cirrhinus mrigala exposed to silver nitrate: Gill Na+/K+-ATPase, plasma electrolytes and biochemical alterations

“…During stress condition fish may mobilize protein to meet energy demand to maintain increased physiological activity [72]. Blood and structural proteins and carbohydrate reserves may convert to energy under stress condition leading to a significant decrease in serum protein concentrations [73]. Hyproteinemia in toxicant stressed animals indicate a generalized response to any stress.…”

Toxicity Effects of the Environmental Hormone 4-Tert-Octylphenol in Zebrafish (Danio Rerio)

“…However, several investigations have reported that the unstable property of APEs in environment cause rapid degradation to hydrophobic and more toxic alkylphenols including 4-nonylphenol (4-NP) and 4-t-OP. Based on hematological and biochemical parameters examined, the study elucidated that OP had a relatively greater effect than NP and affected hematological enzymes leading to serious impairment of the metabolism and physiology in African sharptooth catfish (C. gariepinus) [25]. Other study reported that zebrafish embryos exposed to 1 µM of 4-t-OP developed normally [26], however our results showed that zebrafish exposure to 1 µM of 4-t-OP resulted in cardiovascular defect.…”