Mathan Ramesh

Toxicological effects of arsenate exposure on hematological, biochemical and liver transaminases activity in an Indian major carp, Catla catla.

The impact of acute and sublethal toxicity of arsenate on hematological, biochemical and enzymological parameters of an Indian major carp Catla catla were estimated. The median lethal concentration of sodium arsenate to the fish Catla catla for 96h was found to be 43.78 mg/L. During acute treatment (43.78 mg/L), hemoglobin (Hb), hematocrit (Ht), red blood cell count (RBC), white blood cell count (WBC), plasma glucose, plasma protein, liver aspartate and alanine aminotransferase (AST and ALT) levels decreased, whereas corpuscular indices like mean cell volume (MCV), mean cell hemoglobin (MCH) and mean cell hemoglobin concentration (MCHC) increased in arsenate treated fish. In sublethal treatment (4.378 mg/L), Hb, Ht, RBC, plasma protein levels decreased while MCHC and plasma glucose levels increased throughout the exposure period. A biphasic trend was noticed in WBC, MCV, MCH, liver AST and ALT levels. The alterations of these parameters can be effectively used as a rapid method to assess health of fish exposed to arsenate in the aquatic environment.

Hematological, biochemical and ionoregulatory responses of Indian major carp Catla catla during chronic sublethal exposure to inorganic arsenic.

In the present study the acute toxicity of arsenic trioxide in fingerlings of Catla catla an Indian major carp was evaluated with renewal bioassay method. The median lethal concentration of arsenic trioxide to the fish C. catla for 96 h was found to be 20.41 ppm (with 95% confidence limits). From this a non-lethal dose of (2.041 ppm; 1/10th of LC 50 96 value) was selected and fingerlings were exposed to 35 d and hematological, biochemical and ionoregulatory responses were studied at days 7, 14, 21, 28 and 35. Arsenic trioxide produced a significant increase in hemoglobin, hematocrit, WBC count, plasma GPT levels and reduction in RBC count, plasma sodium, chloride, potassium, glucose, protein, GOT, LDH levels as compared to the control group. Gill Na(+)/K(+)-ATPase activity was influenced by arsenic trioxide exposure. A biphasic response was noted in the value of MCH and MCV. However the MCHC level was not altered in arsenic trioxide treated fish throughout the study period. Results of the present investigation suggest that arsenic trioxide affects the hematological, biochemical and ionoregulatory parameters of fish and alterations of these parameters can be useful in environmental biomonitoring of arsenic contamination.

Ecotoxicological impacts of clofibric acid and diclofenac in common carp (Cyprinus carpio) fingerlings: hematological, biochemical, ionoregulatory and enzymological responses.

Investigation on the toxic effects of pharmaceutical drugs namely clofibric acid (CA) and diclofenac (DCF) were studied in a common carp Cyprinus carpio at different concentrations such as 1, 10 and 100 μg L(-1) for a short-term period of 96 h under static bioassay method. At all concentrations, red blood cell (RBC), plasma sodium (Na(+)), potassium (K(+)), and glutamate oxaloacetate transaminase (GOT) levels were decreased in fish treated with CA and DCF. Contrastingly, white blood cell (WBC), plasma glucose, protein, lactate dehydrogenase (LDH) and gill Na(+)/K(+)-ATPase level were increased. However, a mixed trend was observed in hemoglobin (Hb), hematocrit (Hct), plasma chloride (Cl(-)), mean cellular volume (MCV), mean cellular hemoglobin (MCH), mean cellular hemoglobin concentration (MCHC) and glutamate pyruvate transaminase (GPT) levels. There was a significant (P<0.01 and P<0.05) change in all parameters measured in fish exposed to different concentrations of CA and DCF. In summary, the alterations in hematological, biochemical, ionoregulatory and enzymological parameters can be used as biomarkers in monitoring the toxicity of CA and DCF in aquatic environment. However, more detailed studies on using of specific biomarkers to monitor the human pharmaceuticals are needed.

Effects of Ibuprofen on hematological, biochemical and enzymological parameters of blood in an Indian major carp, Cirrhinus mrigala

In the present investigation, the most commonly used pharmaceutical drug Ibuprofen (IB) was exposed to an Indian major carp Cirrhinus mrigala under static bioassay method to estimate its toxicological effects for a period of 35 days. The median lethal concentration (LC 50) of IB to the fish C. mrigala for 24h was found to be 142 ppm. In sublethal treatment (1/10th of LC 50 24h value, 14.2 ppm), a significant decrease in erythrocyte (RBC), mean cellular hemoglobin concentration (MCHC) and plasma protein levels were observed throughout the study period when compare to that of their respective controls. In contrast, haemoglobin (Hb), hematocrit (Hct), mean cellular volume (MCV), mean cellular hemoglobin (MCH), leucocyte (WBC), plasma glucose and alanine transaminase (ALT) levels were increased in this study period. On the other hand, a mixed trend was noticed in aspartate aminotransaminase (AST) enzyme activity. Alterations of these parameters can be effectively used as potential biomarkers in monitoring of IB toxicity in the aquatic organisms. However, more detailed studies on these specific biomarkers are needed to assess the impacts of human pharmaceutical drugs in the field of pharmacotoxicology and aquatic toxicology.

Influence of cypermethrin toxicity on ionic regulation and gill Na+/K+-ATPase activity of a freshwater teleost fish Cyprinus carpio

The effects of acute and sublethal toxicity of cypermethrin, a synthetic pyrethroid insecticide on plasma electrolytes (Na(+), K(+) and Cl(-)) levels and gill Na(+)/K(+)-ATPase activity in a common carp Cyprinus carpio were examined. The 24h LC(50) value of cypermethrin for C. carpio was 1.86ppm. During acute exposure, cypermethrin caused adverse effects in the form of hyponatreima, hypokalemia and hypochloremia and inhibition of gill Na(+)/K(+)-ATPase activity. In sublethal exposure to cypermethrin (0.186ppm for 35 days), plasma Na(+) was decreased throughout the exposure period except 7th day whereas plasma K(+) level was increased up to 28th day, then declined. However, plasma Cl(-) level was decreased. Likewise, gill Na(+)/K(+)-ATPase activity was decreased as the exposure period extended. The present study indicates that cypermethrin was highly toxic to freshwater fish and ion levels in blood as measured by specific ion concentrations (Na(+), K(+) and Cl(-)) and changes in gill Na(+)/K(+)-ATPase activity may represent a sensitive and useful nonspecific biomarkers of chemical exposure and effects.

Endocrine disruption and reproductive impairment in zebrafish by exposure to 8:2 fluorotelomer alcohol

The fluorotelomer alcohols (FTOHs) have been detected in the aquatic environment and shown potential estrogenic activity, but the effects on fish reproduction remain unknown. In the present study, 4-month-old zebrafish were exposed to different concentrations of 8:2 FTOH (0, 10, 30, 90, 270microg/L) for 4 weeks, and the impact on reproduction was investigated. The plasma testosterone (T) and estradiol (E2) levels were significantly increased in the females, while T and E2 levels were decreased and increased in the males, respectively. The average number of eggs spawned and sperm production were reduced upon exposure to the chemical, which also resulted in thinning of eggshell, and reduced protein content and egg diameter. Histological examination showed promotion of oocyte maturation and retarded spermiation in female and male fish, respectively. The gene transcription of follicle-stimulating hormone beta (FSHbeta) and luteinizing hormone beta (LHbeta) in the pituitary were up- and down-regulated in female and male fish, respectively. Up-regulation of vitellogenin (VTG1) and zona pellucida protein 2 (ZP2a) gene transcription was observed in the males, indicating estrogenic activity. However, down-regulation of gene transcription of VTG1 and ZP2a was measured in the females, associated with decreased fecundity. In addition, exposure of adult zebrafish to 8:2 FTOH caused reduced hatching rates in the offspring. The results demonstrated that waterborne exposure to 8:2 FTOH caused disruption of sex hormone biosynthesis and impaired reproduction in adult zebrafish, ultimately resulting in decreased hatching rates in the offspring.

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

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. Copyright

Toxicity of Moringa oleifera seed extract on some hematological and biochemical profiles in a freshwater fish, Cyprinus carpio

The study was carried out to investigate the acute and sublethal toxicity of Moringa oleifera seed extract on hematological and biochemical variables of a freshwater fish Cyprinus carpio under laboratory conditions. The 96 h LC50 value of M. oleifera seed extract to the fish C. carpio was estimated by probit analysis method and was found to be 124.0 mg/L (with 95% confidence limits). For sublethal studies a non lethal dose of 1/10th of 96 h LC50 value (12.40 mg/L) was taken. During acute treatment (96 h), hematological variables like red blood cell count (RBC), hemoglobin (Hb), hematocrit (Hct), and mean corpuscular hemoglobin concentration (MCHC) were significantly (P<0.05) decreased in fish exposed to seed extract. However a significant (P<0.05) increase in white blood cell count (WBC), mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) value was observed in the exposed fish during above treatment period when compared to that of the control groups. Biochemical parameters such as plasma protein and glucose levels significantly declined in fish exposed to seed extract while a significant (P<0.05) increase in aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activity was observed. During sublethal treatment (12.40 mg/L), WBC count, MCV, MCH, plasma glucose, AST, ALT and ALP activities were gradually elevated (P<0.05) at the end of 7, 14, 21, 28 and 35th days in seed extract exposed fish, whereas plasma protein level declined. However, a biphasic trend was noticed in Hb, Hct, RBC and MCHC levels. This study may provide baseline information about the toxicity of M. oleifera seed extract to C. carpio and to establish safer limit in water purification.

Short and long-term effects of clofibric acid and diclofenac on certain biochemical and ionoregulatory responses in an Indian major carp, Cirrhinus mrigala

Extensive use of pharmaceuticals in human and veterinary medicine and aquaculture practices pose a serious threat to aquatic organisms. In the present investigation, Cirrhinus mrigala an Indian major carp was exposed to different concentrations of clofibric acid (CA) and diclofenac (DCF) and certain biochemical and ionoregulatory responses were assessed under short and long term exposures. During short-term (96h) exposure period, plasma glucose and sodium (Na(+)) levels were increased at all concentrations (1, 10 and 100μgL(-1)) of CA and DCF treated fish. Plasma protein and chloride (Cl(-)) levels were found to be decreased at all concentrations of CA and DCF exposed fish comparatively to control groups. Meanwhile an increase in plasma potassium (K(+)) level was noted in fish exposed to CA treatments alone and in DCF treatments it was decreased. In long-term exposure (35d), plasma Na(+) and Cl(-) levels were found to be significantly increased at all concentration of CA and DCF. However, a biphasic trend was observed in plasma glucose, protein and K(+) levels. In both the treatments, a significant (P<0.01 and P<0.05) changes were observed in all parameters measured in fish exposed to different concentrations of CA and DCF. The results of the present investigation indicate that both the drugs caused significant changes in biochemical and ionoregulatory responses of fish at all concentrations. The alterations of these parameters can be useful in monitoring of pharmaceutical residues present in aquatic environment.

Short-term mercury exposure on Na+/K+-ATPase activity and ionoregulation in gill and brain of an Indian major carp, Cirrhinus mrigala

Recently mercury pollution has been increased considerably in aquatic resources throughout the world and it is a growing global concern. In this study, the 96 h LC50 value of waterborne mercuric chloride for Cirrhinus mrigala was found to be 0.34 mg/L (with 95% confidence limits). Fingerlings of C. mrigala were exposed to 0.068 and 0.034 mg/L of mercuric chloride for 96 h to assess the Na(+)/K(+)-ATPase activity and ionoregulation (Na(+), K(+) and Cl(-)) in gill and brain. Results showed that Na(+)/K(+)-ATPase activity and ionic levels (Na(+), K(+) and Cl(-)) in gill and brain of fish exposed to different concentrations of mercuric chloride were found to be significantly (p<0.05) decreased throughout the study period. Mercury inactivates many enzymes by attaching to sulfur atoms in which the enzyme Na(+)/K(+)-ATPase is highly sensitive to mercury. The inhibition of gill and brain Na(+)/K(+)-ATPase activity might have resulted from the physicochemical alteration of the membrane due to mercury toxicity. Moreover, inhibition of Na(+)/K(+)-ATPase may affect the ion transport and osmoregulatory function by blocking the transport of substances across the membrane by active transport. The present study indicates that the alterations in these parameters can be used in environmental biomonitoring of mercury contamination in aquatic ecosystem.