Assessment of hematological and biochemical alterations as markers in an Indian major carp Catla catla exposed to various concentrations of zinc oxide nanoparticles

Fingerlings of Catla catla were exposed to 1, 5, and 25 mg/L of zinc oxide nanoparticles (ZnO NPs) for 15 days, and specific hematological and biochemical parameters were evaluated to assess the toxicity. During the exposure period, red blood cell (RBC) count was found to decrease (except at the end of the 5th day in 1 mg/L) whereas white blood cell (WBC) count was found to increase in ZnO NPs treated fishes. A significantly higher hematocrit (Hct) level was recorded in fish exposed to 1 mg/L when compared with control and a higher concentration of ZnO NPs (5 and 25 mg/L). Erythrocyte indices such as mean cellular volume (MCV) and mean cellular hemoglobin (MCH) values (except at the end of 5 and 10th day at 1 and 10 mg/L exposed groups) were significantly increased. Mean cellular hemoglobin concentration (MCHC) level was found to be increased at 1 and 25 mg/L treated groups compared to 10 mg/L. Compared to the control group, plasma glucose level was increased significantly in fish exposed to 5 and 25 mg/L concentrations of ZnO NPs, while the plasma glucose level was decreased at the end of the 15th day in all the concentrations. Plasma protein level was increased at the end of the 5th day while the level of plasma protein was decreased on the 10 and 15th day. A significant increase in glutamate oxaloacetate transaminase (GOT) (except at the end of 10th day) and glutamate pyruvate transaminase (GPT) activity in gill and liver (except at the end of 10 and 15th day in gill) were noted in all the concentrations tested when compared to control groups. The results of the present study indicate that ZnO NPs at 1, 5, and 25 mg/L can alter the hematological and biochemical parameters of fish and the toxicity data may provide the ecotoxicological impact of ZnO NPs on the aquatic environment.

Bioaccumulation of silver and its effects on biochemical parameters and histological alterations in an Indian major carp Labeo rohita

Extensive usage of silver in several applications may contaminate the freshwater compartment and affects the health status of aquatic organisms. In the present investigation, fingerlings of Indian major carp Labeo rohita were exposed (35 days) to sublethal concentrations of silver nitrate (AgNO3) and bioaccumulation pattern, biochemical and histological alterations were evaluated. Initially, the median lethal concentration (LC 50) of silver nitrate to the fish Labeo rohita for 96 h was calculated and it was found to be 0.035 mg L−1. To assess the toxicity of ionic silver two sublethal concentrations (0.0035 mg L−1: 1/10th of LC 50 and 0.007 mg L−1; 1/5th of LC 50) were selected and the experiment was conducted for a period of 35 days. A considerable quantity of AgNO3 was accumulated in the gill, liver and kidney tissues of Labeo rohita. Accumulation of AgNO3 was high in liver tissue compared to other organs/tissue. Membrane-bound enzyme (Na+/K+/-ATPase) activity was inhibited in both the concentrations when compared with the control group. Likewise, plasma electrolytes (Na+, K+ and Cl−) level were significantly decreased when compared with untreated groups. On the other hand, a noticeably increased level of glucose was observed in fish exposed to 0.0035 and 0.007 mg L−1 of AgNO3. Moreover, declining protein level was assessed during the initial days (7 and 14 days), and the level was increased in the rest of the exposure period. Extensive histopathological abnormalities were noticed in gill (hyperplasia, epithelial lifting, curling of lamellae) and liver (degeneration of hepatic nucleus, vacuolization, hepatic necrosis) of fish treated with silver nitrate when compared to control groups. The results obtained in the present study revealed that the bioaccumulation pattern, alterations in membrane-bound gill-ATPase activity, plasma electrolytes, biochemical and histological parameters of fish can be useful for biomonitoring the changes in the environment and health condition of fish in freshwater ecosystem contaminated with silver

Evaluation of acute and sublethal effects of chloroquine (C18H26CIN3) on certain enzymological and histopathological biomarker responses of a freshwater fish Cyprinus carpio

In this study the toxicity of antimalarial drug chloroquine (CQ) on certain enzymological (GOT, GPT and LDH) and histopathological alterations (Gill, liver and kidney) of a freshwater fish Cyprinus carpio was studied after acute (96 h) and sublethal (35 days) exposure. The median lethal concentration (96 h) of CQ was 31.62 mg/ml. During acute treatment (CQ at 31.62 mg/ml) the treated fish groups showed a significant increase in GOT and GPT activities in blood plasma; whereas LDH activity was decreased when compare to control groups. To analyse the effects of drug at the lowest concentration, the fish were exposed to 3.16 mg/ml (1/10th of 96 h LC50 value) for 96 h. In sublethal treatment (3.16 mg/ml) GOT activity increased up to 14th day and decreased during the rest of the exposure period (21, 28 and 35th day). A biphasic response in GPT activity was observed. LDH activity was found to be increased throughout the study period (35 days) compare to control groups. The alterations in enzyme activities in blood plasma were found to be significant at p < 0.05 (DMRT). Many histopathological changes in vital organs such as gill, liver and kidney of fish were observed in CQ treated group (acute and sub-lethal) compare to normal group. The alterations in the enzymological and histopathological study in the present investigation indicate that the drug CQ has toxic effects on non-target organisms. We conclude that the alterations in enzymological parameters and histopathological changes can be used as biomarker to assess the health of the aquatic organism/environment. Further data on molecular studies are needed to define the mode of action and toxicity of these emerging pollutants. Keywords: Chloroquine, Biomarker, GOT, GPT, LDH, Histopathology, Acute, Sublethal, C.carpi