Resumen
In the present study, the median lethal concentration (LC 50) of neem leaf extract to Cirrhinus mrigala for 24 h was found to be 1.035 g l-l. During the study period, the haematological parameters including Hb, Hct, RBC, MCV, MCH and MCHC levels were significantly decreased in neem leaf extract exposed fish when compared to the control fish whereas WBC count was increased. Similarly, plasma Na+ and Cl- levels were significantly lower and K+ level were significantly higher when compared to the control. In biochemical study, elevated plasma glucose and induced protein levels were noticed. The enzymes, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities were increased significantly in gill, liver and muscle of treated fish compared to that of their control groups. The results of the present investigation suggest that neem leaf extracts affects the hematological, ionoregulatory, biochemical and enzymological parameters of fish and alterations of these parameters can be useful in environmental biomonitoring of neem based products in freshwater environment.Keywords: Azadirachta indica, Acute toxicity, Cirrhinus mrigala, Haematology, Ion regulation, Biochemical and Enzymological parameters.