Ravi S. Pandey

Analysis of some heavy metals in the riverine water, sediments and fish from river Ganges at Allahabad.

The river Ganges has been one of the major recipients of industrial effluents in India. The present paper deals with the study related to occurrence and bioaccumulation of heavy metals (Cu, Cr, Cd, Pb, Zn) in the riverine water, sediment, and the muscles of two cat fish species, Channa punctatus (C. punctatus) and Aorichthys aor (A. aor) procured from the river Ganges at Allahabad. The data obtained after water analysis reflected the order of occurrence of heavy metals to be Zn > Pb > Cu > Cr > Cd, respectively. The analysis of heavy metals in sediment indicated that among the five heavy metals tested; Zn was maximally accumulated followed by Pb, Cr, Cu and Cd. The trend of heavy metals accumulation in fish muscles was found to be similar to that observed in sediment and water such as Zn > Pb > Cu > Cr > Cd. Data indicated that Zn accumulated maximally in the sediment as well as muscles of both of the fish species in comparison to other metals.

Cypermethrin induced alterations in nitrogen metabolism in freshwater fishes

In the present study, two fresh water fishes namely, Channa punctatus and Clarias batrachus, were exposed to three sub-acute concentrations of synthetic pyrethroid, cypermethrin, for 96 h to evaluate the role of amino acids in fulfilling the immediate energy needs of fishes under pyrethroid induced stress as well as to find out the mechanism of ammonia detoxification. The experiments were designed to estimate the levels of free amino acid, urea, ammonia and the activities of aspartate aminotransferase (AAT), alanine aminotransferase (AlAT), glutamate dehydrogenase (GDH), glutamine synthetase (GS) and arginase in some of the vital organs like brain, gills, liver, kidney and muscle of both fish species. The significant decrease in the levels of amino acids concomitant with remarkable increase in the activities of AAT, AlAT and GDH in these vital tissues of fish species elucidated the amino acid catabolism as one of the main mechanism of meeting out the immediate energy demand of the fishes in condition of cypermethrin exposure. The levels of ammonia were significantly increased at 10% of 96 h LC(50) of cypermethrin in the different organs such as brain, gills, liver, kidney and muscle of both fish species while 15% and 20% concentrations of 96 h LC(50) of cypermehrin registered remarkable decline in both fish species. The differential increment in the activities of GDH, GS and arginase and in the level of urea established three different alternative mechanisms of ammonia detoxification. The results indicated that in C. punctatus, the prevalent mode of nitrogen excretion is in the form of conversion of ammonia into glutamine and glutamate while in C. batrachus, the excessive nitrogen is excreted in the form of urea synthesized from ammonia.

Alterations in nitrogen metabolism in freshwater fishes, Channa punctatus and Clarias batrachus, exposed to a commercial‐grade λ‐cyhalothrin, REEVA‐5

In the present study, two freshwater fishes Channa punctatus and Clarias batrachus were exposed to sub‐acute concentrations of a commercial‐grade λ‐cyhalothrin, REEVA‐5, for 96 h to observe the changes in amino acid catabolism under pyrethroid‐induced stress and to investigate the comparative mechanisms of ammonia detoxification in both fishes. The experiments included the estimation of levels of free amino acid, urea, ammonia and the specific activities of aspartate aminotransferase (AAT), alanine aminotransferase (AlAT), glutamate dehydrogenase (GDH), glutamine synthetase (GS) and arginase in different vital organs of fishes. λ‐cyhalothrin caused significant decline in the levels of amino acids along with simultaneous significant increase in the activity of AAT, AlAT and GDH, which indicated amino acid catabolism as one of the important mechanisms to meet out immediate energy demand of fishes. The level of ammonia was observed to be enhanced considerably at lower concentrations of λ‐cyhalothrin while higher concentrations caused remarkable decline. The λ‐cyhalothrin treatment resulted in significant increase in the activities of GDH and GS with concomitant increase in the activity of arginase and level of urea, indicating activation of two different mechanisms of ammonia detoxification. The mechanism of ammonia detoxification through its conversion into glutamate and glutamine was more prominent in C. punctatus, while C. batrachus demonstrated ureogenesis as the major route. In fishwise comparison, C. batrachus was observed to be more sensitive with respect to the above‐mentioned parameters. Another important finding was that unlike the liver, the kidney appeared as one of the primary sites of ureogenesis in fishes.

Cypermethrin and λ -cyhalothrin induced in vivo alterations in nucleic acids and protein contents in a freshwater catfish, Clarias batrachus (Linnaeus; Family-Clariidae)

The fresh water fish, Clarias batrachus, were exposed to sub-acute concentrations of cypermethrin and λ -cyhalothrin for 96 h to assess their impact on the levels of nucleic acids and protein in different organs of fish. DNA content was found almost unchanged with a single exception of liver, which showed significant increment in the levels of DNA in response to the separate treatments of both compounds. Both RNA and protein contents declined in brain, liver, and muscle while sharp increase was observed in gills. However, in kidney, RNA contents depicted significant enhancement only at higher concentrations, with initial decline at lower concentrations. The trends of alterations in RNA/DNA and protein/DNA ratios were quite similar to the corresponding results explained above for RNA and protein. The results clearly indicated that both of these pyrethroids exerted their effects at transcriptional and translational levels while DNA synthesis was found to be unaffected by these compounds with an exception of liver.

Hepatoprotective Effect of Citrus limon Fruit Extract against Carbofuran Induced Toxicity in Wistar Rats

Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol methylcarbamate), is known to induce oxidative stress and to cause inhibition of acetylcholinesterase activity. The present work was envisaged to evaluate the effect of carbofuran on redox indices and its interactions with hepatic markers in rat. The ameliorating effect of Citrus limon fruit extract on carbofuran induced toxicity was also monitored. The results indicated that carbofuran treatment caused significant alterations in the levels of activities of AST, ALT, and LDH in liver tissues and serum. The levels of enzymatic oxidative stress markers such as SOD and catalase and nonenzymatic redox molecules such as total thiol, GSH, and protein thiol also showed significant perturbations in rat liver due to carbofuran treatment. The administration of Citrus limon fruit extract, however, was able to markedly ameliorate the toxicity of carbofuran by protecting the levels of aforesaid biomarkers to near normal levels. The ameliorative effect of Citrus limon fruit extract may be due to the presence of different antioxidants in it which may neutralize the ROS and RNS generated in the body tissue due to pesticide stress. These results suggested that Citrus limon fruit extract may be utilized as a potential supplement in proper management of pesticide intoxication in association with relevant therapeutics.

λ-Cyhalothrin and cypermethrin induce stress in the freshwater muddy fish, Clarias batrachus

In order to understand the level of health risk posed by pyrethroid insecticides with strong soil-binding properties to freshwater fish, specifically living in muddy region of aquatic bodies, changes were examined in different biochemical stress markers in a freshwater muddy fish, Clarias batrachus, exposed to pyrethroid insecticides, cypermethrin and λ-cyhalothrin, in low sub-acute concentrations parts per million (ppm) for 96 hr. Data showed significant increase in levels of lipid peroxidation and in activities of lactate dehydrogenase, acid, and alkaline phosphatases along with marked decline in the specific activity of acetylcholinesterase in a concentration-dependent manner. The marked alterations in stress biomarkers indicate that pyrethroids induce significant stress in C. batrachus. This risk assessment study draws attention towards the potential health risk of freshwater muddy fish, which are continuously being exposed to the high concentrations of such insecticides accumulated as runoff in the muddy bottom of aquatic bodies.

Evaluation of acute toxicity of triazophos and deltamethrin and their inhibitory effect on AChE activity in Channa punctatus

Graphical abstract

Assessment of the acute toxicity of chlorpyrifos and cypermethrin to Heteropneustes fossilis and their impact on acetylcholinesterase activity

Abstract In the present study, the acute toxicity of chlorpyrifos (an organophosphate, OP) and cypermethrin (a pyrethroid) pesticides was estimated for 96 h in Heteropneustes fossilis. The LC50 for chlorpyrifos (CPF) and cypermethrin was found to be 1.90 mg/L and 0.085 mg/L, respectively. The acetylcholinesterase (AChE, EC 3.1.1.7) activity in Heteropneustes fossilis exposed to both the insecticides was assayed in brain, muscle and gills. In general, tissue specific as well as dose-dependent decrease in the AChE activity was exhibited by both pesticides. In response to the increasing concentrations of chlorpyrifos and cypermethrin as well, a significant decrease in the activity of AChE was found in brain while muscle and gills exhibited lesser inhibition. Thus, the brain was the main target organ for both insecticides, followed by muscle and gills. Between the two pesticides chlorpyrifos acted as more potent AChE inhibitor than cypermethrin since more intense changes in behavioral pattern was observed with the chlorpyrifos. These changes indicate that the effects of these pesticides are at neural as well as neuromuscular level.

Observation on the life cycle of Bulbochaete allahabadensis sp. nov. (Chlorophyta, Oedogoniacea)

Bulbochaete allahabadensis sp. nov. is described from a temporary pond at Allahabad. Most of its life-cycle stages have been observed. It differs from other known species of the genus Bulbochaete in having characteristic oospores and interesting behaviour of androspores. Andropores after liberation from normal vegetative cells may germinate anywhere and form dwarf males or produce several celled branched germlings with precocious formation of antheridia. Such zoospore-like behaviour of androspores confirms the observations made by other workers under culture conditions.