Cypermethrin

Abstract: Five pyrethroid insecticides: cypermethrin, deltamethrin, fenpropathrin, fenvalerate and permethrin, were tested for their ability to induce micronuclei in both whole-blood (WB; three donors) and isolated human lymphocyte (IL, 2 donors) cultures, by using the cytokinesis-block method with 6 micrograms/ml cytochalasin B (Cyt-B). Fenvalerate and permethrin were tested with two different concentrations of Cyt-B (3 and 6 micrograms/ml). At the concentration ranges tested, all the five pyrethroids induced clear dose dependent cytotoxic effects, fenpropathrin being the most toxic. Nuclear division index (NDI) and the newly introduced index of cytotoxicity, the cytokinesis block proliferation index (CBPI), reflected the dose dependency more accurately than the percentage of binucleated cells did. CBPI is similar to NDI except that it estimates the average number of cell divisions that the cell population has gone through, and, therefore, classifies both trinucleate and tetranucleate cells into the same category. Cypermethrin and fenpropathrin slightly increased the number of MN and micronucleated cells in WB lymphocyte cultures from two out of the three donors. Deltamethrin produced a positive response only in WB cultures of one donor and in IL cultures of another donor. Permethrin gave mostly negative results, although it increased the MN frequency in WB cultures of one donor when 6 micrograms/ml Cyt-B was used. Fenvalerate did not significantly induce MN. With certain reservations to the purity and isomer composition of each pesticide, the existing information appears to support the idea that pyrethroid insecticides have a weak (cypermethrin, deltamethrin and fenpropathrin) or nule (fenvalerate and permethrin) genotoxic activity in vitro.

Abstract: The present study was designed to compare the responses in freshwater fish Oreochromis niloticus exposed to a synthetic pyrethroid, cypermethrin (CYP); an essential metal, copper (Cu); and a nonessential metal, lead (Pb). Fish were exposed to 0.05 μg/l CYP, 0.05 mg/l Cu, and 0.05 mg/l Pb for 4 and 21 days, and the alterations in serum enzyme activities, metabolite, and ion levels were determined. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased in response to CYP, Cu, and Pb exposures at both exposure periods. While elevations in alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities and in cholesterol level were observed in pesticide-exposed fish at 4 and 21 days, they increased in Cu- and Pb-exposed fish at 21 days. Although metal-exposed fish showed increases in cortisol and glucose levels at 4 days followed by a return to control levels at the end of the exposure period, their levels elevated in pesticide-exposed fish at both exposure periods. Total protein levels decreased in Pb- and pesticide-exposed fish at 21 days. Na+ and Cl− levels decreased in pesticide-exposed fish at both exposure periods and in Cu- and Pb-exposed fish at 21 days. The exposures of pesticide and metals caused an elevation in K+ level at the end of the exposure period. The present study showed that observed alterations in all serum biochemical parameters of fish-treated pesticide were higher than those in fish exposed to metals.

Abstract: The effect of exposure to sub-lethal concentrations of cypermethrin, a synthetic pyrethroid pesticide, on biochemical parameters of muscle, blood and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied. The sub-lethal exposure studies were done for up to 45 days at 1/10 and 1/50 of 96 h LC(50) of cypermethrin. The 96 h LC(50) was found to be 0.139 ppm. RNA levels decreased while DNA levels were elevated. Acid phosphatase was unchanged while alkaline phosphatase was depleted. Brain acetylcholinesterase activity was decreased significantly (P<0.05) over a period of 45 days at both cypermethrin concentrations. Lactate dehydrogenase activity in brain and liver was elevated, but inhibited in kidney. Succinate dehydrogenase and ATPase activities were depleted in brain, kidney and liver. There was a decrease in serum protein level over control at both concentrations of the pyrethroid. Blood glucose level and total leucocytes were elevated compared with controls at either concentration from day 15 to day 45. Haemoglobin percentage and total erythrocytes decreased in both sub-lethal concentrations. Extracts of the herb Datura stramonium were effective in countering the toxicity of this pesticide. Our data suggest that sub-lethal exposure of cypermethrin alters the biochemical, haematological parameters and enzymes of organs tissue and exert stress on the fish. Plant extracts may be useful in counteracting some of these effects.