Cypermethrin and λ-cyhalothrin induced alterations in nucleic acids and protein contents in a freshwater fish, Channa punctatus

In this study, a freshwater fish Channa punctatus was exposed to subacute concentrations of synthetic pyrethroid insecticides (cypermethrin and lambda-cyhalothrin) for 96 h to evaluate their impact on the levels of nucleic acids and protein in its different organs. Significant enhancement in the level of DNA was recorded in all tissues of the fish at high concentration of cypermethrin, whereas RNA and protein contents increased in tissues at all concentrations of cypermethrin tested. In contrast, lambda-cyhalothrin treatment caused an increase in the level of DNA only in liver and brain, whereas increase of RNA and protein varied to different levels in different tissues. Cypermethrin treatment induced RNA/DNA ratio in all fish organs tested, whereas lambda-cyhalothrin caused a sharp decrease in the ratio. Protein/DNA ratios were found to be tissue specific in treatments with both of the insecticides. The results clearly indicated that both of these pyrethroids exerted their effects in a similar manner in fish liver but differed in other tissues. These insecticides acted as potential biomodulators in C. punctatus, though following different routes. The results may be an indicator of aquatic pollution affecting freshwater fauna and flora and thus signaling the need for strict regulation on the indiscriminate input of pyrethroids from agricultural sites.