Effect of oxidative stress caused by Dactylogyrus (Monogenea: Dactylogyridae) parasites on DNA damage, lipids and proteins in gill tissue of common carp (Cyprinus carpio)

Its reported that certain parasites can create oxidative stress in fish tissues, causing a wide range of damage to vital biochemical compounds. The aim of this study was to evaluate the effects of Dactylogyrus spp. oxidative stress on DNA damage, lipids and proteins in gill tissue of common carp (Cyprinus carpio). Sample of 120 common carp were obtained from different fish farms of West Azerbaijan Province. After dissection and microscopic examination of their gill tissues, 22 (17.74%) of the fish were found infected with Dactylogyrus parasites, and uninfected fish were used as control group. To investigate the oxidative stress of Dactylogyrus parasites in gill tissue, the amount of damage to DNA by alkaline commet assay, the amount of damage to the lipids by measuring the amount of malondialdehyde and the amount of damage to proteins by the amount of carbonylation protein (thiol group) were measured and compared in infected and non-infected fish (as control group). After analyzing the data, the results showed that Dactylogyrus spp. through increasing the level of DNA damage, increased levels of malondialdehyde and carbonylation proteins significantly (P˂0.05) caused oxidative stress in infected gill tissue.