Ali Khosravanizadeh, Abdolali Rahdari, Sahel Pakzad Toochaei,
Volume 32, Issue 2 (7-2023)
Abstract
This study aimed to evaluate the effect of 2-phenoxyethanol on antioxidant enzymes capacity including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in various tissues (blood, mucus, brain, gill, and liver) of rainbow trout (Oncorhynchus mykiss) at immediately and 24 h after induction anesthesia. First, the fish (n=180, with an average weight of 5.82±0.8) were divided into six groups (each group with 3 repetitions) and exposed to 0.2, 0.3, 0.4, 0.5, and 0.6 mL/L of 2-phenoxyethanol for the determination of its lowest concentration for inducing anesthesia. The minimum concentration for anesthesia was determined 0.3 mL/L. Then, 72 fish (with an average weight of 5.79±0.73) were assigned to control and experiment groups (36 fish in each group) to evaluate the effect of this concentration of anesthetic on antioxidant enzymes capacity in various tissues of rainbow trout. The samples of blood serum, mucus, and tissue extract (brain, gill, and liver) were prepared from fish in each group, along with measuring various enzymes (SOD, CAT, and GPx) and protein, at 0 (immediately after anesthesia) and 24 h (after induction anesthesia). The results showed that the anesthetic 2-phenoxyethanol inhibited the antioxidant capacities in different tissues, probably through the increase of reactive oxygen species (ROS) and oxidative damage. The comparing the results of the capacity of antioxidant enzymes in different tissues of rainbow trout anesthetized with 2-phenoxyethanol and the obvious difference in the downward or upward course of these enzymes shows that the non-invasive method (mucus and blood samples) to express the status of the antioxidant defense system of rainbow trout is not suitable when faced with the anesthetic 2-phenoxyethanol.
