Effect of diet administration of Myrtus essential oils (Myrtus communis L.) on biochemical and antioxidant parameters of Common carp (Cyprinus carpio) blood serum

Phytogenic feed additives include herbal powders, essential oils, and plant extracts that, due to their bioactive compounds such as phenols and flavonoids can have numerous beneficial effects on animal health. The purpose of this study is the investigation the effects of diet administration of Myrtus essential oils (Myrtus communis L.) on biochemical and antioxidant parameters of blood serum of Common carp (Cyprinus carpio). In present research, serum wae exsanguinated from 3 groups of 20 common carp with 6 replications. One group served as control and the other two groups were fed with a diet enriched with M. communis essential oil at concentrations of 500 and 700 mg/kg. Blood samples were taken from the tail of fish in different treatments at the end of the 60-day. Then enzymatic indices such as liver enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), total protein, and antioxidant enzyme catalase (CAT) were measured. Statistical analysis showed that ALP and AST levels in fish serum were significantly decreased in the treatment groups compared to the control group (P<0.05). In contrast to ALT and LDH in the treatment with 500 mg/Kg of essential oil in the diet were higher than in the 700 mg/kg and control groups, but the differences were not significant (P>0.05). Changes in total protein were also not significant, but in the treatment groups, a decrease in CAT activity was observed (P<0.05). It can be concluded that the levels of these biochemical changes are not abnormal and affected by stressful conditions and so, these feed additives did not affect fish health.