The effect of terebinth (Pistacia terebinthus) aqueous methanolic extract on the digestive system and antioxidant enzyme activity in rainbow trout (Onchoryhnhus mykiss)

In this study the effect of the methanolic extract of meningy, Pistacia terebinthus (PT), fruits supplemented diet on digestive enzymes activity, antioxidant enzymes activitiy, non-specific immunty, heamatological parameters and growth performance were evalated in juvenile rainbow trout, Onchoryhnhus mykiss. A total number 480 fish with initial mean body weight, 15.77±0.13g were divided into four main groups in triplicate (twelve tank, 40 fish per tank). Fish fed a diet containing three doses of PT extract [PT 0,(Control) PT 0.5%, PT 0.1% and PT 1% / kg diet] individually for 63 days. The samples were collected every 21 days. The digestive enzyme results indecated that pepsin and lipase activities were significantly increased in all treated groups. In addition, trypsin acitivity in PT 0.1% and PT 1% groups were significantly improved. While, amylase enzyme activity was significantly increased in PT 0.5% and PT 1% compared to the control. Also, significantly improvement in hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glucose-6-phosphate dehydrogenase (G6PDH) activities in all treatment groups and in all sampling times except in PT 0.5%. At the same time hepatic CAT activity was a significantly reduced on 63 days. In addation, a significant declined in hepatic and white muscle lipid peroxidation level (LPO) level in all treated groups and in all sampling times compared to the control.Nitroblue tetrezoliu (NBT), myeloperoxidase (MPO) and lyspzyme activities were enhanced in all treated groups and in all sampling times compared to the control. Heamatological parameters (red blood cell, RBC; hemoglobine, Hb; hematocrit (Hct), mean volüme of red blood cells, MCV; mean cell hemoglobine, MCH and mean cell hemoglobine concentration, MCHC) values in were no significant changes than the control. Final weight (FW), weight gain (WG) and specific growth rate (SGR) were significantly improved in all experimental groups. However, food conversion ratio (FCR) of experimental groups were significantly reduced compared to the control. These results indicated that the supplementation of methanolic extract of P. terebinthus to the diet of O. mykiss is beneficial because it increases the digestive enzyme secretion, antioxidant enzyme activities, nonspecific immune responses and growth performance parameters.