IMMUNOSTIMULANT AND DIGESTIVE ENZYME ACTIVITY OF POMEGRANATE PEEL Punica granatum AQUEOUS METHANOLIC EXTRACT IN RAINBOW TROUT FINGERLINGS Oncorhynchus mykiss

The immune stimulating, digestive enzyme activity and hematological effects of pomegranate peel (Punica granatum) aqueous methanolic extract in rainbow trout fingerlings (Oncorhynchus mykiss) was evaluated. Four different concentrations of pomegranate peel (0 (Control), 250, 500 and 1000 mg kg^-1) were added to the basal diet and the fish were fed the diet during 60 days. Every 20^th day of the study, immune responses of fish were determined. In the study respiratory burst was significantly decreased in group 500 and 1000 mg kg^-1 compared to control (P < 0.05). No differences was observed between control and 250 mg kg^-1 group on 20^th day of the study. On 40^th day of the study respiratory burst was significantly increased in group 250 mg kg^-1. At the end of the study the highest value of respiratory burst was observed in 500 mg kg^-1 group.  Myeloperoxidase activity (MPO) was increased in group 250 mg kg on 20^th day of the study. At the end of the study all experimental groups MPO activity was significantly decreased compared to control. Lysozyme activity was increased in all experimental group compared to control. At the end of the study, amylase was significantly decreased in all experimental groups compared to control. Pepsin was increased 250 mg kg^-1 group but not in the other experimental groups. Trypsin activity was also decreased in group 250 mg kg^-1 and the other groups showed no differences compared to control.  WBC count was significantly decreased in 1000 mg kg^-1 group. HGB was increased in 250 mg kg^-1 group. Generally no differences was observed in all the other group's hematological values FCR was decreased in group 500 mg kg^-1 but SGR was also significantly decreased compared to control. The results indicate that the humoral immune responses of pomegranate aqueous methanolic extract showed a stimulator effects.