Single and combined effects of Chicory (Cichorium intybus L.) and Hypericum perforatum extracts on immune indices and antioxidant enzymes activity of rainbow trout (Oncorhynchus mykiss)

The aims of present study were to investigate the effects of Chicory (Cichorium intybus L.) and Hypericum perforatum extracts on immune indices and antioxidant enzymes activity of rainbow trout (Oncorhynchus mykiss). For this purpose, 720 fish with an average weight of 100±5 g were randomly allocated to four distinct treatments including: a control group, 3% chicory extract, 3% extract of H. perforatum and combined treatment containing 1.5% chicory extract and 1.5% extract of ) H. perforatum). The experiments lasted for 12 weeks. Immune parameters including lysozyme, alternative complement activity and total immunoglobulin content of serum along with the activity of antioxidant enzymes namely catalase, superoxide dismutase and glutathione peroxidase were measured. Our results showed that dietary supplementation of 3% chicory extract significantly increased total immunoglobulin and lysozyme enzyme activity compared to the control group (p<0.05). The highest level of alternative complement activity was observed in simultaneous supplementation of 1.5% chicory and 1.5% H. perforatum extract (p<0.05). Also, single and combined dietary inclusion of both herbal extracts resulted in increased SOD and GPX enzymes activity in comparison to control group received diet devoid of any herbal extract (p<0.05). In addition, the highest and lowest activity of catalase was observed in the control group and 3% H. perforatum, respectively (p<0.05). In conclusion, dietary inclusion of 3% Chicory extract would improve the immune indices and including 3% H. perforatum extract increased the antioxidant enzymes activity of rainbow trout.