Antioxidant and immune-stimulating effects of Sargassum angustifolium extract on the common carp (Cyprinus carpio) juvenile

In this study, the effects of different concentrations of Sargassum angustifolium extract on the immune system and antioxidant defense mechanism of the common carp juvenile (43.85±12.25g) were investigated during a three weeks culture period. For this experiment first a stock solution of 10% sargassum seaweed was prepared by adding 10 grams of dried powder of sargassum to 100mL of double distilled water. Four aquariums each containing 10 liters of water and five fish were set up as treatments and control. Then concentrations of 1%, 5% and 10% of the sargassum extract was prepared in treatment aquariums by adding proportional volumes of the stock solution. Sampling of fish was conducted on days 7, 14 and 21 for measurement of antioxidant enzymes and immune indexes. The results revealed that the activity of catalase and glutathione in all samples taken at different days of the experiment did not show any significant differences with control group (P>0.05). The Superoxide dismutase activity level in 5% and 10% treatments demonstrated a significant increase compared to the control group (P<0.05). Based on the results, the 10% treatment had the highest immune stimulation and antioxidant effect on the fish compared to the other treatments by showing the highest antioxidant capacity (8.56 ± 0.65 µmol/g) at the final day of the experiment. Among the immune indices, the total number of white blood cells in 10% treatment and the lysozyme activity in all treatments showed a significant increase (P<0.05) compared to the control treatment.