Investigation on the effects of Spirulina on some immun and antioxidant system parameters in rainbow trout (Oncorhynchus mykiss, Walbaum,1792) exposed to copper sulfate

Using medicinal plants or plant extracts can be considered as a novel trend for control of fish diseases and hoping to achieve the same results as in the use of antibiotics and to overcome the problem of antibiotic resistance. The aim of this study is mainly focused to evaluate of effect of spirulina on antioxidant and immune system of rainbow trout. In this study; with average 99.20 g ± 9.71 g (89-120 g) weigth about 1500 rainbow trout (Oncorhynchus mykiss) were used. Sublethal dose (0.2 mg / ml) of copper sulfate determined by toxicity test was applied to the fish with bath for 21 days. Pure spirulina was practiced to the fish with both orally (200-400-800 mg/ kg feed) and by injection (200-400-800 mg/ kg fish). Some immunological (blood glucose, hemoglobin, nitroblue tetrazolium (NBT) activity, ceruloplasmin, total plasma protein, total immunoglobulin) and antioxidant system parameters (MDA, catalase, superoxide dismutase, glutathione S-transferase) were examined from blood and tissue samples. As a results of studies, stressed fish by exposure to sublethal dose of copper sulfate, some parameters of the immune system applied by spirulina were significanly changed (p<0,05). NBT, total protein and total immunoglobulin levels in only copper sulfate applied fish were decreased, but in control and 3 spirulina applied groups those parameters were increased (p<0,05). While stress indicator MDA in spirulina applied groups were found to be low (p<0,05), considering enzme activity; catalase, superoxide dismutasa and glutathion S- transferase activities were found to be higher compared to control groups (p<0,05). In terms of reducing stress formed by copper sulfate, although more prevalent in application with injection, positive effects of orally administrated spirulina on immune and antioxidant mechanism is shows that it can be used safely in fisheries.