Effect of black cumin seed oil (Nigella sativa) and nettle extract (Quercetin) on enhancement of immunity in rainbow trout, Oncorhynchus mykiss (Walbaum)

The study was performed to examine the efficacy of dietary black cumin seed oil (Nigella sativa) and nettle extract (Quercetin) on the immune response of rainbow trout, Oncorhynchus mykiss. Fish were divided into 7 groups before being fed for 14 days with 0.1%, 0.5% and 1% of Quercetin, 1%, 2% and 3% of N. sativa oil and with unsupplemented commercial diet as the control. Humoral immune parameters including lysozyme, antiprotease, total protein, myeloperoxidase, bactericidal activity, and IgM titers were investigated. Treatment groups recorded enhancement in all parameters compared to their respective controls. Groups fed the highest doses, i.e. 1% Quercetin and 3% N. sativa oil, showed a highly significant difference (p<0.05) in lysozyme, total protein, antiprotease and bactericidal activity. With the exception of the 1% dose of nettle extract, all treatment groups recorded significant differences in total serum IgM levels compared to controls (p<0.05). Therefore, the results suggest that by using these supplements there will be an increase in the immune function of rainbow trout. (c) 2013 Elsevier B.V. All rights reserved.